JPS6144527B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a reverse gravity passing device using a pressure-resistant mesh passing plate.

The overpressure of fluid is generally carried out by natural overpressure with gravity, and even when other pressures are added to gravity, it is best to pass the overflowed fluid along the direction of gravity. General. However, in such a direction of gravity,
The slag is separated from the passing fluid on the top surface of the hole, is pressed downward by gravity, and is deposited on the top of the hole, blocking the flowing of the passing fluid into the hole, resulting in clogging very early. . To recover from this clogging, it is necessary to interrupt the flow and take special clogging recovery measures, making continuous flow impossible.
Overefficiency is severely impaired.

However, the situation changes completely when the holes are made of metal meshes arranged substantially horizontally, and the permeable fluid is passed through from the bottom to the top, opposite to the direction of gravity. The slag is separated from the permeate fluid at the lower surface of the mesh holes by means of a sieve. The separated slag is of course subjected to upward pressure due to overpressure, but at the same time is also subject to downward pressure due to gravity to counteract this pressure.

Therefore, the force of gravity that would have pressed the slag against the hole below it in the case of a gravitational force, now acts to pull the slag away from the hole and cause it to settle and diffuse into the permeable fluid stored below. . This effect becomes especially noticeable when the overpressure is stopped and the upward overpressure disappears. According to the above,
In the case of reverse gravity flow using metal mesh as holes,
Since gravity acts to slow down the progress of clogging, the onset of clogging is postponed, and combined with the possibility of simple and effective backwashing, which will be described later, it is possible to run the system continuously for quite a long time, reducing overefficiency. It can be significantly improved.

Of course, the above-mentioned advantages of the mesh reverse gravity flow are due to the reverse gravity flow method, but at the same time, a great deal is owed to the use of metal mesh holes, which have excellent characteristics as holes. There is something.
The excellent features of the metal mesh holes as holes and how these features contribute to the reverse gravity will be explained in detail below.

Metal mesh refers to the length and width of the mesh.
It is a quadrilateral cylindrical space that is separated by a total of four wire rods, with the width of the wire rods being the length of one side and the diameter of the wire rods being the depth. The cross section of this mesh space is A of the mesh hole model shown in Figures 1A to 1C.
The area surrounded by B, C, and D (hereinafter referred to as the narrowest cross-sectional area) has the minimum area (hereinafter referred to as the narrowest cross-sectional area), and from this point on, the area before and after it rapidly widens to the end. spread.

When the overflowing fluid is forced into this mesh space, any solids larger than the narrowest cross-sectional area mixed in the fluid are blocked from flowing in at the narrowest cross-sectional area and are separated into the space in front of it. It is left behind and becomes so-called slag. Small solid objects that are able to pass through the narrowest cross-section only expand the cross-sectional area of the mesh space, but do not become narrower than the narrowest cross-sectional area. overflow outside. Therefore, there is no solid matter that stagnates and accumulates in the mesh space after the narrowest cross section. Due to the above-mentioned structural features, metal mesh holes as holes exhibit the following excellent advantages.

(1) Required overpressure is low.

The pressure drop due to the passage of the turbid fluid through the hole, and therefore the required overpressure, is proportional to the length of the hole depth, other things being equal.
It is inversely proportional to the cross-sectional area of the pore. The depth of metal mesh holes is extremely long, several hundred times the diameter, such as holes in sand layers in sand filters, holes in floors made of unglazed, sintered metal, sponge plastic, etc. Compared to a hole, it is incomparably shorter, only about one time the opening of the eye, and the required overpressure is also incomparably low. Therefore, in high-precision over-use holes in bisque sintered metals, sintered metals, sponge plastics, etc., the two factors that increase the required overpressure, namely the long hole and the small hole diameter, overlap, and even if the required overpressure becomes extremely high, Metal mesh holes are advantageous because of their short depth, which is a low required overpressure factor, and high overpressure to the left is not required even though the overaccuracy is the same.

As mentioned above, in the case of reverse gravity, the downward force of gravity counteracts the upward force of overpressure and slows down the progress of clogging. Therefore, the smaller the overpressure, the more effective the clogging alleviation effect of gravity becomes. In this sense, the mesh hole made of gold layer, which can keep the required overpressure to a relatively low level, is extremely suitable as a hole for reverse gravity overpressure, especially for high precision overpressure that requires a large overpressure. It can be said that it is an essential hole in the process.

(2) Recovery from clogging is easy.

