JPH08150306A - Method for washing filter press filter cloth for cement base waste water - Google Patents

Abstract

PURPOSE: To shorten jet washing to reduce wear of filter cloth due to high pressure jetting by, after washing of a filter cloth after dehydration in a filter press is finished, closing a drain line of a filter plate and leaving the device as it is in a state in which a filter chamber is filled with fresh water until the next dehydration starts. CONSTITUTION: After a day's dehydration is finished and cake 18 is made to fall, filter plates 1, ... are closely adhered to each other to form one body. At this time, a discharge valve 5 remains open and a valve 6 is opened, and remaining sludge in a sludge tank 4 and remaining liquid in a pump 8 and a line are returned to a storing tank 7 to perform washing. Next, the filter plates 1, ... are opened to wash the surface of filter cloths 2, .... After that, the filter plates 1, ... are made one body again, and a drain valve 10 is closed, and also a fresh water valve 17 is opened to make all filter chambers 14, ...filled to capacity. Then, water supply is stopped to leave the device as it is until next dehydration. In this state, the ion content of sludge water permeated in filter cloth fiber is eluted into fresh water to prevent insoluble matter to be deposited.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cleaning a filter cloth of a cement-type wastewater filter cloth fixed type filter press.

[0002]

2. Description of the Related Art A conventional method for cleaning a filter cloth of a fixed filter cloth filter press is to wash the surface of a filter cloth of a filter plate by a high pressure jet nozzle, manually or by an automatic washing machine, as washing with water. As the rinsing and washing, there are adopted a method in which fresh water is pressure-fed for washing and filtering, or a so-called back washing method in which water is passed from the side of the filtration channel of the filter plate. In either method, the washing water is a method for washing the filter cloth in a running water state for a short time.

[0003]

If the dehydrated cake can be made into a strong hard cake, it can be effectively used as a resource. For that purpose, it is necessary to immediately dehydrate the wash drainage and return concrete without leaving them as they are generated. Since the admixture is mixed in the fresh concrete, the shorter the elapsed time after the fresh concrete is mixed, the poorer the dehydration property is, and the activated cement permeates into the fibers of the filter cloth, and the high-pressure water jet cleaning is performed every day. Even if it is carried out, if the number of days overlaps, a clogging phenomenon will occur, the dehydration efficiency will decrease each day, and the number of days to replace the filter cloth will also decrease.

In view of the above points, the present invention was invented for the purpose of significantly reducing working hours by providing an effect that cannot be achieved by conventional filter cloth washing by a method that requires no equipment cost. Is.

[0005]

[Means for Solving the Problems] This is a washing step to be added after the dewatering in a filter press is finished and the washing of a filter cloth by a conventional method is completed. And the drain valve is provided below the collecting pipe. The movable plate presses the filter plate to form an integral unit, the drain valve is closed, and the filter chamber is left as it is until the next dehydration start time while being filled with fresh water.

[0006]

The present invention has been made by paying attention to the cause of the activated cement causing the clogging of the filter cloth and the process thereof, that is, as in the conventional case, the filter cloth can be removed from both the front and back sides by high pressure water. Even if it is directly washed, a part of the cement that permeates the inside of the filter cloth fiber remains. The cement component in the immediate dehydration is an activated cement that has not completed the hydration reaction, and the cement component that has penetrated into the fiber of the filter cloth is solidified inside the fiber by the drying of the filter cloth, and the filter cloth fiber _{Cao-Sio 2} -H 2 o based compound is adhered to.
Even if the residual amount is very small, it accumulates over days, and Cao-
The Sio ₂ -H ₂ o component is deposited in the fiber and becomes extremely difficult to drop, and eventually the filter cloth becomes clogged, resulting in a reduction in dewatering efficiency.

[0007] Since it has been understood that such a mechanism is provided, it is necessary to prevent the cement component that permeates the inside of the filter cloth fiber and the cement component that partially remains on the back surface of the filter cloth from solidifying. the cloth without drying, by further immersion in constantly Shimizu, ion content was completely eluted in Shimizu, wherein, the next time prevents Cao-Sio 2 _-H 2 _o compound is deposited on the fiber When the dehydration process starts, the compound is released to the outside of the filter cloth by the dehydration pressure.

