JP2019209299A - Filter cloth washing method and filter cloth washing device of filter press - Google Patents

Abstract

To provide a filter cloth washing method and a washing device of a filter press appropriately performing washing against the clogging of each filter cloth.SOLUTION: In a filter cloth washing method of a filter press where a filter chamber is formed by arranging a plurality of filter plates 5 in parallel whose front and rear surfaces are stretched with a filter cloth 6, a dewatered cake formed in the filter chamber is discharged by opening the filter plates 5, the filter cloth 6 is washed with a washing pipe 7 provided for each filter cloth 6 and a washing water amount is controlled by opening and closing an electric valve 20 at the washing pipe 7,: a reference filtrate amount V0 and a reference opening D0 of the electric valve 20 having a wide range beforehand are set and an accumulated filtrate amount V permeated from each filter cloth 6 is calculated; the filter cloth 6 having the accumulated filtrate amount V in the range of the reference filtrate amount V0 is washed with opening smaller than the reference opening D0 of the electric valve 20; and the washing water amount of the clogged filter cloth 6 having smaller accumulated filtrate amount V than the reference filtrate amount V0 is increased by performing washing at the reference opening D0 of the electric valve 20.SELECTED DRAWING: Figure 9

Description

The present invention relates to filter cloth cleaning of a filter cloth traveling type filter press that treats water sludge, sewage sludge, industrial wastewater sludge, and the like, and relates to a filter cloth cleaning method that controls the amount of water to be washed according to the amount of filtrate discharged.

Conventionally, as in Patent Document 1, a filter press having a plurality of filtration chambers and installing a pair of filter cloths for each filtration chamber is configured to run dehydrated cakes by running the filter cloths of all the filtration chambers all at once. It was peeling. A plurality of washing nozzles are provided below the filter plate, and all the filter cloths are washed at once by spraying washing water onto the traveling filter cloth.

As a filter cloth cleaning method, a filter press that runs an endless filter cloth detects clogging by detecting a change in the air pressure of the blower that is in close proximity to the filter cloth. A technique for cleaning the filter cloth by controlling the above is disclosed in Patent Document 2.

Japanese Patent Publication No. 02-57963 JP 59-127608 A

In general, a filter press supplies stock solutions to a plurality of filtration chambers and performs dehydration in each of the filtration chambers. Therefore, the degree of dirt on the filter cloth differs for each filtration chamber. For example, when the filter cloth is run and the dehydrated cake peels off quickly, clogging of the filter cloth is unlikely to occur, but when the dehydrated cake gets deeply into the gap of the filter cloth, it can not be peeled even if the filter cloth is run, Filter cloth causes clogging.

In order to wash the clogged filter cloth, a filter press as in Patent Document 1 that travels a pair of filter cloths at the same time is washing all the filter cloths simultaneously. However, since the cleaning water is sprayed on all the filter cloths, the filter cloths that are not clogged are excessively cleaned, and a large amount of cleaning water is required.

In addition, when a detection unit that detects clogging of a plurality of pairs of filter cloths is provided and the filter cloths are individually cleaned, it is necessary to provide detection units and cleaning devices for all the filter cloths. As a result, the manufacturing cost also increases.

In the filter press of Patent Document 2, the cleaning effect is enhanced by controlling the amount of washing water and the water pressure according to the degree of clogging of the filter cloth, but if the filter cloth cleaning device is provided in one place, the filter cloth It takes a long time to clean the entire surface. Moreover, since the detection part which detects clogging is provided in the back | latter stage of the filter cloth washing | cleaning apparatus, clogging cannot be eliminated if the filter cloth washing | cleaning apparatus is controlled after detecting clogging of the filter cloth.

The present invention relates to a filter cloth cleaning method and a filter press for determining the degree of clogging of each filter cloth from the amount of filtrate in each filtration chamber and controlling the amount of washing water in accordance with the degree of clogging of each filter cloth. A cloth cleaning apparatus is provided.

