JPH0356763B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an improvement of a filtration dehydrator with a squeezing mechanism used for dewatering slurry.

[Prior art] Conventionally, Japanese Patent Publication No. 47639/1983 and Japanese Patent Application Laid-open No. 1983-47639
A filtration/dehydration machine with a squeezing mechanism for dewatering slurry is already known, as disclosed in Japanese Patent No. 42310 and the like.

These filtration/dehydration machines basically have a configuration as shown in FIG. That is, the filtration dehydrator shown in the figure has a pair of front and rear filter plates 1a, 1b.
Two filter cloths 2a, 2b are sandwiched between them, and a filter chamber 3 in which a slurry injection pipe 4 opens is provided between the filter cloths 2a, 2b, and the inner surface of one filter plate 1b and the filter cloth 2b are With the diaphragm 5 sandwiched between them, they are brought into contact with each other at the periphery, and the filtrate discharge pipes 6a, 6b are passed behind both filter cloths, and pressurized water is injected between the diaphragm 5 and the inner surface of the filter plate 1b. The pipe 7 is communicated.

When slurry is dehydrated using such a filtration dehydrator with a squeezing mechanism, the slurry injected from the slurry injection pipe 4 is filtered by the filter cloths 2a, 2b, but as the filtration progresses, the cake 8 is separated from the filter cloths 2a, 2b.
As the slurry is deposited on the inner surface of the filter chamber 3, a liquid slurry 9 remains in the center of the filter chamber 3, and since the slurry must pass through the cake, the thicker the cake 8 becomes, the more difficult it is to dehydrate the slurry.

[Problems to be Solved by the Invention] An object of the present invention is to enable rapid filtration of the slurry in the center of the filter chamber using an impressive device, thereby increasing the filtration speed per filter plate of a filtration dehydrator with a squeezing mechanism. There is a particular thing.

[Means for Solving the Problems] In order to achieve the above object, the filtration dehydrator of the present invention has a front filter cloth and a rear filter cloth, each of which has a pair of front and rear filter cloths stacked on top of each other, between a pair of front and rear filter plates. At the same time, a diaphragm is sandwiched between one of the filter plates and the filter cloth, and they are butted against each other at the periphery, and slurry injection pipes are opened between each of the two front and rear filter cloths. The front and rear filter cloths are fixed opposite each other so that each filtered rice can be opened, and a filtrate discharge pipe is communicated behind the front and rear filter cloths to connect the diaphragm and the filter plate. It is configured by communicating with a pressure water injection pipe.

[Function] When filtering slurry, the slurry is forced into both filter chambers from the slurry injection pipe, filtered by each filter cloth, and discharged from the filtrate discharge pipe. The filtrate flowing out during this period flows between the filter cloths, reaches the periphery of the filter cloth, passes through the filter cloth again, and is discharged from the filtrate discharge pipe. the result,
The cake is deposited on the inner surface of each filter cloth between the front filter cloth and the rear filter cloth, and the cake and slurry in the filter chamber are squeezed by injecting pressurized water from the pressure water injection pipe. The slurry is dehydrated.

Therefore, the slurry in the center of the filter chamber is filtered quickly, and the filtration rate per filter plate of the filter-dehydrator is increased.

[Examples] Examples of the present invention will be described in detail below.

The filtration dehydrator shown in FIGS. 1 and 2 has a pair of front and rear filter plates 11a, 11 substantially in the shape of a square plate.
b, and between them, a set of two front filter cloths 12a, 13a and a rear filter cloth 12b, 1 are provided.
At the same time, a diaphragm 14 with a stop plate 15 layered around the periphery is sandwiched between the filter cloth 13b and the filter plate 11b, and the diaphragm 14 is brought into contact with each other at the periphery. Between the front filter cloths 12a, 13a and the rear filter cloths 12b, 13 which are stacked on top of each other,
Between b, slurry injection pipes 17a and 1 are respectively provided.
The front filter cloths 12a, 13a and the rear filter cloths 12b, 13b are fixed opposite each other so that the filter chambers 16a, 16b can be opened, with filter chambers 16a, 16b having openings 7b interposed therebetween. Filter cloth filter plate 11
The filtrate discharge pipes 18a and 18b are communicated behind the filter cloths 13a and 13b located on the sides a and 11b, that is, between the filter cloth 13a and the front filter plate 11a and between the filter cloth 13b and the diaphragm 14, and the diaphragm 1
4 and the filter plate 11b are communicated with a pressure water injection pipe 19.

