JP3398356B2 - Filtration dehydration apparatus and filtration dehydration method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filtration / dehydration apparatus and a filtration / dehydration method, and more particularly to a printed wiring board (hereinafter, referred to as "P
(CB)), which is suitable for the treatment process for the waste liquid generated in the surface polishing process in the manufacturing process of "CB"), and to improve the operation efficiency of the filtration / dehydration device, the service life of the filter cloth, and the saving of the filter aid. .

[0002]

2. Description of the Related Art In a PCB manufacturing process, a surface-polishing step is performed before applying a photosensitive resist or screen printing to a copper clad laminate. The purpose of this is to improve the adhesion of the photosensitive resist and the wiring pattern printing material by polishing the surface of the copper in advance so that accurate etching can be performed.

In this case, a large amount of fresh water is required for the actual polishing step and the cleaning after polishing, and naturally the polished copper fine particles are turbid in the drainage after use. Further, when using abrasive grains as an abrasive, fine particles obtained by crushing the abrasive grains also become turbid in the discharged liquid. The fine particles contained in the drainage liquid in the polishing step are about 0.1 to 50 (μm), and the concentration of the fine particles is about 50 to 100 (mg / l), which is relatively low. Discharge of water is prohibited by the Water Pollution Control Law, and it is obliged to reduce the concentration of fine particles to a certain standard by filtration and then discharge.

On the other hand, with the widespread use of personal computers, mobile phones and the like, the demand for PCBs has dramatically increased, and recently, it is not uncommon to fully operate the drainage filtration apparatus for 24 hours. It is desired to improve the filtration efficiency of a filtration / dehydration device, to automate it, and to extend the life of the filter cloth.

Conventionally, there are various types of filter dehydrators for drainage treatment in the surface-polishing step, but one example is an apparatus in which the basic structure of a filter press type dehydrator is diverted for filter dehydration. Has been applied. The filtration / dehydration device has a structure as shown in FIG. In the figure, first, 1 and 2 are side plates, and each of the side plates 1 and 2 is an upper and lower frame 3 and 4 and a guide rod 5 which are horizontally mounted between them.
It is fixed by a and 5b. The guide rods 5a and 5b are laterally arranged on the left and right, and three filter plates 6, 7 and 8 are formed between them and hooks (9a and 9b) are formed on both side faces thereof.
b), (10a, 10b), (11a, 11b) are locked to the respective guide rods 5a, 5b, the filter plate 6 is fixed to the side plate 1, but the other filter plates 7, 8 are The guide rods 5a and 5b guide it so that it can move in the front-rear direction.

A hydraulic cylinder 12 is provided on the outer surface of the side plate 2.
Is attached, and its operating rod 12a is fixed to a pressing plate 13 which penetrates the side plate 2 and is joined to the filter plate 8. Therefore, when the hydraulic cylinder 12 is operated, the filter plate
8 can be moved back and forth, but between the hooks (9a, 9b), (10a, 10b), (11a, 11b) of each filter plate 6, 7, 8 a chain (14
a, 14b), (15a, 15b) are connected, and when the hydraulic cylinder 12 projects the operating rod 12a forward, the filter plates 6, 7, 8 are joined together, and conversely, they operate as shown in FIG. When the rod 12a is pulled in, the filter plates 6, 7, 8 are separated by a distance corresponding to the length of the chains (14a, 14b), (15a, 15b).

Next, a container 16 is installed below the pressing plate 13 so as to extend laterally to the moving section side of the filter plates 7 and 8. The container 16 is discharged from each of the filter plates 6, 7 and 8. It is for receiving filtered water, and the filtered water is introduced from the container 16 to the precoat tank as described later. In addition, 17 is a shooter for receiving the filter cake separated from each of the filter plates 6, 7, 8 and 18 is a carriage for receiving and carrying the filter cake dropped from the shooter 17,
Numeral 19 is a stamper for vibrating the filter cloth stretched on each of the filter plates 6, 7 and 8 when the filter cake attached to the filter cloth (described later) is peeled off.

By the way, as shown in FIG. 8, each filter plate 6, 7, 8 is composed of a frame portion 6a, 7a, 8a and a central plate portion 6b, 7b, 8b,
The filter plates 6 and 8 on both sides form recesses only on the surface facing the center filter plate 7, and the center filter plate 7 forms recesses on the surface facing the filter plates 6 and 8 on both sides. There is. Then, referring also to FIG. 9 (a cross-sectional view of the state in which the frame portions 6a, 7a, 8a of the respective filter plates 6, 7, 8 are joined together), a description will be given between the respective filter plates 6, 7, 8 The filter chambers 21 and 22 are formed by the respective concave portions, but the filter chambers 2 in the central plate portions 6b, 7b and 8b of the respective filter plates 6, 7 and 8 are
Filter cloths 27, 28, 29, 30 are spread on the 1, 22 side with metal (or resin) nets 23, 24, 25, 26 interposed. Here, the nets 23, 24, 25, 26 are applied by knitting metal wires (or resin wires) with a certain thickness, but a punching board having a large number of holes is used as a center plate part through a spacer. 6
b, 7b, 8b may be installed in a state of being separated from each other, or a method in which the central plate portions 6b, 7b, 8b are provided with irregularities, etc., and in any case, the filter cloth 27, 28, 29, Any method may be used as long as it forms a water passage behind 30.

