JPH0232923B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for over-operating a filter press, particularly to an over-operating method for reducing the moisture content of a cake.

(Prior art) In a filter press with a large number of plates arranged in parallel, if a large amount of cake adheres to the cloth spread on the plates and the overefficiency decreases, the supply of stock solution is stopped and the plates are separated and cake is deposited on the cloth. Remove loose cake and clean or replace clogged cloths as necessary. In the operation of the filter press mentioned above, since the cake contains a large amount of stock solution, there are various problems in loss of stock solution and post-processing of the cake. A method is used in which an air chamber is formed with an elastic plate between the cake and the cake, compressed air is fed into the air chamber, and the cake is compressed by the expansion of the elastic plate to reduce the moisture content.

(Problems to be solved by the invention) The method for compressing a cake using the above elastic plate is as follows:
Although it is possible to reduce the amount of undiluted solution in the cake,
Since elastic plates are used, the equipment is complicated and expensive, and the elastic plates can be damaged, making handling difficult.

(Means for Solving the Problems) This invention provides a plate A in which at least one passage provided through an end of the plate opens on the side surface, and a passage provided through the other end at a position away from the said end. In this filter press, plates B and B having at least one passage opening on the top surface are arranged alternately, and a stock solution is supplied between opposing cloths spread on both sides of each plate, and the liquid passed through the cloth is passed through both plates A, A pasting process in which water is discharged from at least one passage of each of the plates B and the cake is attached to the surface of the cloth, and water is supplied from at least one passage of the plate B between the surface of the plate B and the back side of the cloth. A water flow step in which the cake on the surface of the cloth B is compressed to the side of the plate A to integrate the cakes adhering to the surfaces of both cloths, and the undiluted solution in the cake is passed through and discharged from at least one passage of the plate A. , a drainage process in which low-pressure air is introduced through one passage of plate B and water between the surface of plate B and the cloth is discharged from another passage of plate B; After sequentially operating a dewatering process in which air is supplied and water remaining between plates A and B and moisture in the cake is discharged from at least one passage of plate A, the plates are separated and the cake is allowed to fall. This is a method for over-operating a filter press, which is characterized by the following.

In the filter press applied to this invention, the passage opening into plate A and the passage opening into plate B are provided at separate positions. and there is at least one passageway opening in each plate,
If there is one passage that opens on plate A, there are two passages that open on the other plate B. This makes it easy to sequentially switch the above operations. In the case of a commonly used rectangular plate, the passages are provided at the top, bottom, left and right corners of the plate, but the passages may also be provided at the center of the top, bottom, left and right sides of the plate.
Further, the passage for supplying the stock solution may be located at either the center or the corner of the plate.

In this invention, after the passing process, water is supplied between the plate B and the back surface of the cloth from the passage of the plate B, and the cloth of the plate B and the cake on the surface of the cloth are pressed toward the plate A side, and the surface of both cloths is The adhering cake is integrated, and the liquid is discharged from the passage of plate A by passing through the liquid in the cake, thereby reducing the loss of the liquid. Next, low-pressure air is introduced through the passage of plate B, and the water accumulated in the space between plate B and the back surface of the cloth is drained from another passage of the same plate B. The cake is dehydrated by supplying higher pressure air and discharging the water existing between plates A and B and the moisture in the cake from the passage in plate A. That is, in this invention, after the remaining stock solution in the cake is filtered and replaced with water in the second step of water conveyance step, in the third step of draining step,
By introducing low-pressure air into the space between plate B and the back side of the cloth, the cloth of plate B is kept in a separated state parallel to the surface, leaving the cake compressed on the side of plate A as it is. Then, the water accumulated in the above-mentioned space is quickly drained, thereby smoothly performing the fourth step of dewatering using high-pressure air.

(Example) An example of the structure of the plate of the filter press of the present invention will be explained with reference to FIGS. 1 and 2. Boards A, B
The stock solution passages 1a and 1b are in the center of the , the lower left passages 2a and 2b and the lower right passages 3a and 3b are in the left and right ear parts 2 and 3 at the lower end, and the upper left passage 4 is in the left ear part 4 at the upper end.
a and 4b are provided through the plates, and these passages are communicated when the plates are brought into close contact with each other. The lower left passage 2a of plate A has a lower left opening 5a on the front and back sides of plate A, and the lower right passage 3b and upper left passage 4b of plate B have a lower right opening 5b and an upper left opening on the front and back sides of plate B. 6b, respectively. The plates A and B are arranged alternately as shown in FIG.

