JPH0224568B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a dewatering method using a filter press that can efficiently dewater a slurry in which solid particles such as coal/water slurry are mixed with water.

[Conventional technology]

Conventionally, the applicant has invented a dewatering method using a filter press to further improve the solid content concentration of a cake formed by dewatering a slurry in which solid particles and water are mixed, and has already filed a patent application (special patent application). (Gan Sho 58-199763).

The outline of this process is to supply compressed air into the slurry supplied to each filter chamber of the filter press, pass it between the solid particles of the slurry, and discharge the interstitial water (filtrate) and air that remains between the particles to the outside of the filter chamber. do,
This is to dehydrate slurry.

[Problem that the invention seeks to solve]

By the way, in the conventional dehydration method, air blowing is performed by opening and closing an air blow valve provided in a compressed air supply pipe communicating with each filter chamber according to a set time. However, since the air blowing time required to dehydrate the slurry differs in each filter chamber, the time may be insufficient in one filter chamber and excessive in the other.
Compressed air could not be used effectively, resulting in poor efficiency.
Furthermore, since the solid content concentration of the cake differs depending on the filter chamber, the dehydration ability was low.

This invention was devised to solve the above problems, and it makes effective use of compressed air, reduces the cost of each equipment of the compressed air supply source, and improves the dewatering capacity of a filter press. The purpose is to provide a method.

[Means for solving problems]

This invention uses a filter press that has a plurality of filter plates that overlap each other, a filter chamber is formed between each filter plate, and a through hole is formed that passes through the filter plate and communicates with each filter chamber, In a dewatering method using a filter press, in which the slurry is supplied into each filter chamber through the through-hole, and then compressed air is supplied into the slurry in each filter chamber to dehydrate the slurry, alternately provided on the sides of each of the filter plates. A compressed air supply pipe and a filtrate discharge pipe having a filtrate flow rate measuring means are provided at opposite positions, and compressed air is supplied to one of the two supply pipes of the adjacent filter plates until the flow rate of the filtrate becomes almost 0. After that, compressed air is then supplied to the other supply pipe on the opposite side, and these processes are repeated in sequence.

〔Example〕

FIG. 1 shows an embodiment of the present invention, in which reference numeral 1 denotes an air compressor for air blowing and back blowing, 2 a main ON-OFF valve, 3 an air receiver tank, and 4 a filter press. The filter press 4 has a plurality of filter plates 4a that overlap each other, a filter chamber 4b is formed between each filter plate 4a, and a through hole passes through the filter plate 4a and communicates each filter chamber 4b. 4c is formed. A slurry supply pipe 9 communicating with a slurry storage tank (not shown) is connected to one end of the through hole 4c.
A back blow pipe 11 communicating with the air receiver tank 3 is connected to the other end of the through hole 4c. A pressure gauge 14 and a slurry supply valve 10 are attached to the slurry supply pipe 9, and a back blow slurry discharge pipe 16 is disposed between the through hole 4c and the slurry supply valve 10. A back blow slurry discharge valve 13 is attached to the back blow slurry discharge valve 13. Further, a back blow valve 12 is attached to the back blow pipe 11.

On the sides of each filter plate 4a, air blow pipes 18, 18' and drain pipes 19 are arranged alternately on opposite sides.
19' are provided and these tubes 18,1
8', 19, 19' communicate with the filter chamber 4b. The air blow pipes 18, 18' communicate with the air receiver tank 3 via air blow valves 5, 6 attached to each filter plate 4a side and an air blow source valve 15 attached to the air supply side. Drain pipe 19,1
Drain valves 7, 8 and interstitial water flow rate detectors 17, 17' are attached to each filter plate 4a side of 9'.

Next, the dewatering method of the present invention will be explained based on embodiments shown in the drawings.

With the slurry supply valve 10 open, the pressure gauge 1
4 detects a predetermined pressure.
The slurry is supplied into each filter chamber 4b of the filter press 4 through the through hole 4c. At this time, the air blow valves 5 and 6 are closed, and the drain valves 7 and 8 are closed.
Leave it open.