In the closed frame state shown in FIG. 9, each filter plate 6, 7, 8 is
The frame portions 6a, 7a, 8a of the filter cloths 27, 28, 29, 30 pinch the peripheral edges of the filter cloths via a seal member, and the filtration chambers 21, 22 have filter cloths 27,
Although the space is lined with 28, 29 and 30, the drainage of the polishing process into the filtration chamber 21 is injected through the center plate 6b of the filter plate 6, the net 23 and the injection pipe 31 that penetrates the filter cloth 27. The filtration chamber 21 and the filtration chamber 22 are communicated with each other by a communication pipe 32 that penetrates the central plate portion 7b, the nets 24 and 25, and the filter cloths 28 and 29.
A flange nut is fitted in the openings of the injection pipe 31 and the communication pipe 32, and the net and the filter cloth are tightly attached to the central plate portion by the flange nut. Further, drain holes 33, 34, 35, 36 are formed at the positions corresponding to the lowermost portions of the nets 23, 24, 25, 26 in each of the filter plates 6, 7, 8, and the nets 23, 24, 25, The water flowing into the aquifer composed of 26 is drained downward.

The entire system of the filtration and dehydration apparatus having the above structure is shown in FIG. In this system, the pre-coating process is executed during the initial operation and each filter plate
Valve 4, with valves 6, 7 and 8 closed and valves 41 and 49 closed
2, 43 are opened, and the pump 44 is driven to supply the precoat water in the precoat tank 45 to the filtration chambers 21, 22. Here, the precoat water is obtained by mixing a filter aid (diatomaceous earth or perlite) with water and stirring, and the precoat water flows from the injection pipe 31 into the filtration chamber 21 and communicates while filling the filtration chamber 21. Although it flows into the filtration chamber 22 through the pipe 32 and fills the filtration chamber 22, the precoat water is filtered by the filter cloths 27, 28, 29, 30 and the filtered water is net 23, 24, 25, 26. From the constructed water-passing layer, the water is discharged through the drain holes 33, 34, 35, 36 into the container 16 corresponding to the tray, and the filtered water in the container 16 is returned to the precoat tank 45.

Therefore, the circulation channel is formed, and the fine particles of the filter aid mixed in the precoat water adhere to the surface of the filter cloths 27, 28, 29, 30 to form a so-called precoat layer. Form. That is, if the meshes of the filter cloths 27, 28, 29, 30 are made fine enough to capture fine particles such as copper contained in the polishing drainage liquid in the surface-polishing step, the filter cloths can be removed in a short period of time. 27,2
Although the fine particles are clogged in the 8,29,30 eyes, the filtration resistance becomes large and the filtration efficiency is extremely lowered and the life of the filter cloth is shortened, but the particles of the filter aid contained in the precoat water are compared. The size of the filter cloth 27, 28, 29, 30 is made large, and the precoat layer composed of particles of the filter aid is used as the filter layer to continuously filter with low filtration resistance. Allow it to run. Incidentally, at the stage where the precoat process is completed, the filter aid is consumed for forming the precoat layer, and the stored water in the precoat tank 45 is almost close to fresh water.

When the precoating process is completed, the process proceeds to the original polishing drainage filtering process. In this filtration process, the valve 42 is closed and the valve 41 is opened, and the pump 44 is driven to introduce the polishing effluent of the stock solution layer 46 into the filtration chambers 21 and 22,
The fine particles of the polishing effluent are captured by the precoat layer formed on the surface of the filter cloth 27, 28, 29, 30 in advance, and the filter cloth 27, 28, 29, 30
→ Water layer of the nets 23, 24, 25, 26 → The filtered water flowing out through the drainage holes 33, 34, 35, 36 is once stored in the container 16, and the filtered water is made to flow into the precoat tank 45. Therefore,
The substantial filtering action on the polishing effluent is due to the precoat layer, and as shown in FIG.
8, 29 and 30 are in a state in which a deposition layer 48 of the fine particles contained in the polishing effluent is attached to the surface side of the precoat layer 47 formed in advance.

When the polishing drainage is filtered for a certain period of time, in FIG. 10, the pump 44 is stopped, the valve 43 is closed, and the valve 49 is opened to supply air from the air supply system side to the injection pipe 31. Supply. by this,
The unfiltered polishing effluent is expelled while being forcibly filtered, and by further supply of air, the precoat layer 47 and the particulate deposition layer 48 are dehydrated to form a cake.

As a result, after the air supply for a certain period of time is completed, the hydraulic cylinder 12 draws in its operating rod 12a to open the filter plates 6, 7, 8 as shown in FIG. The precoat layer 4 attached to the filter cloths 27, 28, 29, 30 when vibration is applied while pulling the cloths 27, 28, 29, 30 upwards
7 and the deposited layer 48 of fine particles are peeled off (a part needs to be scraped out), and the container 16 is moved in FIG.
If removed from the lower side of 7,8, the cake will fall through the shooter 17 to the trolley 18, and the fine particles of copper obtained by filtration will be collected. Note that in the filtration process, as shown in FIG. 10, the filtered water that has become fresh water is stored in the precoat tank 45, but the water that overflows from the precoat tank 45 is transferred to another circulation utilization tank 50, Is used as cleaning water in the polishing process.

