JP5483263B2 - Filter press squeezing dewatering method and squeezing dewatering device - Google Patents

Description

The present invention relates to an improvement in a press dewatering method and a press dewatering apparatus of a filter press that presses and dehydrates a stock solution by press-fitting and dehydrating.

Conventionally, as a filter press for treating the sludge of clean water, as in Patent Document 1, the stock solution is press-fitted into the filter press, and the press-fitting filtration is performed by the press-fitting pressure of the stock solution. After performing, the technique of supplying pressing liquid to a diaphragm chamber and performing press dehydration like patent document 2 is known.

JP 59-209621 A Japanese Patent Publication No. 03-026083

In the press-fitting type dehydration by the press-fitting pressure of the stock solution, the moisture content of the cake increases in the vicinity of the supply port of the filtration chamber and on the filtration floor surface away from the supply port. Since the stock solution itself has a high water content, the water content is high in the vicinity of the supply port, and on the filtration bed surface away from the supply port, the stock solution is filtered through a filtration bed between the supply port and a dehydrated cake is formed, and the injection from the supply port This is because the pressure becomes difficult.
As a result, a cake having a non-uniform moisture content in the filtration chamber may cause a cake peeling failure in the opening plate process. In order to lower the moisture content of the local high moisture content cake, it is necessary to further push the stock solution and press-fit, but the efficiency is poor because the stock solution itself has a high water content. If the press-in time is increased, the water content of the local high water content cake can be decreased. However, the dehydration time is increased, the filtration rate is decreased, and the throughput is decreased.

If the entire filtration bed is squeezed and dehydrated with a diaphragm, dehydration can be accomplished in a short time at the end of the press-fitting dehydration where the solid load increases. Moreover, since the whole cake in a filtration chamber is uniformly squeezed with a diaphragm, the variation in the moisture content in the filtration chamber can be improved.
However, a stock solution with good filterability can reduce the moisture content of the cake in the filtration chamber only by press-fed supply, and the local high moisture content in the vicinity of the liquid supply port to the filtration chamber or away from the liquid supply port. A diaphragm covering the entire filtration bed is not necessary just to squeeze the rate part. When a diaphragm that covers the entire surface of a conventional filter bed is used, the volume in the diaphragm is large, so that the time for supplying and discharging the compressed fluid becomes long. In addition, a large-capacity driving machine is required to keep the pressing pressure constant. In addition, the diaphragm is a consumable and has a short life and is expensive, and the diaphragm on the entire filtration bed has a high running cost and generates a large amount of waste as a single part.

The present invention provides a press dewatering method and a press dewatering device for a filter press that eliminates the generation of a locally high water content cake in a filtration chamber, improves the peelability of the dewatered cake, and makes the water content of the dewatered cake uniform. To do.

The filter press dewatering method of the present invention is a filter press in which a large number of filter plates are juxtaposed on a horizontally provided guide rail, a filtration chamber is formed between these filter plates, and the stock solution is pressed and dehydrated. A local diaphragm is installed in the high moisture content part of the filtration chamber formed between the filter plates, the filter plate is tightened to form a large number of filtration chambers, and the stock solution is supplied to each filtration chamber via the supply port. A press-fitting process for press-fitting, a squeezing process to squeeze only the high water content of each filtration chamber with a local diaphragm, a filtrate discharge process for discharging the filtrate through the filtrate discharge path, and opening the filter plate, Since the plate opening process for discharging the cake in the filtration chamber is provided, a small amount of pressing fluid for expanding the diaphragm is required, and the pressing time can be shortened. Moreover, the moisture content of the cake in the filtration chamber is made uniform, and the peelability from the filter cloth is improved.

The filter press squeezing and dehydrating apparatus of the present invention has a large number of filter plates arranged in parallel on a horizontally provided guide rail, a filtration chamber is formed between these filter plates, and the stock solution is press-fitted from a supply port communicating with the filtration chamber. In the filter press for dewatering, a local diaphragm is disposed on the filter bed of the filter plate of the portion with high cake moisture content in the filtration chamber according to the position of the supply port of the stock solution communicating with the filtration chamber. The diaphragm is small and the production cost and the amount of waste generated after consumption are reduced.

