JP6924347B2 - Air blow device and air blow method for filter press - Google Patents

Description

The present invention relates to an air blow of a filter press, and relates to an air blow device and an air blow method of a filter press that returns and reuses the air discharged from the filter press.

Patent Document 1 discloses an air blow device for removing moisture between cake particles, which is difficult to extrude by mechanical pressing pressure, with high-pressure air as a technique for further reducing the moisture content of the cake pressed by the diaphragm in a filter press. Is known as.

Further, Patent Document 2 discloses a technique in which an eliminator is installed after the filter press to separate the fluid after air blowing into gas and liquid.

Further, in Patent Document 3, the dehydrated cake is dried by the hot air dryer by the hot air generated by the hot air generator, and a part of the gas separated from the solid air separator (cyclone) in the subsequent stage is returned to the hot air generator. The technology to do is disclosed.

Special Publication No. 63-347666 Jikkenhei 1-32705 Gazette JP-A-2017-006824

In the conventional air blow device as in Cited Document 1, high pressure air is supplied to the filtration chamber of the filter press at high pressure, and the air exhausted from the filtration chamber is released to the atmosphere as it is, so that the consumption of air increases. It costs a lot of running cost.

In the apparatus of Cited Document 2, the fluid after air blowing is gas-liquid separated by an eliminator, but the liquid is recovered by the eliminator and the gas is released to the atmosphere.

In the apparatus of Cited Document 3, a part of the hot air obtained by drying the dehydrated cake is returned and reused, but a suction fan is used to return the hot air, which increases the equipment cost and the maintenance cost. , When returning to the main pipe (when merging), a large pressure loss may occur due to collision between the airflows and the efficiency may decrease.

In the present invention, in the air blow device of the filter press, a gas-liquid separation device is installed after the dehydrator to separate the air from the air blow into gas and liquid, and the separated air is efficiently returned and reused to efficiently return and reuse the air at the time of air blow. Provided are an air blow device and an air blow method for a filter press that reduce consumption.

The present invention is a filter press in which a plurality of filter plates are arranged in parallel to form a filtration chamber between the filter plates, and after performing a mechanical filtration process in the filtration chamber, high pressure air is supplied to perform an air blow process. An air supply pipe that connects an air supply source and connects the other end to the filtration chamber, an air discharge pipe that connects one end to the filtration chamber and the other end to the gas-liquid separator, and high-pressure air and filtrate. Since it is equipped with a gas-liquid separation device that separates gas and liquid, and a return pipe that connects one end to the exhaust section of the gas-liquid separation device and the other end to an ejector inserted in the air supply pipe, the dehydrated cake contains water by air blowing. The rate can be reduced, and the amount of air used for air blowing can be reduced.

Further, a discharge hole provided on the filter plate for discharging the filtrate from the filtration chamber, a filtrate pipe connected to each discharge hole, an air supply pipe connected to one of the filtrate pipes communicating with the filtration chamber, and filtration. If an air discharge pipe connected to the other filtrate pipe communicating with the chamber is provided, the filtrate pipe line can be used for intake and exhaust of high-pressure air to the filtration chamber.

In a filter press in which a plurality of filter plates are arranged in parallel to form a filtration chamber between the filter plates, a filtration step of supplying sludge to the filtration chamber to dehydrate the filter, and an air blow process of supplying high-pressure air to the filtration chamber after the filtration step. , A gas-liquid separation step that separates the high-pressure air discharged from the filtration chamber, and a return mixing that returns the high-pressure air separated in the gas-liquid separation step and mixes it with the air supply pipe that supplies the filtration chamber via the ejector. Since it has a process, it is possible to reduce the water content of the dehydrated cake by air blowing, and it is possible to reduce the amount of air used for air blowing.

The air blow device of the filter press according to the present invention can reduce the moisture content of the dehydrated cake by air blowing and can reduce the amount of air used for air blowing. Since the filtrate can be used for intake and exhaust of high-pressure air to the filtration chamber, there is no need to form a separate pipeline. Since the gas-liquid separation device installed in the exhaust section is a device that uses the laws of nature, there is no running cost.

It is a conceptual diagram of the filter press which concerns on this invention. Similarly, it is a cross-sectional view of a filtration chamber. Similarly, it is sectional drawing of the filtration chamber of another Example. Similarly, it is a cross-sectional view of a gas-liquid separator. Similarly, it is a cross-sectional view of the ejector.