[0015]

As described above, it has been desired to improve the filtration efficiency and prolong the service life of the filter cloth in the above-described filtration / dehydration apparatus. The problem is whether the filtration can be continuously performed while keeping the filtration medium formed by the deposited layer of the fine particles at a state where the filtration resistance is always small. Regarding the filter cloth, various improvements have been made in terms of the roughness of the mesh, the material, the weave, etc. in consideration of the peelability at the time of collecting the cake, but the above problems are solved only by the conditions related to the filter cloth. It is not possible.

On the other hand, paying attention to the relationship between the precoat layer 47 and the particulate deposition layer 48 shown in FIG. 12, the precoat layer 47 with relatively large particles of the filter aid is used while using the coarse filter cloth 27. Is formed, and the polishing drainage is filtered by using it as a substantial filtration function layer. If the fine particles of the polishing drainage are aggregated into large aggregated particles, the filtration resistance in the deposition layer 48 becomes small. Therefore, it becomes possible to improve the filtration efficiency.

In general, as a method of aggregating colloidal particles of a suspension, an inorganic aggregating agent that lowers the zeta potential of the colloidal particles to agglomerate the molecules with each other, or a polymer having a function of aggregating the colloidal particles by a crosslinking action. There is a method using a flocculant. However, a filtered solution in which a coagulant is dissolved is not suitable for circulation and reuse in the surface polishing process.

Further, the filter aid used in the precoat is collected together with the deposited layer of fine particles, and the copper is reused by separating the filter aid and the copper fine particles in the above surface polishing and the like. Therefore, the filter aid is a consumable item, and it is desirable to suppress the amount of use as much as possible. Also, ideally, only fine copper particles are obtained after filtration, making the separation process unnecessary.

Therefore, the present invention provides a structure of a filter body capable of promoting the agglomeration of colloidal particles to improve the filtration efficiency without using a flocculant, and also to open the filter body in the filtration process. To provide a filtration method that enables a work for a long time while sequentially attempting to recover the filtration functional layer without further providing a filtration method that suppresses the use amount of a filter aid or eliminates the use thereof. It was created for the purpose.

[0020]

According to a first aspect of the present invention, a filter cloth is spread on a central plate portion of a filter plate composed of a central plate portion and a frame portion with a water-permeable layer interposed therebetween, and a plurality of filters are filtered. The filter body is provided with one or more filtration chambers by joining the frame portions of the plates together, and the filter plate at one end of the filter body is provided only on the central plate portion and the filtration chamber side. In the case where a plurality of filtration chambers are provided with an injection pipe penetrating the water layer and the filter cloth, the central plate portion of the filter plate located in the middle and the water-permeable layer and the filter layer provided on both side surfaces of the center plate portion. A communication pipe that penetrates the cloth is provided,
Inject the liquid to be filtered into the filtration chamber from the outside through the injection pipe,
In a filtration / dehydration device that discharges filtered water to the outside through a drain hole provided at the bottom of the water flow layer of each filter plate, an injection pipe and a communication pipe are provided in the lower region of the filtration chamber, and the filtration pipe side of the injection pipe is provided. Also, the present invention relates to a filtration / dehydration device characterized in that a water guiding member for guiding the liquid to be filtered to the vicinity of the bottom surface of the filtration chamber is continuously provided on the outflow side of the communication pipe.

According to the present invention, the liquid to be filtered, which is caused to flow into the filtration chamber from the injection pipe or the communication pipe, always contacts the bottom of the filtration chamber, and the liquid to be filtered in the filtration chamber is agitated in such a manner that the liquid to be filtered is rolled up from below. The colloidal particles contained in the liquid to be filtered collide due to Brownian motion to form flocs, but in the case of coarse particles larger than the colloidal particles, slow agitation increases the chances of collision and efficient aggregation is promoted. Larger coarse particles are produced rapidly. The configuration of the injection pipe or the position of the communication pipe and the water guide member in the present invention causes the slow stirring in the filtration chamber only by injecting the liquid to be filtered, and thus the flocculation is continuously performed by promoting the aggregation action. Coarsening occurs, and the filtration resistance in the precoat layer and the deposition layer due to the coarsening particles is reduced, and the filtration efficiency can be improved. As the water guide member, for example, a tube member formed in an elbow shape or having a length corresponding to the thickness of the filtration chamber, a hollow portion is formed in the axial direction of the injection pipe and the communication pipe, It is possible to apply a molding member having an opening formed on the lower side thereof.

According to a second aspect of the present invention, in the above filtration dehydration apparatus, a pressure gauge for measuring the pressure inside the pipe is provided in the pipe passage for supplying the liquid to be filtered to the injection pipe, and the air for supplying air to the pipe passage is provided. When a supply system is installed and the measured value of the pressure gauge exceeds a predetermined value, the injection of the liquid to be filtered is temporarily stopped, the air is blown from the air supply system to the pipe path, and then the object to be filtered The present invention relates to a method for filtering and dehydrating, which comprises performing a process of restarting liquid injection.