[0008]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a structural view of the present invention, and FIG. 2 is a side sectional view of a filter plate.
In the structure as one embodiment of the present invention, a collecting pipe 9 is laid down and a drain valve 10 is provided below each filter plate, and a flexible pipe 12 is provided above the collecting pipe from a drain port 11 of the filter plate. A connection port 13 for connection is provided. A fresh water pipe 16 above the sludge tank 4
Is provided to control the supply of fresh water.

The method of cleaning the filter cloth according to the present embodiment will be described including the plain cleaning and the water spray cleaning described in the prior art.
After one day of dehydration is completed and the last cake 18 is dropped, the movable plates 3 again press the filter plates 1 to bring the adjacent filter plates into close contact with each other to form a pair. The valve 6 is opened while the discharge valve 5 of the sludge tank 4 remains open. The residual sludge in the sludge tank and the residual liquid in the pump 8 and its pipeline are returned to the storage tank 7. After closing the valve 6, the fresh water valve 17 is opened to supply a predetermined amount of water to the sludge tank 4. While the drain valve 10 is open, the pump 8 is operated to wash and discharge the filtration chamber surface including the inside of the pump casing and the pipeline. The pump 8 is stopped after a predetermined time has elapsed. Up to this point, it is a plain wash.

Next, the filter plate is opened, and the surface of the filter cloth is washed automatically or manually with high-pressure jet water. Up to the above process, the conventional cleaning method is used, and when the process is completed, the present invention is carried out.

The filter plates are pressed again by the movable plate to be integrated, and the drain valve 10 of the collecting pipe is closed. The fresh water valve 17 is opened to fill the entire filtration chamber through the sludge tank to stop the water supply. Leave it as it is until the next dehydration. When in this standing state, the ionic components of the sludge water permeating into the filter cloth fiber are eluted into the fresh water, and the insoluble matter is prevented from being deposited in the filter cloth fiber. After opening the drain valve 10 to drain water, the dehydration process of the day starts.

Other than the structure of the above-mentioned embodiment, as long as it has a structure in which fresh water can be freely filled in the filter chamber and the pipe line in the filter plate and drained, the filter cloth of the present invention can be used. Cleaning method is applied.

[0013]

[Effect] As is clear from the above detailed description, it is difficult to prevent clogging by dehydrating activated cement sludge with high-pressure jet water on the surface of the filter cloth and jet water from the back surface as in the conventional case. Is. By using the cleaning method of the present invention together, the conventional spray cleaning is greatly shortened, and therefore the wear of the filter cloth due to the high pressure spray is reduced. The remarkable effect is to prevent the deterioration of the dehydration efficiency by reducing the clogging, and the filter cloth replacement days can be greatly extended. Particularly in the case of manual filter cloth washing, shortening the washing time greatly contributes to the reduction of labor costs. It has the above effects.

[Brief description of drawings]

FIG. 1 is a structural diagram of an embodiment of the present invention.

FIG. 2 is a sectional side view of a filter plate.

[Explanation of symbols]

 1 Filter Plate 2 Filter Cloth 3 Movable Plate 4 Sludge Tank 5 Discharge Valve 6 Valve 7 Reservoir 8 Pump 9 Collecting Pipe 10 Drain Valve 11 Drainage Port 12 Flexible Pipe 13 Connection Port 14 Filtration Chamber 15 Filtration Channel 16 Clean Water Pipe 17 Fresh Water Valve 18 cakes

Claims (1)

[Claims] 1. A plurality of filter plates are vertically arranged side by side, a filter chamber is formed between each filter plate, a filter cloth is attached to each filter plate, and each filter plate and the filter cloth are penetrated to each other. A through-hole that connects the filter chamber is formed, and in a filter press for dewatering by pressing the stock solution into the filter chamber, after the washing of the filter cloth after the dehydration is finished, the drain pipe line of the filter plate is closed, Leave fresh water in the filtration chamber until the next dehydration starts,
Cement-based wastewater filter press filter cloth washing method characterized by performing a soaking and placing method.