JP7522433B2 - Filtration Equipment - Google Patents

Description

The present invention relates to a filtration device for liquids with a backwash function that efficiently separates and sifts out substances that do not need to be removed from the substances captured in the filter element, prevents clogging, and reduces the frequency of backwashing and cleaning.

2. Description of the Related Art Conventionally, various filtering devices have been used for the purpose of capturing and removing fine particles, dust, and the like contained in the filtering of water such as seawater, lake water, river water, drinking water, and sewerage water; filtering of liquids generally used in industry such as cooling water or process liquid for various devices; and filtering of various fluid raw materials including gases, powders, granules, and particulate matter used in chemical plants and the like.
When filtration using a filtration device is continued for a long period of time, the solid matter and gel-like dust that cannot pass through the openings of the filter element and are captured accumulate on the filter medium surface, increasing the resistance to the fluid passing through the openings of the filter medium, and ultimately making it difficult to filter the fluid. To deal with this, for example, a procedure called "backwashing" is periodically performed in which a fluid is passed through the filter element in the opposite direction to that during filtration to peel off the captured substances that have adhered to the filter element, thereby restoring the filtering performance of the filter element.

Although backwashing is an effective method, the captured substances attached to the filter element may not be completely removed by backwashing, and may remain. In such a case, even if the filter element is repeatedly regenerated by filtration and backwashing, the resistance of the filter material constituting the filter element to the fluid may not decrease, making it difficult to filter the target fluid.
In response to this, Patent Document 1 (Patent No. 6450056) discloses an operating method of a filtration device equipped with a backwashing head having a suction port arranged to come into contact with a part of the primary side of the filter medium constituting the filter element and sucking in the primary side fluid of the filter medium by passing it through the filter medium, a brush planted around the suction port and sliding against the primary side of the filter medium, and a backwashing fluid discharge pipe that discharges the fluid sucked into the backwashing head to the outside of the casing. According to this, when the brush of the backwashing head rotates relative to the primary side of the filter medium, the detachment of the captured substance, the dispersion of the captured substance, and the sieving of the captured substance are assisted, thereby recovering the filtration performance of the filter medium.
However, because the brush of the backwash head only comes into contact with the outer surface of the filter medium, there was a problem in that substances that passed through the filter medium during brushing and entered its interior diffused into the filter element and became mixed into the filtrate.

This point will be explained in more detail.
During backwashing, fluid is passed in the opposite direction to that during filtration, so backwashing can cause substances to accumulate on the filter medium and inside the filter medium from the opposite direction to that during filtration, resulting in clogging.
Particles captured by the filter medium are not only particles larger than the opening diameter of the filter medium, but also particles smaller than the opening diameter that have aggregated to a size exceeding the opening diameter, small particles that form a cake partially near the opening of the filter medium, amorphous particles such as fibrous particles that change their passing diameter depending on the passing direction, and particles that are not particles but are gel-like and therefore adhere to the filter medium and cannot pass through the opening, etc. Some of these can be changed into a form that can pass through the filter medium by dispersing or detaching them.
Patent Document 1 proposes a method of operating a filtration device in which the captured substances captured on the primary side of the filter medium during filtration are dispersed by brushing and then passed through the filter medium to recover from clogging. This method of operating a filtration device in which the clogged filter medium is recovered by brushing alone can minimize the number of times backwashing is performed, and is highly effective in preventing clogging from the opposite direction (secondary side) of the filter medium.

However, because the capture substances are dispersed by brushing, the capture substances (solid components) that pass through the filter and are dispersed into the filtrate chamber are diffused and included in the filtrate. Therefore, if the purpose of filtration is to reduce the concentration of solid components in the filtrate, if brushing is the only method used, the amount of solid matter passing through the filter will increase, making it impossible to achieve the purpose.
In this case, the objective of lowering the solid component concentration in the filtrate can be achieved not only by brushing with the filtration device shown in Patent Document 1, but also by performing brushing while backwashing with a backwash head.
In this case, however, since backwashing is performed, clogging cannot be prevented from occurring in the reverse direction, that is, from the filtrate chamber side surface (secondary side surface), and solid components accumulate on the secondary side surface.
12 is a schematic cross-sectional view explaining the effect of brushing in Patent Document 1. In a configuration in which the backwash head 510 moves relative to the filter medium 500, two brush rows 525a and 525b constituting the brush 525 planted in a ring shape along the periphery of the suction port 520 are arranged in parallel with each other through a space S. When the front brush row 525a brushes and disperses the capture substances on the filter surface while the backwash head 510 moves in the direction of the arrow, the dispersed capture substances that are smaller than the openings of the filter medium pass to the filtrate chamber. At this time, the filter surface 500a located in the space S between the front and rear brush rows has a smaller resistance than other filter surface parts as a result of the clogging recovery by brushing, making it easier for the fluid to pass through.

However, there is a problem in that solid components that pass through the filter surface 500a and enter the filtrate chamber during brushing diffuse into the filter element and become mixed into the filtrate.
Next, when the raw liquid chamber side (primary side) of the filter medium is brushed with only a single brush row 560 as shown in FIG. 13, since there is no rear brush row 525b as shown in FIG. 12, the captured material (solid components) dispersed by brushing with a single brush row scatters to the raw liquid chamber side and spreads widely in the raw liquid in the casing. If a void S is formed between the two brush rows as in the configuration example of FIG. 12, and the solid components that are about to be dispersed in the raw liquid by brushing can be retained in the void S and passed to the filtrate chamber side (secondary side) immediately after brushing, the opening of the filter surface is in a state where clogging has been restored by brushing, and the dispersed solid components can be efficiently passed to the filtrate chamber side. However, in the configuration example of FIG. 13, the solid components are widely dispersed in the raw liquid in the casing, and filtration is performed by the filter surface 500b whose clogging has been restored by brushing. In this case, not only the solid components dispersed in the raw liquid are crushed by brushing and become smaller than the opening diameter of the filter surface, but also the aggregated particles originally present in the raw liquid are concentrated on the filter surface 500b where the clogging has been removed, and are filtered, causing re-aggregation and being captured again. In other words, in the configuration example of Figure 13, the solid components that are about to be dispersed in the raw liquid by brushing cannot be efficiently passed to the filtrate chamber side immediately after brushing. Therefore, when the solid components diffused widely in the raw liquid gradually become concentrated, and most of them try to pass through the filter surface 500b where the clogging has been removed, the filter surface 500b is likely to have already re-clogged. Also, as in the case of Figure 12, the solid components that have passed through the filter surface 500b where the clogging has been removed are dispersed in the filtrate.

Patent No. 6450056

The present invention was made in consideration of the above, and aims to solve the problem that, when a backwash head is placed on one side of the filter media that constitutes the filter element, substances that pass through to the other side of the filter media by brushing diffuse into the filtrate.

In order to achieve the above object, the filtration device according to the present invention comprises a filter element that captures substances in a fluid on one side of a filter material during filtration by passing a fluid from one side to the other side of the filter material, and that removes the captured substances from the filter material during backwashing by passing a fluid from the other side to the one side of the filter material; a filtration mechanism that passes an undiluted liquid from one side to the other side of the filter material; a backwashing mechanism that passes a filtrate obtained by filtering the undiluted liquid from the other side to the one side of the filter material as a backwashing fluid; a suction mechanism that is disposed on the other side of the filter material and sucks in the fluid that has flowed in from the one side of the filter material during filtration by the filtration mechanism; a drive unit that rotates at least one of the backwashing mechanism and the suction mechanism, or the filter element relative to the other; a casing that supports at least the filter element, the filtration mechanism, the backwashing mechanism, and the suction mechanism; The filter mechanism, the backwash mechanism, the suction mechanism, and a control means for controlling the drive unit, the backwash mechanism includes a backwash head having a first suction port that sucks the fluid on the other side of the filter material by passing it through the filter material, and a first rubbing member that rubs against one side of the filter material, and a backwash fluid discharge pipe that discharges the fluid sucked by the backwash head to the outside of the casing, and the suction mechanism includes at least one suction head having a second suction port that is arranged to face a part of the filter material from the other side of the filter material and sucks the fluid on the one side of the filter material by passing it through the filter material, and a second rubbing member that is arranged along the periphery of the second suction port and rubs against the other side of the filter material, and a suction fluid discharge pipe that discharges the fluid sucked by the suction head through the other side of the filter material to the outside of the casing.

According to the present invention, when a backwash head is placed on one side of the filter medium, it is possible to prevent substances that have passed through the filter medium to the other side by brushing from diffusing into the filtrate.

1A is a longitudinal sectional view of the filtering device according to the first embodiment of the present invention (a sectional view taken along line AA in FIG. 1B), and FIG. 1B is a sectional view taken along line BB in FIG. FIG. 2 is a perspective view showing the configuration of a suction head and a suction fluid discharge pipe. FIG. 2 is an enlarged cross-sectional view of an example of a filter medium. FIG. 2 is a cross-sectional view illustrating a state in which the backwash head and the suction head face each other with a filter medium sandwiched therebetween in this embodiment. 13A and 13B are perspective views showing other examples of the installation of the removal brushes that constitute the backwash head and the suction head. 4 is a flowchart showing an operation procedure of the filtration device of the present invention. 1A and 1B are enlarged cross-sectional views of a main part of a filter medium showing a state in which sieving is being performed by brushing. 5A is a cross-sectional view of a main portion of a filtering device according to a second embodiment of the present invention, and FIG. 5B is a perspective view showing the configuration of a first removal brush. 1A is an oblique view showing another example of the configuration of the suction head used in the filtration device of the present invention (third embodiment), FIG. 1B is a cross-sectional view showing the positional relationship with the backwash head when the suction head of FIG. 1A is assembled to the filtration device, FIG. 1C is an explanatory diagram showing the positional relationship between the suction head and the backwash head, and FIG. 1D is an oblique view showing another example of the configuration of the suction head (backwash head). 1A is a cross-sectional view showing the peripheral configuration of a suction head 151 according to a fourth embodiment of the present invention (corresponding to the B-B cross-sectional view of FIG. 1A), FIG. 1B is a cross-sectional view taken along CC of FIG. 1A, and FIG. 1C is an oblique view of the main parts showing a rotation mechanism. 5A and 5B are longitudinal sectional views (sectional view taken along line AA in (b)) and BB in (a) showing the configuration of a filtering device according to a fifth embodiment of the present invention. FIG. 1 is a schematic cross-sectional view illustrating the effect of brushing in Patent Document 1. FIG. 13 is an explanatory diagram of the case where the side surface of the concentrate chamber of the filter medium is brushed with only a single brush row.

