JPH0513686B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electroosmotic dewatering apparatus that performs filtration while passing a direct current through a raw solution such as sludge to be filtrated.

Conventional Technology It has been known that when a direct current is passed through sludge during the process of sludge dewatering or pressure dewatering, water in the sludge moves to the outside by electroosmosis, promoting dewatering. Attempts have been made to combine electroosmosis with various dehydrators. An example of this is a belt press type pressurized dehydrator in which sludge is sandwiched between two moving cloths and subjected to continuous dehydration treatment, in combination with electroosmosis. In this case, there is a problem that there is not enough time for the current to be applied, and that the thickness, water content, electrical resistance, etc. of the sludge change as the cloth runs, resulting in uneven current distribution. On the other hand, a batch pressure dehydrator such as a filter press has fewer problems as described above, and is most effective in reducing the moisture content of the cake by using both pressure and electroosmosis. An example of a filter press using electroosmosis is the following (Japanese Patent Publication No. 14034/1983).

That is, as shown in FIG. 17, a chamber 42 surrounded by cloths 41, 41 is formed between adjacent conductive plates 40, 40, and a conductive plate 43 is placed between both plates 40 so as to divide the chamber 42 into two. , 40 via an insulating packing 44, and a DC voltage is applied between the plate 40 and the conductive plate 43 so that the plate side has the same polarity as the charge charged on the sediment particles. Configure it to do so. Then, the stock solution is pressurized into the chamber 42, and in parallel with pressurized dehydration due to the pressure of the stock solution, the voltage between the plate 40 and the conductive plate 43 is set to the same sign as the voltage charged on the precipitate particles. Applying a DC voltage so that electrophoresis and electroosmosis occur,
The precipitate particles move toward the conductive plate, while the liquid moves toward the conductive plate on the fabric side and is discharged outside, forming a hard dehydrated solid layer on the surface of the fabric 41, resulting in significant overresistance. This is to eliminate the increase in the amount of water and make it more efficient.

Problems to be Solved by the Invention However, with the structure described above, the distance between the indoor board formed between the boards and the conductive plate is fixed, so if the problem progresses to a certain extent and the liquid in the room decreases, the sludge becomes sludge. As the electrical resistance increases, it is necessary to maintain a current value sufficient to cause electroosmosis by applying a high voltage between the electrodes. In addition, indoor sludge concentration occurs between the raw solution supply point and other points, and this difference in sludge concentration causes a difference in electrical resistance, making it impossible to obtain a uniform current distribution, making it difficult to perform electroosmotic dewatering efficiently. There was a problem that I was told could not be done.

Furthermore, even if the positive and negative electrodes 39, 45 are made to approach each other as the diaphragm 31 expands, as described in Japanese Patent Application Laid-open No. 50-143155, these electrodes , consists of a positive electrode 39 consisting of a large number of compression-molded carbon electrodes on a rubber sheet 40, and a negative electrode 45 fixed to a rubber sheet 43 in the form of a wire mesh. During osmotic dehydration, the distance between the electrodes becomes uneven, causing problems such as uneven dehydration.

Therefore, an object of the present invention is to solve the above-mentioned problem, and even if the dehydration progresses and the liquid component in the room decreases, it is possible to efficiently perform electroosmotic dehydration on the stock solution in the room, Another object of the present invention is to provide an electroosmotic dehydration device that can effectively prevent uneven dehydration by uniformizing the distance between electrodes during electroosmotic dehydration.

Means for Solving the Problems In order to achieve the above object, the present invention is configured such that one electrode can be moved in parallel with the other electrode. That is, a chamber surrounded by cloth is formed between adjacent plates, and one plate is provided with a flat first conductive plate, while the other plate is provided with a second conductive plate, and the first conductive plate and the first conductive plate are provided with a second conductive plate. An electroosmotic dehydration apparatus is provided, in which opposite electrodes are connected to the second conductive plate, and a DC voltage is applied to the stock solution in the chamber to perform electroosmotic dehydration on the stock solution,
The one plate is provided with an elastic membrane on a surface facing the other plate of the plate body, and the plate body is provided with a fluid supply passage for supplying fluid that inflates the elastic membrane between the elastic membrane and the plate body. In preparation for this, the first conductive plate is fixed to the outer surface of the elastic membrane, and a conductive plate supporting plate having substantially the same shape as the first conductive plate is arranged on the inner surface of the elastic membrane, and the elastic membrane is sandwiched between the first conductive plate and the first conductive plate. The first conductive plate and the conductive plate support plate are connected and fixed so that the first conductive plate moves toward the second conductive plate due to elastic expansion of the elastic membrane, and a hole is formed in the plate. At the same time, the conductive plate support plate and the first
A guide is provided to guide the parallel movement of the conductive plate. Here, since the conductive plate is provided on the plate, the plate may be made of a conductive material and the plate and the conductive plate may be formed as one component. Alternatively, a frame may be inserted between adjacent plates to enlarge the chamber.