A filter chamber is formed by arranging a plurality of filter plates with filter cloth stretched on the front and back, and the filter plate is opened to discharge the dehydrated cake formed in the filter chamber, and the filter cloth is washed with a washing tube provided for each filter cloth. In the filter cloth cleaning method of the filter press that controls the amount of water to be washed by opening and closing the electric valve of the cleaning pipe, set the reference filtrate amount with a width in advance and the reference opening of the electric valve, Calculate the cumulative filtrate amount permeated from the filter cloth, and filter cloth whose cumulative filtrate volume is within the standard filtrate volume range is washed at an opening smaller than the standard opening degree of the motorized valve. For filter cloths with less than the reference filtrate volume, wash the motorized valve at the standard opening, and for clogged filter cloths, increase the amount of water to wash and increase the cleaning capacity. In contrast, the amount of washing water is reduced and excessive washing is not performed.

In the filter cloth cleaning device of the filter press that forms a filtration chamber by paralleling a plurality of filter plates with filter cloth stretched on the front and back, a filtrate passage that opens to the filtration bed and penetrates the outside of the filter plate, and each filtrate Corresponds to the flow meter provided in the passage, the washing pipe for washing each filter cloth, the electric valve provided for each washing pipe to control the amount of washing water, and the filter cloth that has permeated the filtrate measured by each flow meter. A control device for controlling each of the electric valves of the cleaning pipe, wherein the control device sets a reference filtrate amount having a predetermined width and a reference opening of the electric valve, and is discharged from the filtrate passage. Calculate the cumulative filtrate volume.If the cumulative filtrate volume is within the range of the standard filtrate volume, the motorized valve is made smaller than the reference opening, and if the cumulative filtrate volume is less than the standard filtrate volume, By setting the opening to the reference opening, the amount of washing water is increased for clogged filter cloths. Increase the washing capacity, for the filter cloth that is not clogged, to reduce the amount of wash water does not perform excessive cleaning.

The control device sets a reference filtrate amount having a width in advance and a reference opening of the electric valve, calculates a cumulative filtrate amount discharged from the filtrate passage, and the cumulative filtrate amount is a reference filtrate. If the amount is within the range, fully close the motorized valve, and if the accumulated filtrate volume is less than the reference filtrate volume, use the motorized valve opening as the reference opening to greatly increase the amount of wash water used. Can be reduced.

When the accumulated filtrate amount is larger than the reference filtrate amount, the filter press is stopped and an alarm is issued to notify the filter cloth breakage.

In a filter press that performs dehydration using multiple filter cloths, the filter cloths that are not clogged are raised by increasing only the amount of washing water that is ejected from the washing tube that cleans the clogged filter cloths. Against excessive washing. For filter cloths that are not clogged, the washing water spray may be stopped, and the amount of washing water used can be reduced.
Only by installing a flow meter in the filtrate discharge path, the clogging condition of the filter cloth in each filtration chamber can be determined, so that no large equipment is required. Further, since the injection amount of the washing water is controlled only by controlling the opening degree of the electric valve, the apparatus is simple.

1 is a schematic side view of a filter press according to the present invention. Similarly, it is a schematic longitudinal sectional view of a closed filter plate. Similarly, it is a schematic longitudinal cross-sectional view of the opened filter plate. It is a general | schematic longitudinal cross-sectional view of the closed filter board of the other form 1 which concerns on this invention. It is a substantially longitudinal cross-sectional view of the opened filter plate of another form 1 which concerns on this invention. It is a general | schematic longitudinal cross-sectional view of the filter plate which carried out the closed plate of another form 2 which concerns on this invention. It is a substantially longitudinal cross-sectional view of the opened filter plate of another form 2 which concerns on this invention. It is a front view of the filter board which concerns on this invention. Similarly, it is a block diagram of a control device.

