JPH0542283B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a filter press that performs squeeze filtration without using a squeeze membrane, and a filter plate member used in the filter press.

BACKGROUND ART Conventionally, filter presses with various structures are known. For example, a disc-shaped stock solution supply member is fixed to each of a pair of filter cloths arranged between adjacent filter plates, and the through hole of the stock solution supply member and the stock solution supply hole of the filter cloth are communicated, and the stock solution supply member A recess is formed on the surface of the filter plate, so that when the stock solution supply member comes into contact with the stock solution supply member of an adjacent filter plate when the filter plate frame is closed, the recess is formed between the pair of filter cloths between the adjacent filter plates. Some filters communicate with the filter chamber, and the stock solution supplied from the stock solution supply through hole is supplied into the filter chamber through the recess.

Among such filter presses, the present applicant has recently invented a filter press that can perform press filtration without a press membrane by controlling the method of supplying the stock solution to the filtration chamber. That is, when supplying the stock solution into the filter chamber, the filter chambers arranged adjacent to each other are divided into, for example, two groups, and the stock solution supply pressure is increased alternately for each group to expand the filter chamber on the high pressure side. , the filter residue in the filter chamber on the low pressure side is compressed. In this way, in the filter press, the stock solution is supplied to the first group of filter chambers through the concave portion of the stock solution supply member, while the stock solution is supplied to the second group of filter chambers through the stock solution supply member. No recess is formed, and no stock solution is supplied through the stock solution supply through hole of the stock solution supply member.
The stock solution is supplied into the filter chamber of the group.

Problems to be Solved by the Invention However, with the above-mentioned structure, it is necessary to provide a stock solution supply system for the filtrate filtration section and the frame section, respectively, resulting in a problem that the overall structure of the filter press becomes complicated. It was hot.

Therefore, an object of the present invention is to provide a filtration member and a filter press that have a simple structure and can perform squeeze filtration without using a squeeze membrane, in order to solve the above problems. .

Means for Solving the Problems In order to achieve the above object, according to the filter plate member of the present invention, at least two stock solution supply through holes are formed in the filter cloth and the stock solution supply plate, and one of the two through holes is provided. One of the through holes formed a concave portion for a stock solution supply passage communicating with the filter chamber, while the other through hole was configured to communicate with the other through hole of the opposing stock solution supply plate without communicating with the filter chamber. That is, a filter plate consisting of a frame, each filter cloth arranged on both sides of the filter plate and having at least two stock solution supply holes, and a pair of filter cloths sandwiching the filter plate in a space inside the frame for the filtrate. A pair of stock solution supply plates that are connected by sandwiching the filter cloth, each having a through hole for stock solution supply that communicates with at least two stock solution supply holes of each filter cloth, and that are adjacent to each other when the filter plate frame is closed. The filter plate member is such that the opposed stock solution supply plates are in contact with each other between the pair of filter cloths located between the filter plates, and at least one of the pair of stock solution supply plates is provided.
Two stock solution supply plates are formed between one stock solution supply through hole and the pair of filter cloths between the adjacent filter plates on the surface facing the stock solution supply plate supported by the filter cloth of the adjacent filter plate. A concave portion for an undiluted solution supply passage was formed to communicate with the filtration chamber, and the undiluted solution was supplied from the concave portion into the filtration chamber and filtered.

Further, in the above configuration, when the pair of filter cloths are connected by the pair of stock solution supply plates, one stock solution supply through hole of one stock solution supply plate is connected to the other stock solution supply plate of the other stock solution supply plate. It can also be configured to communicate with the supply through hole.

Further, in the above configuration, the other stock solution supply plate of the pair of stock solution supply plates may be constituted by a plate-like member having the pair of stock solution supply through holes.