Hereinafter, a configuration example of a filtering device according to an embodiment of the present invention will be described.
FIG. 1(a) is a longitudinal cross-sectional view of a filtering device according to a first embodiment of the present invention (cross-sectional view taken along line A-A in FIG. 1(b)), (b) is a cross-sectional view taken along line B-B in FIG. 1(a), and FIG. 2 is a perspective view showing the configuration of a suction head and a suction fluid discharge pipe. FIG. 3 is an enlarged cross-sectional view of an example of a filter medium. FIG. 4 is a cross-sectional view illustrating a state in this embodiment in which a backwash head and a suction head face each other with a filter medium sandwiched therebetween. FIGS. 5(a) and 5(b) are perspective views showing other examples of planting of removal brushes constituting the backwash head and the suction head.
This filtration device filters, for example, ballast water of a ship, and filters the fluid introduced from a fluid inlet 6 by passing it through a filter element and discharging it from a fluid outlet 7.
The filtration device according to the first embodiment generally comprises a casing 1, a partition wall 2, a filter element 3, a geared motor (drive unit) 13, a filtration mechanism 120 (fluid inlet 6, fluid outlet 7, concentrate chamber 8, etc.), a backwash mechanism 140, a suction mechanism 150, and a control means (CPU, etc.) 600.

This filtration device includes a filter element 3 that captures substances in the fluid on one side during filtration by passing a fluid from one side (raw liquid chamber side = primary side) to the other side (filtrate chamber side = secondary side) of a cylindrical filter material 31 that constitutes the filter element, and separates the captured substances captured on one side of the filter material from the filter material during backwashing by passing a fluid from the other side of the filter material to the one side; a filtration mechanism 120 that passes the raw liquid from one side to the other side of the filter material; a backwash mechanism 140 that passes the filtrate obtained by filtering the raw liquid from the other side to the one side of the filter material as a backwash fluid; a suction mechanism 150 that is disposed on the other side of the filter material and sucks in the fluid that has flowed in from the one side of the filter material during filtration by the filtration mechanism 120; a drive unit 13 that rotates at least one of the backwash mechanism, the suction mechanism, and the filter element relative to the other; and a casing 1 that supports at least the filter element 3, the filtration mechanism 120, the backwash mechanism 140, and the suction mechanism 150.
The backwash mechanism 140 includes a first suction port (backwash suction port) 143 arranged so as to come into contact with a portion of the filter material from one side (raw liquid chamber side) of the filter material 31 and sucks in fluid from the other side (filtrate chamber side) of the filter material by passing it through the filter material, a backwash head 141 equipped with a first removal brush (first rubbing member) 144 planted (protruding) along the periphery (edge) of the first suction port and in sliding contact with one side of the filter material, and a backwash fluid discharge pipe 145 that discharges the fluid sucked into the backwash head to the outside of the casing 1.

The suction mechanism 150 comprises a suction head 151 having a second suction port 152a arranged to face a portion of the filter material 31 from the other side thereof (not facing the entire surface of the filter material, but facing a local portion that is elongated in the axial direction) and which sucks fluid from one side (concentrate liquid chamber side) of the filter material by passing it through the filter material, and a second removal brush (second rubbing member) 154 which is planted (protruding) along the periphery (edge) of the second suction port and comes into rubbing contact with the other side of the filter material, and a suction fluid discharge pipe 160 which discharges the fluid sucked by the suction head to the outside of the casing via the other side of the filter material (in Figure 1, this means the inside of the filter connected to the filtrate chamber 9).
The control means 600 controls the filtering mechanism 120 , the backwash mechanism 140 , the suction mechanism 150 , and the drive unit 13 .

This filtration device uses a backwash mechanism 140 consisting of a backwash head 141 that is arranged to face and contact a portion of the primary side (outer peripheral surface) of the filter element 3, and exerts a high backwash effect by the strong rubbing force of the removal brush 144 and the strong suction force from the first suction port 143.

The casing 1 forms the outer shell of the filtration device and is composed of a casing body 1a and a casing lid 1b. The casing body 1a is formed in a bottomed tubular shape (e.g., cylindrical shape), rectangular parallelepiped shape, etc., and has, for example, a fluid inlet 6 at the upper part of the side wall through which fluid flows in from the outside, and a fluid outlet 7 at the lower part of the side wall through which fluid filtered inside flows out to the outside. The casing lid 1b is a lid placed on the casing body 1a and seals the inside of the casing 1.
A partition wall 2 is provided horizontally at the lower part inside the casing 1. This partition wall 2 is a wall that separates the inside of the casing 1 into an original liquid chamber 8 (upper side) that communicates with a fluid inlet 6 and contains a fluid before filtration, and a filtrate chamber 9 (lower side) that communicates with a fluid outlet 7 and contains a fluid after filtration. A through hole 2a is provided in the center of the partition wall 2, and a cylindrical portion 10 is fitted into the through hole and protrudes upward.
Inside the casing 1 and above the partition wall 2, a cylindrical filter element 3 is provided vertically in the concentrate chamber 8, the inner periphery of the lower end of the filter element 3 is rotatably supported by the outer periphery of the cylindrical portion 10, and the inside of the filter element communicates with the filtrate chamber 9 via the inside of the cylindrical portion 10. This filter element 3 serves as a filter that filters fluid by passing it from the concentrate chamber side to the filtrate chamber side, and has a filter medium 31 forming a cylindrical surface, a lower blocking plate 32 forming the lower end, and an upper blocking plate 33 forming the upper end, and passes the target fluid through the filter medium 31 from the outside to the inside, capturing and filtering solids and gel-like dust contained in the fluid.

The filter material 31 may be, for example, as shown in FIG. 3, a multi-layer structure in which the outermost layer, i.e., the raw liquid chamber side (primary side), has the finest mesh and the mesh gradually becomes coarser toward the inside. A multi-layer structure made of wire meshes sintered together to increase strength and molded into a cylindrical shape is preferred. Although it is not a mesh because the outermost layer is the finest and gradually becomes coarser, a cylindrical notched wire or wedge wire can be used. In the case of a sintered structure, the mesh size of the outermost layer may be appropriately selected from 10 to 200 μm, and the mesh size of the inner layer may be appropriately selected from 100 to 5000 μm. In this case, the reinforcing mesh and protective mesh other than the outermost layer are related to the strength of the filter element 3, and the number of layers, mesh size, and wire diameter are selected so that the required strength is obtained. In addition, the weaving method of the mesh may be plain weave, twill weave, satin weave, tatami weave, twill tatami weave, etc. Alternatively, the outermost layer may be a wire mesh, and on the outside of the wire mesh, for example, a cylindrical punching plate with numerous square holes or a reinforcing member made of multiple thin rods arranged vertically and horizontally may be arranged and sintered.
In addition, the opening of the filter medium 31 on the raw liquid chamber side is small, and the opening becomes coarser toward the filtrate chamber side. Therefore, if clogging occurs on the surface of the filter medium on the filtrate chamber side due to backwashing, brushing the filter medium from the filtrate chamber side will be ineffective because the coarse mesh will be an obstacle. In other words, the second removal brush 154 arranged on the filtrate chamber side only has a sealing effect (the effect of forming the second space S2 as a semi-closed space).

The lower blocking plate 32 is disk-shaped, its outer periphery is fitted and fixed to the cylindrical filter material 31, and a through hole 34 is provided in the center, into which the cylindrical part 10 is rotatably fitted. A groove is provided on the inner periphery of the through hole 34, and an O-ring 12 is provided to form a seal with the outer periphery of the cylindrical part 10.

On the other hand, the upper blocking plate 33 is also disk-shaped, and its outer periphery is fitted and fixed to the cylindrical filter material 31. The center of this upper blocking plate 33 is connected to a rotating shaft 14 that extends from a geared motor (drive unit) 13 provided on the upper side of the casing lid 1b through the through hole 1d of the casing lid 1b. This allows the filter element 3 to rotate by the geared motor 13. An O-ring 1b' is provided on the inner periphery of the through hole 1d, forming a seal between it and the rotating shaft 14.

The backwash mechanism 140 is arranged so as to come into contact with a part of the filter medium 31 of the filter element 3 from the raw liquid chamber 8 side, and sucks the fluid (filtrate or backwash fluid supplied through the valve VG) on the filtrate chamber 9 side through the filter medium 31, and discharges the sucked fluid to the outside of the casing 1 to backwash the filter medium 31. It includes a backwash head (primary side head) 141 and a backwash fluid discharge pipe 145. In this specification, "suction" is not necessarily limited to drawing in a fluid at a pressure lower than atmospheric pressure, but generally means drawing in a fluid to the side with a relatively lower pressure when there is a pressure difference. This backwash mechanism 140 and a rotation mechanism of the filter element 3 consisting of a geared motor 13 and the like as a contact position moving means constitute the backwash means of this embodiment.
The backwash head 141 is disposed so as to face and come into contact with a portion of the filter medium 31 and serves as a means for sucking the fluid on the filtrate chamber 9 side through the openings (filter holes) of the filter medium 31 .
The backwash head 141 is a substantially tubular member with both axial ends closed, and is provided with a backwash duct 142 arranged in close proximity (opposite arrangement) to the outer surface of the filter medium 31 and parallel to its axis, a slit-shaped first suction port (primary side suction port = backwash suction port) 143 formed in a portion (opposing surface) where the backwash duct faces the outer surface of the filter element and covers substantially the entire length of the filter medium 31, and a first removal brush (first rubbing member) 144 with bristles planted along the entire periphery of the first suction port. The backwash fluid discharge pipe 145 penetrates a suitable position at the bottom of the casing body 1a and communicates with the inside of the backwash duct 142.

The first removal brush 144 is planted along the entire periphery of the suction port 143, so that its tip is in sliding contact with the primary side of the filter material. The first removal brush 144 as a whole forms an annular brush row, and the inside of the annular brush row forms a first space (primary side space) S1 that communicates with the suction port 143. The planting density of the first removal brush 144 is set to a level that isolates and blocks the inside of the first space S1 from the external filtrate to make it a semi-closed space. As will be described later, it is not essential that the annular brush row made up of the first removal brush extends continuously and without interruption all around. Even if there is some variation in the planting density in some areas or there are some areas that are not planted with bristles, there is no problem as long as the first space S1 can perform its function of retaining solid components by isolating it to a certain extent from the external filtrate.

By backwashing the filter element 3 while rotating it with the geared motor 13 in relation to the non-rotating backwash head 141, it is possible to backwash the entire surface of the filter medium 31 while scraping off the captured substances with the first removal brush 144.
Although not shown, it is of course possible to adopt a configuration in which the backwash head 141 (suction head 151) is rotated while the filter element is fixed.
The material of the bristles of the first removal brush 144 may be, for example, natural or synthetic fibers, or metal wires such as steel, copper, or brass, and is selected depending on the intended use of the filtration device and the fluid to be passed through.