FIG. 1 is a schematic side view of a filter press according to the present invention.
In the filter press 1 according to the present invention, a pair of parallel guide rails 4 supported by a front frame 2 and a rear frame 3 are supported. A plurality of filter plates 5 are placed on the guide rail 4 so as to be able to move forward and backward. Between the plurality of filter plates 5, filter cloths 6 are respectively provided on the front and back of the filter plate 5. A cleaning tube 7 is supported along the filter plate 5 above the plurality of filter plates 5, and a plurality of nozzles are arranged in the cleaning tube 7.

An opening / closing device 8 is supported on the rear frame 3, and the opening / closing device 8 is extended to close the filter plate 5 by pressing the movable head 9 provided on the rear frame 3 side of the filter plate 5 in the direction of the front frame 2. When the stock solution is supplied to the filtration chamber 10 between the closed filter plates 5, the stock solution is separated into solid and liquid by the filter cloth 6, and the filtrate passes through the filter cloth 6 and is discharged to the outside. The solid matter captured by the filter cloth 6 is dehydrated while forming a cake layer in the filtration chamber 10.

After dehydration, the opening / closing device 8 is contracted to open the filter plate 5. The filter plates 5 can be simultaneously opened at a predetermined interval determined by the connecting link 11. And the cake in the filtration chamber 10 is dropped and discharged out of the machine.
A plurality of filter plate groups composed of a plurality of filter plates 5 may be formed and opened and closed for each filter plate group to discharge the cake.

FIG. 2 is a schematic longitudinal sectional view of a closed filter plate of the filter press according to the present invention.
Each filter plate 5 has concave filter beds 12 formed on the front and back sides. A filter cloth 6 is stretched on each of the filter beds 12, and the filter chamber 10 is partitioned between the filter beds 12 facing each other of the adjacent filter plates 5 when the filter plate 5 is closed.

A liquid supply plate 13 is disposed between the filter cloths 6 in the filtration chamber 10, and when the parallel filter plates 5 are closed, an opening of the liquid supply plate 13 is formed in the upper center of the filter plate 5. To communicate with each other.
A stock solution passage 15 communicating with the filtration chamber 10 is formed from the opening of the liquid supply plate 13, and the stock solution is supplied from the stock solution supply passage 14 to the filter cloth 6 of the filtration chamber 10 through the stock solution passage 15. The stock solution supplied to the filtration chamber 10 is solid-liquid separated by the filter cloth 6, and the filtrate that has passed through the filter cloth 6 flows into the filtrate passages 16 a and 16 b opened at the lower part of the filter bed 12 on the front and back of the filter plate 5.

The filtrate passages 16 a and 16 b penetrate the filter plate 5 independently and are connected to the discharge pipe 17 outside the filter plate 5.
The filtrates that have passed through each filter cloth 6 flow into separate filtrate passages 16a and 16b, and the filtrates that have passed through the respective filtrate passages 16a and 16b are discharged from the discharge pipe 17 all at once. A flow meter 18 is provided in each filtrate passage 16a, 16b, and the amount of filtrate permeated from each filter cloth 6 is measured.
At this time, if the filter cloth 6 is clogged, the amount of filtrate passing through the filter cloth 6 is reduced, and the amount of filtrate flowing into the filtrate passage 16 is also reduced. Further, if the filter cloth 6 is damaged, leakage occurs from the damaged portion, and the amount flowing into the filtrate passage 16 increases.

FIG. 3 is a schematic longitudinal sectional view of an opened filter plate of the filter press according to the present invention.
After the stock solution is dehydrated, the parallel filter plates 5 are opened, so that the dehydrated cake formed in the filtration chamber 10 is discharged from the filtration chamber 10.
A washing water supply pipe 19 is provided above the filter plate 5, and the washing pipe 7 is connected to the washing water supply pipe 19 via an electric valve 20. The cleaning pipe 7 is provided for each filter cloth 6 suspended from the front and back of the filter plate 5, and the same number of cleaning pipes 7 as the filter cloth 6 are provided.