Further, according to the filter press of the present invention, at least two through holes for stock solution supply are formed in the filter cloth and the stock solution supply plate, and one of the two through holes is used for the stock solution supply passage communicating with the filter chamber. forming a concave portion, the other through-hole communicates with the other through-hole of the opposing stock solution supply plate without communicating with the filter chamber, and dividing the stock solution supply system into at least two parts;
By changing the stock solution supply pressure between the stock solution supply systems, the filter chamber of the stock solution supply system on the high pressure side compresses and filters the filter residue in the filter chamber of the stock solution supply system on the low pressure side. That is, a pair of stock solution supply plates are arranged in the filtration space of a filter plate consisting of a frame body, and each filter cloth arranged on both sides of the filter plate is sandwiched and connected in the space. The plate has a stock solution supply through hole that communicates with at least two stock solution supply holes of each filter cloth, and has a relative position between the pair of filter cloths located between adjacent filter plates when the filter plate frame is closed. The filter press is configured such that the stock solution supply plates are in contact with each other, and the stock solution supply plate supplies the two stock solutions on the surface facing the stock solution supply plate supported by the filter cloth of the adjacent filter plate. forming a recess for a stock solution supply passage that communicates one of the stock solution supply through holes with a filter chamber formed between the pair of filter cloths between the adjacent filter plates; A filter that supplies the stock solution into the filter chamber and communicates with one of the stock solution supply holes of each of the filter cloths and communicates through the stock solution supply through hole of the stock solution supply plate and its recess. A first stock solution supply system consisting of a chamber, and a filter that communicates with the other stock solution supply hole of the stock solution supply holes of each of the filter cloths and communicates through the stock solution supply through hole of the stock solution supply plate and its recess. A second stock solution supply system consisting of a chamber, the stock solution supply pressure being changed between the two stock solution supply systems, and a filter chamber communicating with the stock solution supply system on the high pressure side and a filter chamber communicating with the stock solution supply system on the low pressure side. It was configured to press the filter residue in the room to perform compression filtration.

In the configuration of the filter press, the filter chambers of the first stock solution supply system and the filter chambers of the second stock solution supply system may be arranged alternately.

In addition, in the configuration of the filter press mentioned above,
The other stock solution supply plate among the above pair of stock solution supply plates is
It can also be constructed from a plate-like member having the pair of through-holes for supplying the stock solution.

Effects of the Invention According to the above configuration, the pair of stock solution supply plates are connected by sandwiching the filter cloths on both sides of the filter plate of the filter plate member within the space of the filter plate. At this time, for example, one of the stock solution supply through holes of one of the stock solution supply plates is connected to the other stock solution supply through hole of the other stock solution supply plate through the stock solution supply port of one of the filter cloths. The other stock solution supply through-hole of one stock solution supply plate is arranged so as to communicate with one stock solution supply through hole of the other stock solution supply plate through the other stock solution supply port of the filter cloth. When the filter plate frame is closed, inside the filter chamber between the pair of filter cloths between adjacent filter plates,
In cases where opposing stock solution supply plates are in contact with each other and only one stock solution supply plate has a recess, the recess on one stock solution supply plate forms a stock solution supply passage between the surface of the other stock solution supply plate, and In the case where recesses are formed in both stock solution supply plates, both recesses oppose each other to form a stock solution supply passage, and one stock solution supply through hole and the filter chamber are communicated through the stock solution supply passage,
A stock solution is fed into the filter chamber. At this time, the other stock solution supply through hole does not communicate with the filtration chamber and sends the stock solution as it is to the next filter chamber. In the filter chamber adjacent to the above filter chamber,
Similarly to the above, between the opposing stock solution supply plates, the other stock solution supply through hole communicates with the filter chamber via the recess, that is, the stock solution supply passage, and the stock solution is supplied into the filter chamber, while one stock solution supply The through-hole does not communicate with the filter chamber and is sent directly to the next filter chamber.
Therefore, if the stock solution supply pressure is changed in the stock solution supply system that communicates the two stock solution supply ports of each filtration chamber with each other, the stock solution supply system on the low pressure side will be changed in the filter chamber that communicates with the stock solution supply system on the high pressure side. Pressure filtration of the filter residue in the communicating filter chambers can be performed.

Effects of the Invention According to the above configuration, only one of the two through-holes for stock solution supply in the stock solution supply member communicates with the filter chamber and can reliably supply the stock solution, so that it can be used as a filter plate member. It is only necessary to provide two stock solution supply ports for the stock solution supply system in the filtration part of each filter cloth, and by simply changing the stock solution supply pressure or flow rate in each stock solution supply system, the filter chambers can be expanded alternately. Press filtration can be performed without using a press membrane. Therefore, by using the above filter plate member, the structure of the entire filter press is not complicated, and the structure of the filter press as a whole becomes simple. That is, conventionally,
There were problems in that it was necessary to provide a stock solution supply system in both the filtration part and the frame part of each filter plate, and the structure of the filter plate members became complicated, making the structure of the filter press as a whole complicated. However, according to the present invention, since it is only necessary to provide the stock solution supply system in the filtering portion of each filter plate of the filter plate member, the structure of the entire filter press becomes simple.

Examples Examples according to the present invention will be described in detail below with reference to FIGS. 1 to 10.