On the other hand, a backwash fluid discharge pipe 145 is connected to the vicinity of the lower end of the axially long backwash head 141 on the opposite side to the contact surface side with the filter medium 31. This backwash fluid discharge pipe 145 is a means for discharging the fluid sucked into the backwash head 141 to the outside of the casing 1, and extends to the outside through a through hole provided on the side of the casing body 1a and is connected to an external discharge pipe 147. This backwash fluid discharge pipe 145 is provided with an opening/closing valve VF as a stop valve. This opening/closing valve VF controls the outflow/stop of the backwash fluid, and is opened when the filtration device is backwashed and closed at other times. The discharge side of this opening/closing valve VF is connected to a drain side that is open to a pressure lower than the pressure of the fluid outlet 7, for example, atmospheric pressure P0.
In addition, a pipe 147a for supplying a cleaning fluid and a valve VH for opening and closing this pipe are arranged in the external discharge pipe 147 upstream of the opening and closing valve VF (on the filter element side). By opening the valve VH with the opening and closing valve VF closed and supplying the cleaning fluid from the discharge pipe 147 toward the backwash duct 142, clogging of the filter medium due to backwashing can be restored. That is, solid components attached to the inner surface of the filter medium due to backwashing are removed from the filter medium by supplying the cleaning fluid in the reverse direction and discharged outside the machine through the suction fluid discharge pipe 160, the suction fluid discharge port 162, and the stop valve VE. At this time, the faster the speed at which the cleaning fluid passes through the filter medium, the higher the cleaning effect can be obtained.
The cleaning fluid supply unit (not shown), the opening/closing valve VF, the valve VH, the backwash mechanism 140 (the backwash fluid discharge pipe 145, the backwash duct 142, the suction fluid discharge pipe 160, etc. constitute a first cleaning fluid supply mechanism.

As an external piping system for the fluid to be filtered that is connected to the filtration device, an inlet side pipe 121 is connected to the fluid inlet 6 of the casing 1, and the inlet side pipe 121 has an inlet side valve VI in the middle and is connected to a raw liquid supply source (filtration mechanism) having a primary pressure (P1). On the other hand, an outlet side pipe 122 is connected to the fluid outlet 7 of the casing 1, and this outlet side pipe 122 has an outlet side valve VO in the middle and is connected to a filtrate storage tank or the like having a secondary pressure (P2).

Next, a suction head (secondary side head) 151 is arranged on the secondary side of the filter material, sandwiching the suction port 143 of the backwash head 141 and the filter material portion facing the removal brush (rubbing member) 144, and the inner diameter side opening 152b of the suction head 151 is connected to the inside of a suction fluid discharge pipe 160 fixedly arranged coaxially with the rotation axis of the filter element 3.
The suction head 151 generally comprises a suction duct 152 having a second suction port (secondary suction port) 152a arranged opposite to the first suction port (primary suction port) 143 of the backwash duct 142, and a second removal brush (second rubbing member) 154 planted along the entire periphery of the second suction port 152a and having its tip in sliding contact with the secondary side of the filter medium. The inner diameter side opening 152b of the suction duct 152 communicates with the inside of the suction fluid discharge pipe 160. The inner diameter side opening 152b is configured as a slit that is long in the axial direction, similar to the second suction port 152a. The second suction port 152a communicates with a slit 160a that is provided in the suction fluid discharge pipe 160 and extends in the axial direction. That is, in this embodiment, the suction duct 152 is integrated with the suction fluid discharge pipe 160 on the inner diameter side.

The opening shape and size of the second suction port 152a of the suction duct 152 may be the same as the first suction port 143 of the backwash duct, or may be a large opening shape that includes the entire periphery of the first suction port 143. In short, it is sufficient that the fluid flowing from the first space S1 through the filter medium to the secondary side can be sucked into the second space (secondary side space) S2 without leakage.
A bearing 156 for smooth rotation of the upper blocking plate 33 is disposed between the upper part of the suction duct 152 and the upper blocking plate 33 .
The lower part of the suction fluid discharge pipe 160 passes through the lower opening of the filter element 3, bends laterally in the filtrate chamber 9, and penetrates the lower part of the casing body 1a to project to the outside. The outer end of the suction duct 152 constitutes the suction fluid discharge port (concentrated liquid outlet) 162, which is controlled to open and close by the stop valve VE. When the backwash valve VF is closed and the stop valve VE is opened, the outside of the concentrated liquid outlet 162 is at a lower pressure than the filtrate. If necessary, suction is performed by a pump or the like. As a result, the captured material (solid components) removed from the primary side of the filter medium by the relative movement between the first removal brush 144 and the filter medium flows from inside the first space S1 of the backwash duct 142 through the filter medium, flows into the secondary side, and is directly led into the second space S2. The solid components that flow into the second space S2 are discharged through the secondary suction port 152a and the inner diameter side opening 152b to the suction fluid discharge pipe 160 and the suction fluid discharge port 162. Therefore, when a backwash head is disposed on one side of the filter medium that constitutes the filter element, the material that has passed through to the other side of the filter medium by brushing is prevented from diffusing into the filtrate, and the concentration of solid components in the filtrate can be reduced.
FIG. 4 is a cross-sectional view illustrating a state in which the backwash head and the suction head face each other with a filter medium sandwiched therebetween.

During filtration by the filtration device, the first removal brush 144 is rotated relative to the filter material 31 without backwashing by the backwash mechanism 140, whereby unnecessary substances that cannot be removed from the captured substances by filtration without brushing with a brush are sifted out based on their size from substances that need to be removed, and a sifting operation is performed in which only the unnecessary substances pass through to the other side.
The overall shape of the first removal brush 144 is an axially elongated ring-shaped body when viewed from the filter material 31 side, so in the cross-sectional view of Figure 4, the front removal brush row 144a located in front of the first removal brush in the relative movement direction, the rear removal brush row 144b located behind the relative movement direction, and the first gap S1 can be seen.
The backwash head 141 has a structure in which the removal brush (row) 144 planted around the entire periphery of the suction port 143 is protruded toward the filter surface and the brush tip is brought into contact with the filter surface by moderate pressure, so that the backwash head 141 and the suction mechanism 150 move relative to the filter element 3 in the directions indicated by the arrows in the figure, and the front removal brush row 144a located in front of the suction port 143 comes into contact with the captured material and breaks it down. At this time, a flow (liquid flow) is formed from the outside (raw liquid chamber) toward the first space S1 between both removal brush rows 144a and 144b as indicated by the arrow F1 through a gap formed between the tip of the front removal brush row 144a and the surface of the filter medium due to the relative rotation, which contributes to the dispersion of the captured material.

In addition, the "moderate pressure" in the above "configuration in which the brush tip is brought into contact with the filtration surface with moderate pressure" means a pressure that forms a flow (liquid flow) F from the outside (concentrate liquid chamber) toward the first space S1 between the two removal brush rows 144a, 144b through the gap formed between the tip of the removal brush row 144a and the filter material surface, while maintaining a state in which the pressure in the first space S1 is lower than the concentrate liquid chamber 8 (semi-closed space state).
That is, since the first space S1 surrounded by the first removal brush 144 and the filter material 31 is in the semi-closed space state described above, the pressure in the first space S1 is lower than the raw liquid chamber 8 outside it, and higher than the pressure in the second space S2 located downstream through the filter material 31. Therefore, while a liquid flow F1 is generated from the raw liquid chamber 8 toward the first space S1, filtration is performed smoothly by a liquid flow F2 flowing toward the second space S2 through the brushed filter surface 31N facing the first space S1. In particular, in this embodiment, the second space S2 is communicated with the atmospheric pressure P0 through the suction fluid discharge pipe 160 with the opening and closing valve VF of the backwash fluid discharge system closed, and the second space S2 is set to a pressure lower than the first space S1 by a predetermined value, so that the liquid flow F2 exerts a strong suction force.

The inlet valve VI and the outlet valve VO are opened continuously, intermittently, or as needed, and the opening/closing valve VF of the backwash fluid discharge system is closed.
That is, the brushing by the front removal brush row 144a breaks down the captured substances and separates them into large particles that need to be removed and small particles that do not need to be removed, and they leave the filter surface, but most of the substances that need to be removed and the substances that do not need to be removed are carried by the liquid flow F1 and introduced into the first space S1 between the two removal brushes 144a, 144b (the liquid flow F1 promotes the breakup caused by brushing). On the other hand, the rear removal brush row 144b (and the removal brush rows in both directions perpendicular to the paper plane of the drawing) have a lower pressure in the first space S1 than the original liquid chamber and are pressed against the filter surface, so that it exerts a sealing effect that prevents substances introduced into the first space S1 from escaping outside the first space S1, and also exerts the original brushing effect of removing substances attached to the filter surface. In other words, due to the sealing effect of both removal brush rows 144a, 144b (the entire annular first removal brush 144), the substances (substances that need to be removed and substances that do not need to be removed) removed from the filter surface by the front removal brush row 144a and dispersed are collected in the first space S1 without scattering into the concentrate chamber 8, and are effectively filtered by the filter surface 31N immediately after the clogging is cleared.

On the other hand, most of the fluid that has passed through the filter surface 31N flows into the second space S2, which is disposed opposite the filter surface 31N and is set at a lower pressure than the filtrate chamber. In other words, the fluid containing a large amount of solid components as substances that do not need to be removed flows into the second space S2. The fluid that has flowed into the second space S2 is discharged through the secondary side suction port 152a and the inner diameter side opening 152b to the suction duct 152 and the suction fluid discharge port 162. Therefore, the fluid that is sucked by the suction fluid discharge pipe 160 is in a state in which solid components as substances that do not need to be removed are concentrated.
In this way, the solid components that have passed through the filter medium via the first space S1 by brushing on the primary side are sucked into the second space S2 on the filtrate chamber side, and the solid components can be mixed into the filtrate and discharged in a concentrated liquid state from the suction fluid discharge port 162. Also, the filtrate that has passed through the filter medium without being sucked by the suction mechanism 150 and flowed into the filtrate chamber is in a state in which the captured substance is not mixed in.

The filtration device according to the present invention is characterized by the configuration in which the solid components captured on the primary side of the filter medium 31 during filtration are held in a crushed state in the first space S1 by providing the suction mechanism 150, and are circulated through the second space S2 via the filtered filter surface 31N facing the first space S1, so that the solid components that have passed through the filter medium can be extracted from the suction fluid outlet 162 in a concentrated state. As a result, a remarkable effect is achieved in that the filtrate and the solid components can be separated without backwashing, which causes clogging of the filter medium from the filtrate chamber side. In addition, when it is desired to remove solid components from the filtrate, that is, when it is desired to use the filtrate from which the solid components have been removed, the filtrate in the filtrate chamber, which is not a fluid in which the solid components have been concentrated and which is sucked in by the suction mechanism 150 and discharged from the suction fluid outlet 162, is used. Conversely, when it is desired to use the solid components, it is only necessary to use the fluid in which the solid components have been concentrated and which is discharged from the suction fluid outlet 162.