Also in the above filter dehydrator, the filtration resistance increases as the deposition layer becomes thicker as the filtration progresses.
This is probably because small gel-like coarse particles are clogged between the large coarse particles in the deposited layer, but once the injection of the liquid to be filtered is stopped and the positive blow is performed, the gel-like coarse particles are condensed. As a result, water permeability can be secured again, and the filtering action of the filter medium (filter cloth, precoat layer, and deposited layer) can be restored.

[0024] A third aspect of the present invention, in the state in which the process based on the measurement value of the pressure gauge in the second aspect of the invention is continuously executed a plurality of times, the pressure is applied from the start of supplying the liquid to be filtered to the injection pipe. Measure the time until the measured value of the meter exceeds a predetermined value, and when the measured time becomes less than the predetermined value, stop the injection of the liquid to be filtered and supply air from the air supply system to the pipe path. A forward blow for dewatering the filter cake adhering to the filter cloth and a reverse blow for supplying air to the drain holes of each filter plate to give peelability to the filter cake are performed, and then each blow is performed. The present invention relates to a filtration / dehydration method, characterized in that the bonded state of a filter plate is opened to separate a filter cake from a filter cloth.

Even in the process of continuously recovering the filtration medium of the second invention to continuously carry out the filtration, the thicker the deposited layer becomes, the higher the filtration resistance becomes, and the recovery of the filtration action of the filtration medium is naturally limited. is there. In the present invention, the above limit is determined by using the time from the start of the supply of the liquid to be filtered until the measured value of the pressure gauge becomes a predetermined value or more as a guide. By using the judgment standard as a guide, it is possible to execute the open frame and the collection of the filter cake at the timing when the most efficient operation and operation of the filtration and dehydration device can be performed according to the real-time filtration status.

A fourth aspect of the present invention is the filtration and dehydration apparatus of the first aspect, wherein a part of the filter cake that has been peeled and collected in advance is mixed with a normal filter aid when precoating is performed. , Or a filter dehydration method in which a part of the recovered cake is applied as a filter aid instead of the usual filter aid.

In the filtration and dehydration apparatus of the first invention, a usual filter aid is used at the start of the initial filtration process, but the deposited layer of the filter cake obtained in the filtration process is agglomerated and coarsened particles. The suspension of fine particles such as copper has a strong cohesive force and extremely excellent water permeability. Therefore, when a part of the collected filter cake is mixed with a filter aid to be used, a good precoat layer can be formed, and the amount of the filter aid used can be reduced. In addition, when the mixing ratio of the filter cake is increased by repeating the filtration process, the ratio of aggregated coarse particles on the solution side to be filtered in the filter cake increases,
Gradually, a filter cake composed of a precoat layer in which the coarse particles are extremely high in purity and a deposition layer in which the components are the same is obtained. As a result, finally, without using a normal filter aid, it is possible to construct a filter medium having extremely low filtration resistance using the filter cake collected in advance as a filter aid, and to the collected filter cake. The component contained in the liquid to be filtered can be reused as it is, instead of the filter aid, without any separation treatment.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the "filtration dehydration apparatus and filtration dehydration method" of the present invention will be described in detail below with reference to Figs. First, FIG. 1 is a cross-sectional view of a state in which a filter plate is closed in this embodiment, and corresponds to FIG. 9 in the above-mentioned conventional technique. Here, the elements indicated by reference numeral “X” or “X ′” in FIG.
Although the basic configuration is the same as the element indicated by reference numeral “X” in FIG. 3, the element related to the reference numeral “X ′” is based on the fact that the positions of the injection pipe 31 ′ and the communication pipe 32 ′ are different. 3
Since the positions of the through holes for 1'and 32 'are different, they are shown as "X'" to show the difference. Therefore,
The overall structure of the filter body itself and each element are almost the same as those described with reference to FIG. 9. Therefore, the description thereof will be omitted and only the characteristic points will be described in detail.

The characteristics of this filter are as will be apparent from a comparison of FIGS. 1 and 9; the injection pipe 31 and the communication pipe 32 in FIG.
Is provided substantially in the center of the central plate portion 6b, 7b of each filtration plate 6, 7, while the placement position of the injection pipe 31 'and the communication pipe 32' is the bottom of each filtration chamber 21 ', 22'. Downward pipes 51, 52 are connected in series to the inlets of the injection pipe 31 ′ and the communication pipe 32 ′ into the respective filtration chambers 21 ′, 22 ′, which are close to each other, Pipe 51,
The end of 52 is located at a point facing the bottom of each filtration chamber 21 ', 22'.

Also in this characteristic structure, the polishing effluent flowing from the injection pipe 31 'fills the filtration chamber 21' and the communication pipe 32 '.
Through the filter chamber 22 ', the filter cloth 27', 28 ', 29', 30 and the precoat layer preformed on their surfaces in each of the filter chambers 21 ', 22' is used for continuous filtration,
The filtrate is discharged to the outside from the drain holes 33 ', 34', 35 ', 36 through the water-permeable layer formed by the nets 23', 24 ', 25', 26. However, based on the above and
The polishing effluent flowing into the filtration chambers 21 ', 22' from the 31 'and the communication pipe 32' immediately collides with the bottom of the filtration chambers 21 ', 22' and is pushed upward while forming a vortex turbulent flow from the bottom. Be done. Therefore, as shown in FIG. 2, the polishing effluent that has flowed into each of the filtration chambers 21 ′ and 22 ′ moves upward in a manner that winds up the polishing effluent that has flowed in first, thereby causing each of the filtration chambers 21 ′ to be rotated. The polishing effluent in 22,22 'is constantly agitated slowly, and the aggregating action of copper fine particles is dramatically accelerated.