For the center feed type filter press, the supply port is provided in the vicinity of the center of the filter bed of the filter plate, the local diaphragm is provided in an annular shape at the supply port, or the supply port is provided in the filter bed near the seal surface of the filter plate, If a local diaphragm is installed on the filtration bed far from the supply port, cakes with a high moisture content in the filtration chamber can be efficiently dehydrated, and the moisture content of the cake in the filtration chamber becomes uniform, and the The peelability is improved.

For top-feed type filter presses, a supply port is provided on the sealing surface of the filter plate, the stock solution is supplied to the filtration chamber via the liquid supply plate, and a local diaphragm is installed on the filter bed near the supply port, or a supply port is provided. Provided on the sealing surface of the filter plate, supply the stock solution to the filtration chamber through the liquid supply plate, and if a local diaphragm is disposed on the filter bed far from the supply port, about the cake of the high moisture content portion of the filtration chamber, It can be efficiently dehydrated, the moisture content of the cake in the filtration chamber becomes uniform, and the peelability from the filter cloth is improved.

The press dewatering method and the press dewatering device of the filter press according to the present invention are configured as described above, and the diaphragm is locally provided only in the portion where the moisture content in the filter chamber is high. Generation of typical high water content cake can be eliminated, and the time required for dehydration of the stock solution can be shortened. The moisture content of the cake in the filtration chamber becomes uniform, and the peelability from the filter cloth is improved. A small amount of compressed fluid is required to expand the diaphragm, and the drive unit for supplying the compressed fluid can be reduced in size and power consumption can be suppressed. Since the area of the diaphragm is small, the running cost is low and the amount of waste generated after replacement is reduced.

It is a schematic side view of the filter press which has a pressing dehydration apparatus concerning the present invention. Similarly, it is a front view of a filter plate of a center feed type filter press. Similarly, it is a longitudinal cross-sectional view of a filtration chamber of a center feed type filter press. Similarly, it is a longitudinal cross-sectional view of a filtration chamber of another embodiment of a center feed type filter press. Similarly, it is a front view of a filter plate of another embodiment of the center feed type filter press. Similarly, it is a longitudinal cross-sectional view of a filtration chamber of another embodiment of a center feed type filter press. Similarly, it is a longitudinal cross-sectional view of a filtration chamber of another embodiment of a center feed type filter press. Similarly, it is a front view of a filter plate of a top feed type filter press. Similarly, it is a longitudinal cross-sectional view of the filtration chamber of a top feed type filter press. Similarly, it is the longitudinal cross-sectional view of the filtration chamber of the other Example of a top feed type filter press. Similarly, it is a front view of the filter plate of other examples of a top feed type filter press. Similarly, it is the longitudinal cross-sectional view of the filtration chamber of the other Example of a top feed type filter press. Similarly, it is the longitudinal cross-sectional view of the filtration chamber of the other Example of a top feed type filter press.

An embodiment of the present invention will be described in detail with reference to the drawings. First, FIG. 1 is a schematic side view of a filter press according to the present invention. A pair of guide rails 4, 4 are bridged horizontally on the front frame 2 and the rear frame 3 constituting the filter press 1. A large number of filter plates 5 are supported on the guide rail 4 so as to be openable and closable. A tightening cylinder 7 disposed on the rear frame 3 is connected to the movable head 8, and the movable head 8 is moved to the rear frame 3 side to open the parallel filter plates 5.

FIG. 2 is a front view of a filter plate of a center feed type filter press that supplies the stock solution from the filter surface of the filter plate. A supply port 10 is provided on the surface of the filter bed 11 of the filter plate 5 in order to supply the stock solution to the filtration chamber 9 formed between the filter plates 5 and 5. The filter plate 5 has a sealing surface 12 around the filtration bed 11 and a swellable diaphragm 14 provided in a part of the filtration bed 11.
The center feed type described here is a filter press in which a supply port 10 is provided in the filtration bed 11 of the filter plate 5.
In the center feed type filter press of the present embodiment, the supply port 10a is opened near the center of the filtration bed 11, and the water content tends to increase in the vicinity of the supply port 10a. A local diaphragm 14a is arranged in an annular shape. Since the local diaphragm 14a is disposed not on the entire surface of the filtration bed 11 but in a limited range, a small amount of compressed fluid may be supplied, and the discharge time of the filtrate is shortened.