In Figure 4, the second removal brush 154, which is an annular body, forms a second gap S2 as a semi-closed space with a sealing effect between the filter surface 31N and the brush row 154a, the brush row 154b, and the end brush rows connecting both longitudinal ends of the two brush rows.
That is, the second space S2 surrounded by the second removal brush 154 and the filter medium 31 is a semi-closed space, and due to the effect of negative pressure (a pressure lower than the secondary pressure P2 in FIG. 1(a)) from the suction fluid discharge pipe 160, the pressure in the second space S2 is lower than the pressure inside the filter element on the outside and the filtrate chamber 9. For this reason, a strong liquid flow F2 is generated from the first space S1 toward the second space S2, and smooth filtration is performed via the filter surface 31N.
In the device configuration of Figure 1, when valve VH is opened to supply cleaning fluid to the backwash duct 142, the cleaning effect can be improved by making the pressure on the original liquid chamber side of the filter surface 31N as high as possible and making the pressure on the filtrate chamber side of the filter surface 31N as low as possible.

In the above embodiment, the first removal brush 144 and the second removal brush 154 are configured as a continuous annular brush row, but as shown in FIG. 5(a), the second removal brush 154 may be configured as front and rear removal brush rows 154a and 154b arranged in parallel, and one end of each brush row may not be connected (open) to the other brush row. In other words, even if two removal brush rows 154a and 154b are arranged in parallel with the second space S2 between them and only one end is connected by the brush row, most of the captured material (solid components) broken down by the removal brush row can be caused to flow into the second space S2 by the liquid flow F1, and the effect of preventing the diffusion of solid components into the filtrate by suction from the second space S2 can be sufficiently demonstrated. The part where the removal brush row does not exist is called the missing part 154c of the brush row. The missing portion 154c includes cases where the removal brush (rubbing member) is completely absent, where the brush is less dense and more sparse than in other areas, and where the brush is present but is too short to come into contact with the filter surface.

5(b), the first removal brush 154 may be configured with front and rear removal brush rows 154a, 154b arranged in parallel, with no brush rows arranged between the longitudinal ends of each removal brush row (missing portion 154c of brush row). In other words, even with a configuration in which two removal brush rows 154a, 154b are simply arranged in parallel with the first space S1 in between, most of the disintegrated captured material (solid components) can be caused to flow into the second space S2 by the liquid flow F1, and the effect of preventing the diffusion of solid components into the filtrate by suction from the second space S2 can be sufficiently exhibited.
As long as the effect of preventing diffusion of solid components into the filtrate due to suction from the second space S2 can be sufficiently exhibited, the notched portions 154c may be provided not only at both longitudinal ends of the brush row but also in the middle of the brush row.

As described above, at least two parallel brush rows are provided facing each other on the primary side (raw liquid chamber side) and secondary side (filtrate chamber side) of the filter medium, and while preventing backwashing by the backwashing mechanism on the primary side, the secondary suction mechanism 150 is operated to connect the concentrated liquid discharge port 162 to a location with a lower pressure than the filtrate (secondary pressure P2 in Figure 1 (a)). Then, as explained in Figure 4, the substances captured by the filter element can be discharged to the low pressure side from the suction fluid discharge port 162 as a concentrated liquid discharge port without being mixed into the filtrate (although complete separation is not possible).

The filtering device of the first embodiment configured as above operates as follows.
During filtration, the filter element 3 is rotated, the inlet valve VI and the outlet valve VO are opened continuously, intermittently, or as required, and the on-off valve VF of the backwash fluid discharge system is closed. The fluid to be filtered flows from the fluid inlet 6 into the raw liquid chamber 8 of the casing 1 as shown by the solid arrow a in Fig. 1, passes through the part of the cylindrical filter medium 31 that is not in contact with the backwash head 141, and flows into the inside of the filter element 3, where it is filtered. The filtered fluid flows into the filtrate chamber 9 and flows out through the fluid outlet 7 to the outside as shown by the arrow b.
At this time, captured substances (solids, gel-like dust, etc.) that are about to adhere to or have adhered to the outer surface of the filter material that the first removal brush 144 is in contact with are brushed by rotating the filter element, and the adhesion is eliminated, or lumps of unwanted substances are crushed and pass through the openings of the filter material. In this way, the brushing during filtration separates the unwanted substances from the substances to be removed, and the unwanted substances can pass through to the secondary side.

Therefore, not only can most of the unwanted substances contained in the captured material be discharged to the secondary side, but also the increase in the filtration differential pressure can be significantly delayed.
In this way, the screening process during filtration makes clogging less likely to occur, so that the filtration duration can be extended, the number of backwashes can be reduced, and the operating rate of the device can be increased. In addition, the reduction in the number of backwashes can also reduce the occurrence of clogging due to backwashing.
Furthermore, in this embodiment, a suction head 151 is disposed on the secondary side facing the backwash head 141 with the filter medium 31 therebetween, and the first space S1 formed by the first removal brush 144 is communicated with the second space S2 formed by the second removal brush 154. Therefore, most of the captured substances that have been removed and crushed by the first removal brush and are now in a state that they can pass through the openings of the filter medium are discharged from the second space S2 to the outside of the casing via the first space S1, making it possible to prevent the diffusion of solid components into the filtrate.

Next, during backwashing using the backwash mechanism 140, the inlet valve VI and the outlet valve VO continue to be open, and the on-off valve VF of the backwash fluid discharge system is opened, and the pressure inside the backwash head 141, which is connected via the backwash fluid discharge pipe 145, drops. In addition, the concentrated liquid that was once discharged outside the machine through the stop valve VE during filtration is backflowed into the suction fluid discharge pipe 160 as a backwash fluid, and this concentrated liquid passes through the suction head 151, passes through the filter medium 31 as shown by the white arrow, and flows into the backwash duct 142 from the first suction port 143. At this time, the fluid that passes through the second removal brush 154 and enters the second space S2 backwashes the vertically elongated band-shaped portion of the filter medium 31 that comes into contact with the first suction port 143.

In the above backwash procedure, the backwash fluid used is a concentrated liquid, so there is a high possibility of clogging the filter from the filtrate chamber side due to backwashing. Therefore, the stop valve VE provided at the suction fluid outlet 162 of the suction fluid outlet pipe 160 may be closed, and the valve VG provided at the backwash fluid supply pipe 163 connected between the stop valve VE and the suction fluid outlet 162 may be opened to supply the backwash liquid from the suction fluid outlet 162 into the suction fluid outlet pipe 160. According to this, the backwash fluid is caused to flow out to the first space S1 side via the second space S2 and the filter 31, so that the vertical strip-shaped part of the filter 31 that contacts the first suction port 143 is backwashed more efficiently. In particular, it is possible to effectively prevent clogging from the filtrate chamber side due to backwashing.
In other words, while closing the stop valve VE, pressurized backwash fluid (clean water, etc.) can be supplied from the valve VG through the backwash fluid supply pipe 163 to the suction fluid discharge pipe 160 and the suction duct 152 (suction head 151), thereby assisting the backwashing by the backwash mechanism 140.
When the valve VG is opened to supply backwash fluid from the suction fluid discharge port 162 into the suction fluid discharge pipe 160, the backwash fluid supply section, valve VG, stop valve VE, suction fluid discharge port 162, suction fluid discharge pipe 160, suction head 151, etc. (not shown) constitute a first backwash fluid supply mechanism.

In addition, by rotating the filter element 3 by the geared motor 13, the entire surface of the filter medium 31 is backwashed while the first removal brush 144 scrapes off the captured substances. However, even during backwashing, the fluid to be filtered flows from the fluid inlet 6 into the raw liquid chamber 8 as shown by the solid arrow a, so that filtration continues in the part of the cylindrical filter medium 31 that does not face the backwash head 141. Backwashing is performed at a predetermined frequency for a predetermined time according to the operating conditions of the filtration device (such as the filtration speed and the amount of foreign matter in the fluid).
In the embodiment of Fig. 1, the second removal brush 154 seals only the filter surface 31N, which is the part of the filter medium located in the second space S2. To clean the inside of the filter medium, a cleaning fluid is introduced into the backwash duct 142 from the valve VH, and the fluid passes through the part of the filter medium and flows into the second space.

The filtration device according to the first embodiment comprises a first removal brush 144 that is arranged to be movable relative to the outer surface (primary side) of the filter medium 31 that constitutes the filter element 3 and assists in the detachment (removal) of captured substances and in sieving the captured substances during the relative movement, a drive unit 13 that moves at least one of the first removal brush or the filter element relative to the other, a filtration mechanism, a backwash mechanism, and a control means 600 that controls the drive unit, filtration mechanism, and backwash mechanism, and implements an operating method in which backwashing is initiated when the filtration differential pressure between both sides of the filter medium during filtration exceeds a predetermined value or after a predetermined time has elapsed, and filtration is resumed after the differential pressure is eliminated or after the predetermined time has elapsed.
In this operating method, the control means drives the drive unit during filtration to move the brush relative to the filter material, sieving out the unwanted matter from the captured material and allowing the unwanted matter to pass to the other side.

6 is a flow chart showing the operation procedure of the filtration device of the present invention. The operation procedure according to this flow chart is commonly applied to the other embodiments described below.
When starting filtration, the control means 600 opens the inlet valve _VI and the outlet valve _VO , closes the on-off valve _VF of the backwash fluid discharge system, and rotates the filter element 3 to periodically or continuously (always) brush the primary side of the filter medium with the removal brush 144 to sieve out the unwanted substances from the captured substances and pass the unwanted substances through to the other side (steps S1 and S2). Note that the brushing in step S2 may be intermittent brushing.

Next, in step S3, a measuring device for the filtration differential pressure (not shown) is used to determine whether the filtration differential pressure has reached a predetermined value, in other words, whether the filtration differential pressure has exceeded an allowable value, and if it has exceeded the allowable value, the process proceeds to step S4, where backwashing is started while brushing. If it has not exceeded the allowable value, the process returns to step S2. Note that in step S3, a timer may be used to measure the filtration time, and when a predetermined filtration time has elapsed, the process proceeds to step S4, where backwashing is started.
In the backwash operation, the inlet valve _VI and the outlet valve _VO are kept open, and the on-off valve _VF of the backwash fluid discharge system is opened. At this time, the backwash fluid (concentrated liquid) may be supplied to the suction fluid discharge pipe 160 via the stop valve VE by opening the stop valve VE and closing the valve VG, or the backwash fluid (cleaning fluid) may be supplied to the suction fluid discharge pipe 160 and the suction duct 152 via the valve VG by closing the stop valve VE and opening the valve VG.
When the backwash fluid (concentrated liquid) is supplied to the suction fluid discharge pipe 160 via the stop valve VE by opening the stop valve VE and closing the valve VG, the backwash fluid supply section, the stop valve VE, the valve VG, the suction fluid discharge port 162, the suction fluid discharge pipe 160, the suction head 151, etc. (not shown) constitute a second backwash fluid supply mechanism.