The filter press having the filter plate member according to this embodiment has side beams 4, 4 disposed on both sides between the front and rear stands 1, 3, as shown in Figs.
A large number of filter plate members are arranged between the front and rear stands 1 and 3. That is, each filter plate member consists of only the frame 2c and is movable back and forth between the side beams 4, 4.
The filter plate 2 suspended and supported by the filter plate 2 and the adjacent filter plates 2, 2
It consists of a pair of filter cloths 5, 5 arranged between them, and a pair of stock solution supply plates 7, 7 connected by a space 2f in the frame 2c of each filter plate 2.

As shown in FIG. 4, the filter plate 2 is generally composed of a frame 2c surrounding a space 2f. The frame 2c is made of a member having a pentagonal horizontal cross-section and a vertical cross-section, and has inclined surfaces 2e on its inner surface that are inclined on both sides from the center in the thickness direction.
Inside this frame 2c, the stock solution supply plates 7, 7 are suspended and supported by the filter cloths 5, 5, as described later. A handle 2 is provided at the top of each outer surface of each frame 2c.
d, and the front and rear stands 1 and 3 of the filter press are installed.
The above-mentioned side beams 4, 4 installed on each side between
The handles 2d, 2d are slidably placed on the filter plate 2 to suspend and support the filter plate 2, and guide the back and forth movement of each filter plate 2. A filtrate recovery port (not shown) penetrating in the thickness direction of the filter plate is formed at each lower corner of the filter plate 2, and a filtrate recovery port passing through both filtrate recovery ports and the internal space 2f of the filter plate 2 is formed. Recessed grooves (not shown) are formed on either the front or rear surface of the frame 2c, respectively.

Further, each of the filter cloths 5 is arranged replaceably before and after each of the filter plates 2, and the inner space 2f of the frame 2c of the filter plate 2 is sandwiched between the pair of filter cloths 5, 5. Each filter cloth 5 has a first stock solution supply hole 5a and a second stock solution supply hole 5b formed above and below in a portion corresponding to the spaces 2f, 2f of each filter plate 2. A pair of filter cloths 5, 5 are sandwiched between the adjacent filter plates 2, 2, and filter chambers 6a, 6b, 6c, 6d are formed between the filter cloths 5, 5, respectively. Each filter cloth 5 is given an expansion allowance, and when the stock solution is supplied to each filter chamber 6, it expands under the pressure of the stock solution and comes into contact with the filter cloth 5 forming the adjacent filter chamber 6. It is arranged so that it can be pressed. In addition, the filter cloth 5 can be expanded by giving slack to the filter cloth 5 to secure an expansion allowance, or by making the filter cloth itself from an elastic material so that the filter cloth 5 can be expanded by the pressure of supplying the stock solution. The cloth 5 may be expanded by stretching.

On the other hand, each stock solution supply plate 7 is made of a disc made of synthetic resin such as polypropylene or metal such as stainless steel, and has a pair of stock solution supply through holes 7a and 7b formed at the top and bottom in FIG. The stock solution supply holes 5a, 5b or 5b, 5a of the cloth 5 are communicated with each other. The back surface of the stock solution supply plate 7 is made flat as shown in FIG. 10 and comes into contact with the filter cloth 5. On the other hand, in the lower half of the surface, in FIG.
d, and the half-moon-shaped portion 7c and the crescent-shaped portion 7e in the upper half are in contact with the corresponding half-moon portion 7c and crescent-shaped portion 7e of the opposing stock solution supply plate 7, and the adjacent filter plate 2 , 2, a filter chamber 6 is formed between a pair of filter cloths 5, 5.

The stock solution supply plates 7, 7 configured in this manner are connected by bolts 8, . do. At this time, the pair of stock solution supply plates 7, 7 are attached to the filter cloths 5, 5 so that their vertical phases are opposite to each other. Therefore, when the filter plates 2, .
In the filter chamber 6 between the filter cloths 5 and 5, the two recesses 7d,
A stock solution supply passage 1 communicating with the filter chamber 6 through 7d
5, so that the stock solution flowing through the stock solution supply through-hole is supplied into the filter chamber 6 via the stock solution supply passage 15 to perform filtration.

