JPS6115711A - Water draining method of diaphragm in filter press - Google Patents

Abstract

PURPOSE:To make it possible to perfectly discharge pressurized water in a diaphragm, by injecting compressed air into the diaphragm in a filter press prior to injecting pressurized water. CONSTITUTION:After sludge is introduced into a filter chamber under pressure and dehydrated, compressed air A with pressure of 3-5kg/cm<2> is injected into a diaphragm from the injection port 2 of pressurized water to inflate the diaphragm and the sludge introduced under pressure and dehydrated is pressurized and dehydrated in the filter chamber. Subsequently, pressurized water is injected in the diaphragm under pressure of 10-20kg/cm<2> and sludge is further pressurized and dehydrated. At this time, previously injected compressed air A is present in the diaphragm in a state compressed by pressurized water. When pressurized water is drained after the completion of pressurization, the drain port of pressurized water is opened to forcibly discharge pressurized water by compressed air.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a method for draining water from a diaphragm in a filter press with a diaphragm for squeezing. That is, the present invention relates to an effective method for draining high-pressure water within a diaphragm after completion of squeezing.

``Conventional technology'' The conventional method for removing pressurized water from the diaphragm in a filter press with a squeezing device is to drain it naturally from the bottom of the diaphragm, then inject high-pressure air from the top, and then adsorb it with a vacuum pump. is common.

This conventional method takes time for natural drainage and requires air supply to drain the residual water, but since the diaphragm used in the filter press is flat, the air supply is distributed throughout the filter press. Otherwise, the water may not drain completely due to a short circuit to the drain outlet. This state is shown in FIGS. 1 and 2.

"Problems to be Solved by the Invention" A filter press is a machine that operates in a batch manner, and the draining of the compressed water after the above-mentioned compression and the supply of air to the diaphragm are carried out for filtration and dehydration, which is the purpose of the operation of the filter press. does not contribute at all.

In other words, the longer it takes for compressed water to drain, the lower the machine operation efficiency becomes. Conventional air supply operations are designed to speed up drainage, but as mentioned above, short circuits, etc. In reality, complete drainage is not possible.

``Means to Solve the Problem'' Therefore, this invention, when draining compressed water, discharges the air supply from the drain sump to the diaphragm after natural drainage, which has been a problem in the past, and supplies pressurized water to the diaphragm. Before injection, compressed air 'XA' is sent into the diaphragm. In other words, the pressure line air sent into the diaphragm is not used to discharge the water inside, but is used to pressurize the sludge in the previous stage of compression. In addition to being used for filtration and dehydration, the compressed water inside the diaphragm can be completely discharged using the introduced air.

Hereinafter, the present invention will be described in detail with reference to the attached drawings. As shown in the drawings, sludge, etc. is injected and dehydrated into the Okinouchi chamber formed between a large number of parallel p-boards 1... The cake is pressed and dehydrated using a diaphragm installed on one side of the filter chamber.
The pressure path air A of ~5~ is injected from the pressure water inlet 2, and then compressed water is injected to compress the cake, and then the compressed water is drained.

1. As mentioned above, the compressed air sent to the diaphragm before injection of compressed water expands the diaphragm, pressurizes the sludge that has been pressurized into the overflow chamber (not shown) on either side of the diaphragm, and Dehydrate this. The sludge is then further squeezed and dewatered into a cake by squeeze water (usually 10%-20 vI) injected into the diaphragm. At this time, the previously injected compressed air is compressed by the compressed water and exists within the diaphragm.

When the compressed water is discharged after the completion of the compression as described above, the compressed water is forced out by the compressed air A by opening the drain port 2 of the compressed water. This situation −
In contrast to the conventional methods shown in FIGS. 2(a) and 2(b), the method according to the present invention for squeezing a cake using the diaphragm has a method in which the cake is squeezed over the entire area at the upper part of the diaphragm as shown in the figure. The trapped compressed air pushes down the compressed water over the entire surface, so it can be discharged without leaving any compressed water behind, and can be discharged in a short time. Note that the above explanation has only explained the main part of the method according to the present invention, but
The actual filtration and dehydration process in a filter press is performed in the following steps.

Conventional method Method according to the present invention (1) Dewatering by injecting sludge into the furnace chamber (1) Same as on the left (3) By diaphragm (3) Squeezing by feeding into the diaphragm (10 to 20
Air (3~5~)~) (3) Clean the sludge in the supply channel (8) Sweep and squeeze with diaphragm (10~20~)
) (4) Inside the diaphragm (4) Sweeping the sludge in the supply channel with natural drainage using water from the ditch (5) Inside the diaphragm (6) Draining the air supply and pressurized water to drain the inside of the diaphragm (Enclose (6)
Vacuum suction (Diamond (6) same left flamm return) ``Effect'' As is clear from the above explanation, the greatest feature of this invention is that in a filter press, the pressure water in the diaphragm is discharged and the pressure water is removed for the next compression. In preparing for Unlike the conventional air blown into the diaphragm to discharge pressurized water, this compressed air A expands the diaphragm and contributes to filtration and dehydration, and also contributes to filtration and dehydration. is a device that acts uniformly on the entire compressed water inside the diaphragm and can discharge all of it, shortening the time that does not contribute to filtration and greatly increasing dewatering efficiency. It is.

In addition, the air initially sealed in the diaphragm does not escape and is used for draining the compressed water, so during the compression by water compression, the compressed air A that is used at the beginning of the next compression can be stored. Therefore, the capacity of the compressor may be small,
In this respect as well, there is an advantage that the device can be made inexpensive.

[Brief explanation of drawings]

FIG. 1 is a schematic side view of a filter press according to the present invention, FIG. )
and (b) are front views of the same according to the present invention. Code explanation 1, 枦板 2. Inlet A Compressed air port

Claims (1)

[Claims] (1) In a filter press in which sludge or the like is dehydrated by pressurizing it into a filter chamber formed between a large number of parallel filter plates 1, the dehydrated cake is compressed and dehydrated using a diaphragm installed on one side of the filter chamber. , When squeezing the cake with the diaphragm, first, 3 to 5 kg/cm is applied inside the diaphragm.
A method for draining a diaphragm in a filter press, which comprises injecting compressed air A from the compressed water inlet 2, then injecting compressed water to compress the cake, and then draining the compressed water.