Effect of the Invention In the above structure, after the stock solution is supplied into the chamber surrounded by cloth and passed through, the stock solution supply hole is closed, and the fluid is supplied to the plate body of one of the plates at a pressure higher than the stock solution supply pressure. and an elastic membrane to expand the elastic membrane, move the first conductive plate in parallel to the second conductive plate side, further squeeze out the stock solution between both conductive plates, and then 2. Electroosmotic dehydration is performed on the stock solution in the room by applying a DC voltage to the conductive plate.
In this way, as dehydration progresses, the distance between the electrodes decreases, and a sufficient current value necessary for electroosmosis is maintained.

Embodiments Below, embodiments of the present invention will be described in detail based on the drawings.

The electroosmotic dehydration apparatus according to this embodiment includes a first
As shown in Figures 2 and 3, a pair of frames 2, 2 are sandwiched between a pair of plates 1, 1 of the compression type filter press, and a compression plate 3 is inserted between the pair of frames 2, 2.
A cathode-side conductive plate 4 is fixed to the facing surface of each plate 1, and an anode-side conductive plate 5 is provided on the surface of the pressure rubbing plate 3 facing the plate 1, and further,
Cloths 6, 6 are hung so as to cover both sides of the frames 2, 2, respectively, and the frames 2 are inserted between the plate 1 and the pressing plate 3, respectively, and the cloths 6, 6 are placed within the frame of the frame 2. After forming an enclosed chamber 7 and pressurizing the stock solution into the chamber 7, electroosmotic dehydration is performed by applying a DC voltage to the conductive plates 4 and 5, and the solution in the stock solution is applied to the cathode conductive plate side of the plate 1. The liquid component moves and is discharged from the liquid recovery path of the plate 2 through the cloth 6 to the outside of the machine, while the solid component is drawn toward the anode conductive plate side of the pressing plate 3 and remains in the chamber 7. , which performs electroosmotic dehydration of the stock solution. In addition, the first
In the figure, 15 is a stock solution supply hole, and 30 is an electrode connection terminal, respectively. In addition, in Fig. 3, 8 is the plate 1, 1,
A guide rail on which handles 9, . The movable plate 10 moves back and forth by the drive of
is moved back and forth along the guide rail 8 to close or open the mold relative to the main plate 12.

As shown in FIGS. 4 and 5, each plate 1 has a large number of vertical grooves 1a extending in the vertical direction and communicating with through holes 22, 22 for liquid recovery, which penetrate through the upper and lower corners of one side surface, respectively. ..., 1a is provided. On the one side surface having the concave portion 1b, the octagonal conductive plate 4 covers the portion 1b, and the outer peripheral edge of the conductive plate 4 is connected with a large number of bolts 1.
3, . . . , 13 are fixed to the above one side. This conductive plate 4 has a large number of holes 4a, .
4a into the recess 1b, and is discharged from the liquid recovery port 22. A cathode side connecting rod 14 fixed to the plate 1 is connected to the conductive plate 4, as shown in FIGS. 6 and 7. In addition, the fourth
In the figure, 15 is a through hole for supplying the stock solution, and 21 is a through hole for supplying compressed air.

Further, each of the frames 2 has a hole 2a penetrating through the center, as shown in FIGS. The hole 2a is inclined so as to have a small diameter, and is provided with a stock solution supply hole 15 penetrating the upper corner of the frame 2, and the stock solution supply hole 15 is connected to the eighth,
Three through holes 16,..., 16 as shown in Figure 11
It communicates with the hole 2a through the hole 2a so that the stock solution can be supplied from the stock solution supply hole 15 into the hole 2a. Of the pair of through holes on the lower side of the frame, the left through hole 21 is for supplying compressed air, and the right through hole 22 is for liquid recovery.