Therefore, as shown in FIGS. 4 and 5, each filter cloth 5 is connected to the stock solution supply hole 5a on the upper side and the stock solution supply plate 7
A filtration chamber 6a in which one of the stock solution supply through holes 7a and the other stock solution supply hole 7d communicate alternately, and a filter chamber 6a that communicates with the stock solution supply holes 5b on the lower side of each filter cloth 5 and the other of the stock solution supply plate 7. The stock solution supply through holes 7b and the filter chambers 6b, which are alternately communicated with one of the stock solution supply through holes 7a, are arranged alternately between the front and rear stands 1 and 3. As a result, the filter chamber 6 is divided into two groups. That is, the filter chamber 6a,
..., the first stock solution supply system communicating with 6a, and the filter chamber 6
b, .

According to the above configuration, it operates as follows.

That is, by moving the movable plate 11 forward, all the filter plates 2,
..., 2 to the front stand 1 side to close the frame. In this state, the stock solution supply plate 7 suspended and supported by the filter cloths 5, 5 on each filter plate 2 faces the stock solution supply plate 7 similarly supported on the adjacent filter plate 2, and the part where the recess 7d is not formed. That is, the crescent-shaped portion 7c, the crescent-shaped portion 7e and the crescent-shaped portion 7e contact each other, and the filter chamber 6 is formed between the pair of filter cloths 5, 5 between the adjacent filter plates 2, 2. form. Then,
In each stock solution supply system, the stock solution supply hole 5 of each filter cloth 5
a; 5b and the stock solution supply through hole 7a of the stock solution supply plate 7
Or 7b; 7b or 7a will be in communication.

Then, open the supply valve 9 of the first stock solution supply system,
The supply valve 10 of the second stock solution supply valve remains closed,
The stock solution is caused to flow from the movable plate 11 side toward the front stand 1 into the stock solution supply holes 5a on the upper side of each filter cloth 5 and the stock solution supply through holes 7a and 7b of the stock solution supply plate 7,
Filtration is performed by supplying the stock solution into each filtration chamber 6a from the stock solution supply passage 15 formed by each pair of recesses 7d, 7d.

When each filter chamber 6a is almost filled with the stock solution, the supply valve 10 of the second stock solution supply system is provided,
Close the supply valve 9 of the first stock solution supply system. Then,
The stock solution is caused to flow from the front stand 1 side toward the movable plate 11 side into the stock solution supply holes 5b on the lower side of each filter cloth 5 and the stock solution supply through holes 7a and 7b of the stock solution supply plate 7,
Filtration is performed by supplying the stock solution into each filtration chamber 6b from the stock solution supply passage 15 formed by each pair of recesses 7d, 7d. At this time, the supply of the stock solution from the first stock solution supply system is stopped, and the stock solution continues to be supplied only from the second stock solution supply system. As a result, each filter chamber 6a
is not supplied with the stock solution, but the stock solution is supplied to each filter chamber 6b, so the filter cloths 5, 5 surrounding each filter chamber 6b
expands and contacts and presses the filter cloths 5, 5 surrounding each filter chamber 6a. As a result, the filter sludge in the filter chamber 6a is compressed and filtered from both sides due to the expansion of the filter chamber 6b. Then, conversely, when the stock solution is again supplied to the first stock solution supply system and the stock solution supply from the second stock solution supply system is stopped, the filter chamber 6a expands and the filter chamber 6b
The filter residue inside is pressed from both sides, and the filter residue is subjected to compression filtration.

In addition, in filtration by squeezing action, when the water content in the filter residue falls below a certain amount, the filtration efficiency decreases rapidly, and the discharge flow rate of the filtrate per unit time decreases sharply. Therefore, efficient operation can be achieved by detecting this timing and switching the open/close states of the supply valves 9 and 10.

Another method for determining the switching timing is, for example, by measuring the internal pressure of the first stock solution supply system and the second stock solution supply system, respectively, and when the difference in the measured pressure exceeds a certain tolerance value. The opening and closing states of the valves 9 and 10 may be switched at the same time.

As another filtration method, the above switching operation may be performed after opening both the supply valves 9 and 10 to supply a certain amount of stock solution to both stock solution supply systems.

The compressed filter residue is held between the pair of filter cloths 5, 5, and the filtrate flows down through the filter cloth 5 and is collected at the filtrate collection port of each filter plate 2, respectively. As is well known, after one filtration process,
The movable plate 11 is moved backward to move each filter plate 2 backward, and the filter residue held by the pair of filter cloths 5, 5 between the filter plates 2, 2 is collected in preparation for the next filtration.