As a result, the coarse particles in which the copper fine particles are agglomerated are constantly grown and generated and deposited on the precoat layer, and the coarse particles have a strong cohesive force and have an extremely good water permeability. Therefore, it is possible to suppress an increase in filtration resistance even when the filtration process is performed for a long time, and it is possible to improve filtration efficiency. On the other hand, according to the configuration of FIG. 9, the polishing effluent flowing from the injection pipe 31 and the communication pipe 32 into the filtration chambers 21 and 22 hits the wall surfaces of the filter cloths 28 and 30 which face each other, and the filtration chambers 21 and 22 respectively. It does not promote aggregation because it only drifts inside and has little stirring action. That is, in the filter body of this embodiment, a rational stirring action in the filter chambers 21 ′, 22 ′ is induced only by performing the mechanical improvement related to the above, and further coarseness due to collision between coarse particles is caused. It promotes particle formation and continuously produces a clogging-free deposited layer.

Next, FIG. 3 shows the system configuration of a filtration / dehydration apparatus to which this filter is applied. Also in this figure, the basic configuration is almost the same as that of the system shown in FIGS. 7 and 10 according to the related art. The difference is that
In addition to the filter body being applied, the injection tube 3
A pressure gauge 54 is provided in the flow path for polishing wastewater to 1 '(also used as the air supply flow path for forward blow) 53, and a switching valve is provided in the middle of the pipe path after the air supply system is connected. 55 is provided, and each drainage hole 33 'of each filter plate 6', 7 ', 8
34 ', 35', 36 is provided with a reverse blow pipe path 56 for attachment / detachment, and a switching valve 55 supplies air to the injection pipe 31 'side at the time of forward blow, and each drain hole 33', 34 at the time of reverse blow. ',
It is configured to supply air to the 35 'and 36 sides.

The operation procedure of this system is shown in the flowchart of FIG. First, each filter plate 6 ', 7', 8
Filter plates 27 ', 28', 29 'and 30 are spread on the filter plates
6 ′, 7 ′, 8 are closed, and the precoat process is executed (S1, S2). In this case, the precoat tank 45 may be mixed with an ordinary filter aid such as diatomaceous earth or perlite and stirred, but if the filtration process is performed first, the carriage 18
If the filter cake has been collected in 1, a part of it or a mixture of the part and a usual filter aid may be used, and its advantages will be described later.

In the pre-coating process, the reverse blow pipe path 56 has the drain holes 33 ', 34', 35 ', of the filter plates 6', 7 ', 8'.
It is removed from 36, and the container 16 is set under the filter. In that state, the valves 41 and 49 are closed, the valves 42 and 43 are opened, and the switching valve 55 is connected to the injection pipe 31 '.
The pump 44 so that the flow path to the
Drive. Therefore, the liquid in the precoat tank 45 flows into the filter chambers 21 ', 22' of the filter body, and the filter cloths 27 ', 28', 29 ', 30
The filtered water after being filtered by is discharged from the drain holes 33 ', 34', 35 ', 36 to the container 16, and the filtered water returns to the precoat tank 45 and again pumped to the filtering chambers 21', 22 '. Since the circulation path that is sent is constructed, the filter cloth 2 of each filter plate 6 ', 7', 8
A precoat layer is formed on 7 ', 28', 29 'and 30. Although the time of this precoat process varies depending on the volumes of the filtration chambers 21 'and 22' and the pumping amount of the pump 44, the precoat layer is formed by a relatively short circulation operation of about 2 to 3 minutes.

When the precoating process is completed, the polishing effluent filtration process is started.
42 is closed and the valve 41 is opened, and the polishing waste liquid of the stock solution layer 46 is continuously injected into the filtration chambers 21 and 22 while keeping the other settings (S3). Further, in this embodiment, the time measurement is started from the time when the injection of the polishing waste liquid is started (S4). Then, by the injection of the polishing drainage liquid, the stationary relaxation is performed based on the positions of the injection pipe 31 'and the communication pipe 32' and the downward pipes 51, 52 in the filtration chambers 21 ', 22' of the filter body. The rapid stirring state occurs, the rapid coarsening of the copper fine particles is promoted, and the coarsened particles adhere to the surface of the precoat layer to form a deposited layer, which has been described with reference to FIGS. 1 and 2. It is as follows.

By the way, as the filtration process progresses and the thickness of the deposited layer increases, the filtration resistance increases and the filtration efficiency decreases. In this embodiment, the injection pressure of the polishing effluent at the time of filtration is constantly measured by the pressure gauge 54, and when the pressure measurement value exceeds a predetermined value, the measurement time T is read and the measurement time T It is confirmed whether or not is within a predetermined time ΔTs (for example, 40 seconds) (S5, S6).