FIG. 1 is a conceptual diagram of a filter press according to the present invention.
In the filter press 1, a large number of filter plates 5 ... Are movably supported on a guide rail 4 bridged between the front and rear frames 2 and 3. A switchgear 6 provided on one of the frames 3 moves a large number of filter plates 5 ... In the axial direction. A concave filtration bed 7 is formed on the filter plate 5, a filter cloth 8 is stretched on the filtration bed 7, and a filtration chamber 9 is formed between the adjacent filter plates 5 and 5.

An air supply pipe 10 communicating with the filtration chamber 9 is connected to the filter plate 5, and high-pressure air is supplied to the filtration chamber 9 from the supply source 11. Further, one end of the air discharge pipe 12 is connected to the filter plate 5, and high-pressure air is discharged from the filtration chamber 9 to the air discharge pipe 12.

The other end of the air discharge pipe 12 is connected to the gas-liquid separation device 13, and the high-pressure air discharged from the filtration chamber 9 is gas-liquid separated by the gas-liquid separation device 13. The liquid (filter liquid) is discharged downward, and the gas (high pressure air) is allowed to flow into the return pipe 14 from above.

The other end of the return pipe 14 is connected to an ejector 15 provided in the air supply pipe 10, is sucked by the flow of high-pressure air from the supply source 11, and is supplied to the filtration chamber 9 again.

As the supply source 11 for generating high-pressure air, a known technique such as a compressor can be used.

FIG. 2 is a cross-sectional view of the filtration chamber.
Concave-shaped filtration beds 7 and 7 are formed on the adjacent filter plates 5 and 5, respectively, to form the filtration chamber 9. A sludge press-fitting communication pipe 16 is provided above the filter plate 5, and sludge is press-fitted into the filtration chamber 9 from a stock solution supply pipe (not shown) to perform solid-liquid separation with the filter cloth 8. The separated filtrate is discharged to the filtration beds 7 and 7 of the filter plates 5 and 5, extracted from the filtrate discharge holes 17 and 17 provided at the lower ends of the filter plates 5 and 5, and discharged to the filtrate tubes 18 and 18. I try to do it.

An air supply pipe 10 is connected to one of the filtrate pipes 18 communicating with the filtration chamber 9, and high-pressure air can flow into the filtration chamber 9 from the discharge hole 17 of the filtration bed 7. The high-pressure air that has flowed into the filtration bed 7 penetrates the dehydrated cake and is discharged from the discharge hole 17 of the other filtration bed 7. An air discharge pipe 12 is connected to the other filtrate pipe 18 communicating with the filtration chamber 9, and the high-pressure air discharged from the filtration chamber 9 flows into the air discharge pipe 12.

At this time, since the high-pressure air conveys the water content in the dehydrated cake to the other filtration bed 7, the water content of the dehydrated cake in the filtration chamber 9 can be further reduced.

When a plurality of filtration chambers 9 ... Are arranged in parallel, the air supply pipe 10 and the air discharge pipe 12 are continuously connected to the respective filtrate pipes 18.

FIG. 3 is a cross-sectional view of the filtration chamber of another embodiment.
A filter plate 5a having a concave back surface and a filter plate 5b formed on a flat surface are alternately opened and closed in parallel, and the front and rear filter plates 5a and 5b are closed to form a filtration chamber 9. I have to. A sludge press-fitting communication pipe 16 is provided above the filter plates 5a and 5b, and sludge is press-fitted into the filtration chamber 9 from a stock solution supply pipe (not shown) to perform solid-liquid separation with the filter cloth 8. The separated filtrate is discharged to the filtration beds 7 and 7a of the filter plates 5a and 5b, extracted from the filtrate discharge holes 17 and 17 provided at the lower ends of the filter plates 5a and 5b, and discharged to the filtrate pipe 18. I have to. The filtrate pipe 18 communicates between the adjacent filtration chambers 9 and 9, and the filtrate of the adjacent filtration chambers 9 and 9 is discharged at the same time.

An air supply pipe 10 is connected to one of the filtrate pipes 18 communicating with the filtration chamber 9, and high-pressure air can flow into the filtration chamber 9 from the discharge hole 17 of the filtration bed 7. The high-pressure air that has flowed into the filtration bed 7 penetrates the dehydrated cake and is discharged from the discharge hole 17 of the other filtration bed 7a. An air discharge pipe 12 is connected to the other filtrate pipe 18 communicating with the filtration chamber 9, and the high-pressure air discharged from the filtration chamber 9 flows into the air discharge pipe 12.

The filter plate 5 and the filtration chamber 9 are not limited to this embodiment, and other known configurations can be used.