The stock solution passages 1a, 1b are connected to the stock solution supply pipe 7 attached to the fixed end plate C of the filter press, the lower left passages 2a, 2b are connected to the left liquid discharge pipe 8, and the lower right passages 3a, 3b are connected to the right liquid discharge pipe. 9, upper left passage 4a,
4b are connected to the high pressure air supply pipes 10, the left liquid discharge pipe 8 is connected to an exhaust pipe 11, and the right liquid discharge pipe 9 is connected to the exhaust pipe 11.
A water supply pipe 12 and a drain pipe 13 are connected to the high-pressure air supply pipe 10, and an air supply pipe 10a is connected to the high-pressure air supply pipe 10 so as to be switchable. By switching each of the above-mentioned pipes, a passing process, a water conveying process, a drainage process, and a dewatering process are carried out in sequence. After that, the plate is separated and the cake is peeled off from the cloth and allowed to fall.

The first over-step is shown in FIG.
The flow flows through the cloths 15a, 15b which are spread over the plates A, B and facing each other, and the cakes 16a, 16b are attached to the surfaces of the cloths.
As the thickness of 16b increases, the stock solution becomes cake 16a,
16b performs a so-called caking process. The liquid passed through the cloth 15a is discharged from the left liquid discharge pipe 8 through the lower left opening 5a of the plate A, the lower left passage 2a, and the liquid passed through the cloth 15b is discharged from the lower right opening 5b of the plate B. , and is discharged from the right liquid discharge pipe 9 via the lower right passage 3b. Note that in this step, the high pressure air supply pipe 10, the air supply pipe 10a,
The exhaust pipe 11, the water supply pipe 12, and the drain pipe 13 are all closed.

The second water flow step is shown in FIG. 4, and when the thickness of the cake increases in the above-mentioned passing step, the amount of liquid discharged decreases, and the overefficiency decreases, the supply of the stock solution from the stock solution supply pipe 7 is stopped. At the same time, close the right liquid discharge pipe 9, open the water supply pipe 12, and drain the lower right passage 3.
a, 3b, water flows from the lower right opening 5b of plate B between the surface of plate B and cloth 15b, and the cloth 15b of plate A is moved by water pressure to the cloth 15 of plate A.
Cake 16a,1 by moving it to side a
6b are compressed together to form a new cake layer 16. Due to the above compression, the undiluted solution remaining in the cake layer 16 is passed through the cloth 15a, and the liquid is passed through the lower left opening 5a of the plate A and the lower left passage 2.
a and the left liquid discharge pipe 8. In addition, in this water flow process, a small amount of the water flowing into the cloth 1
5a and may be discharged from the left liquid discharge pipe 8 in the same way as the liquid.

The third drainage step is shown in FIG. 5. After the undiluted solution in the cake is discharged in the water flow step, the left liquid discharge pipe 8 and the water supply pipe 12 are closed, and the air supply pipe 10a and the drain pipe 13 are opened. The low-pressure air vented from the air supply pipe 10a pushes out the water between the surface of the plate B and the cloth 15b from the upper left opening 6b of the plate B, and the water flows through the lower right opening 5 of the plate B.
b, passes through the lower right passages 3a and 3b, and is discharged from the drain pipe 13.

The fourth dewatering step is shown in FIG. 6. After the draining step is completed, the drain pipe 13 is closed, the exhaust pipe 11 is opened, and high-pressure air is vented through the high-pressure air supply pipe 10. The cake 16 is squeezed through the cloth 15b from the opening 6b, and the moisture in the cake is removed from the cloth 15a, the lower left opening 5a, and the lower left passage 2.
The cake 16 is dehydrated by being discharged from the exhaust pipe 11 through a.

When the cake dehydration process described above is completed, the supply of high-pressure air is stopped, and when the pressure in the room reaches normal pressure, each plate is separated and the cake adhering to the cloth is allowed to fall.