Even if the measurement of the filtration differential pressure in step S3 detects that the filtration differential pressure exceeds the allowable value, when backwashing while brushing is started thereafter, the measurement device may detect a filtration differential pressure lower than the allowable value when the element has rotated only a small angle, for example, about 15 degrees, which does not reach one rotation. However, at this stage, backwashing by brushing has not been completed on the entire circumferential surface of the filter element, and trapped material still remains on the surfaces that have not been brushed. To address this problem, a timer must be used to check that the element has rotated at least once against the brush, and in this embodiment, a maximum of three times, to ensure that brushing and backwashing have been performed evenly on the entire circumferential surface of the element.

If the filtration differential pressure measurement in step S5 after performing backwashing while brushing in step S4 results in the filtration differential pressure decreasing to a predetermined value (e.g., 0.002 MPa), the process returns to step S2 after the backwashing is completed.
If it is determined in step S5 that the filtering differential pressure has not decreased from the predetermined value, the process proceeds to step S6, where filtering is stopped, and an alarm is sounded in step S7 to warn that maintenance is required.

Next, FIG. 7 is an enlarged cross-sectional view of a main part of the filter medium, showing a state in which sieving is being performed by brushing.
In Fig. 7(a), the openings 3A of the metal mesh material constituting the filter medium 31 are clogged with particulate unwanted substances M on the primary side, but by sliding the removal brush 144 along the primary side of the filter medium, the tip of the removal brush breaks down the particles M in the agglomerated state and disperses them into individual particles. This allows the individual particles to ride the flow of the fluid during filtration and pass through to the secondary side, eliminating the clogging. Note that the objects to be removed are not shown in the figure.
In Fig. 7(b), fibers N become entangled with particles M, which are substances that do not need to be removed, causing clogging of the opening 3A, but by sliding the removal brush 144 along the primary side of the filter medium, the tip of the removal brush separates the entangled particles M and fibers N and disperses them into individual particles. This allows the individual particles to ride the flow of the fluid during filtration and pass through to the secondary side, eliminating clogging.

Next, Fig. 8(a) is a cross-sectional view of the main part of a filtering device according to a second embodiment of the present invention, and (b) is a perspective view showing the configuration of the first removal brush. The same parts as in Fig. 4 are denoted by the same reference numerals. The first suction port for backwashing may be provided at an appropriate position in the casing body 1a constituting the outer wall of the raw liquid chamber 8, and is not shown in Fig. 8.
In this embodiment, a single removal brush row 144c is used as the first removal brush 144 on the primary side, which is planted (fixed) to the support member 146 and arranged along the axial direction of the filter medium 31, while a second removal brush 154 is planted (protruding) in a ring shape along the periphery of the second suction port 152a arranged on the filtrate chamber 9 side, sandwiching the filter medium therebetween. The positional relationship between the primary removal brush row 144c and the second space S1 is such that the primary brush row 144c and the front removal brush row 154a of the second removal brush 154 on the secondary side are opposed to each other at almost the same circumferential position, sandwiching the filter medium therebetween, as shown in the figure. By configuring in this way, the second space S2 is located downstream of the captured material (solid component) removed and crushed by the primary brush row 144c and flows in on the liquid flow F2, and it becomes possible to efficiently flow into the second space S2, which is in a negative pressure state, from the filter surface 31N immediately after clogging is eliminated. The negative pressure from the second suction port 152a causes suction, making it possible to quickly suck in and filter most of the solid components that tend to diffuse into the concentrate chamber 8.

This prevents the material immediately after being removed and crushed from the filter surface by the removal brush row 144c from scattering throughout the entire liquid chamber and becoming trapped in other clogged filter media portions, thereby increasing the clogging, thereby improving filtration performance.
In other words, the first removal brush 144 does not necessarily have to be a circular brush row that forms the first space S1, and even if there is a single brush row, the dispersed captured material can be collected by suction on the filtrate chamber side.

9(a) is a perspective view showing another example of the configuration of the suction head used in the filtration device of the present invention (third embodiment), (b) is a cross-sectional view showing the positional relationship with the backwash head when the suction head of (a) is assembled to the filtration device, (c) is an explanatory diagram showing the positional relationship between the suction head and the backwash head, and (d) is a perspective view showing another example of the configuration of the suction head (backwash head).
A plurality of suction heads 151A according to this embodiment are arranged along the longitudinal direction of the suction fluid discharge pipe 160 and at circumferentially shifted positions. Each suction head 151A is formed by annularly implanting a second removal brush 154 along the periphery of a second suction port 152a, which is an opening at the tip end side of a cylindrical suction duct 152. An inner diameter side opening 152b is formed in the center of the circular bottom surface of the suction duct 152, which is connected in communication with the suction fluid discharge pipe 160 via a branch pipe 165. Each branch pipe 165 according to this embodiment is arranged at a different position on the axial direction of the suction fluid discharge pipe 160, and further, the circumferential positions of each branch pipe 165 relative to the peripheral surface of the suction fluid discharge pipe 160 are slightly shifted so as not to overlap.

The multiple suction heads 151, fixed with their inner diameter openings 152b connected to each branch pipe 165, are arranged in close succession in the axial direction so that each second space S2 formed by the annular second removal brush 154 covers the entire axial surface of the inner surface of the filter medium 31. In other words, the second spaces S2 of each suction head 151 are arranged at different axial and circumferential positions, but are arranged without interruption in the axial direction of the filter medium. Therefore, when the filter medium rotates once relative to each fixed suction head, the entire axial surface of the filter medium passes through one of the second spaces and is rubbed by the second removal brush 154.

9(b), a plurality of suction heads 151A are arranged at different axial positions around the entire circumference of the suction fluid discharge pipe 160 inside the filter element 3 (filtrate chamber 9), and backwash heads 141A having the same shape as the suction heads are arranged in the raw liquid chamber 8 through the filter medium so as to face each of the suction heads 151A. Note that in some parts of the figure, a first brush 144 consisting of a single brush row is shown as the backwash head 141A instead of the annular first brush, but a first brush consisting of a single brush row may also be used in this way.
9(c) shows an example of a configuration in which a first removal brush 144 is planted on the periphery of a first suction port 143 of a cylindrical backwash duct 142 as a backwash head 141A constituting the backwash mechanism 140, similar to each suction head 151A. By configuring in this way, a first space S1 is formed inside the first removal brush consisting of an annular brush row. The two spaces S1 and S2 are arranged opposite each other so as to communicate with each other via a filter medium.

In the illustrated configuration example, multiple suction heads 151A are arranged along the axial direction of the filter medium with circumferential positions shifted, but they may be arranged in a straight line along the axial direction without circumferential position shifting. Also, a group of suction heads 151A arranged in this straight line may be arranged in multiple rows in parallel in the circumferential direction.

Figure 9 (d) shows a modified example of the suction head 151A (and the backwash head 141A). The suction heads in the same figures (a), (b), and (c) have the second removal brush 154 planted along the entire periphery of the second suction port 152a, but in this embodiment, a missing portion (gap) 154c through which fluid can enter and exit is provided in a part of the second removal brush. Even if there is a part of the second removal brush where no brush is present, the missing portion 154c is acceptable as long as it does not interfere with the formation of the second space S2 that forms a semi-closed space between the filter material 31 and the brush. In other words, if the second space S2 is made at a lower pressure than the first space S1, and filtration is performed smoothly by the liquid flow F2 flowing toward the second space S2 through the brushed filter surface 31N (see Figure 4), the presence of the missing portion does not pose a problem.

The pros and cons of providing the removal brush with a missing portion also apply to the other second removal brush 154 shown in Figures 1, 2, 5, and 8. In addition, this also applies to the first removal brush 144 in the same manner as the second removal brush.
In each of the configuration examples of FIG. 9, the first removal brush is configured in a circular ring shape, but it may be configured in an elliptical ring shape, another ring shape, a square shape, or a polygonal shape.
In the above embodiments, the removal brush is shown as the rubbing member that forms the second space S2 between the filter surface 31N, but this is only one example. It is also possible to use rubbing members other than brushes, such as elastic resin or metal plates, rubber spatulas, etc. In this case, it is sufficient to configure the rubbing member so that the inflow of fluid from the surroundings into the second space S2 formed by surrounding the second suction port is reduced. However, a brush is preferable in consideration of the solid dispersion ability, error absorption ability, and effect on rotational resistance.

This also applies to the other embodiments described below.
Next, Figure 10(a) is a cross-sectional view showing the peripheral configuration of a suction head 151 relating to a modified example of the first embodiment (fourth embodiment) (corresponding to the B-B cross-sectional view of Figure 1(a)), (b) is a CC cross-sectional view of (a), and (c) is an oblique view of the main parts showing the rotation mechanism.
In the device configuration of Fig. 1, during backwashing, the concentrated liquid or a separately prepared backwashing fluid must pass through the filter material 31 as shown by the white arrow and flow into the backwashing duct 142 from the first suction port 143. In other words, the narrow band-shaped filter material portion (filter surface 31N in Fig. 4) facing the first space S1 formed by the first removal brush 141 is in a state where the flow of the filtrate in the filtrate chamber 9 is hindered by the second removal brush 154, preventing the filtrate as the backwashing liquid from flowing into the first space S1, and the first space S1 and the second space S2 face each other (communicate). Both spaces form a semi-closed space via the filter material, and as long as the two spaces are in a communicated state, it is difficult for the backwashing fluid to flow in except for the backwashing fluid flowing into the first space S1 through the second space S2. For this reason, it is necessary to use the concentrated liquid or a separately prepared backwash fluid (cleaning fluid) for backwashing through the suction fluid outlet 162, and the filtrate in the filtrate chamber 9 cannot be used effectively.

As a countermeasure for this, in this embodiment, during backwashing, the filter element is rotated by an arbitrary angle, for example 90 degrees, in the clockwise direction shown by the dashed line from the position shown by the solid line in Fig. 10(a) to retreat the second space S2 of the suction head 151 to a circumferential position that does not communicate with the first space S1. Backwashing can be performed simply by closing the valve VG, the stop valve VE, and the valve VH in Fig. 1(a) and opening the opening/closing valve VF, and there is no need to supply a backwashing fluid from the outside or to backflow the concentrated liquid.
That is, in this embodiment, the suction fluid discharge pipe 160 is composed of a fixed part 160A on the lower side which does not rotate, a movable part 160B which is supported in an appropriate position of the fixed part 160A (in this embodiment, the upper part of the fixed part) so as to be freely rotatable within a predetermined angular range, and a stopper 200 which restricts the rotation range of the movable part within a predetermined range, and is characterized by the configuration in which the suction duct 152 of the suction head 151 is integrated with the movable part 160B.