According to the above embodiment, only one of the two through holes 7a and 7b of the stock solution supply member 7 communicates with the filter chamber 6 to reliably supply the stock solution, so that the stock solution can be reliably supplied to the filter plate. As for the components, there are two stock solution supply ports 5 for the stock solution supply system only in the filtration part of each filter cloth 5.
a and 5b, and by simply changing the stock solution supply pressure or flow rate in each stock solution supply system, the filtration chambers 6 can be expanded alternately to perform squeeze filtration without a squeeze membrane. Therefore, by using the above filter plate member, the structure of the entire filter press is not complicated, and the structure of the filter press as a whole becomes simple. That is, in the past, it was necessary to provide a stock solution supply system in both the filtration part and the frame part of each filter plate, which complicated the structure of the filter plate member.
There was a problem that the structure of the filter press as a whole became complicated, but according to the present invention, since it is only necessary to provide the stock solution supply system in the filtration part of each filter plate 2 of the filter plate member, the filter press has a complicated structure. The structure of the entire press becomes simple.

Further, the stock solution supply plate 7 has a semicircular portion 7c.
By abutting the corresponding portions of the stock solution supply plates 7 and the crescent-shaped portions 7e, respectively, a filter chamber space can be reliably formed between the pair of filter cloths 5, 5 that sandwich each filter plate 2.

Note that the present invention is not limited to the above-mentioned embodiments, and can be implemented in various other embodiments. For example, the manner in which the stock solution supply plate 7 is attached to each filter cloth 5 may be changed so that two filter chambers 6a and two filter chambers 6b are arranged alternately. In this case, the squeezing action is carried out from one side of the two squeezed filtration chambers, which are arranged side by side and opposite to each other. Therefore, it is preferable that only one filter chamber is provided at both ends. Further, the shape of the stock solution supply plate 7 is not limited to a disk shape, but may be a rectangular plate as shown in FIGS. 6 and 7, or may be configured in any other shape such as a hexagonal plate. I can do it.
Further, the half-moon-shaped portion 7c and the crescent-shaped portion 7e of each stock solution supply plate 7 are not limited to this shape, and may be columnar protrusions or the like, which are in contact with the opposing stock solution supply plate 7 and are connected to the pair of filter cloths 5, 5. Any shape and structure may be used as long as the filter chamber 6 is formed between them. Further, an annular packing is fixed to the half-moon-shaped part 7c around the stock-solution supply through-hole 7a of the stock solution supply plate 7, so that when the filter plate frame is closed, the opposing half-moon parts 7c are in close contact with each other. The communication between the through holes 7a, 7a may be made more reliable. Further, the arrangement of the through holes 7a and 7b is not limited to the vertical direction, but may be arranged at any position such as the horizontal direction.

Further, as shown in FIGS. 8 to 10, a pair of filter cloths 5 and 5 are connected to each other by a pair of stock solution supply plates 7 and 7 having the same structure.
Instead of connecting the recesses 7d to form the stock solution supply passage 15, the structure of one of the stock solution supply plates may be simplified and the stock solution supply passage 15 may be formed using only one of the recesses 7d. good. That is, as shown in FIG. 9, one of the first stock solution supply plates 17 is composed of a simple disc with stock solution supply holes 17a and 17b formed on the upper and lower sides, and the other second stock solution supply plate is constructed as shown in FIG. It is configured as a stock solution supply plate 7. Therefore, when the filter plate frame is closed, the surface of the first stock solution supply plate 17 is aligned with the second stock solution supply plate 7 between the pair of filter cloths 5, 5.
in contact with the surface of each stock solution supply hole 7a, 7b and 17.
a, 17b are in communication with each other, and a stock solution supply passage 15 is formed between the recess 7d of the second stock solution supply plate 7 and the surface of the first stock solution supply plate 17.
5 communicates with the filter chamber 6.

[Brief explanation of the drawing]

Figures 1 and 2 are a front view and a side view of a filter plate member according to an embodiment of the present invention with the stock solution supply plate attached to a filter cloth, and Figures 3 and 4 are respectively views of the filter plate member in use. Fig. 5 is an enlarged sectional view of the main part of Fig. 4, and Figs. 6 and 7 are a side view and a front view of a stock solution supply plate according to other embodiments, respectively. , and FIGS. 8 to 10 are an enlarged sectional side view of a main part of a filter press according to other embodiments, a front view of a first stock solution supply plate, and a back view of a second stock solution supply plate, respectively. 1... Front stand, 2... Filter plate, 2c... Frame, 2f... Space, 3... Rear stand, 4... Side beam, 5... Filter cloth, 5a, 5b... Stock solution supply hole, 6, 6a, 6b... Filter chamber, 7, 17... Stock solution supply plate, 7a, 7b, 17a, 17b... Penetration hole for stock solution supply, 7c... Half-moon shaped part, 7d... Recessed part, 7e... Crescent moon Part, 8...Bolt, 9,1
0... Supply valve, 11... Movable plate, 15... Stock solution supply passage.