In the above example, the concentrate passage is provided through the center of the plate, but the concentrate passage may be the upper right passage of plates A and B, and each plate A and B may be provided with an opening at the lower right. Also, in the above example, low pressure air and high pressure air are switched and vented from the lower left passage.
Another high-pressure air supply pipe may be connected to the upper right passages of plates A and B, and an upper right opening may be provided in the upper right passage of plate B.

The stock solution supply pressure in the above process is 0.2-1.5Kg/
cm ² , the water flow pressure supplied from the water supply pipe 12 is 1~
8Kg/cm ² , the low pressure air sent from the air supply pipe 10 is
Preferably, the pressure is 0.5 to 1.5 Kg/cm ² , and the high pressure air pressure is 2 to 8 Kg/cm ² , and these pressures are appropriately selected depending on the weave density of the fabric, the viscosity of the stock solution, the properties of the cake, etc. The above range may be exceeded.

(Effects of the Invention) According to the present invention, after the filtration is completed, the stock solution contained in the cake is pushed out into water and filtrated.
Less loss of stock solution. Moreover, since the cake inside the room is unified by the squeezing action of flowing water, the cake can be easily peeled off from the cloth. Therefore, the present invention has the advantage that it has a wider range of applicability and lower equipment costs than the conventional method of unifying the cake and peeling it off by blowing a large amount of air or squeezing with an elastic plate. Since a drainage process using low-pressure air is interposed between the water flow process and the dehydration process using high-pressure air, high-pressure air is poured into the space after the water in the space between plate B and the back surface of the fabric is completely drained. As a result, compared to when high-pressure air is immediately introduced and dehydrated while water remains in the void, high pressure is applied to the water in the void, causing the fabric to tear or the cake to crack. Cake dehydration using high-pressure air is carried out smoothly.

[Brief explanation of drawings]

Fig. 1 is a plan view of plates A and B used in an embodiment of the present invention, Fig. 2 is a perspective view showing the connection of various pipes in the fixed end plate, Fig. 3 is a passing process, and Fig. 4 is a plan view of plates A and B used in an embodiment of the present invention. FIG. 5 is a cutaway side view of the plate showing the water conveyance process, FIG. 5 is the drainage process, and FIG. 6 is the dewatering process. A, B: Board, 1a, 1b: Stock solution passage, 2a,
2b: lower left passage, 3a, 3b: lower right passage, 4a,
4b: Upper left passage, 5a: Lower left opening of plate A, 5
b: Lower right opening of plate B, 6b: Upper left opening of plate B, 7: Stock solution supply pipe, 8, 9: Liquid discharge pipe, 1
0: High pressure air supply pipe, 11: Exhaust pipe, 12: Water supply pipe, 13: Drain pipe, 14: Room, 15a, 15
b: Cloth, 16: Cake.

Claims (1)

[Scope of Claims] 1. A plate A in which at least one passageway penetrating an end of the plate is open to the surface, and at least one passageway penetrating the other end at a position away from the said end. In a filter press in which plates B with openings on the sides are alternately arranged, a stock solution is supplied between opposing cloths spread on both sides of each plate, and the liquid passed through the cloths is distributed to at least one portion of each of both plates A and B. The cake is discharged from two passages and adheres to the surface of the cloth, and water is supplied from at least one passage of plate B between the surface of plate B and the back side of the cloth to surface the cloth of plate B. cake on board A
A water flow step in which the cakes adhering to the surfaces of both cloths are compressed to the side and integrated, and the liquid is discharged from at least one passage of plate A through the undiluted solution in the cake, and one passage of plate B. A drainage process in which water between the surface of plate B and the cloth is discharged from other passages of plate B by introducing lower pressure air; , B, and a dewatering process in which the water remaining in the cake is discharged from at least one passage of the plate A, and then the plates are separated and the cake is dropped. Over-manipulation method. 2. A method for over-operating a filter press according to claim 1, in which the stock solution is supplied between the plates A and B from the central portion of the plates A and B. 3 Board A, B from the passage at the other end of Board A, B
2. A method for over-operating a filter press according to claim 1, wherein a stock solution is supplied in between.