An arc-shaped stopper 200 is fixed to the outer peripheral surface of the upper end of the fixed part 160A. The outer peripheral surface of the movable part 160B is rotatably supported on the inner peripheral surface of the stopper 200 via a slide bearing 202. Therefore, the fixed part 160A and the movable part 160B can rotate forward and backward within the range of the opening 200a of the stopper 200 in a coaxial positional relationship. The suction head 151 protruding from the outer peripheral surface of the movable part 160B is located within the opening 200a of the stopper, and cannot rotate beyond the circumferential angle of the opening 200a. Therefore, the movable part 160B and the suction head 151 rotate between the position shown by the solid line and the position shown by the dashed line.
The movable part 106B does not need to be rotated by a special drive source, but may be configured to rotate by being co-rotated via the first removal brush 144 that comes into contact with the filter medium when the filter element 3 rotates.
The fixed part 160A, the movable part 160B, the plain bearing 202, and a motor (not shown) constitute a rotation mechanism.

In the device configuration shown in FIG. 10 (FIG. 1), during filtration by the filtration mechanism 120, the fluid (raw liquid) flowing in from the fluid inlet 6 passes through the filter medium 31 from the outside of the filter element and flows into the inside. At this time, the filter element is rotated counterclockwise in FIG. 10(a), so that the suction head 151 is maintained in the initial position shown by the solid line (the position where the second removal brush 154 faces the first removal brush 144). In addition, the stop valve VE of the suction fluid discharge pipe 160 is opened to be in a suction state (the valve VH, the opening and closing valve VF, and the valve VG are all closed). Therefore, when the particles constituting the unnecessary removal substance on the outer surface of the filter element are in a multiple agglomerated form, the first removal brush 144 is moved relative to the outer surface of the filter element to break up the agglomerated particles into a size that can pass through the opening of the filter medium, and the particles can be collected from the suction fluid discharge pipe 160 by passing through the filter medium as part of the filtrate.
During backwashing, the filter element is rotated clockwise in Fig. 10(a), and the suction head 151 rotates with it, and the second removal brush 154 moves from the initial position shown by the solid line to the retracted position shown by the dashed line (the position where the second removal brush 154 does not face the first removal brush 144), and this state is maintained. Therefore, the first and second spaces S1 and S2 are not in communication. To perform backwashing in this state, the backwashing opening and closing valve VF is opened and suction is performed from the discharge pipe 147, while the first removal brush 144 brushes the outer surface of the filter element in the circumferential direction to remove the trapped material. The trapped material removed from the filter material flows into the backwashing fluid discharge pipe 145 through the first space S1 by the suction force from the backwashing fluid discharge pipe 145. By operating the filtering mechanism 120 even during the backwashing operation, the fluid (raw liquid) flowing in from the fluid inlet 6 can be filtered in parallel to pass through the part of the filter medium 31 that is not in contact with the first removal brush and flow out to the outside. During the backwashing operation performed in parallel with this filtering, the stop valve VE and the valve VG connected to the suction fluid outlet 162 are closed.
The backwash head 141, the suction head 151, the backwash head, and the filter element 3 which can be rotated forward and backward relative to the suction head, their drive unit 13, the control means (CPU, etc.) 600, the suction fluid discharge pipe 160 (fixed units 160A, 160B), etc. constitute a third backwash fluid supply mechanism.

Next, in Fig. 10(a), the filter element is rotated counterclockwise to maintain the suction head 151 in the initial position shown by the solid line, and the backwash opening and closing valve VF connected to the discharge pipe 147 is closed, and the valve VH is opened to supply pressurized cleaning fluid (clean water) from the discharge pipe 147 toward the backwash fluid discharge pipe 145 and the backwash duct 142, thereby recovering the clogging inside the filter medium (inside the thickness of the filter medium) caused by the backwash. That is, when the valve VH is opened to supply the cleaning fluid from the discharge pipe 147 toward the backwash fluid discharge pipe 145 and the backwash duct 142, and the stop valve VE is opened to discharge the cleaning fluid from the suction fluid discharge port 162, the filtration flow rate of only the part surrounded by the brush 154 can be increased to flush out the foreign matter stuck inside the filter surface of the filter medium.
During this cleaning fluid supply operation, valve VG is closed and stop valve VE is left open, so that the cleaning fluid that has passed through the filter medium and entered the inside of the filter element is discharged outside the machine through suction fluid outlet 162.
In this case, the discharge pipe 147, the backwash fluid discharge pipe 145, the backwash head 141, the opening/closing valve VF, the valve VH, the suction fluid discharge pipe 160, the valve VG, the stop valve VE, etc. constitute a second cleaning fluid supply mechanism, and this second cleaning fluid mechanism is a means for supplying cleaning fluid from the backwash fluid discharge pipe 145 via the backwash head 141 to the suction fluid discharge pipe 160.

Next, while the suction head 151 is maintained in the initial position shown by the solid line, the valve VG is opened while the stop valve VE is closed, and pressurized backwash fluid (clean water, etc.) is supplied from the backwash fluid supply pipe 163 to the suction fluid discharge pipe 160 and the suction duct 152 (suction head 151), thereby assisting the backwash using brushing by the backwash mechanism 140. Then, the foreign matter stuck inside the filter medium can be flushed out by increasing the filtration flow rate only in the part surrounded by the second removal brush 154. At this time, the backwash fluid discharged from the backwash fluid discharge pipe 145 is discharged outside the machine through the discharge pipe 147 by closing the valve VH and opening the opening/closing valve VF.
In this case, the backwash fluid supply pipe 163, the suction fluid discharge pipe 160, the suction duct 152 (suction head 151), the stop valve VE, the valve VG, etc. constitute a fourth backwash fluid supply mechanism, and this fourth backwash fluid supply mechanism is a means for supplying the backwash fluid introduced from the suction fluid discharge port 162 of the suction fluid discharge pipe 160 toward the suction head 151 and the backwash mechanism 140.
The configuration of this embodiment can be applied to all the embodiments shown in FIGS.

11(a) and (b) are a vertical cross-sectional view (a cross-sectional view taken along line AA in (b)) and a cross-sectional view taken along line BB in (a) showing the configuration of a filtering device according to a fifth embodiment of the present invention.
In this embodiment, the backwash head 141 constituting the backwash mechanism 140 is disposed inside the filter element 3 (concentrate chamber 8), and the suction head 151 constituting the suction mechanism 150 is disposed outside the filter element 3, i.e., in the space between the filter material and the casing body 1a (filtrate chamber 9), which is a configuration different from the first embodiment in FIG.
In addition, the filtration device according to the fifth embodiment will be described mainly focusing on the differences from the first embodiment, and components that perform the same functions will be given the same symbols, and descriptions of duplicated configurations and functions will be omitted.
The filtration device according to the fifth embodiment generally comprises a casing 1, a partition wall 2, a filter element 3, a drive unit 13, a filtration mechanism 120, a backwash mechanism 140, a suction mechanism 150, and a control means (such as a CPU) 600.
The filtration mechanism 120 has a fluid inlet 6 located at the lower part of the side wall of the casing for allowing a fluid (undiluted liquid) to flow into the inside of the casing from the outside, a fluid outlet 7 located at the side wall above the fluid inlet 6 for discharging the fluid filtered inside to the outside, and an undiluted liquid chamber 8 located at the lower part of the casing and inside the filter element.
This filtration device comprises a filter element 3 that captures substances in the fluid on one side during filtration by passing a fluid from one side (inner side) to the other side (outer side) of the filter material 31, and releases the captured substances from the filter material during backwashing by passing the fluid from the other side to the one side of the filter material, a filtration mechanism 120 that passes the raw liquid from one side to the other side of the filter material, a backwash mechanism 140 that passes the filtrate obtained by filtering the raw liquid from the other side to the one side of the filter material as a backwash fluid, a suction mechanism 150 that is disposed on the other side of the filter material and sucks in the fluid that has flowed in from the one side of the filter material during filtration by the filtration mechanism, a drive unit 13 that rotates at least one of the backwash mechanism, the suction mechanism, and the filter element relative to the other, and a casing 1 that supports at least the filter element 3, the filtration mechanism 120, the backwash mechanism 140, and the suction mechanism 150.

The backwash mechanism 140 according to the fifth embodiment includes a backwash head 141 having a first suction port (backwash suction port) 143 arranged so as to come into contact with a part of the filter medium from one side (raw liquid chamber 8 side) of the filter medium 31 and sucking in the fluid on the other side (filtrate chamber 9 side) of the filter medium by passing it through the filter medium, and a first removal brush (first rubbing member) 144 that is bristled (protruding) along the periphery (edge) of the first suction port and rubs against one side of the filter medium, and a backwash fluid discharge pipe (fluid discharge pipe) 145 that discharges the fluid sucked into the backwash head to the outside of the casing 1. The first suction port 143 is a slit on the outer diameter side of the backwash duct 142, and the inner diameter side opening of the backwash duct 142 is connected to the communication port 145a of the backwash fluid discharge pipe 145. The backwash fluid discharge pipe 145 is a means for discharging the fluid sucked into the backwash head 141 to the outside of the casing 1, and its lower part passes through the lower opening of the filter element 3, bends laterally within the raw liquid chamber 8, protrudes outside the casing, and connects to the discharge pipe 147.

The suction mechanism 150 according to the fifth embodiment includes a suction head 151 having a second suction port 152a arranged to face a portion of the other side (outer side) of the filter material 31 and sucking fluid on one side (inner side) of the filter material by passing it through the filter material, and a second removal brush (second rubbing member) 154 planted (protruding) along the periphery (edge) of the second suction port and in sliding contact with the other side of the filter material, and a suction fluid discharge pipe 160 that discharges the fluid sucked by the suction head to the outside of the casing via the other side of the filter material.

This filtration device uses a backwash mechanism 140 consisting of a backwash head 141 that is arranged to face and contact a portion of the primary side (inner peripheral surface) of the filter element 3, and provides a high backwash effect by using the strong rubbing force of the removal brush 144 and the strong suction force from the first suction port 143.

That is, the backwash mechanism 140 has a configuration similar to that of the backwash mechanism of the first embodiment, except that it is disposed inside the filter element, i.e., inside the raw liquid chamber 8. That is, the backwash mechanism 140 includes a backwash head (primary side head) 141 and a backwash fluid discharge pipe 145.
The backwash head 141 is a substantially tubular member with both axial ends closed, and is provided with a backwash duct 142 that is in contact with the inner surface of the filter medium 31 and is parallel to its axis, a slit-shaped first suction port (primary side suction port = backwash suction port) 143 that is opened and formed in the contact portion of the backwash duct (opposing surface to the inner surface of the filter element) and covers substantially the entire length of the filter medium 31, and a first removal brush (first rubbing member) 144 that is planted and protruded along the entire periphery of the first suction port. The backwash fluid discharge pipe 145 is arranged coaxially with the filter element and parallel to the rotation center axis of the filter element.

The first removal brush 144 is planted along the entire periphery of the suction port 143 so that its tip is in sliding contact with the primary side of the filter material. The first removal brush 144 as a whole forms a ring-shaped brush row, and the inside of the ring-shaped brush row forms a first void (primary side void) S1 that communicates with the suction port 143.

