JPH0249766B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of operating a filter press,
Specifically, in a filter press operation method that consists of repeating a series of operations of forming a chamber, pressurizing excessive dehydration, cleaning the inside of the stock solution supply section, and discharging the dehydrated cake from the opening of the chamber as one process, cleaning the inside of the stock solution supply section ( The present invention relates to a method for processing a cleaning supply fluid (hereinafter referred to as cleaning fluid) containing a pressurized liquid and drying gas used for header blowing (hereinafter referred to as header blow).

Conventionally, the sealed raw solution is squeezed by the pressurized over-dehydration operation of a filter press, and the liquid is squeezed out of the cloth and discharged, forming a dehydrated cake in the chamber. Because the squeezing force is often insufficient, part of the raw solution does not become a dehydrated cake, and is not considered a so-called final cake, which has an extremely high moisture content compared to the formed cake. It may stick to the skin and remain in those areas even after the dehydrated cake discharge operation. If the process is repeated with this residue left unattended, the inside of the stock solution supply section of the dehydrator will become constricted, reducing the effectiveness of pushing the stock solution during subsequent supply of the stock solution, or clogging some of the fabrics, resulting in This reduces local hypersensitivity, leading to a vicious cycle in which as the process is repeated, more and more final cakes are produced. Therefore, by performing a header blow operation without opening the frame after pressurized over-dehydration and supplying cleaning fluid under pressure, it is possible to clean the main parts and further dehumidify before moving on to the next operation. I have to.

This prior art header blowing operation has various problems, and these problems will be explained with reference to FIG.

A plurality of plates 4 between the fixed end plate 1 and the movable end plate 2
are horizontally and movably supported, a cloth 5 is stretched on the surface of each plate 4, and these plates 4 are connected to the movable end plate 2.
A fluid pressure cylinder 3 whose tip is fixed to the end face of
is tightened between the end plates 1 and 2 to form a chamber, over-operation is performed, and then the space between each plate is opened to remove the formed cake.
For over-operation, after tightening each plate, close the valve 14 and valves 16 and 17, open the valve 12, and let the stock solution flow through the piping 11 and the flexible tube 10 to form a straight pipe opening in both end plates and each plate. Passing through the road (hereinafter referred to as header),
Flowing into each chamber, the solid particles in the concentrate form a cake on the surface, and the liquid exits through the cloth through the openings 9 at the bottom of the plate. Valve 1 at the end of the
2 is closed, valves 14 and 17 are opened to supply the liquid into the header, and after a cleaning operation is performed to remove the stock solution remaining in the header, valve 17 is closed and valve 16 is opened to introduce air to the header. Remove fresh water in the header,
After dehumidification, a series of header blow operations are performed to close valve 14. The air during this header blowing is introduced into the air separation tank 19 from the pipe 3 and separated into air and water.The air is released into the atmosphere through the pipe 20 and the water is released into the atmosphere through the pipe 21, and the water is temporarily sent to the water tank. After being discharged, the water is sent from there by a pump 23 to a sewage treatment facility for reprocessing. However, general-purpose air separation tanks that are economical generally have low separation performance, so that sewage mist is mixed into the discharged air, often contaminating the surrounding area every time this header blow operation is performed.
Furthermore, since the amount of cleaning fluid is controlled by changing the opening and closing time of the valve, the consumption amount changes depending on the pressure inside these supply pipes, which sometimes fluctuates, and as a result, cleaning fluid tends to be wasted. be.

The present invention was devised in view of the above-mentioned prior art, and aims to eliminate the above-mentioned drawbacks of header blow and its water removal operation, and to reuse the energy of used cleaning fluid. That is.

An embodiment of the method of the present invention will be explained with reference to FIG.

In the present invention, after the above-mentioned overoperation is completed, the valve 12 is closed, the valve 14 is opened, and the pressure inside the filter press, etc. is released, and then the valve 17 is further opened to introduce the cleaning liquid into the filter press, and the inside of the header etc. The remaining sludge is washed away and this liquid is poured into a sealed tank 24.
When the liquid level in the sealed tank 24 reaches a certain level using the liquid level gauge 25, the valve 17 is closed to stop the supply of cleaning liquid, and the valve 16 is opened to send compressed gas for cleaning to the filter. The remaining cleaning liquid is introduced into the closed tank 24 through the press, and after the pressure gauge 26 in the tank 24 measures a constant pressure, the valves 14 and 16 are closed. The liquid and gas generated by this operation, including the residue of the final cake, are temporarily stored after this operation is completed, and the valve 14 is opened at the beginning of the over-operation of the next step, and the closed tank 24 is stored. This method utilizes the pressure within the tank 24 to return the stored material to the filter press for overtreatment. When the entire amount of the liquid containing the above-mentioned residue in the closed tank 24 is discharged and the pressure gauge 26 in the tank 24 drops below the pressure before introducing the cleaning fluid, the valve 14 is closed and the valve 12 is opened to drain the undiluted solution. Do the same thing. It should be noted that these series of operations can be fully automated by controlling each measuring instrument using an automatic control instrument such as a contact point.

As mentioned above, the method of the present invention includes the closed tank 24
By installing a single tank, the air separation tank, drainage tank, and drainage pump that were conventionally used for the treatment operation are no longer necessary, and the pressure energy applied to the cleaning fluid eliminates the need for additional equipment and energy. It has the advantage that there is no wastage of cleaning fluid and no secondary contamination such as generation of sewage mist.

[Brief explanation of drawings]

Figure 1 shows a conventional header cleaning device;
The figure is an explanatory diagram of a header cleaning device according to an embodiment of the present invention. 1, 2... End plate, 3... Fluid pressure cylinder, 4...
...board, 5...cloth, 6,7,8...header,
9...Liquid outlet, 10...Flexible tube, 12,1
4, 16, 17... Valve, 24... Sealed tank, 25...
...Liquid level gauge, 26...Pressure gauge.

Claims (1)

[Scope of Claims] 1. After the cleaning fluid is supplied to the stock solution supply section, it is gradually introduced into a closed tank to become a reservoir under pressure, and this reservoir is used during the initial operation of the next pressurized over-dehydration process. A method for processing a cleaning liquid for a filter press, characterized in that the cleaning liquid is returned to a chamber for treatment according to its retained pressure. 2. In the method for treating a cleaning liquid according to claim 1, the operation of returning the stored material to the chamber is performed by:
A method for treating a cleaning liquid for a filter press, which is carried out by controlling the amount and pressure of the stored material.