Further, in this embodiment, the high-pressure air is sucked and exhausted by using the filtrate discharge holes 17 formed in the filtrate pipe 18 and the filter plate 5, but a dedicated pipe for sucking and exhausting only the high-pressure air is provided. May be good.

FIG. 4 is a cross-sectional view of the gas-liquid separator.
In the gas-liquid separation device 13, a main body portion 21 is formed by connecting a conical portion 20 whose diameter gradually decreases below the cylindrical portion 19. An intake portion 22 is provided on the upper side of the main body portion 21, and is connected to the air discharge pipe 12 so as to flow in the circumferential direction of the cylindrical portion 19. An exhaust portion 23 is provided at the top of the cylindrical portion 19 and is connected to the return pipe 14. A drainage portion 24 is provided at the lower end of the conical portion 20, and the filtrate is discharged through a pipeline (not shown).

Air and a small amount of filtrate are mixed in the air discharge pipe 12 that transfers the high-pressure air discharged from the filtration chamber 9. This high-pressure air enters the inside of the main body 21 from the intake portion 22 of the gas-liquid separation device 13, goes downward while making a swirling motion as shown by a thin arrow, and reverses and rises. The centrifugal force of the swirling motion at this time separates the gas and the water, the gas is exhausted from the exhaust unit 23, and the water descends along the inner wall surface of the main body 21 and is discharged from the drainage unit 24.

The gas-liquid separation device 13 is not limited to this embodiment, and other known gas-liquid separation devices can be used.

FIG. 5 is a cross-sectional view of the ejector.
Air supply pipes 10 and 10 are connected to both ends of the ejector 15, one of the air supply pipes 10 (lower part of FIG. 5) is connected to the supply source 11 and the other (upper part of FIG. 5) is connected to the filter press 1. ..

The ejector 15 includes a nozzle hole 26 that is inserted into the cylindrical portion 25 and has a reduced opening at the tip, an bleeding portion 27 that is connected to the cylindrical portion 25 near the opening of the nozzle hole 26, and a diffuser portion that has a reduced pipe diameter behind the nozzle hole 26. It is composed of 28.

The bleed air section 27 is connected to the return pipe 14, and the high-pressure air separated by the gas-liquid separation device 13 is introduced into the ejector 15 through the bleed air section 27.

The ejector 15 is not limited to this embodiment, and a known ejector capable of inhaling air by the Venturi effect can be used.

Each step of the air blow method of the filter press 1 will be described in detail with reference to FIGS. 2 and 3.
The air supply pipe 10 is connected to one of the filtrate pipes 18 ... Communicating with the filtration chamber 9, and is provided with a valve V1 on the upstream side of the connection portion with the filtrate pipe 18, and the filtrate is provided on the downstream side of the connection portion. The pipe 18 ... is provided with a valve V2 ...
An air discharge pipe 12 is connected to the other filtrate pipe 18 ... Communicating with the filtration chamber 9, and the air discharge pipe 12 on the downstream side of the connection portion is provided with a valve V3. A valve V4 is provided on the downstream side of the conduit in which the respective filtrate pipes 18 ... communicating with the filtration chamber 9 are grouped.

<Filtration step S1>
In the filtration step S1 in which sludge is supplied to the filter press 1 and solid-liquid separation is performed in the filtration chamber 9, the filter plate 5 ... Is first closed and then provided in the filtrate pipe 18 communicating with the filtration chamber 9. The valve V2 ... And the valve V4 are opened, and the valve V1 provided in the air supply pipe 10 and the valve V3 provided in the air discharge pipe 12 are closed.

After confirming that the filtrate does not flow into the air intake / exhaust pipeline, sludge is supplied to the filtration chamber 9.
In the filtration chamber 9, sludge is solid-liquid separated by press-fitting and squeezing action, the dehydrated cake remains in the filtration chamber 9, the filtrate passes through the filter cloth 8 and is discharged from the filtrate pipe 18 through the discharge hole 17 of the filter plate 5. Will be done.
After performing the filtration step S1 for a predetermined pressure or time, the process proceeds to the air blow step S2.

<Air blow process S2>
In the air blow step S2 in which high-pressure air is supplied to the filtration chamber 9 and the moisture between the cake particles of the dehydrated cake is accompanied and removed by the high-pressure air, first, the valves V2 ... And the valves V4 provided in the filtrate pipe 18 are closed, and the air is closed. The valve V1 provided in the supply pipe 10 and the valve V3 provided in the air discharge pipe 12 are opened.