Further, as shown in FIGS. 12 and 13, the pressing plate 3 is provided with recesses 3b on both sides of the plate main body 3a. An octagonal conductive plate support plate 17 is fitted into each of the recesses 3b so as to be able to move in and out of the recess 3b. An elastic membrane 18 covering almost the entire surface of both sides of the pressing plate 3 is hung from the upper side of the pressing plate, and both ends of the elastic membrane 18 are fixed to the lower side of the plate with bolts 19, . . . , 19. The central part of the frame body is supported by pins 20, 20 on the upper part of the frame body. The anode side conductive plate 5 includes the conductive plate support plate 1
7, and is fixed to the conductive plate support plate 17 with conductive bolts 25, . The lower corner of the pressing plate 3 is provided with an air supply through hole 21, and the through hole 21 is connected to the through hole 2.
4, the conductive plate support plate 17 and the plate main body 3
a and the elastic membrane 18, compressed air is supplied into the gap 23, the elastic membrane 18 expands, and the conductive plate support plate 17 is integrated with the anode side conductive plate 5. The conductive plate 4 is moved toward the conductive plate 4 side with respect to the plate main body 3a. Two anode side connecting rods 26 fixed to the conductive plate 5 and the pressing plate 3
and are elastically connected. That is, the 14th, 1st
As shown in FIG. 5, one end of each connection rod 26 on the anode side is fixed to the side of the pressing plate 3, and one end of a braided and flexible shield wire 27 is attached to the other end of the connection rod 26. While fixing with conductive bolts 28, the shield wire 27 is bent into a U-shape and the other end is attached to the back surface of the conductive plate support plate 17.
and the conductive bolt 28a that fixes the conductive plate 5.
Fix it with. Therefore, even if the elastic membrane 18 expands and the conductive plate 5 moves together with the conductive plate supporting plate 17, the connecting rod 26 and the anode side conductive plate 5 will only be opened by opening the curved portion of the shield wire 27. Make sure you are always connected. In addition, a pair of holes 3c, 3 are provided in the upper and lower center portions of each pressing plate 3, as shown in FIG. 16a.
c, and a guide 17c having one end 17b fitted into the hole 17a of the conductive plate support plate 17 is fixed, and this guide 17c is movably fitted into the hole 3c of the pressing plate 3 to form an elastic membrane 18. When the conductive plate support plate 17 moves at the same time, the conductive plate 5 is moved parallel to the plate surface via the conductive plate support plate 17 by the guide 17c, as shown in FIG. 16b.

Further, the cloths 6, 6 are arranged so as to hang over both sides of the pressing plate 3 from above. Also,
Other cloths 6 are arranged so as to be sandwiched between each board 1 and each frame 2, and the cloth 6 between the pressing board 3 and the frame 2 and the cloth between the board 1 and the frame 2 6 to form a chamber 7 surrounded by the cloth 6 inside the frame 2, and the liquid component of the stock solution supplied into the frame 2 is passed through the cloth 6 to the through-hole 22 for liquid recovery on the side of the plate 1. While the solid components of the stock solution are discharged outside the machine, the solid components of the stock solution remain in the chamber 7.

According to the above configuration, FIGS. 1, 2a and 3
As shown in the figure, the movable plate 10 is moved toward the main plate 12 side by the drive of the drive device 11, and each plate 1 etc. is tightened, and as shown in FIG. 2b, the cloth 6, forming a chamber 7 surrounded by 6;
The stock solution is forced into the chamber 7 through the stock solution supply holes 15, 15 of the frame 2. Close the stock solution supply holes 15, 15,
Compressed air is supplied to the gap 23 between the elastic membrane 18 of the compressed plate 3 and the plate main body 3a and the conductive plate support plate 17 to inflate the elastic membrane 18, as shown in FIG. 2c.
The conductive plate support plate 17 and the conductive plate 5 are integrally moved toward the plate body 3a, and the stock solution is squeezed out. Then, by applying a DC voltage to both conductive plates 4 and 5, an electrophoresis phenomenon is caused, and the liquid component in the stock solution is moved to the cathode conductive plate 4 side of the plate 1, while the solid component in the stock solution is squeezed out to the plate 1. 3 to the anode conductive plate 5 side to perform electroosmotic dehydration.
The conductive plate 5 and the conductive plate support plate 17 are
moves until it contacts the inner circumferential surface 2b of the hole 2a of the frame 2, and electroosmotic dehydration is further performed. When the electroosmotic dehydration is completed, the movable plate 10 is moved by the drive device 11.
The plates 1, 1, frames 2, 2, and pressing plate 3 are opened, and the cake, which is a solid component in the stock solution, remaining in each frame 2 is discharged from the hole 2a of the frame 2. When the cleaning of each cloth 6 is completed, the movable plate 10 is moved forward again by the drive device 11 to close the plates 1, 1, frames 2, 2, and pressing plate 3 to the main plate 12 side. Prepare for the next electroosmotic dehydration.