In holes that are extremely deep compared to their diameter, such as holes in the sand layer of a sand filter, or holes in unglazed, sintered metal, or sponge plastic beds, clogging occurs throughout the long hole. Occur. There is no way that clogging that occurs deep within the floor can be recovered by cleaning or brushing from the surface or back of the floor. Also, backwashing loses its momentum while passing through long holes, making it less effective.
In short, there is no simple and effective method to recover from clogging in these holes. On the other hand, in metal mesh holes, all clogging occurs only in the front of the narrowest cross-section, and all slag concentrates in the space in front of the narrowest cross-section. It is easy to remove by cleaning and brushing the front side of the narrowest cross-sectional view, and backwashing also removes slag stuck at the entrance of the hole by passing through the extremely short hole with a powerful fluid. , which is nothing more than pushing it back outwards, and can be extremely effective.

According to the above, in a reverse gravity flow in which the metal mesh holes are arranged substantially horizontally,
All of the slag is separated into the flowing fluid at the bottom of the mesh hole, and unlike in the case of gravitational flow, there is nothing below to support the slag, so gravity acts on it immediately and causes the slag to flow into the flowing fluid. This results in sedimentation and diffusion, which gradually recovers from clogging. This is the actual effect of the clogging alleviation effect of gravity in the above-mentioned mesh reverse gravity flow, and this effect can only be achieved by using metal mesh holes. In addition, backwashing is a method in which the waste fluid stored in the upper part of the mesh holes is dropped vertically with sufficient force through short holes to push the slag in the above-mentioned state back out of the holes, thereby eliminating clogging. It is possible to recover extremely easily and effectively. In that case, if a part of the waste fluid is stored outside the filter, pressurized by a pump, etc., and flowed down together for backwashing, a more complete backwashing effect can be achieved in a shorter time. By automating this process, automatic backwashing and continuous filtration becomes possible. This is an effective backwash that can only be expected from mesh holes.

(3) Desired overaccuracy can be obtained by plating, vapor deposition, etc.

Since the metal mesh is woven from metal wire, the mesh opening can be arbitrarily narrowed by thickening the wire by plating or vapor deposition, and the overaccuracy can be improved to about a single-digit micron number. Moreover, the newly prepared net is still a metal net, only the wire diameter of the woven wire rod is larger than that of the old net, so it has the advantages of the metal net as a hole. is well maintained. High-precision reverse gravity overflow is possible only with this plated (vapor-deposited) precision mesh hole, which has minimal pressure loss and easy recovery from clogging even with high precision. It is. With long, high-precision holes made of unglazed, sintered metal, sponge plastic, etc., the full effect of reverse gravity cannot be expected.

Next, we will discuss the pressure-resistant mesh plate.

As mentioned above, metal mesh holes have excellent characteristics as holes, and it is only through these metal mesh holes that the full effect of reverse gravity can be achieved. If a single mesh made of mesh is used as a hole, it will not have enough rigidity to withstand overpressure, and the woven wire material will also be delicate and brittle, making it difficult to handle high overpressure in cases of high precision or when clogging progresses. There is a risk that the product will not be able to withstand such high temperatures and will be damaged and irreversibly deformed. Therefore, the metal mesh used as the counter-gravity overflow hole must be sufficiently reinforced with pressure resistance, but this reinforcement has the advantages of metal mesh holes, such as minimal pressure loss and no clogging. It must be such that it does not impair its feature of easy recovery and does not reduce its overefficiency in any way compared to the case of using mesh holes alone.

The pressure-resistant mesh overplate is a pressure-resistant metal mesh hole for reverse gravity that meets this requirement, and its structure is as shown in Figures 2A to 2C.The structure of the pressure-resistant mesh overboard will be explained below with reference to the figures. do.

A mesh plate 1, which is a metal mesh plate with a mesh size suitable for a desired overaccuracy, is disposed at the forefront of the pressure-resistant mesh plate on the fluid inflow side. At the rearmost part of the pressure-resistant mesh overplate, there are a large number of holes with sufficiently large diameters that are rigid enough to withstand the overpressure and internal pressure that can be applied, and that can minimize pressure loss when the overflowing fluid flows. A rigid plate 3 is provided with through holes 4 for excessive fluid flow distributed over the entire surface. Between the mesh plate 1 and the rigid plate 3, there is provided a metal mesh having a larger wire diameter and opening than the metal mesh of the mesh plate 1;・Having a pressure-resistance strength capable of withstanding the internal pressure of the over-container; b) Having a pressure-resistance reinforcing ability capable of supporting the net and withstanding the over-pressure and internal pressure of the over-container; c) The total amount of the overflow fluid that has passed through the holes is A wire diameter capable of forming, between the rigid plate surface and a passage for passing the passed fluid, the cross section of which is sufficiently wide to allow the fluid to flow to the through hole without clogging and with minimal pressure loss. A reinforcing mesh board 2, which is a metal mesh board that satisfies conditions a to c above, is provided, and the peripheral portions of these three sheets are welded together without any gaps to reduce the overload. The structure is such that the fluid can flow through the mesh of the mesh plate, the mesh of the reinforcing mesh plate, the passed fluid passage between the reinforcing mesh plate and the rigid plate surface, and the through holes in this order.