Next, a suction head (secondary side head) 151 is arranged on the secondary side of the filter material, sandwiching the suction port 143 of the backwash head 141 and the filter material portion facing the removal brush (rubbing member) 144, and the outer diameter side opening of a suction duct 152 that constitutes the suction head is connected to the inside of the suction fluid discharge pipe 160.
The configuration of the suction head 151 is the same as that of the suction head of the first embodiment, but differs from that of the first embodiment in that it is arranged outside the filter medium. The suction head 151 roughly comprises a suction duct 152 having a second suction port (secondary suction port) 152a arranged opposite to the first suction port (primary suction port) 143 of the backwash duct 142, and a second removal brush (second rubbing member) 154 planted along the entire periphery of the second suction port 152a and having its tip in sliding contact with the secondary side of the filter medium. The other configurations are the same as those described in the first embodiment.

The suction fluid discharge pipe 160 protruding from the lower part of the suction duct 152 to the outside constitutes the suction fluid discharge port 162, and is controlled to open and close by the stop valve VE. When the backwash opening and closing valve VF is closed to prevent backwashing, and the stop valve VE is opened, suction is performed by a pump or the like so that the outside of the suction fluid discharge port 162 is at a lower pressure than the filtrate. As a result, the captured material (solid components) that is removed from the primary side of the filter medium by the relative movement between the first removal brush 144 and the filter medium and disintegrated is passed through the filter medium from inside the first space S1 of the backwash duct 142 and flows into the secondary side, and is directly led into the second space S2. The solid components that flow into the second space S2 are discharged to the suction fluid discharge pipe 160 and the suction fluid discharge port 162 via the secondary side suction port 152a and the inner diameter side opening 152b.

In addition, a pipe 147b for supplying a cleaning fluid and a valve VH for opening and closing this pipe are arranged in the external discharge pipe 147 upstream (filter element side) of the backwash opening and closing valve VF. With the backwash opening and closing valve VF closed, the valve VH is opened to supply cleaning fluid from the discharge pipe 147 toward the backwash fluid discharge pipe 145, thereby recovering the clogging of the filter medium caused by backwashing. In other words, solid components and the like that have adhered to the inside of the filter medium due to backwashing from the outside of the filter element are removed from the filter medium by supplying the cleaning fluid in the reverse direction and discharged from the backwash fluid discharge pipe 145 to the outside of the machine.
The action and effect of the filtering device of the first embodiment described in FIG. 4, i.e., the ability to recover solid components that have passed through the filter medium via the first space S1 by brushing on the primary side, without being mixed into the filtrate, by sucking the solid components on the filtrate side using the negative pressure of the second space S2, also applies to the fifth embodiment.

In addition, the configuration in which multiple small annular suction heads 151A shown in Figures 9(a) to (d) are arranged along the axial direction of the filter material and at different circumferential positions can also be applied to the embodiment of Figure 11.
Also, the backwash head 141 of FIG. 11 may be configured with a single row of non-annular brushes as shown in FIGS.
10 may be applied to the backwash head 140 of FIG. 11 so that a part of the backwash fluid discharge pipe 145 rotates with respect to the filter element. That is, the lower side of the backwash fluid discharge pipe 145 is a fixed part 145A (see fixed part 160A in FIG. 10) that does not rotate, while the fixed part 145A of the backwash fluid discharge pipe 145 supports the upper part of the backwash fluid discharge pipe 145 so that it can rotate freely within a predetermined angle range, and this rotatable part is a movable part 145B (see movable part 160B in FIG. 10). The rotation range of the movable part 145B is restricted by a stopper (not shown) similar to the stopper 200 in FIG. 10. The movable part 145B of the backwash fluid discharge pipe is integrated with the backwash duct 142 of the backwash head 141, so that the removal brush 144 can rotate with respect to the filter element 3 within a predetermined angle range while being restricted by the stopper.

In other words, the first removal brush 144 attached to the backwash head 141 can face the second removal brush 154, which is located outside the filter element and whose circumferential movement is fixed, via the filter element, or can face a direction offset by a predetermined angle, for example, 90 degrees, depending on the forward and reverse rotation of the filter element. The stopper is a means for restricting the relative rotation range of the first removal brush 144.
In the device configuration shown in FIG. 11, during filtration by the filtration mechanism 120, the fluid (raw liquid) flowing in from the fluid inlet 6 passes through the filter medium 31 from inside the filter element and flows out to the outside. At this time, the filter element is rotated counterclockwise in FIG. 11(b) to maintain the backwash head 141 in the initial position shown by the solid line (the position where the first removal brush 144 faces the second removal brush 154). In addition, the stop valve VE of the suction fluid discharge pipe 160 is opened to be in the suction state. Therefore, even if MBEC is not written in katakana, if katakana is written somewhere in the catalog, website, etc., it is considered that there is a low possibility of infringing "emBeCK" even if MBEC is used. When the particles constituting the removal unnecessary substance are in a multiple-piece agglomerate form, the first removal brush 144 is rotated relative to the filter medium wall to break down the agglomerate particles into a size that can pass through the opening of the filter medium, and the particles can be passed through the filter medium as part of the filtrate to recover the fluid with concentrated particles from the suction fluid discharge pipe 160.

During backwashing, by continuing to rotate the filter element clockwise in FIG. 11(b), the first removal brush 144 rotates with the backwash head 141, and the backwash head 141 moves from the initial position shown by the solid line to the retracted position shown by the dashed line (the position where the first removal brush 144 does not face the second removal brush 154), and maintains this state. Therefore, the first and second spaces S1 and S2 are not in communication. To perform backwashing in this state, the backwashing opening and closing valve VF is opened and suction is performed from the discharge pipe 147, while the first removal brush 144 brushes the inner surface of the filter element in the circumferential direction to remove the trapped material. The trapped material removed from the filter material flows into the backwashing fluid discharge pipe 145 through the first space S1 by the suction force from the backwashing fluid discharge pipe 145. By operating the filtering mechanism 120 even during the backwashing operation, the fluid (undiluted liquid) flowing in from the fluid inlet 6 can be filtered in parallel with the backwashing operation, passing through the part of the filter medium 31 that is not in contact with the first removal brush and flowing out from the inside of the filter element to the outside. During the backwashing operation performed in parallel with the filtering operation, the stop valve VE and the valve VG connected to the suction fluid outlet 162 are closed.
The backwash head 141, the backwash fluid discharge pipe 145 (fixed part 145A, movable part 145B), the suction head 151, the backwash head, the filter element 3 which can be rotated forward and backward relative to the suction head, its drive part 13, the control means (CPU, etc.) 600, the suction fluid discharge pipe 160, etc. constitute a fifth backwash fluid supply mechanism.

Next, in Fig. 11 (b), the filter element is rotated counterclockwise to maintain the backwash head 141 in the initial position shown by the solid line, and the backwash opening and closing valve VF connected to the discharge pipe 147 is closed, and the valve VH is opened to supply pressurized cleaning fluid (clean water, etc.) from the discharge pipe 147 toward the backwash fluid discharge pipe 145, thereby recovering the clogging of the filter element caused by the backwash. That is, when the valve VH is opened to supply the cleaning fluid from the discharge pipe 147 toward the backwash fluid discharge pipe 145 and the backwash duct 142, and the stop valve VE is opened to discharge the cleaning fluid from the suction fluid discharge port 162 of the suction fluid discharge pipe 160, the foreign matter clogged inside the filter material can be flushed out by increasing the filtration flow rate only in the portion surrounded by the brush 154.
During this cleaning fluid supply operation, valve VG is closed and stop valve VE is left open, so that the cleaning fluid that has passed from the inside to the outside of the filter element is discharged from the suction fluid outlet 162 and the backwash fluid supply pipe 163.
In this case, the discharge pipe 147, the backwash fluid discharge pipe 145, the backwash head 141, the opening/closing valve VF, the valve VH, the suction fluid discharge pipe 160, the valve VG, the stop valve VE, etc. constitute a third cleaning fluid supply mechanism, and the third cleaning fluid supply mechanism is a means for supplying cleaning fluid from the backwash fluid discharge pipe 145 to the backwash head 141.
Next, while maintaining the backwash head 141 in the initial position shown by the solid line, the stop valve VE is closed and pressurized backwash fluid (clean water, etc.) is supplied from the valve VG, which is in the open state, through the suction fluid outlet 162 to the suction fluid discharge pipe 160 and the suction duct 152 (suction head 151). This assists backwashing by utilizing brushing by the backwash mechanism 140, and increases the flow rate only in the area surrounded by the brush 154 to flush out foreign matter stuck on the filtering surface of the filter element.
In this case, the suction fluid discharge pipe 160, the suction head 151, the stop valve VE, the valve VG, the opening/closing valve VF, the valve VH, etc. constitute a sixth backwash fluid supply mechanism, which is a means for supplying the backwash fluid introduced from the suction fluid discharge port 162 of the suction fluid discharge pipe 160 toward the suction head 151.

Summary of the configuration, action, and effects of the present invention
The filtration device according to the first embodiment of the present invention comprises a filter element 3 that captures substances in a fluid on one side during filtration by passing a fluid from one side (raw liquid chamber side) to the other side (filtrate chamber side) of a filter medium 31, and releases the captured substances from the filter medium during backwashing by passing a fluid from the other side to the one side of the filter medium, a filtration mechanism 120 that passes raw liquid from one side to the other side of the filter medium, a backwash mechanism 140 that passes filtrate obtained by filtering the raw liquid from the other side to the one side of the filter medium as a backwash fluid, a suction mechanism 150 that is disposed on the other side of the filter medium and sucks in the fluid that has flowed in from the one side of the filter medium during filtration by the filtration mechanism, a drive unit 13 that rotates at least one of the backwash mechanism and the suction mechanism, or the filter element, relative to the other, a casing 1 that supports at least the filter element, the filtration mechanism, the backwash mechanism, and the suction mechanism, and the filtration mechanism, The backwash mechanism 140 includes a backwash head 141 having a first suction port 143 for sucking fluid from the other side of the filter material by passing it through the filter material, and a first rubbing member 144 for rubbing against one side of the filter material, and a backwash fluid discharge pipe 145 for discharging the fluid sucked by the backwash head to the outside of the casing. The suction mechanism 150 includes at least one suction head 151 having a second suction port 152a arranged to face a part of the filter material from the other side of the filter material and sucking fluid from one side of the filter material by passing it through the filter material, and a second rubbing member 154 arranged along the periphery of the second suction port and rubbing against the other side of the filter material, and a suction fluid discharge pipe body 160 for discharging the fluid sucked by the suction head to the outside of the casing via the other side of the filter material.

