JPH042285B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention relates to a filter plate used in an apparatus for superconcentrating sludge.

[Prior art and its problems]

Generally, sludge discharged from water purification plants and sewage treatment plants contains more than 90% water. Therefore, before sludge treatment, the sludge is guided into a supertank of a superconcentrator and a filter plate is used to The water is removed and the water content of the sludge is reduced before it is discharged.The superconcentrator passes through a cloth that covers the entire area or part of the filtration plate, and discharges the supertreated water through a liquid discharge pipe. Meanwhile, the dewatered sludge is discharged from the bottom of the tank.

For example, FIG.
This figure shows a layout diagram of the main parts of the superconcentrator disclosed in Publication No. 87808. In FIG. 8, at least one liquid-absorbing plate 2 is disposed in the superconcentrating tank 1, and this liquid-absorbing plate 2 is made of a nonwoven fabric such as nylon, tetron or metal fiber, sponge, etc. It is made into a thick plate and has cloth attached to both sides of the plate. The filter plate 2 is located within the superconcentrator tank 1 and positioned below the liquid level of the superconcentrator tank 1 so that the liquid to be filtered can flow over the entire outer circumference thereof. The bottom of the superconcentrator tank 1 is suitably shaped like a hopper, and a cake discharge valve 3 is installed at the lower end.
A cake outlet 4 is provided. On the other hand, one end of the liquid discharge pipe 5 is inserted into the upper part of the passing plate 2,
It is led out to the outside of the superconcentrator tank 1 via the connection part 6. Liquid discharge pipe 5 led out to the outside of the superconcentrator tank 1
The other end is connected to the top of a vertically arranged siphon tube 7. The siphon pipe 7 is provided with an air vent valve 8, an on-off valve 9 for controlling liquid discharge, and a trap 10 at the bottom, but the explanation of these is omitted here.

FIG. 9 schematically shows the over plate 2 in FIG. 8 as a partial perspective view. As shown in FIG.
It has a structure in which a letter b is pasted on it. However, the over-plate 2 has a problem in that a cake (not shown) adheres to the cloth 2b during use, reducing its performance.There is a method of blowing compressed air into the over-plate 2 to remove the cake, If the layer of cake adhering to 2b is thin, the cake may not be peeled off completely, and if compressed air is introduced with the plate immersed in the sludge, the sludge will be agitated and the cake that has been peeled off will be crushed. Because of the inconvenience that the concentration and amount of cake decrease, the present inventors proposed the method shown in Fig. 10 of Passing Plate 2 in Japanese Unexamined Patent Application Publication No. 1983-1999.
It is disclosed in Publication No. 190616.

FIG. 10 is a sectional view of the overplate 2 shown together with the attached cake 11, in which the same parts as in FIG. 4 are designated by the same reference numerals. In FIG. 10, cloth 2b is applied to both surfaces of a support material 2a made of, for example, non-woven fabric, and sewn at several places to form an overboard 2, with reference numeral 12 representing the seams. By configuring the overboard 2 in this way, when the pasting progresses and the cake 11 adheres to the surface of the cloth 2b, and the pasting performance decreases, compressed air is supplied into the overboard 2 so that a plurality of cloths 2b are formed. As a result, the attached cake 11 cannot follow the local deformation of the cloth 2b, and the cake 11
can be easily peeled off even from the surface of the cloth 2b to the thin and soft cake 11.

Although the filter plate of the sludge superconcentrator is constructed as described above, subsequent research by the present inventors has revealed that the following problems still exist.

Conventional support materials use thick fibers, sponges, etc., and there are many parts that come into contact with the cloth, where a certain amount of sludge particles that are mixed in with the liquid that has passed through the cloth adhere and accumulate. I come to do it. It is possible to remove a considerable amount of adhered sludge from the cloth of the filter plate by backwashing or surface washing, but in both backwashing and surface washing, it is necessary to remove the sludge particles that are strongly bound to the cloth. Water must be applied directly to the areas where the deposits have adhered, and in the case of large plates, many pipes are required to introduce water for backwashing and surface washing to these areas, which increases equipment and operating costs considerably, so this is not practical. As mentioned above, it is difficult to remove adhered sludge particles. Furthermore, using this adhered sludge as a nucleus, sludge particles are allowed to adhere to areas of the fabric where the fabric and support material are not in contact, and this progress also occurs due to the growth of microorganisms when the BOD of the liquid is high. These things cause the overplate to become clogged and cause a decrease in overefficiency.

On the other hand, in a superconcentrator, a passage is required between the cloths of the overplates to discharge the liquid to the outside, but the cloths of the overplates are used by the pressure of the sludge and the negative pressure associated with the discharge of the liquid. As the support material is compressed, the overplate is subjected to a force that is opposed to ensuring the passage of liquid. Therefore, conventional overplates have the disadvantage that the fluid passages are compressed by forces that crush them.