Claims (1)

[Scope of Claims] 1. A filter plate 2 consisting of a frame 2c, and at least two filter plates disposed on both sides of the filter plate 2.
Each filter cloth 5 having a number of stock solution supply holes 5a, 5b is connected by sandwiching the pair of filter cloths 5, 5 which sandwich the filter plate 2 in the space 2f in the frame 2c of the filter plate 2. , a stock solution supply through hole 7 that communicates with at least two stock solution supply holes 5a and 5b of each filter cloth 5.
a, 7b; a pair of filter cloths 5, which are equipped with a pair of stock solution supply plates 7, 7, 17 formed with 17a, 17b, respectively, and are located between adjacent filter plates 2, 2 when the filter plate frame is closed; At least one stock solution supply plate 7 of the pair of stock solution supply plates 7, 7, 17 is connected to the adjacent filter plate 2. A hole is formed on the surface facing the stock solution supply plate 7 supported by the filter cloth 5 between one stock solution supply through hole 7a and the pair of filter cloths 5, 5 between the adjacent filter plates 2, 2. A filter plate member characterized in that a recess 7d for an undiluted solution supply passage is formed to communicate with the filtration chamber 6, and the undiluted solution is supplied from the recess 7d into the filtration chamber 6 and filtered. 2 When connecting the pair of filter cloths 5, 5 with the pair of stock solution supply plates 7, 7, one stock solution supply through hole 7a of the one stock solution supply plate 7 is connected to the other stock solution supply plate 7. The filter plate member according to claim 1, wherein the filter plate member penetrates through the other stock solution supply through hole 7b. 3. The filter according to claim 1 or 2, wherein the other stock solution supply plate 17 among the pair of stock solution supply plates 7, 7, 17 is constituted by a plate-like member having the pair of stock solution supply through holes 17a, 17b. plate member. 4 A pair of stock solution supply plates 7 arranged in the filtration space 2f of the filter plate 2 consisting of the frame body 2c, and connecting the filter cloths 5 arranged on both sides of the filter plate 2 by sandwiching them in the space 2f. , 7, 17, and each stock solution supply plate 7, 17 has stock solution supply through holes 7a, 7b; ,and,
Supplying the pair of stock solutions by using a filter press in which the stock solution supply plates facing each other are in contact with each other between the pair of filter cloths 5, 5 located between the adjacent filter plates 2, 2 when the filter plate frame is closed. At least one stock solution supply plate 7 among the plates 7 and 17 has the two stock solution supply through holes on the surface facing the stock solution supply plate 7 and 17 supported by the filter cloth 5 of the adjacent filter plate 2. 7
a, 7b, 17a, and 17b, the stock solution supplying through hole 7a and the filter chamber 6 formed between the pair of filter cloths 5, 5 between the adjacent filter plates 2, 2 are communicated. A supply passage recess 7d is formed, and the recess 7d supplies the stock solution into the filter chamber 6, while communicating with one of the stock solution supply holes 5a and 5b of each of the filter cloths 5, and , a first stock solution supply system consisting of a filter chamber 6a communicating through the stock solution supply through holes 7a and 7b of the stock solution supply plate 7 and the recess 7d thereof, and a stock solution supply hole 5a of each of the filter cloths 5,
A through hole 7a for stock solution supply of the stock solution supply plate 7, which communicates with the other stock solution supply hole 5b among the stock solution supply holes 5b,
7b and a filter chamber 6b communicating through its recess 7d.
The filtration chamber 6 communicates with the high-pressure side undiluted solution supply system and the filtration chamber 6 communicates with the low-pressure side undiluted solution supply system by changing the undiluted solution supply pressure between the two undiluted solution supply systems. A filter press characterized in that filter residue in a chamber 6 is pressed to perform compression filtration. 5. The filter press according to claim 4, wherein the filter chambers 6a of the first stock solution supply system and the filter chambers 6b of the second stock solution supply system are arranged alternately. 6. The filter according to claim 4 or 5, wherein the other stock solution supply plate 17 of the pair of stock solution supply plates 7, 7, 17 is constituted by a plate-like member having the pair of stock solution supply through holes 17a, 17b. press.