Washing water is sprayed from the washing nozzle of the washing tube 7 to wash the filter cloth 6. The electric valve 20 of each cleaning pipe 7 can control the amount of cleaning water by manipulating the opening, and when the filter cloth 6 is clogged, the electric valve 20 so that the amount of cleaning water in the corresponding cleaning pipe 7 is increased. To control clogging.

FIG. 4 is a schematic longitudinal sectional view of a closed filter plate according to another embodiment 1 of the present invention.
In the filter press according to another embodiment 1 of the present invention, the filtrate passage 16 opened on the front and back of the filter plate 5 communicates inside the filter plate 5 and penetrates the filter plate 5 to the outside of the filter plate 5, so that one filter plate 5 is provided from one place. Drain the filtrate. The flow rate of the filtrate which permeate | transmitted the filter cloth 6 stretched on the front and back of the filter plate 5 can be measured by providing the flow meter 18 in the filtrate passage 16 joined from the front and back of the filter plate 5.

FIG. 5 is a schematic longitudinal sectional view of an opened filter plate according to another embodiment 1 of the present invention.
When the filtrate passage 16 is formed as shown in FIG. 4, the flow meter 18 measures the flow rate of the filtrate permeated from the filter cloth 6 stretched on the front and back of the filter plate 5, and therefore the filter plate 5 Clogging of the filter cloth 6 stretched on the front and back can be determined. Therefore, in the filter press of the different form 1, the two filter cloths 6 stretched on the front and back of the filter plate 5 are washed based on the measurement value of the flow meter 18.

A cleaning tube 7 is provided at the top of each filter plate 5, and the cleaning tube 7 has a cleaning nozzle disposed toward the filter cloth 6 stretched on the front and back of the filter plate 5. Each cleaning pipe 7 and cleaning water supply pipe 19 are connected via an electric valve 20. In accordance with the filtrate flow rate measured by the flow meter 18, the electric valve 20 connected to the cleaning pipe 7 corresponding to the filter plate 5 on which the flow meter 18 is arranged is controlled to change the amount of cleaning water.

FIG. 6 is a schematic longitudinal sectional view of a closed filter plate according to another embodiment 2 of the present invention.
In the filter press 2 according to another embodiment 2 of the present invention, the filtrate passage 16 opened on either the front or the back of the filter plate 5 penetrates to the outside of the filter plate 5, so that the filtrate in each filtration chamber 10 is passed through. Discharge. By providing the flow meter 18 in the filtrate passage 10, the flow rate of the filtrate discharged from each filtration chamber 10 can be measured.

FIG. 7 is a schematic longitudinal sectional view of an opened filter plate according to another embodiment 2 of the present invention.
When the filtrate passage 16 is configured as shown in FIG. 6, the flow meter 18 measures the flow rate of the filtrate permeated from the pair of filter cloths 6 stretched on the front and back of the adjacent filter plates 5 that form the filtration chamber 10. In order to measure, the clogging of the pair of filter cloths 6 forming the filtration chamber 10 can be determined from the value of the flow meter 18. Therefore, in the filter press of another form 2, the pair of filter cloths 6 forming the filtration chamber 10 are washed based on the measurement value of the flow meter 18.

A cleaning tube 7 is provided at the top of each filtration chamber 10, and the cleaning tube 7 has a cleaning nozzle disposed toward a pair of filter cloths 6 stretched on the filtration chamber 10. Each cleaning pipe 7 and cleaning water supply pipe 19 are connected via an electric valve 20. In accordance with the filtrate flow rate measured by the flow meter 18, the electric valve 20 connected to the cleaning pipe 7 corresponding to the filtration chamber 10 in which the flow meter 18 is arranged is controlled to change the amount of cleaning water.

The filter cloth cleaning device and the cleaning method of the present invention will be described below based on the filter press shown in FIGS.
FIG. 8 is a front view of a filter plate according to the present invention.
FIG. 9 is a configuration diagram of a control device according to the present invention.
One end of a filtrate passage 16 for discharging the filtrate is opened at the lower part of the filtration bed 12 where the filtrate collects, and the other end passes through the thickness of the filter plate 5 and the outer side of the filter plate 5. It connects with the discharge pipe 17 provided in the.
A filtrate passage 16 is connected from each filtration chamber to the discharge pipe 17, and the filtrate flowing in from the filtrate passage 16 is discharged to the outside through the discharge pipe 17.
Each filtrate passage 16 is provided with a flow meter 18 to measure the flow rate of the filtrate that has passed through each filter cloth 6.