The filter element is not limited to a cylindrical shape, but may also be conical or flat.
The first and second rubbing members are not limited to brushes, but may be plates made of resin, rubber, metal, or the like.
The first rubbing member may be configured in an annular shape, or may be configured in the form of a brush or a plate-like body in the form of a flat plate as in the configuration example shown in FIG.
The backwashing methods in each of the embodiments of Figures 1, 10, and 11 include a method in which the stop valve VE is opened to supply the concentrated liquid from the suction fluid discharge pipe 160 via the suction mechanism 150 to the backwashing mechanism 140, and a method in which the valve VG is opened to supply a backwashing fluid (cleaning fluid).
In the second filtering device according to the present invention, the second rubbing member 154 is an annular body arranged along the periphery of the second suction port 152a, and is characterized in that it forms a second cavity as a semi-closed space between the filter material.

Since the second space S2 is at a lower pressure than the original liquid chamber (first space S1) on the opposite side of the filter material due to the negative pressure from the second suction port, the captured material removed and crushed by the first rubbing member can be efficiently absorbed and discharged outside the casing.
At least a part of the second sliding contact member is absent, or a missing portion in which the protruding length of the second sliding contact member is short is present.
The brush or plate-like body constituting the second rubbing member does not need to be present continuously along the entire circumference of the second suction port, and may be partially missing.

A plurality of suction heads 151 each equipped with a second rubbing member 154 are arranged adjacent to each other along the axial direction of the filter medium.
The second rubbing member may be a rectangular ring-shaped body covering the entire axial length of the filter medium as in the first embodiment, or may be a plurality of short ring-shaped bodies that do not reach the entire axial length of the filter medium arranged along the axial direction. In this case, the circumferential positions of the individual short second rubbing members may be shifted. Alternatively, they may be arranged in a straight line in the axial direction without shifting the circumferential positions.

In the third filtering device according to the present invention, the first suction port 143 is arranged so as to face a portion of one side of the filter material, and the first rubbing member forms an annular body arranged along the periphery of the first suction port, forming a first cavity as a semi-closed space between the filter material and the first suction port.
When the first rubbing member constituting the backwash head 141 is configured as a ring-shaped body, a first space S1 is formed between the filter material and the first rubbing member, so that the capture substance removed and crushed by the first rubbing member is secured within the first space without being diffused into the raw liquid.
In the filtering device according to the fourth aspect of the present invention, the second space S2 is capable of communicating with the first space via the filtering medium.
The captured substance removed and disintegrated by the first rubbing member is secured within the first space without being dispersed in the raw liquid, and is immediately sucked into the second space S2.
In the filtration device according to the fifth aspect of the present invention, the backwash mechanism is disposed between the peripheral surface of the cylindrical filter element and the casing, the suction mechanism is disposed inside the cylindrical filter element, and the suction fluid discharge pipe body is disposed coaxially with the rotation axis of the filter element.
In this configuration example, the backwash mechanism is disposed in an original liquid chamber 8 formed on the outside of the filter element, and the suction mechanism is disposed in a filtrate chamber 9 formed on the inside of the filter element.

In the sixth filtering device according to the present invention, the suction fluid discharge pipe 160 is composed of a fixed part 160A which does not rotate, and a movable part 160B which is provided with a suction head 151 and supported by the fixed part so as to be freely rotatable within a predetermined angular range, and the suction head 151 rotates together with the filter element.
When the first space S1 and the second space S2 face each other, they form a semi-closed space via the filter material. Therefore, as long as the two spaces are connected, it may become difficult to flow the backwash fluid from inside the filter material into the first space S1.
As a countermeasure for this, in this embodiment, during backwashing, the second space S2 of the suction head 151 is retreated to a circumferential position where it does not communicate with the first space S1.
The movable part and the suction head are rotated together with the filter element without using any special driving means, so that the device can be prevented from becoming large and expensive.

A filtering device according to a seventh aspect of the present invention is characterized in that the backwash mechanism is disposed inside a cylindrical filter element, the suction mechanism is disposed between an outer peripheral surface of the cylindrical filter element and a casing, and the backwash fluid discharge pipe is disposed coaxially with the rotation axis of the filter element.
In this configuration example, the backwash mechanism is disposed in a filtrate chamber 9 formed inside the filter element, and the suction mechanism is disposed in a raw liquid chamber 8 formed outside the filter element.

In the filtration device according to the eighth aspect of the present invention, the backwash fluid discharge pipe 145 is composed of a fixed part 145A that does not rotate and a movable part 145B that is provided with the backwash head 141 and is supported by the fixed part so as to be freely rotatable within a predetermined angular range, and the backwash head 141 rotates together with the filter element within the predetermined angular range.
In this configuration example, the backwash fluid discharge pipe located inside the filter element may be configured so that the portion holding the backwash head moves around the filter element.
During backwashing, the filter element is rotated relative to the suction head 151 and the backwash head 141 to retract the second space S2 to a circumferential position that does not communicate with the first space S1. In this state, the backwashing opening/closing valve VF is opened to perform suction from the discharge pipe 147, while the first removal brush 144 brushes the inner surface of the filter element in the circumferential direction to remove the trapped material.
The filtration device according to the ninth aspect of the present invention is characterized by including a backwash fluid supply mechanism for supplying backwash fluid from the suction fluid discharge pipe 160 toward the suction head 151 .
This configuration example can be applied to the backwashing of the filter medium in all the embodiments of Fig. 1, Fig. 10, and Fig. 11. For example, by using this backwashing fluid supply mechanism to flow the backwashing fluid to the first space S1 side via the second space S2 and the filter medium 31, the part of the filter medium that contacts the first suction port 143 is backwashed more efficiently. In particular, it becomes possible to effectively prevent clogging from the filtrate chamber side due to backwashing.
The filtration device according to the tenth aspect of the present invention is characterized by including a cleaning fluid supply mechanism that supplies cleaning fluid from the backwash fluid discharge pipe 145 toward the backwash head 141.
This configuration example can be applied to the cleaning of the filter medium in all of the embodiments shown in Figures 1, 10, and 11. For example, by using this cleaning fluid supply mechanism, foreign matter stuck on the filtering surface of the filter medium can be flushed out by increasing the filtration flow rate of only the filter medium portion surrounded by the first removal brush 144.

1...Casing, 1a...Casing body, 3...Filter element, 3A...Opening, 6...Fluid inlet, 7...Fluid outlet, 8...Raw liquid chamber, 9...Filtrate chamber, S1, S2...Vacuum, 10...Cylindrical portion, 11...Bearing, 12...O-ring, 13...Geared motor (drive unit), 14...Rotating shaft, 31...Filter material, 31N...Filter surface, 32...Lower blocking plate, 33...Upper blocking plate, 34...Through hole, 120... Filtration mechanism, 121... inlet side piping, 122... outlet side piping, 140... backwash mechanism, 141... backwash head, 141A... backwash head, 142... backwash duct, 143... suction port, 144... first removal brush (first rubbing member), 144a... front removal brush row, 144b... rear removal brush row, 144c... removal brush row, 145... backwash fluid discharge pipe, 146... support member, 147... discharge pipe , 150...suction mechanism, 151...suction head, 151A...suction head, 152...suction duct, 152a...secondary side suction port, 152b...inner diameter side opening, 154...second removal brush (second rubbing member), 154a...front removal brush row, 154b...rear removal brush row, 154c...missing portion, 156...bearing, 160...suction fluid discharge pipe, 160a...slit, 160A...fixed portion, 16 0B...movable part, 162...suction fluid outlet (concentrated liquid outlet), 163...backwash fluid supply pipe, 165...branch pipe, 200...stopper, 200a...opening, 202...slide bearing, 500...filter material, 500a...filter surface, 500b...filter surface, 510...backwash head, 520...suction port, 525...brush, 525a...brush row, 525b...brush row, 560...brush row, 600...control means.

Claims (6)

The filter element captures substances in a fluid on one side of the filter material during filtration by passing a fluid from one side to the other side of the filter material, and separates the captured substances from the filter material during backwashing by passing a fluid from the other side to the one side of the filter material; a filtration mechanism that passes an undiluted liquid from one side to the other side of the filter material; a backwashing mechanism that passes a filtrate obtained by filtering the undiluted liquid from the other side to the one side of the filter material as a backwashing fluid; a suction mechanism that is disposed on the other side of the filter material and sucks in a fluid that has flowed in from the one side of the filter material during filtration by the filtration mechanism; a drive unit that rotates at least one of the backwashing mechanism and the suction mechanism, or the filter element relative to the other; a casing that supports at least the filter element, the filtration mechanism, the backwashing mechanism, and the suction mechanism; and a control unit that controls the filtration mechanism, the backwashing mechanism, the suction mechanism, and the drive unit.
The backwash mechanism includes a backwash head having a first suction port for sucking the fluid on the other side of the filter medium through the filter medium and a first rubbing member for rubbing against one side of the filter medium, and a backwash fluid discharge pipe for discharging the fluid sucked by the backwash head to the outside of the casing;
The first suction port is arranged to face a part of one side of the filter medium, and the first rubbing member forms an annular body arranged along the periphery of the first suction port and forms a first space as a semi-closed space between the filter medium and the first suction port.
The suction mechanism includes at least one suction head having a second suction port arranged to face a portion of the filter medium from the other side of the filter medium and sucking fluid from one side of the filter medium by passing it through the filter medium, and a second rubbing member arranged along the periphery of the second suction port and rubbing against the other side of the filter medium, and a suction fluid discharge pipe body that discharges the fluid sucked by the suction head through the other side of the filter medium to the outside of the casing,
The second rubbing member is an annular body arranged along the periphery of the second suction port, and forms a second space as a semi-closed space between the second rubbing member and the filter medium;
The second space can be communicated with the first space via the filter medium,
A filtration device characterized by comprising a backwash fluid supply mechanism that supplies backwash fluid from the suction fluid discharge pipe toward the suction head during backwashing . The backwash mechanism is disposed between an outer peripheral surface of the cylindrical filter element and the casing,
The suction mechanism is disposed inside the filter element,
2. The filtration device according to claim 1 , wherein the suction fluid discharge pipe is disposed coaxially with the rotation axis of the filter element. The suction fluid discharge pipe is composed of a fixed part that does not rotate, and a movable part that includes the suction head and is supported by the fixed part so as to be rotatable within a predetermined angle range,
3. The filtering device according to claim 2 , wherein the suction head rotates with the filter element within the predetermined angular range. The backwash mechanism is disposed inside the cylindrical filter element,
The suction mechanism is disposed between an outer peripheral surface of the filter element and the casing,
2. The filtration device according to claim 1 , wherein the backwash fluid discharge pipe is disposed coaxially with the rotation axis of the filter element. The backwash fluid discharge pipe is composed of a fixed part that does not rotate, and a movable part that is equipped with the backwash head and is supported by the fixed part so as to be rotatable within a predetermined angle range,
5. The filtration apparatus of claim 4 , wherein the backwash head rotates with the filter element within a predetermined angular range. 2. The filtration device according to claim 1 , further comprising a cleaning fluid supply mechanism for supplying cleaning fluid from the backwash fluid discharge pipe toward the backwash head.

Images