Note that the filtrate discharge pipe 18a is connected to the front filter plate 11a,
The filtrate discharge pipe 18b is connected to the diaphragm stop plate 15,
The pressure water injection pipe 19 is provided on the rear filter plate 11b.
In addition, in the figure, 20a and 20b are slurry injection pipes 1
The injection valves provided at 7a and 17b are shown.

When filtering slurry with the filtration dehydrator having the above configuration, the slurry to be filtered is transferred from the slurry injection pipes 17a, 17b to the filter chambers 16a, 16.
b (injection pressure 0.2 to 0.8 MPa), filter chamber 16
a and 16b are filled with slurry. This slurry is applied to the front filter cloths 12a, 13a and the rear filter cloth 12.
b, 13b, and the filtrate is passed through the filtrate discharge pipe 18.
It is discharged from a and 18b. In addition, the filtrate is filter cloth 1
2a and filter cloth 12b,
The filtrate flows between the back surfaces of the filter cloths 12a and 12b, that is, between the two filter cloths 12a and 12b. The back surfaces of these filter cloths 12a and 12b are in contact with each other, but since the cloths are in contact with each other, there are fine gaps between them. The filtrate passes through the gap, reaches the periphery of the filter cloth, passes through the front filter cloths 12a, 13a or the rear filter cloths 12b, 13b, and enters the filtrate discharge pipe 18.
It is discharged from a and 18b. As a result, the cake is formed between the front filter cloths 12a, 13a and on the rear filter cloth 12a.
It is deposited on the inner surface of each filter cloth between b and 13b.

After a suitable filtration time, the slurry injection valve 20
a and 20b are closed, and pressurized water (water pressure 1 to 2 MPa) is injected from the pressure water injection pipe 19. Along with this, the diaphragm expands, the cake and slurry in the filter chambers 16a and 16b are squeezed, and the slurry is dehydrated. When the slurry in the filter chambers 16a, 16b becomes a cake, the front and rear filter plates 11a, 11b are opened, and the front filter cloths 12a, 13a and the rear filter cloth 12 are removed.
The dewatering process is completed by peeling off the cake from b, 13b and discharging it, and washing the filter cloth.

[Effects of the Invention] In the conventional filtration dehydrator with a squeezing mechanism, as filtration progresses, the thickness of the cake increases, making it difficult to filtrate, leaving slurry in the center of the filtration chamber, resulting in a long dehydration time. However, in the filtration dehydrator of the present invention described above, since there is a filtrate flow gap between the front filter cloth and the rear filter cloth, the slurry in the center of the filter chamber is filtered quickly, and the filtration rate per filter plate is increased. can be raised.

[Brief explanation of drawings]

1 and 2 show embodiments of the present invention;
The figure is a horizontal cross-sectional view at the center of the slurry injection pipe.
FIG. 2 is a side view, and FIG. 3 is a horizontal sectional view of a conventional filtration/dehydrator. 11a...front filter plate, 11b...rear filter plate, 1
2a, 13a...front filter cloth, 12b, 13b...
Rear filter cloth, 14...Diaphragm, 16a, 16
b...Filter chamber, 17a, 17b...Slurry injection pipe, 18a, 18b...Filtrate discharge pipe, 19...Pressure water injection pipe.

Claims (1)

[Claims] 1. A pair of front filter cloth and rear filter cloth are sandwiched between a pair of front and rear filter plates, and at the same time, a diaphragm is sandwiched between one of the filter plates and the filter cloth, and the diaphragm is sandwiched at the periphery. The front and rear filter cloths are placed opposite each other so that each filter chamber can be opened by interposing a filter chamber into which a slurry injection pipe opens between two front filter cloths and between two rear filter cloths. A filtration dehydrator with a squeezing mechanism, characterized in that a filtrate discharge pipe is connected behind the front filter cloth and the rear filter cloth, and a pressurized water injection pipe is connected between the diaphragm and the filter plate.