The filter plate 5 of FIG. 8 is provided with the filtrate passage 16 and the discharge pipe 17 only on one side of the filter plate 5, but the filtrate passage 16 and the discharge pipe 17 are provided on both sides of the filter plate 5. May be measured. The measured filtrate flow rate is transmitted to the control device 21.

Above each filter plate 5, a cleaning tube 7 having a cleaning nozzle for spraying cleaning water onto each filter cloth 6 is provided. The cleaning pipe 7 is provided on each filter cloth 6, and one end of the cleaning pipe 7 is connected to the cleaning water supply pipe 19 via the electric valve 20. The electric valve 20 is opened and closed based on a signal from the control device 21, and the amount of washing water can be adjusted.

The flow rate measured by the flow meter 18 provided in each of the plurality of filtrate passages 16 is transmitted to the control device 21, and the control device 21 calculates the accumulated filtrate amount V discharged through the respective filter cloths 6. When the filter cloth 6 is clogged, the accumulated filtrate amount V decreases, so the opening degree of the electric valve 20 connected to the cleaning pipe 7 corresponding to each filter cloth 6 is determined according to the calculated accumulated filtrate amount V. The electric valve 20 is controlled on the basis of the signal sent from the control device 21, and cleaning is performed with a cleaning water amount corresponding to the clogging of each filter cloth 6.

The control device 21 of the present invention compares the calculated cumulative filtrate amount V with the reference filtrate amount (reference filtrate amount V0), and controls the plurality of electric valves 20 as follows.
The reference filtrate amount V0 is the total amount of filtrate discharged after normal dewatering without clogging the filter cloth 6, and is set to a predetermined value with a width. The reference filtrate amount V0 may be set to a predetermined value, but may be calculated from an average value of the filtrate flow rates discharged from the plurality of filtrate passages 16.
The electric valve 20 sets a reference opening D0 that is a predetermined opening for washing the filter cloth 6.

When the calculated cumulative filtrate amount V is included in the range of the reference filtrate amount V0, the filter cloth 6 is not clogged, so the opening degree of the electric valve 20 is made smaller than the reference opening degree D0 by a predetermined opening degree. The filter cloth 6 is washed.

When the calculated cumulative filtrate amount V is smaller than the reference filtrate amount V0, the opening degree of the electric valve 20 is set as the reference opening degree D0. At this time, since the filter cloth 6 is clogged, it is necessary to increase the amount of washing water in order to eliminate the clogging of the filter cloth 6.
By making the opening degree of the electric valve 20 corresponding to the filter cloth 6 that is not clogged smaller than the reference opening degree D0, the amount of washing water flowing into other washing pipes increases. Accordingly, the amount of cleaning water increases in the cleaning pipe 7 of the electric valve 20 with the reference opening D0, and the clogging of the filter cloth 6 can be eliminated.
The degree of opening of the electric valve 20 may be determined according to the difference between the accumulated filtrate amount V and the reference filtrate amount V0. At that time, the larger the difference, the smaller the opening of the electric valve 20.

Moreover, according to the accumulated filtrate amount V, you may perform control which decreases the opening degree of the electrically operated valve 20 in steps.

When the opening degree of the electric valve 20 becomes a predetermined minimum opening degree, the cleaning ability of the filter cloth 6 is remarkably reduced, so that a warning is issued and the operation of the filter press 1 is stopped.

If the calculated cumulative filtrate amount V is greater than the reference filtrate amount V0, the filter cloth 6 may be damaged and the stock solution may flow out, so an alarm is issued and the operation of the filter press 1 is stopped.

