JPS63151314A - Dehydration method by filter press - Google Patents

Abstract

PURPOSE:To effectively utilize compressed air and to enhance dehydration capacity, by providing a compressed air feed-in pipe and a filtrate discharge pipe having a filtrate flow rate measuring means at positions opposed to each other on the lateral side of a filter plate to alternately perform air blow. CONSTITUTION:A slurry is supplied into each filter chamber 4b of a filter press 4 from a slurry supply pipe 9 and, when a pressure gauge 14 detects predetermined pressure, a drain valve 7 is closed and an air blow valve 5, an air blow original valve 15 and a drain valve 8 are opened to supply compressed air received in an air receiver 3 and the slurry is dehydrated to the discharged from a drain pipe 19'. When a flow rate detector 17' does not detect a flow rate, the drain valve 8 and the air blow valve 5 are closed and an air blow valve 6 and the drain valve 7 are opened to supply compressed air from an air blow pipe 18'. Finally, a back slurry discharge valve 13 and a back blow valve 12 are opened and compressed air is supplied from a back blow pipe 11 to be discharged from a discharge pipe 16.

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]

Previously, 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 (patent application). Showa 58-199763
No.).

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. The slurry is then dehydrated.

[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 on a compressed air supply pipe communicating with each filter chamber at a set time. However, since the air blow time required to dehydrate the slurry differs in each filter chamber, there is insufficient time in one filter chamber and excess time in the other, making it impossible to use compressed air effectively and resulting in poor efficiency. Ta. Furthermore, since the solid content concentration of the cake differed 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 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, the following steps are provided on the sides of each of the filter plates alternately. A compressed air supply pipe and a filtrate discharge pipe having a filtrate flow rate measuring means are provided at opposing positions, and compressed air is supplied to one of the two supply pipes of adjacent filter plates until the flow rate of the filtrate reaches approximately O. 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 is an air compressor for air blowers and bank blowers, and 2 is a main air compressor for air blowers and bank blowers.
N-〇FF valve, 3 is an air receiver tank, and 4 is 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. A pressure gauge 14 and a slurry supply valve 10 are attached to the slurry supply pipe 9.
A backflow slurry discharge pipe 16 is disposed between the through hole 4C and the slurry supply valve 10, and the discharge pipe 16
A bank prose slurry discharge valve 13 is attached to the pump. Further, a bank blow valve 12 is attached to the back blow pipe 11.

On the side of each filter plate 4a, air blow pipes 18.18' and drain pipes 19.19' are provided at alternately opposing positions, and these pipes 18.18'19.19' It leads to room 4b. The air blow pipes 18, 18' communicate with the air receiver tank 3 via air blow valves 5 and 6 attached to each filter plate 4a side and an air blow source valve 15 attached to the air supply side. Drain pipe 19.19'
Drain valves 7 and 8 and interstitial water flow rate detectors 17 and 17' are attached to each filter plate 4a side.

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

■ The slurry supply valve 10 is opened and the slurry is passed through the through hole 4 through the slurry supply pipe 9 until the pressure gauge 14 detects a predetermined pressure.
Slurry is supplied into each filter chamber 4b of the filter press 4 from C. At this time, the air blow valves 5 and 6 are kept closed, and the drain valve 7.8 is kept open.

■ At the same time as the pressure gauge 14 detects a predetermined pressure, the drain valve 7 is closed, and the air blow valve 5 and air blow main valve 1 are closed.
5 and drain valve 8 are opened, the compressed air in the air receiver 3 is supplied from the air blow pipe 18 into the slurry in each filter chamber 4b, and is passed between the solid particles of the slurry, thereby filling the gaps between the particles. Water (filtered air) and air are discharged from the drain pipe 19' outside the system.

■ When the flow rate of pore water reaches almost 0 and the flow rate detector 17' no longer detects the flow rate, close the drain valve 8 and the air blower.
The valve 5 is closed, the air blow valve 6 and the drain valve 7 of the adjacent filter plates 4a located opposite to these are opened, and compressed air is supplied from the air blow pipe 18 into the slurry in each filter chamber 4b. do.

(2) When the flow rate of the interstitial water reaches approximately 0 and the flow rate detector 17 no longer detects the flow rate, the air blow valve 6, drain valve 7, and air blow source valve 15 are closed.

■ Open the bank plow slurry discharge valve 13 and back blow valve 12, supply compressed air from the back blow pipe 11, and remove undehydrated slurry remaining in the through hole 4c from the back plow slurry discharge pipe 16. discharge to.

Each of the steps (1) to (4) described above is controlled by a sequencer, and the supply of slurry to the filter press, the supply of compressed air to each filter chamber, the opening and closing of each valve, etc. are automatically performed.

〔Effect of the invention〕

■ A filtrate flow rate measuring means is installed 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 to perform air blowing, thereby ensuring uniform and good dewatering of each filter chamber. be able to. 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 supply pipe on the side, pressure is evenly applied to the inside of the cake in the filter chamber, improving dehydration ability.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram showing an embodiment of the present invention. 1... Air compressor, 2... Main ○N-0
FF 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 tube, 12
...Back blow valve, 13... Back blow slurry discharge valve, 14... Pressure gauge, 15
... Air blow main valve, 16... Backpros slurry discharge pipe, 17.17'... Pore water flow rate detector, 18.18'... Air blow pipe, 19.19'...Drain pipe

Claims (2)

[Claims] (1) Using 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 penetrates the filter plate and communicates each filter chamber, In a dewatering method using a filter press in which slurry is supplied into each filter chamber through a through hole and then compressed air is supplied into the slurry in each filter chamber to dehydrate the slurry, a filter plate is provided on the side of each filter plate alternately. A compressed air supply pipe and a filtrate discharge pipe having a filtrate flow rate measuring means were provided at opposing positions, and compressed air was supplied to one of the two supply pipes of the adjacent filter plates until the flow rate of the filtrate reached almost 0. After that, compressed air is supplied to the other supply pipe on the opposite side, and these processes are repeated in sequence. (2) The filter press according to claim 1, characterized in that after dewatering the slurry, compressed air is supplied to the through holes to discharge the undehydrated slurry in the through holes to the outside of the filter chamber. Dehydration method.