Effects of the Invention According to the above configuration, when performing electroosmotic dehydration of the stock solution in the room, the elastic membrane is expanded to bring the conductive plate on the anode side closer to the conductive plate on the cathode side, thereby reducing the distance between the two conductive plates. Since direct current is applied between both conductive plates, the electrical resistance of the sludge does not increase significantly.
A current value sufficient to cause electroosmosis can be maintained without applying a high voltage between the electrodes, and efficient dehydration processing can be performed.

In addition, the flat conductive plate and the conductive plate support plate are fixed by sandwiching the elastic membrane, and the guide of the conductive plate support plate is movably fitted into the hole in the plate, so that when the elastic membrane expands, the conductive plate becomes flat. The distance between the electrodes can be maintained uniform during electroosmotic dehydration, and uneven dehydration can be effectively prevented.

[Brief explanation of the drawing]

FIG. 1 is a schematic exploded explanatory diagram of essential parts of an electroosmotic dehydration apparatus according to an embodiment of the present invention, and FIGS. 2 a to c
3 is a side view of the electroosmotic dehydration device, FIGS. 4 and 5 are a front view and a cross-sectional side view of the plate, and FIGS. 6 and 7 are respectively schematic views explaining the operation of the electroosmotic dehydration device. 8 and 9 are a front view and a sectional plan view of the main part, respectively, for explaining the connection state between the connecting rod and the conductive plate, and FIGS. 8 and 9 are a front view and a side view of the frame, respectively.
Figures 10 and 11 are a sectional view taken along the line - in Figure 8 and a partial sectional view taken along the line XI-XI in Figure 8, respectively. Figures 12 and 13 are a front view and a sectional side view of the pressing plate, respectively, and
Figures 4 and 15 are a front view and a cross-sectional plan view of the main part, respectively, for explaining the connection state between the connecting rod and the conductive plate;
FIGS. 16a and 16b are enlarged cross-sectional views of the main parts of a pressing plate, and FIG. 17 is a cross-sectional side view of the main parts of a conventional electroosmotic dewatering device. 1... Board, 2... Frame, 2a... Hole, 3... Pressing board, 4, 5... Conductive plate, 6... Cloth, 7... Chamber, 8
...Guide rail, 9...Handle, 10...Movable plate, 11
...Drive device, 12...Main board, 13, 19, 25, 2
8... Bolt, 14, 26... Connection rod, 15... Through hole for stock solution supply, 16, 24... Through hole, 17... Conductive plate support plate, 18... Elastic membrane, 20... Pin, 21... Through hole for compressed air supply , 22...through hole for liquid recovery, 2
7... Shield wire.

Claims (1)

[Claims] 1. A chamber 7 surrounded by cloths 6, 6 is formed between adjacent plates 1, 3, and one plate 3
is provided with a flat first conductive plate 5, while the other plate 1 is provided with a second conductive plate 4, and the first conductive plate 5 is provided with a second conductive plate 4.
and the second conductive plate 4, respectively, and apply a DC voltage to the stock solution in the chamber 7 to perform electroosmotic dehydration on the stock solution. The plate 3 is provided with an elastic membrane 18 on the surface of the plate main body 3a facing the other plate 1, and the elastic membrane 18 is provided with a fluid that inflates the elastic membrane 18.
The plate body 3a is provided with fluid supply passages 24, 21 for supplying fluid between the elastic membrane 18 and the plate body 3a, and the first conductive plate 5 is fixed to the outer surface of the elastic membrane 18. A conductive plate support plate 17 having substantially the same shape as the first conductive plate 5 is disposed in the area, and the first conductive plate 5 and the conductive plate support plate 17 are connected and fixed with the elastic membrane 18 in between, and the elastic film 18 is Membrane 1
The first conductive plate 5 is moved toward the second conductive plate by the elastic expansion of the conductive plate support plate 1.
A guide 17c is movably fitted into the hole 3c of the plate 3 on the side of the plate 7 and guides the parallel movement of the conductive plate support plate 17 and the first conductive plate 5.
An electroosmotic dehydration device characterized by being provided with.