Further, in the case of a dehydrated cake with good peelability, the electric valve 20 corresponding to the filter cloth 6 that is not clogged is closed (fully closed), and the filter cloth 6 that is not clogged is not washed. Control may be performed.

In addition, when the accumulated filtrate amount V measured by all the flow meters 18 is included in the range of the reference filtrate amount V0, since there is no clogged filter cloth 6, the opening degree of all the electric valves 20 is set. Washing with reference opening degree D0.

The filter cloth cleaning method of the filter press 1 described above will be described in detail.
First, as an initial setting, a filtrate discharge amount (reference filtrate amount V0) when normal dewatering is performed is set with a width.
Moreover, the reference opening degree D0 of the electric valve 20 for washing the filter cloth 6 is set.
All the electric valves 20 are opened at the reference opening D0 in advance.

<Closed plate process>
A plurality of filter plates 5 are closed by an opening / closing device 8, and a filtration chamber 10 is formed between the filter plates 5. A filter cloth 6 is stretched on the filter bed 12 of the filter plate 5, and the filter chamber 10 is covered with the filter cloth 6 stretched on the opposite filter bed 12.

<Press-fit process>
The stock solution is press-fitted between the stock solution supply path 14 and the filter cloth 6 in the filtration chamber 10. The filter cloth 6 separates moisture from the injected stock solution and forms a dehydrated cake between the filter cloths 6. The filtrate separated by the filter cloth 6 flows downward through the filtration bed 12 of the filter plate 5 and is discharged out of the filtration chamber 10 from the filtrate passage 16 opened at the lower part of the filtration bed 12. The filtrate flows into the discharge pipe 17 from the filtrate passage 16 and is discharged out of the machine.
In addition, in the case of the filter press 1 provided with the diaphragm in the filtration chamber 10, you may add the pressing process which expands a diaphragm after a press-fit process and compresses.

<Measurement of filtrate flow rate>
During the press-fitting process (squeezing process), the flow rate of the filtrate discharged through the filter cloth 6 stretched on the front and back of the filter plate 5 is measured by the flow meter 18 provided in each filtrate passage 16. The measured value of the filtrate flow rate measured by the flow meter 18 is transmitted to the control device 21. The control device 21 calculates the accumulated filtrate amount V that has passed through each filter cloth 6 and discharged to the filtrate passage 16 from the filtrate flow rate.

<Comparison of filtrate amount>
The control device 21 compares the accumulated filtrate amount V permeated through each filter cloth 6 and the reference filtrate amount V0, and sets the electric valve 20 corresponding to the cleaning pipe 7 for washing each filter cloth 6 according to the comparison result. Send a signal to control.

<Operation of electric valve>
One electric valve 20a is controlled as follows.
When the cumulative filtrate amount Va calculated by the control device 21 from the measurement value of the flow meter 18a is compared with the reference filtrate amount V0, and the cumulative filtrate amount Va is included in the range of the reference filtrate amount V0, the electric valve 20a Is controlled to be smaller than the reference opening D0 by a predetermined opening.
When the accumulated filtrate amount Va is smaller than the reference filtrate amount V0, the opening degree of the electric valve 20a is controlled to become the reference opening degree D0.
When the accumulated filtrate amount Va is larger than the reference filtrate amount V0, the operation of the filter press 1 is stopped and a warning is transmitted.
Similarly, the other electric valves 20 compare the accumulated filtrate amount V permeated through each filter cloth 6 and the reference filtrate amount V0 and control them.

<Opening process>
After the opening degree of all the electric valves 20 is operated by the control device 21, the filter plate 5 is opened by the opening / closing device 8 in order to discharge the dehydrated cake. The dewatered cake falls to the outside of the machine due to its own weight or the vibration of the filter cloth 6 by opening the plate.