In view of the above, it is desirable that the filter plate of the superconcentrator has an effective cavity for providing a flow path for the liquid and does not cause clogging due to adhesion of sludge particles.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned points, and its purpose is to provide a superconcentration device that can efficiently pass through the liquid without causing the liquid flow passage to become clogged with sludge or the like. The aim is to provide an overboard of

[Key points of the invention]

The present invention uses a supporting material consisting of a large number of contact members that contact cloth at convex portions and a connecting member that connects them together, and places cloth on both the upper and lower surfaces of this supporting material to connect the cloth and the supporting material in many ways. By making almost point contact at certain points, a large number of flow paths are ensured to allow the liquid to flow effectively between the fabric and the supporting material, and an overplate is obtained that does not cause clogging with sludge particles. .

[Embodiments of the invention]

The present invention will be explained below based on examples.

FIG. 1 is a perspective view showing one example of the shape of the support member 13 used in the present invention. Support material 1 in Figure 1
3 consists of a large number of contact members 14 that come into contact with the cloth and a connecting member 15 that connects them together, and the contact members 14 are arranged to sandwich the connecting members 15 and protrude vertically to form the support plate 13. , the connecting member 15 forms a number of holes 16 in the support member 13. If the shape of the contact member 14 that protrudes vertically with the connecting member 15 as a boundary is, for example, a substantially conical shape as shown in FIG.
A large amount of air space is maintained between the cloth and the connecting member 15, and a sufficient number of liquid passages are formed by the large number of holes 16. The contact member 14 can take arbitrary positions on the upper and lower sides of the connecting member 15 without having to be in the same position. What is necessary is just to form it in the connection member 15 with the same structure. It goes without saying that the contact members 14 may be placed in vertically symmetrical positions, but no regularity in position with respect to the support member 13 is required.

Apply cloth to both sides of this support material 13, and
FIG. 2 shows a cross-sectional view taken along the line P-P. As shown in FIG. 2, in the present invention, the contact member 1
The overboard 17 is constructed by placing cloth 2b on both sides of the supporting member 13 consisting of the connecting member 15 and the connecting member 15. In the overboard 17 of the present invention configured in this manner, the contact between the cloth 2b and the support material 13 is made at the apex of the protruding contact member 14 as described above, and there are fewer contact points than when using a conventional support material. A number of cavities, indicated by sections A and B in FIG. 2, are formed in the overplate 17, allowing liquid to freely pass through the holes 16.

Therefore, the overboard 1 installed in the overconcentrator tank 1
Even when the inside of 7 becomes negative pressure from the outside, support material 1
3, it is possible to secure a liquid flow path while keeping an appropriate distance between the front and back cloths 2b,
The filtration proceeds without reducing the effective surface area of the fabric 2b, and the liquid flows unhindered towards the liquid discharge pipe 5. Furthermore, since the passing plate 17 has a small contact area between the support material 13 and the cloth 2b, even if fine sludge particles contained in the sludge pass through the cloth 2b and enter the liquid, the sludge particles will be exposed to the contact area. The sludge particles can flow out together with the liquid through the liquid flow path secured in the manner described above, without being accumulated. Therefore, when using the overplate 17 of the present invention, clogging will not occur during overtreatment.

As described above, in the present invention, the cloth is almost in point contact with the tip of the protruding part of the support material to ensure a liquid flow path, so the contact members and their connecting members constituting the support material are It can take various shapes. Although the contact member 14 in FIG. 1 is shown to have a conical shape, it may of course be pyramid-shaped or rod-shaped. Furthermore, although the connecting member 15 is formed in the form of a plate as a whole of the supporting member 13, the connecting member 15 may be made of filaments to connect the contact members 14, in which case the holes 16 are formed in a mesh shape. Ru.

For example, in FIG. 3, the contact member 14a is spherical, and these are connected by a filament connecting member 15a, and a mesh 18 is formed, and cloth is applied to both sides of the supporting member 13a constructed in this way. Plate 17a
FIG. 4 is a sectional view taken along the line Q--Q in FIG. 3. The cloth 2b contacts the support member 13a and the spherical surface of the contact member 14a to form many spaces A1 and B1. The effect of this overplate 17a is the same as that of the above-mentioned overplate 17, so a description thereof will be omitted.

FIG. 5 similarly shows a cross-sectional view of the overplate, but FIG. 4 differs from the contact member 1 of the connecting member 15b.
This is a modification example in which the connection position with 4a is different.