FIG. 3 is a longitudinal sectional view of the filtration chamber when the plate is closed, and the filter plates 5... Having the filter bed 11 having both sides formed in a concave shape are closed, and the adjacent filter plates are brought into close contact with the seal surface 12. A filtration chamber 9 is formed between 5 and 5. The supply port 10a of each filter plate 5... Is connected to form a stock solution supply path 22, and the stock solution is supplied to the filtration chamber 9.
A filter cloth 15 is stretched on the surface of the filter bed 11 of each filter plate 5. The stock solution pressure-fed and supplied to the filtration chamber 9 is separated into solid and liquid by the filter cloth 15, and the filtrate is taken out through the filtrate discharge passage 17 provided in the filtration bed 11. The cake remaining in the filtration chamber 9 is discharged when the filter plate 5 is opened.
In the filtration chamber 9, there is a part where the moisture content of the cake is locally increased only by the press-fitting filtration of the stock solution, and therefore, a local diaphragm 14 a is provided only in that part.
In the filter plate 5 provided with the local diaphragm 14a, a compressed fluid passage 18 for supplying a compressed fluid to the local diaphragm 14a is penetrated from the side surface. The compressed fluid passage 18 connected to the compressed fluid supply pipe 19 communicates with the diaphragm chamber 20 of the local diaphragm 14a disposed on the filter plate 5, and the local diaphragm 14a is indicated by a broken line by supplying the compressed fluid. Extend as follows.

Further, as shown in FIG. 4, local diaphragms 14a may be provided on both surfaces of the even-numbered filter plates 5 arranged in parallel, and the diaphragm 14 may be locally provided in each filtration chamber 9 to squeeze the cake. For example, the present invention is not limited to the embodiments disclosed in this specification.
Basically, the local diaphragm 14 applied locally to the filter bed 11 on the filter chamber 9 side of the filter plate 5 has no distinction between the conventional filter plate and the diaphragm plate. This is an added configuration.

FIG. 5 is a front view of a filter plate of another embodiment of the center feed type filter press, and the supply port 10b is provided in the filter bed 11 near the seal surface 12. FIG. In this case, the moisture content tends to increase at a location away from the supply port 10b. Therefore, the local diaphragm 14b is provided in a limited manner on the surface of the filter bed 11 farthest from the supply port 10b.

6 and 7 are longitudinal sectional views of the filtration chamber when the plate is closed. Each of the examples in which the local diaphragm 14b is disposed on the filter bed 11 on one side of the filter plate 5 and both surfaces of the even-numbered filter plates 5 are shown. It is the Example which has arrange | positioned the local diaphragm 14b in the filter bed 11 of this.

FIG. 8 is a front view of a diaphragm filter plate of a top feed type filter press that supplies stock solution from above the filter plate. A supply port 10 c is provided in the sealing surface 12 at the upper part of the filter plate 5, and the stock solution is supplied to the filtration chamber 9 formed between the filter plates 5 and 5 through the liquid supply plate 21. In the filtration chamber 9, there is a part where the moisture content of the cake is locally increased only by the press-fitting filtration of the stock solution. Therefore, the diaphragm 14 is locally provided only in that part.
In the present embodiment, since the moisture content tends to increase in the vicinity of the supply port 10c, the local diaphragm 14c is limitedly provided on the filtration floor near the supply port.
In addition, although the supply port 10c is provided in the upper part of the sealing surface 12 currently formed around the filter plate 5, the supply port 10c provided in the seal surface 12 may be on the side or lower side of the filter plate.
The top feed type described here is a filter press in which a supply port 10 is provided on the sealing surface 12 of the filter plate 5.