<Washing process>
Washing water is sprayed from the washing tube 7 onto the filter cloth 6 from which the dewatered cake has been peeled off by opening the plate.
Since the electric valve 20 of the cleaning pipe 7 is smaller than the reference opening D0 for the filter cloth 6 which is not clogged, the amount of cleaning water is reduced.
The cleaning pipe 7 corresponding to the clogged filter cloth 6 is injected because the opening degree of the electric valve 20 is the reference opening degree D0 and the electric valve 20 corresponding to the clogged filter cloth 6 is reduced. Since the amount of water to be washed is increasing, clogging of the filter cloth 6 is eliminated.

In the present embodiment, all the electric valves 20 are opened at the reference opening D0 in advance. However, when the filter cloth 6 that is not clogged is not washed, all the electric valves 20 are fully closed in advance. The effect of the present invention can also be obtained by opening only the electric valve 20 corresponding to the clogged filter cloth 6 to the reference opening D0 and washing.

DESCRIPTION OF SYMBOLS 1 Filter press 5 Filter board 6 Filter cloth 7 Washing pipe 10 Filtration chamber 16 Filtrate passage 18 Flow meter 20 Electric valve 21 Control device

Claims (4)

A plurality of filter plates (5) with filter cloths (6) stretched on the front and back are formed in parallel to form a filtration chamber (10),
The dewatered cake formed in the filtration chamber (10) is discharged by opening the filter plate (5),
Wash the filter cloth (6) with the washing tube (7) provided for each filter cloth (6).
In the filter cloth cleaning method of the filter press that opens and closes the electric valve (20) of the cleaning pipe (7) to control the amount of cleaning water,
A reference filtrate amount (V0) having a width in advance and a reference opening (D0) of the electric valve (20) are set.
Calculate the cumulative filtrate amount (V) permeated from each filter cloth (6),
The filter cloth (6) whose accumulated filtrate amount (V) is within the range of the reference filtrate amount (V0) is washed with an opening smaller than the reference opening (D0) of the electric valve (20),
Filter cloth washing of a filter press characterized by washing the electric valve (20) at a reference opening degree (D0) with a filter cloth (6) having a cumulative filtrate amount (V) smaller than a reference filtrate amount (V0). Method. In a filter cloth cleaning device for a filter press that forms a filtration chamber (10) by paralleling a plurality of filter plates (5) with filter cloths (6) stretched on the front and back,
A filtrate passage (16) that opens to the filtration bed (12) and penetrates to the outside of the filter plate (5);
A flow meter (18) provided in each filtrate passage (16);
A washing tube (7) for washing each filter cloth (6);
An electric valve (20) provided in each cleaning pipe (7) to control the amount of cleaning water;
A control device (21) for controlling the electric valve (20) of the cleaning pipe (7) corresponding to the filter cloth (6) that has permeated the filtrate measured by each flow meter (18),
The control device (21)
A reference filtrate amount (V0) having a width in advance and a reference opening (D0) of the electric valve (20) are set.
Calculate the cumulative filtrate volume (V) discharged from the filtrate passage (16),
When the accumulated filtrate amount (V) is within the range of the reference filtrate amount (V0), the electric valve (20) is made smaller than the reference opening (D0),
A filter cloth cleaning device for a filter press, characterized in that when the accumulated filtrate amount (V) is smaller than the reference filtrate amount (V0), the opening degree of the electric valve (20) is set to the reference opening degree (D0). The control device (21)
A reference filtrate amount (V0) having a width in advance and a reference opening (D0) of the electric valve (20) are set.
Calculate the cumulative filtrate volume (V) discharged from the filtrate passage (16),
When the accumulated filtrate amount (V) is within the range of the reference filtrate amount (V0), the motorized valve (20) is fully closed,
The filter press according to claim 2, wherein when the cumulative filtrate amount (V) is smaller than the reference filtrate amount (V0), the opening degree of the electric valve (20) is set as the reference opening degree (D0). Filter cloth cleaning device. The filter cloth of the filter press according to claim 2 or 3, wherein when the accumulated filtrate amount (V) is larger than the reference filtrate amount (V0), the operation of the filter press is stopped and an alarm is issued. Cleaning device.

Images