By adopting the above-described structure, the pressure-resistant mesh pass plate can satisfy all of the conditions required for the following curved reverse gravity pass mesh holes.

(1) The required pressure resistance can be maintained sufficiently by calculating the strength based on the strength of the metal material used.

(2) Because the cross-sectional area after the mesh of the reinforcing mesh plate is incomparably wider than the area of the mesh of the mesh plate in the flow path of the passing fluid, solid matter that could have passed through the holes is There is nothing that stagnates and accumulates in the passages behind the mesh of the reinforcing mesh plate. Therefore, all the slag is separated into the space in front of the narrowest cross section of the screen plate, and the location where clogging occurs and the method of recovery are not the slightest different from the case where the screen plate alone is used.

(3) For the same reason as 2 above, the pressure loss when the overflowing fluid flows through the flow passage after the mesh of the reinforcing mesh plate is incomparably small compared to the original excessive pressure loss. Therefore, the required overpressure when using the pressure-resistant mesh overplate is almost the same as the required overpressure when using the mesh plate alone.

(4) The gap formed between the reinforcing mesh plate and the rigid plate surface provides a sufficient passage to the through-hole even for the mesh of the mesh plate that is not located above the through-hole.
The entire mesh of the mesh plate can function as holes, and there is no significant decrease in efficiency compared to the case where the mesh plate is alone.

Next, we will discuss the overobject in the mesh reverse gravity overflow.

As is clear from the above description, it is exclusively the action of gravity that slows down the progress of clogging and enables simple and effective backwashing in mesh backflow.
Therefore, paste-like materials, glue-like materials, and other naphthenic materials for which such effects due to gravity cannot be expected
High viscosity fluids such as 120 cylinder oil are not suitable for reverse gravity. In other words, fluids that can be subjected to mesh reverse gravity flow are limited to water and other similar low-viscosity fluids, or fluids that can be made to have a similar viscosity by heating within a range that does not impair the quality of the fluid itself.

Next, an application example of the mesh reverse gravity passing device according to the present invention will be explained.

FIG. 3 is a sectional view of a mesh reverse gravity filter using a pressure-resistant mesh filter plate as the metal mesh holes.
11 is a pressure-resistant mesh plate, 13 is a groove for attaching the "0" ring, 14 is a rigid plate, 14a is a through hole thereof, 1
5 is a reinforcing mesh board, and 16 is a mesh board. 12 is a cylinder for holding down the overplate, 20 is the overloader body, 21 is a male threaded part for tightening the screw with the overloader lid, 22 is "0"
Ring mounting groove, 23 is fluid intake hole, 2
4 is a drained fluid removal hole, 25 is a backwashing slag discharge hole, and 26 is a "0" ring engagement member. 17
1 is an air vent lid, 18 is an air vent pipe mounting screw portion, and 19 is a female screw portion for tightening the screw to the air vent body.

To attach the pressure-resistant mesh overboard 11 to the overboard main body 20 at the start of overheating, attach the "0" ring to the "0" ring attachment groove 13 on the overboard, and then turn the overboard horizontally with the mesh board 16 side facing downward. Insert it into the filter main body 20, place the presser cylinder 12 on top of it, and close the lid 17.
cover and tighten the screws. By tightening this screw,
The over plate 11 is pushed and crushed into the "0" ring engaging member 26 of the over device main body through the holding cylinder 12, and airtightly connects the inside of the main body to the evaporated fluid storage section in the upper part and the covering part in the lower part. Separates into excess fluid retention section. Note that by tightening the screws on the lid 17, the groove 22
The "0" ring installed therein is crushed by the inner side of the lid 17, completely sealing the fluid inside the container from the outside of the container.

To start filtration, first close the backwashing slag discharge hole 25 and the filtrated fluid take-out hole 24, open the air venting peak mounted on the top of the lid, and then open the filtrated fluid intake hole 23 to remove the filtrated fluid. Pressure fluid into the container. The only passage through which the pressurized fluid can flow is the hole in the pressure-resistant mesh plate, and everything else is closed, so all fluid flows upwards against gravity and passes through the hole. Raise the fluid reservoir and expel the partial air from the peak stock. When the air has finished being discharged, the peak stock is closed, the filtrated fluid extraction hole 24 is opened, and filtration is started.