FIG. 9 is a longitudinal sectional view of the filtration chamber when the plate is closed. The filter plates 5... Having the filter bed 11 formed in a concave shape on both sides are closed, and the seal plate 12 is brought into close contact with each filter plate 5. , 6 form a filtration chamber 9. A liquid supply plate 21 communicating with the supply port 10 c of the filter plate 5 is sandwiched between adjacent filter plates 5, 5 to form a supply path 22 of the raw solution, and a liquid supply path 21 a of the liquid supply plate 21 communicating with the filtration chamber 9. To supply the stock solution to the filtration chamber 9.
A filter cloth 15 is stretched on the surface of the filter bed 11 of each filter plate 5, 5. The stock solution pressure-fed and supplied to the filtration chamber 9 is separated into solid and liquid by the filter cloth 15, and the filtrate is taken out through the filtrate discharge passage 17 provided in the filtration bed 11. The cake remaining in the filtration chamber 9 is discharged when the filter plates 5 and 5 are opened.

Further, as shown in FIG. 10, local diaphragms 14c may be provided on both surfaces of the even-numbered filter plates 5 arranged in parallel, and the diaphragm 14 may be locally provided in each filtration chamber 9 to squeeze the cake. For example, the present invention is not limited to the embodiments disclosed in this specification.

FIG. 11 is a front view of a filter plate of another embodiment of the top feed type filter press. In the filter press 1 in which the supply port 10d is disposed on the sealing surface 12 like the top feed type, the moisture content tends to be high even at a location away from the supply port 10d. Therefore, a local diaphragm 14d is limitedly provided on the surface of the filtration bed 11 farthest from the supply port 10d.

12 and 13 are longitudinal sectional views of the filtration chamber when the plate is closed. Each of the examples in which the local diaphragm 14d is disposed on the filter bed 11 on one side of the filter plate 5 and both surfaces of the even-numbered filter plates 5 are shown. It is an Example which has arrange | positioned the local diaphragm 14d in the filtration bed 11 of this.

The shape of the local diaphragms 14a, 14b, 14c and 14d in the center feed type and top feed type filter press is circular, but the water content locally increases depending on the shape of the filtration bed 11 surface, the position of the supply port 10, and the like. Depending on the distribution, it may be appropriately configured.

The filter press 1 in the present invention is configured as described above, and the squeeze filtration method repeats A to D of the A closing plate process, the B press fitting process, the C pressing process, and the D opening plate process.

A. The movable head 8 is moved to the front frame 2 side by the closing plate process tightening cylinder 7, the alternately arranged filter plates 5 and 5 are tightened to form a large number of filtration chambers 9, and the supply port 10 is connected. Thus, the stock solution supply path 22 is formed.

B. While opening the valve V1 arrange | positioned at the press injection process stock solution supply pipe | tube 23, a stock solution supply pump (not shown) is started. The stock solution is press-fitted and supplied to each filtration chamber 9 from the stock solution supply pipe 23 via the supply path 22. The undiluted solution is sufficiently distributed in each filtration chamber 9, and the undiluted solution is solid-liquid separated by the filter cloth 15 stretched in the filtration chamber 9, and the filtering action by the press-fitting pressure proceeds. The filtrate that has passed through the filter cloth 15 and separated into solid and liquid is discharged from the filtrate discharge path 17 to the outside. The press-fitting process continues for a predetermined time. Solids accumulate in the filtration chamber 9 to form a cake.

C. After performing the press-fitting process for a certain period of time, the diaphragm 14 in the filtration chamber 9 is expanded as indicated by the broken line in parallel with the press-fitting process, and the pressing process is performed on the cake in the filtration chamber 9.
Specifically, the valve V2 disposed in the compressed fluid supply pipe 19 is opened and a compressed fluid supply device (not shown) is activated. The compressed fluid supplies the pressure fluid to the diaphragm chamber 20 formed in the filter plate 5 through the compressed fluid supply pipe 19 and the compressed fluid passage 18 to expand the diaphragm 14.
Since the diaphragm 14 is locally disposed in a portion having a high moisture content in the filtration chamber 9, the cake having a high moisture content is dehydrated by the pressing action of the diaphragm 14, and other cakes in the filtration chamber 9 are dehydrated. The water content decreases to the same level.
The stock solution is separated into solid and liquid by a filter cloth 15 by press-fitting supply to the filtration chamber 9 and squeezing by the diaphragm 14, and the filtrate is discharged outside the apparatus through a filtrate discharge passage 17 provided in the filtration bed 11.
The pressing process continues for a predetermined period of time.