If the pressure measurement value exceeds the predetermined value but the time condition is T> ΔTs, the drive of the pump 54 is temporarily stopped (S7), and the filtration chambers 21 'and 22' are operated for a certain time. Forward blow is executed (S8). That is, the switching valve 55 is left as it is, but the valve 43 is closed and the valve 49 is opened, and the air is passed from the flow path 53 through the injection pipe 31 ′ to the filtration chamber 2.
By blowing into 1 ', 22', the polishing effluent in the filtration chambers 21 ', 22' is pushed out by air to give air permeability. By this forward blow, gel-like coarse particles that are clogged in the filter cloths 27 ', 28', 29 ', 30 and the sedimentary layer are condensed to restore the water permeability, and the degree of recovery depends on the filtration medium. Although it depends on the configuration, for example, the measured value of the pressure gauge 54 is 3.2 (kg / c
m ² ), when the positive blow is performed for about 20 seconds, the re-filtration starts at 0.6 to 0.8 (kg / cm ² ), significantly reducing the filtration resistance.

Filter cloths 27 ', 28', 2 by the above-mentioned positive blow
When the water permeability of 9 ', 30 and the sediment layer is restored, each valve is returned to the original setting state and the pump 44 is activated to start the filtration chamber 21,22.
The injection of the polishing effluent is restarted and the time measurement is started again in the same manner as described above (S8 → S3, S4). After that, similarly, when the pressure measurement value becomes equal to or higher than a predetermined value, T> ΔT
If the time condition of s is satisfied, forward blowing and drainage filtration will be repeated (S5, S6 → S7 to S4), and highly efficient filtration will be continuously executed while adaptively restoring water permeability. .

By the way, the thickness of the deposited layer increases as the above steps are repeated, and it is inevitable that the forward blow cannot achieve sufficient recovery. Specifically, for example, the measurement threshold value of the pressure gauge 54 is set to 3.2 (kg / c).
m ² ), the forward blow time is 20 sec, and the time: ΔTs is 40
In the case of sec, the above time condition: T> ΔTs is satisfied at least about 10 times, and during that time, the positive blow and the re-filtration are repeated, but when it becomes about 20 times, the re-filtration is relatively started. The pressure gauge 54 reaches a constant pressure in a short time, and the time condition is not satisfied. This means that the frequency of stopping the filtration and applying the positive blow increases, and as a result, the filtration efficiency cannot be maintained.

Therefore, when T ≦ ΔTs is reached at the time when the measured pressure value exceeds the predetermined value, the pump 44 is stopped and the valve 43 is closed, and the normal blow for dehydration treatment and the separation of the deposited layer are performed. Perform reverse blow to improve sex (S
6 → S9, S10). Here, reverse blow means that each drain hole 3 of the filter body is
Connect pipe path 56 to 3 ', 34', 35 ', 36, and switch valve
Switch the 55 to the pipe path 56 side and net 23 ', 24', 25 ', 26 side
It is done by blowing air from (water passage layer side),
For example, the procedure is such that the forward blow is performed for about 20 seconds and then the reverse blow is performed for about 10 seconds.

After that, the operating rod 12a of the hydraulic cylinder 12
Filter to open the filter body and separate each filter plate
6 ', 7', 8 filter cloths 27 ', 28', 29 ', 30 are pulled by the stamper 19 to give vibration to separate the deposited layers from the filter cloths 27', 28 ', 29', 30. Is collected as a filter cake on the carriage 18 (S11, S12). In this case, in the conventional filter body shown in FIG. 9, since the injection pipe 31 and the communication pipe 32 are provided at the central positions of the central plate portions 6b, 7b of the filter plates 6, 7, respectively, as shown in FIG. In addition, the tension of the filter cloths 27, 28, 29 can be performed only in the area above the central position, and the deposited layer adhering to the area below the center position needs to be manually scraped,
According to this embodiment, as shown in FIG. 1, since the injection pipe 31 'and the communication pipe 32' are provided under the central plate portions 6b ', 7b' of the filter plates 6 ', 7', the filter cloth There is an advantage that almost all regions of 27 ', 28', 29 'and 30' can be pulled, and manual scraping of the filter cake is unnecessary. The above sequence can be performed by manual operation, but it is also possible to automate all of them, and the above advantages are convenient for constructing a system that can be fully operated for 24 hours.

Next, in the above embodiment, FIG. 1 and FIG.
As shown in, the downward pipes 51, 52 are used as the water guiding members for the polishing effluent to the respective filtration chambers 21 ', 22', but the function is to remove the polishing effluent at the bottom of each filtration chamber 21 ', 22'. The downward pipes 51 and 52 are not necessarily used as long as the same function can be realized by introducing the downward guide tubes 51 and 52. For example, a water guide member 61 formed of a molded product as shown in FIG. May be The water guide member 61 is a tubular molded product made of rubber or resin, has a length corresponding to the thickness of each filtration chamber 21 ', 22', and is connected to the injection pipe 31 'and the communication pipe 32'. When provided, a hollow portion 61a is formed in a portion corresponding to each tube axis direction, and a fan-shaped open portion 61b is formed below the hollow portion 61a. Also, the injection tube 31 '
3 holes 61c on the end face to be joined with the communication pipe 32 '
Are formed.