The materials constituting these supporting materials are preferably metals, plastics, etc. in consideration of corrosion resistance and strength, and the shape of the supporting materials is preferably set to maximize overefficiency.

Further, in the overboard of the present invention, as the support material 13b,
As shown in FIG. 6, a partial perspective view of the shape,
A hard polyethylene reticulated plastic net whose trade name is Netron Sheet can be suitably used. Netron sheets are widely used in many industrial fields, including general packaging, medical use, fisheries use, civil engineering netting, earth retention, and many other industrial fields, and can take various forms depending on the purpose of use. When used as the support material 13b for the overboard, it is preferable that the strands 19 and 20 are not flat but have a wavy shape as shown in FIG.
0's intersect to form a mesh 21. This support material 1
When a cloth is applied to 3b to form an overboard, the contact between the cloth and the support material 13b is caused by the strands 19 and 20.
This is done at the apex of the convex part of the waveform. That is, in this case, the strands 19, 20 serve as contact members and at the same time as connection members.

FIG. 7 shows a side view of the overplate 17b constructed using this support material 13b. In FIG. 7, the cloth 2b is similar to FIGS. 2, 4, and 5.
It is obvious that many voids A2, B2 are formed between the support member 13b and the support member 13b, and the same effect as described above is brought about. Note that the shape of the mesh 21 in FIG. 6 is various, such as rhombus, square, hexagon, circular, etc., but it can be selected at will based on the performance of the overboard, such as the shape of the mesh 21 and the diameter of the strands 19 and 20. can do.

The structure and function of the over-plates of the present invention have been described above, but in order to attach the over-plates 17, 17a, 17b, etc. to the superconcentrator, these over-plates should have a contour similar to that of the over-concentrator tank 1 in FIG. It is possible to use the usual method of fitting the plates into a frame (not shown) and inserting the required number of framed plates into the superconcentrator tank 1. Note that these overboards connect the front and back fabrics 2b to the holes 16 and meshes 18, 2 of the supporting material.
The same effect as shown in FIG. 10 can be obtained by using 1 and locking it at several places using rivets (not shown) to form a plurality of divided regions.

〔Effect of the invention〕

Conventionally, the overplate of a superconcentrator that removes moisture from sludge is made of a support material made of fibrous material with cloth attached to both sides, but with this, there are many contact areas between the support plate and the cloth. However, due to the fact that fine sludge particles tend to adhere to and accumulate in the contact area, and the liquid flow path is not sufficiently secured, there is a problem that the overplate becomes clogged and the overperformance decreases. In contrast, as explained in the embodiments, the present invention consists of a support member having a contact member and a connecting member so as to have a protrusion, and the contact with the cloth applied to both the front and back surfaces is made at the apex of the protrusion of the contact member. By doing this, all the contact points between the fabric and the support material are almost in a point contact state, reducing this contact area throughout the overboard, and creating many voids in the overboard.
As a result, even if the inside of the overplate becomes negative pressure during sludge overconcentration, a sufficient liquid flow path is secured between the two cloths supported by this support material, and the support material and cloth are Since sludge particles do not accumulate in the small area of contact with the filter and no clogging occurs over the entire area of the filter plate, when using the filter plate according to the present invention, liquid can be filtered extremely efficiently.

[Brief explanation of drawings]

FIG. 1 is a partial perspective view of a support material used in the overplate of the present invention, FIG. 2 is a partial sectional view of the overplate of the present invention,
Figure 3 is a partial perspective view showing a modification of Figure 1;
5 and 5 are sectional views showing a modification of FIG. 2, FIG. 6 is a partial perspective view of a plastic net used as a support material, and FIG. 7 is a cross-sectional view of a plastic net using the support material of FIG. 6. A partial side view, Fig. 8 is a configuration diagram of the main parts of the superconcentrator, Fig. 9 is a partial perspective view of a conventional superplate, and Fig. 10 shows a cake with a different superplate attached to it. FIG. 1...Superconcentration tank, 2, 17, 17a, 17b
... Passing plate, 2a, 13, 13a, 13b... Supporting material, 2b... Cloth, 14... Contact member, 15...
...Connection member, 16...hole, 18, 21...mesh,
19,20...Strand, A, A1, A2,
B, B1, B2...Empty.

Claims (1)

[Claims] 1. Apply cloth to both the front and back sides of the support material, and connect the entire circumference of this cloth to the support material in a sealable manner,
The plate is placed in a superconcentrator tank to pass water from sludge, and the supporting material is made up of a contact member with a convex portion and a connecting member that connects the contact member to each other. A superconcentrator plate for a superconcentrator, characterized in that the apex of the convex part of the contact member makes almost point contact, and a space is formed between the cloth and the support material.