D. After performing the pressing process for a certain period of time, the valve V1V2 is closed. The movable head 8 is moved to the rear frame 3 side by the opening / closing device 7, and the filter plates 5 ... are opened at regular intervals. The cake in the opened filtration chamber 9 is discharged downward. The cake adhering to the filter cloth 15 does not have a portion having a high water content locally and is constant over the entire surface of the filter bed 11, so that there is no peeling failure from the filter cloth 15.

The press dewatering method and the press dewatering device of the filter press according to the present invention are a filter press that press-fits and dehydrates a stock solution with good filterability that can be dehydrated without chemical injection that does not require pre-aggregation treatment such as clean water and industrial water. No dehydration of new high-moisture stock solution or press dehydration with full-diaphragm is required, so dehydration efficiency is greatly improved, dehydration time is greatly shortened, filtration speed is increased and throughput is increased. Can do. Moreover, the capacity | capacitance fall of the drive machine of a compressed fluid and the fall of a life cycle cost are realizable.
It is possible to reduce the variation in moisture content of the cake separated into solid and liquid in the filtration chamber, and can be easily applied for secondary use such as applying the cake to soil improvement without requiring intermediate treatment. is there.

DESCRIPTION OF SYMBOLS 1 Filter press 4 Guide rail 5 Filter plate 9 Filtration chamber 10, 10a, 10b, 10c, 10d Supply port 11 Filtration bed 12 Sealing surface 14a, 14b, 14c, 14d Local diaphragm 17 Filtrate discharge path 21 Liquid supply plate

Claims (6)

A large number of filter plates (5...) Are arranged in parallel on the guide rails (4, 4) provided horizontally, a filtration chamber (9) is formed between these filter plates (5, 5), and the stock solution is press-fitted. In the filter press that dehydrates
A local diaphragm (14a, 14b, 14c, 14d) is disposed in a portion having a high water content in the filtration chamber (9) formed between the filter plates (5, 5),
Tightening the filter plate (5) to form a number of filtration chambers (9);
A press-fitting step of pressurizing and supplying the stock solution to each filtration chamber (9) via the supply ports (10a, 10b, 10c, 10d);
A squeezing step of squeezing only the high moisture content of each filtration chamber (9) with a local diaphragm (14a, 14b, 14c, 14d);
A filtrate discharging step of discharging the filtrate through the filtrate discharging path (17);
An opening plate step of opening the filter plate (5) and discharging the cake in the filtration chamber (9);
A press dewatering method for a filter press, comprising: A large number of filter plates (5...) Are arranged in parallel on guide rails (4, 4) provided horizontally, and a filtration chamber (9) is formed between these filter plates (5, 5). 9) In the filter press for dehydrating by pressing the stock solution from the supply port (10) communicating with
Depending on the position of the supply port (10a, 10b, 10c, 10d) of the stock solution communicating with the filtration chamber (9), the filtration bed (5) of the filter plate (5) in the filtration chamber (9) having a high cake moisture content ( 11) A filter press squeezing and dehydrating device characterized in that a local diaphragm (14a, 14b, 14c, 14d) is disposed in 11). The said supply port (10a) was provided in the center part vicinity of the filter bed (11) of the filter plate (5), and the local diaphragm (14a) was arrange | positioned circularly at the supply port (10a). 2. A press dewatering device for a filter press according to 2. The supply port (10b) is provided in the filter bed (11) in the vicinity of the sealing surface (12) of the filter plate (5), and a local diaphragm (14b) is disposed in the filter bed (11) far from the supply port (10b). The press dewatering device for a filter press according to claim 2, wherein: The supply port (10c) is provided on the sealing surface (12) of the filter plate (5), the stock solution is supplied to the filtration chamber (9) through the liquid supply plate (21), and the filtration in the vicinity of the supply port (10c) is performed. 3. The press dewatering device for a filter press according to claim 2, wherein a local diaphragm (14c) is disposed on the floor (11). The supply port (10d) is provided on the sealing surface (12) of the filter plate (5), the stock solution is supplied to the filtration chamber (9) through the liquid supply plate (21), and the filter is separated from the supply port (10d). The press dewatering device for a filter press according to claim 2, wherein a local diaphragm (14d) is arranged on the floor (11).

Images