At the same time as the pressure gauge 14 detects a predetermined pressure,
The drain valve 7 is closed, the air blow valve 5, the air blow source valve 15, and the drain valve 8 are opened, and the compressed air in the air receiver 3 is supplied from the air blow pipe 18 into the slurry in each filter chamber 4b to remove the slurry. The interstitial water (filtrate) and air that pass between the solid particles and remain between the particles are discharged from the drain pipe 19' outside the system.

The flow rate of pore water becomes almost 0 and the flow rate detector 1
When 7' no longer detects the flow rate, drain valve 8
Then, the air blow valves 5 are closed, and the air blow valves 6 and drain valves 7 of the adjacent filter plates 4a opposite to these are opened, and compressed air is supplied from the air blow pipes 18 into the slurry in each filter chamber 4b. do.

The flow rate of pore water becomes almost 0 and the flow rate detector 17
When the flow rate is no longer detected, the air blow valve 6, drain valve 7, and air blow source valve 15 are closed.

Back blow slurry discharge valve 13 and back blow valve 12 are opened, compressed air is supplied from back blow pipe 11, and undehydrated slurry remaining in through hole 4c is discharged from the system through back blow slurry discharge pipe 16. let

Each of the above-mentioned steps ~ is controlled by a sequencer, and the slurry supply to the filter press, the compressed air supply to each filter chamber, the opening and closing of each valve, etc. are automatically performed.

[Effects of the Invention] A filtrate flow rate measuring means is provided in the discharge pipe of each filter plate, and compressed air is supplied to each filter chamber until the flow rate of the filtrate reaches almost 0, and air blowing is performed, so that the dehydration of each filter chamber is uniform. and can be performed well. In addition, compressed air can be used effectively, and the cost of each equipment for the compressed air supply source can be reduced.

Each filter plate is provided with a compressed air supply pipe and a filtrate discharge pipe at alternate positions on opposite sides, and after supplying compressed air to one of the two supply pipes of the adjacent filter plate, the compressed air is supplied to the opposite side. Since dehydration is performed by supplying compressed air to the other inlet pipe, pressure is evenly applied to the inside of the cake in the filter chamber, improving dehydration ability.

[Brief explanation of drawings]

FIG. 1 is a conceptual diagram showing an embodiment of the present invention. 1...Air compressor, 2...Main ON-OFF valve, 3
...Air receiver tank, 4...Filter press, 4a...Filter plate, 4b...Filter chamber, 4c...Through hole, 5, 6...Air blow valve, 7, 8...Drain valve, 9...Slurry Supply pipe, 10... Slurry supply valve, 11... Back blow pipe, 12... Back blow valve, 13... Back blow slurry discharge valve, 14... Pressure gauge, 15... Air blow source valve,
16...Back blow slurry discharge pipe, 17,1
7'... Pore water flow rate detector, 18, 18'... Air blow pipe, 19, 19'... Drain pipe.

Claims (1)

[Scope of Claims] 1. A filter press having a plurality of filter plates overlapping each other, a filter chamber being formed between each filter plate, and a through hole passing through the filter plate and communicating the filter chambers. In a dehydration method using a filter press, in which the slurry is supplied into each filter chamber through the through-hole, and then compressed air is supplied into the slurry in each filter chamber to dehydrate the slurry, on the side of each filter plate. A compressed air supply pipe and a filtrate discharge pipe having a filtrate flow rate measuring means are provided at positions that alternately meet and face each other, and air is compressed into one of the two supply pipes of adjacent filter plates until the flow rate of the filtrate becomes almost 0. A dewatering method using a filter press, which is characterized in that after supplying air, compressed air is then supplied to the other supply pipe on the opposite side, and these processes are repeated in sequence. 2. A dewatering method using a filter press according to claim 1, characterized in that after dewatering the slurry, compressed air is supplied to the through holes to discharge undehydrated slurry in the through holes to the outside of the filter chamber. .