The water guide member 61 is connected to the injection pipe 31 'and the communication pipe 32' in the manner shown in FIG. It should be noted that, although the drawing shows only a state in which it is connected to the injection pipe 31 ′ in the filtration chamber 21 ′, the filtration chamber 22 ′ is also connected to the communication pipe 32 ′ with the same configuration. In this embodiment, the injection tube 31 '
Three rods 63 are erected on a flange nut 62 that is screwed to the. The hollow portion 61a and the injection pipe 31 'correspond by press-fitting each rod 63 into each hole 61c of the water guide member 61. The water guide member 61 is attached with such positioning. When the filtration plates 6'and 7'are closed with the water guiding member 61 attached, as shown in FIG.
The tip side surface of 1 is joined to the flange nut 64 on the side of the communication pipe 32 ', and the injection pipe 31' and the hollow portion 61a of the water guide member 61 and the communication pipe 32 '.
And are aligned on one axis.

Based on the configuration of FIG. 6, when the polishing drainage is made to flow from the injection pipe 31 'into the filtration chamber 21' during filtration, the polishing drainage is passed from the hollow portion 61a of the water guiding member 61 to the opening 61b. It is guided to the bottom of 21 ', and the liquid hitting the bottom slowly agitates the polishing effluent in the filtration chamber 21' from below. Further, a part of the polishing effluent that has filled the filtration chamber 21 'is filtered from the hollow portion 61a of the water guide member 61 through the communication pipe 32' to the filtration chamber 2 '.
Although it flows into the 2'side, since a similar water guiding member 61 is connected to the communication pipe 32 'also in the filtration chamber 22', a slow stirring action occurs in that chamber as well. Therefore, the same effect can be obtained by applying the water guide member 61 instead of the downward pipes 51 and 52 in the above-described embodiment. Further, since the water guide member 61 is relatively easily attached and detached, there is an advantage that the replacement work of the filter cloths 27 ', 28', 29 ', 30 is simplified.

By the way, the filter cloths 27 ', 28', 29 'and 30' after the collection of the filter cake are set on the filter plates 6 ', 7'and 8 again, and are in a state similar to the initial state. The procedure of FIG. 4 can be repeated with the procedure of FIG. 4, but in the second and subsequent procedures, a part of the collected filter cake is mixed with a normal filter aid and charged into the precoat tank 45. That is, according to the apparatus of the present embodiment, as a filter cake, a precoat layer (filter aid)
At the same time, a deposited layer composed of coarse particles having a strong cohesive force and good water permeability is obtained, and the amount of the filter aid used can be reduced by mixing it with a new filter aid.

Further, as the ratio of the filter cake to the filter aid is increased each time the procedure of FIG. 4 is repeated, the purity of the coarse particles in the precoat tank 45 gradually increases, and the above-mentioned procedure is repeated several times. It becomes possible to perform the pre-coating process in which the filter cake is directly applied instead of the filter aid. This greatly reduces the amount of consumable filter aid used, and the filtration using only the filter cake eliminates the need to separate the filter aid from the recovered cake, which is included in the polishing effluent as it is. It becomes possible to recover and reuse the copper component that had been used.

[0047]

EFFECTS OF THE INVENTION The present invention having the above-mentioned constitution has the following effects. Claims 1 to 3
Of the invention, the mechanical structure of connecting the downward position of the injection pipe and the communication pipe to the filtration plate and connecting the downward pipe to each other causes a steady slow stirring action in the filtration chamber to colloid the liquid to be filtered. By promoting agglomeration of particles to generate coarse particles having a strong aggregating force and good water permeability, it is possible to significantly improve the filtration efficiency by reducing the filtration resistance. Further, according to the present invention, since it is not necessary to use a coagulant, the circulation and reuse of filtered water is facilitated. The invention of claim 4 makes it possible to perform the filtration process while sequentially recovering the filtration action of the filtration medium (the filter cloth, the precoat layer and the deposition layer), and realizes a great improvement in the filtration efficiency. According to a fifth aspect of the present invention, in the second aspect of the present invention, the real-time filtration status is determined by using the interval time for each recovery process execution as a guide.
The open frame of the filter body and the collection of the filter cake can be performed with the most efficient operation schedule. The invention according to claim 6 significantly reduces the amount of the filter aid used to reduce the amount of industrial waste, and when the recovered filter cake is applied instead of the filter aid, the filter aid is used. No need for agents. Furthermore, when the filter cake becomes a state in which the filter aid is not contained by the execution of several precoating / filtering processes, the fine particle component contained in the liquid to be filtered is recovered and reused without performing the separation treatment. Therefore, there is an advantage that the process for achieving effective use of resources can be simplified.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a filter body (in a state where a filter plate is closed) in a filtration and dehydration apparatus of the present invention.

FIG. 2 is an enlarged cross-sectional view of the lower part of the filtration chamber (also showing a slow stirring state of the filtration chamber).

FIG. 3 is a system configuration diagram of a filtration / dehydration device.

FIG. 4 is a flowchart showing an operation procedure of the system of the filtration and dehydration apparatus.

FIG. 5 is an external perspective view of a water guide member.