After confirming that the high-pressure air does not flow into the filtrate discharge pipe, the high-pressure air is supplied from the supply source 11 into the filtration chamber 9 via the air supply pipe 10. When the high-pressure air passes through the dehydrated cake in the filtration chamber 9, the moisture in the dehydrated cake is conveyed to further reduce the water content of the dehydrated cake.
The air after the air is blown into the filtration chamber 9 is discharged through the air discharge pipe 12.

<Gas-liquid separation step S3>
Air and a small amount of filtrate are mixed in the air discharge pipe 12 that transfers the high-pressure air discharged from the filtration chamber 9. The gas-liquid separation step S3 is a step of removing moisture from the high-pressure air by the gas-liquid separation device 13.

It enters the inside of the main body 21 from the intake portion 22 of the gas-liquid separation device 13 connected to the air discharge pipe 12, goes downward while making a swirling motion as shown by a thin arrow, reverses and rises. The centrifugal force of the swirling motion at this time separates the gas and the water, the gas is exhausted from the exhaust unit 23, and the water descends along the inner wall surface of the main body and is discharged from the drainage unit 24.

<Return mixing step S4>
The air from which the moisture has been removed by the gas-liquid separation device 13 is introduced into the ejector 15 via the return pipe 14 connected to the exhaust unit 23 in the return mixing step S4.

The ejector 15 ejects high-pressure air supplied from the supply source 11 from the nozzle hole 26 to reduce the pressure, sucks the air discharged from the gas-liquid separation device 13 from the bleed air section 27, and mixes the air in the diffuser section 28. Let me. The mixed high-pressure air mixed by the ejector 15 is supplied to the filtration chamber 9 via the air supply pipe 10.

The pressure of the gas discharged from the gas-liquid separator 13 remains, and the gas is efficiently mixed by the ejector 15. Further, since the return air is mixed by the ejector 15, the amount of air blown generated by the supply source 11 can be reduced.

Since the air blow device and the air blow method of the filter press according to the present invention reuse the high pressure air of the air blow supplied to the filtration chamber, the air consumption can be reduced. In general, the cost ratio of the high-pressure air power source at the airport is high, and this device can reduce the running cost. Therefore, in the treatment of purified water sludge, sewage sludge, industrial wastewater sludge, etc., it is effective for a filter press that reduces the dehydrated cake to a low water content by air blowing.

1 Filter press 5 Filter plate 9 Filtration chamber 10 Air supply pipe 11 Supply source 12 Air discharge pipe 13 Gas-liquid separator
14 Return pipe 15 Ejector 17 Discharge hole 18 Filtration pipe
23 Exhaust section S1 Filtration process S2 Air blow process S3 Gas-liquid separation process

Claims (3)

A plurality of filter plates (5 ...) are arranged in parallel to form a filtration chamber (9) between the filter plates (5, 5), and after performing a mechanical filtration step (S1) in the filtration chamber (9), high-pressure air is blown. In the filter press (1) that supplies and performs the air blow step (S2),
An air supply pipe (10) in which a high-pressure air supply source (11) is connected to one end and the other end is communicated with a filtration chamber (9).
An air discharge pipe (12) having one end communicating with the filtration chamber (9) and the other end connected to the gas-liquid separator (13).
A gas-liquid separator (13) that separates gas-liquid into high-pressure air and filtrate,
A return pipe (14) having one end connected to the exhaust portion (23) of the gas-liquid separator (13) and the other end connected to the ejector (15) inserted through the air supply pipe (10).
A filter press air blower characterized by being equipped with. Discharge holes (17, 17) provided in the filter plate (5) to discharge the filtrate from the filtration chamber (9), and
The filtrate pipes (18 , 18 ) connected to each discharge hole (17 , 17), and
An air supply pipe (10) connected to one of the filtrate pipes (18) communicating with the filtration chamber (9), and
An air discharge pipe (12) connected to the other filtrate pipe (18) communicating with the filtration chamber (9), and
The air blow device for a filter press according to claim 1, further comprising. In the filter press (1) in which a plurality of filter plates (5 ...) are arranged in parallel and a filtration chamber (9) is formed between the filter plates (5, 5).
A filtration step (S1) in which sludge is supplied to the filtration chamber (9) for dehydration, and
After the filtration step (S1), an air blow step (S2) for supplying high-pressure air to the filtration chamber (9) and
A gas-liquid separation step (S3) for gas-liquid separation of high-pressure air discharged from the filtration chamber (9), and
A return mixing step (S4) in which the high-pressure air separated in the gas-liquid separation step (S3) is returned and mixed with an air supply pipe (10) supplied to the filtration chamber (9) via an ejector (15).
An air blow method for a filter press, characterized in that it has.

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