The filtration is performed during the process in which the filtrated fluid passes through the screen plate 16. Large solids that are larger than the narrowest cross-sectional area of the hole and cannot pass through the narrowest cross-section are separated and left in the passing fluid below the narrowest cross-section, and those that can pass through the hole are left as slag. The waste fluid is taken out of the vessel from the take-out hole 24.

As mentioned above, the downward gravity acts on the slag separated and left in the fluid being passed through due to the gravitational force, which slows down the progress of clogging. It is only possible to postpone this, and eventually a similar situation will arise. A simple backwash unique to this device is highly effective in recovering from this clogging situation.

For backwashing, first the fluid intake hole 23
Then, the overflow is stopped by closing the overflow fluid extraction hole 24. By stopping the filtration, the slag is freed from the upward overpressure and placed exclusively under the influence of downward gravity, and its sedimentation and diffusion into the filtrated fluid becomes active. After a short time, open the air venting stock and then quickly open the backwashing slag discharge hole 25 fully.
The waste fluid mixed with slag flows out of the vessel from the discharge hole 25. At the same time, the filtrated fluid stored in the upper part of the filtration plate flows down vertically into the hole. As described above, the pressure-resistant mesh plate has a sufficiently wide cross-sectional area for passages through which the fluid flows, and the depth of the holes is extremely short, so that the flow force of the flowing fluid is not reduced.

In this way, the slag present in the overflowing fluid below the narrowest section of the hole is sucked downward by the overflowing overflowing fluid, and on the other hand, it is pushed down by the overflowing fluid flowing down rapidly, leaving the hole space. It separates and sinks into the evaporated fluid, and is discharged from the discharge hole 25 together with the evaporated fluid. In other words, backflow can be performed extremely effectively with extremely simple operations.

Some of the slag solids are strongly embedded in the narrowest section of the hole and cannot be removed by backwashing. These substances accumulate little by little during multiple backwashings, and eventually lead to irreversible clogging during backwashing. In this case, it is necessary to remove the pressure-resistant mesh plate outside the vessel to recover from the clogging. However, unlike clogging in long holes in unglazed or sintered metals, clogging in pressure-resistant mesh plates is limited to the narrowest cross-section of the hole, so recovery is difficult. It is easy to understand.

[Brief explanation of the drawing]

Fig. 1A is a plan view of the mesh hole model, Fig. 1B is a cross-sectional side view taken along the line X-X' in Fig. 1A, Fig. 1C is a cross-sectional side view taken along the line Y-Y' in Fig. 1A, and Fig. 2A is a pressure-resistant Partial cross-sectional plan view of the mesh plate, Figure 2B is Figure 2A
FIG. 2C is an enlarged view of section C in FIG. 2B, and FIG. 3 is a cross-sectional view of an application example of a reverse gravity passing device using a pressure-resistant mesh passing plate according to the present invention. 1...Mesh plate, 2...Reinforcement mesh plate, 3...Rigid plate, 4...Through hole, 11...Pressure resistant mesh plate, 1
2... Cylinder for overplate holding down, 13... Groove for attaching "O" ring, 14... Rigid plate, 14a... Through hole, 1
5... Reinforcement net plate, 16... Net plate, 20... Passage unit body, 23... Fluid intake hole, 24...
Waste fluid take-out hole, 25... backwashing slag discharge hole.

Claims (1)

[Claims] 1. A mesh plate made of a metal mesh having mesh openings that matches the desired overaccuracy is disposed at the forefront of the inflow side of the fluid to be subjected to overflow, and is capable of withstanding applied overpressure and overpressure internal pressure. A rigid plate having a large number of through-holes having a sufficient size to minimize pressure loss when the fluid flows through is disposed at the rearmost part, and the metal of the mesh plate is It is a metal mesh having a larger wire diameter and opening than a manufacturing mesh, and (a) is placed above the through-hole and has the strength to withstand overpressure and internal pressure of the overpressure vessel, and (b) supports the above-mentioned mesh plate to prevent overpressure. , have a pressure-reinforcing ability capable of withstanding the internal pressure of the overcapacitor, and c. have a sufficient width to allow the overflowed fluid that has passed through the mesh plate to flow to the through-hole without clogging and with minimal pressure loss. A reinforcing mesh plate made of a metal mesh that satisfies conditions a to c above is arranged between the mesh plate and the rigid plate. The pressure-resistant mesh plate is installed horizontally with the mesh plate facing down, and the overflowing fluid is passed through from the bottom to the top, opposite to the direction of gravity. Reverse gravity passing device using pressure-resistant mesh passing plate.