FIG. 6 is an enlarged cross-sectional view of the vicinity of the lower part of the filtration chamber when the water guide member of FIG. 5 is applied instead of the downward tube (also showing a slow stirring state of the filtration chamber).

FIG. 7 is a front view (A) and a cross-sectional view (B) taken along the line YY of the filter dehydrator according to the related art.

FIG. 8 is a perspective view showing an open frame state of a filter body.

FIG. 9 is a cross-sectional view of a filter body (state in which a filter plate is closed).

FIG. 10 is a system configuration diagram of a filter dehydrator.

FIG. 11 is a cross-sectional view of the filter body in an open frame state.

FIG. 12 is an enlarged cross-sectional view showing a state in which a precoat layer and a deposition layer are formed on the filtration medium portion after filtration.

[Explanation of symbols]

1,2… side plate, 3,4… frame, 5a, 5b… guide rod, 6,6 ′,
7,7 ', 8 ... filter plate, 6a, 6a', 7a, 7a ', 8a ... frame part, 6b, 6
b ', 7b, 7b', 8b ... central plate part, 9a, 9b, 10a, 10b, 11a, 11b ...
Hook, 12 ... Hydraulic cylinder, 12a ... Actuating rod, 13 ... Pressing plate, 14a, 14b, 15a, 15b ... Chain, 16 ... Container, 17 ... Shooter, 18 ... Cart, 19 ... Stamper, 21, 21 ', 22, twenty two'
… Filtration room, 23,23 ', 24,24', 25,25 ', 26… net (water passage layer), 27,27', 28,28 ', 29,29', 30… filter cloth, 31, 31 '... injection pipe, 32,32' ... communication pipe, 33,33 ', 34,34', 35,35 ', 36
… Drainage holes, 41, 42, 43, 49… Valves, 44… Pumps, 45… Precoat tanks, 46… Stock solution tanks, 47… Precoat layers, 48… Sedimentation layers, 50… Circulation utilization tanks, 51, 52… Downward Pipe, 53 ... Supply channel for polishing waste liquid (also used as air supply channel at the time of forward blowing), 54 ... Pressure gauge, 55 ... Switching valve, 56 ... Pipe path for reverse blowing, 61 ... Water guiding member, 61a ... Hollow part, 61b ... Open part, 61c ... Hole, 62, 64 ...
Flange nut, 63… rod.

Claims (6)

(57) [Claims] 1. A filter cloth is spread on a central plate part of a filter plate composed of a central plate part and a frame part with a water-permeable layer interposed therebetween, and the frame parts of the plurality of filter plates are joined together to form a filter cloth. Or, it is equipped with a filter body that constitutes two or more filtration chambers, and the filter plate at one end that constitutes the filter body is injected through the central plate portion and the water-permeable layer provided only on the filter chamber side and the filter cloth. In the case where a plurality of pipes or a plurality of filtration chambers are configured, a communication pipe is provided which penetrates the central plate portion of the filter plate located in the middle and the water passage layer and the filter cloth provided on both side surfaces thereof. In the filtration and dehydration device that injects the liquid to be filtered into the filtration chamber from the outside through the injection pipe and discharges the filtered water to the outside through the drain hole provided at the bottom of the water passage layer of each filter plate, The communication pipe is provided in the lower region of the filtration chamber, and the liquid to be filtered is filtered on the filtration chamber side of the injection pipe and the outflow side of the communication pipe. A filtration / dehydration device characterized in that a water-conducting member leading to the vicinity of the bottom surface is continuously provided. 2. The filtration / dehydration apparatus according to claim 1, wherein the water guiding member is a pipe member formed in an elbow shape. 3. The water guide member has a length corresponding to the thickness of the filtration chamber, a hollow portion is formed in the axial direction of the injection pipe and the communication pipe, and an open portion is formed on the lower side thereof. The filtration and dehydration apparatus according to claim 1, which is a molded member. 4. The filtration / dehydration device according to claim 1, 2, or 3, wherein a pressure gauge for measuring the pressure in the pipe is provided in a pipe path for supplying the liquid to be filtered to the injection pipe, An air supply system for supplying air to the pipe path is provided, and when the measured value of the pressure gauge exceeds a predetermined value, the injection of the liquid to be filtered is once stopped and the air is supplied from the air supply system to the pipe path. A method for filtering and dehydrating, which comprises performing a forward blow and then performing a process of restarting the injection of the liquid to be filtered. 5. The measurement value of the pressure gauge becomes a predetermined value or more from the start of supplying the liquid to be filtered to the injection pipe in a state where the process based on the measurement value of the pressure gauge is continuously executed a plurality of times. Up to a predetermined time, the injection of the liquid to be filtered is stopped, and air is supplied from the air supply system to the pipe path to attach the filter cake to the filter cloth. To perform dewatering, and reverse blow to supply air to the drain holes of each filter plate to give peelability to the filter cake, and then open the joined state of each filter plate. The filtration dehydration method according to claim 4, wherein the filter cake is peeled from the filter cloth. 6. The filtration / dehydration apparatus according to claim 1, 2, or 3, wherein precoating is performed.
Filtration by applying a mixture of a part of the filter cake that was peeled and collected in advance to a normal filter aid, or by applying a part of the recovered cake as a filter aid instead of the normal filter aid. Dehydration method.