JPH0521603B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a closed type device suitable for filtering various liquids and overconcentrating generated muddy substances in the treatment of clean water, industrial water, sewage, human waste, and industrial wastewater. This is related to the

[Conventional technology]

Conventionally, in a bag filter type filter device, a cylindrical filter element with a cloth, metal, etc. surface formed around the outer periphery of a support member and a cylindrical filter element suspended inside a closed tank, in which a liquid is guided inside and taken out, Filtration was carried out by reducing the pressure on the liquid side using a vacuum pump or the like, or by pressurizing various liquids or muddy substances (hereinafter collectively referred to as undiluted liquid) into a closed tank.

As this process continues, if the turbidity in the stock solution adheres to the surface of the filter element and the water flow resistance on the surface increases, stop the filtration and remove the turbidity from the filter element and clean it. was going there.

To remove and clean turbidity from the filter element, a backwashing method is used in which the entire amount of untreated stock solution remaining in the tank is once drawn out of the tank, and then cleaning water or compressed air is flowed back from inside the filter element. It was getting worse.

[Problem to be solved by the invention]

However, in the conventional bag filter type filtration device, before backwashing the filter element, it is necessary to extract the entire amount of untreated stock solution remaining in the tank out of the tank and return it to the stock solution storage tank, etc. When over-restarting after cleaning, it was necessary to refill the empty tank with stock solution, which caused problems such as complicated operations, longer sloppy time, and reduced processing capacity. It was hot too.

The present invention performs filtration by reducing pressure without using a vacuum pump or the like, and also adds filtration by pressurizing the stock solution at the same time to improve the filtering efficiency, and also makes it possible to remove untreated stock solution from the tank when backwashing the filter element. It is an object of the present invention to provide a processing device that requires almost no processing, can shorten the time for one cycle, and can increase processing capacity.

[Means to solve the problem]

In the present invention, the interior of the sealed tank 1 is arranged in order from the top by partition plates 2 and 3: a vacuum forming chamber 4, a liquid chamber 5, and a liquid chamber 6.
The vacuum forming chamber 4 is equipped with a water level gauge 7 for detecting the water level in the vacuum forming chamber 4, and an air vent valve 8 is connected thereto, and an opening/closing valve is provided between the vacuum forming chamber 4 and the lower discharge pit 11. The vacuum forming chamber 4 and the upper part of the liquid chamber 5 are communicated with the atmosphere through an atmospheric leg forming pipe 10 equipped with a communication valve 12; The opening end in the vacuum forming chamber 4 is set at a position above the set high water level in the vacuum forming chamber 4; a compressed air inlet valve 14 is connected to the liquid chamber 5, and the liquid chamber 5 is connected to the atmospheric leg forming pipe 1.
Liquid pit 1 below the atmospheric leg formed by 0
A liquid outflow pipe 16 equipped with a liquid outflow valve 15 at 7 communicates with the atmosphere in a shut off manner; a cylindrical filter element 1 is provided with a support on the liquid side in the filter chamber 6;
8 is installed to communicate the liquid side of the filter element 18 to the liquid chamber 5, and the over chamber 6 and the vacuum forming chamber 4 are communicated through a bypass pipe 20 equipped with a bypass valve 19, and the raw liquid flows into the over chamber 6. A valve 21 and a drain valve 22 are connected to each other.

[Effect]

First, the stock solution is supplied into the overchamber 6 to fill the overchamber 6, and then continues to be supplied through the bypass pipe 20 into the upper vacuum forming chamber 4 until a certain water level is reached. Next, a part of the stock solution in the vacuum forming chamber 4 flows out from the atmospheric leg forming pipe 10 to the discharge pit 11 to operate the atmospheric leg forming pipe 10 to form an atmospheric leg, and the vacuum forming chamber 4 is -hm, this negative pressure will simultaneously reach the liquid chamber 5 via the communication pipe 13, reducing the pressure on the liquid side of the filter element 18, and reducing the pressure on the liquid side of the filter element 18.
The stock solution in the passage chamber 6 is passed through due to the pressure difference between the inside and outside of the chamber 8. At this time, if the stock solution is continued to be supplied to the filtering chamber 6, the pressure difference between the inside and outside of the filter element 18 will become even larger, and the filtering will be carried out more efficiently.

After continuing such filtration, in order to peel off and backwash the cake trapped on the surface of the filter element 18, compressed air is slowly guided into the filtration chamber 6 from the compressed air inlet valve 14, and the cake is removed from the filtration chamber 6. After flowing the stock solution remaining in the vacuum forming chamber 6 from the bypass pipe 20 to the vacuum forming chamber 4 so as to reach the set HWL, backflow from the bypass pipe 20 is prevented, and the
The stock solution inside is drained from the drain valve 22 to the outside of the tank, the filter element 18 is blown with compressed air, the cake is peeled off, and the cake is discharged from the drain valve 22 to the outside of the tank.

After this cake discharge is completed, the supply of the stock solution for the filtration is restarted again.

〔Example〕

An embodiment of the present invention will be described with reference to the drawings. The inside of the sealed tank 1 is divided into a vacuum forming chamber 4, a vacuum forming chamber 4,
A liquid chamber 5 and a liquid chamber 6 are divided and formed.

The vacuum forming chamber 4 is equipped with a water level gauge 7 for detecting the water level in the chamber 4, and is connected to an air vent valve 8. One end is opened for connection, and the other end of the atmospheric leg forming pipe 10 is sealed with water in the discharge pit 11 and opened.

Furthermore, the upper part of the vacuum forming chamber 4 and the liquid chamber 5 are
The communication pipe 13 penetrates through the upper partition plate 2 and is equipped with a communication valve 12, and the open end of the communication pipe 13 in the vacuum forming chamber 4 is connected to a high water level set in the vacuum forming chamber 4.
It is positioned above HWL.

A compressed air inflow valve 14 is connected to the liquid chamber 5, and one end of a liquid outflow pipe 16 equipped with a liquid outflow valve 15 is connected and opened to the liquid chamber 5, and the other end of this liquid outflow pipe 16 is connected to the atmosphere. The opening is sealed with water in a liquid pit 17 located below the atmospheric leg formed by the leg forming tube 10.

Inside the filter chamber 6, a plurality of cylindrical filter elements 18 that form a surface on the outer periphery of the support member and guide the liquid inside are vertically disposed on the lower partition plate 3, so that the inside of the filter element 18 is connected to the filter chamber 5. communicated with
The overchamber 6 and the vacuum forming chamber 4 are communicated with each other through a bypass pipe 20 equipped with a bypass valve 19.
A stock solution inflow valve 21 and a drain valve 22 are connected to the undiluted solution inlet valve 21 and the drain valve 22 . Note that it is preferable that the support member for the filter element 18 be made of a flexible member such as a coil spring.

In the figure, 23 indicates a pump for supplying the stock solution connected to the stock solution inflow valve 21.

The operating procedure for the above device is as follows.

1 Supply of stock solution (see Figure 1) (1) Stock solution inflow valve 21, air vent valve 8, bypass valve 1
9. Open the liquid outflow valve 15 and the communication valve 12, and close the other valves.

(2) After operating the pump 23 and supplying the stock solution to the overchamber 6 and filling the overchamber 6, the stock solution is further supplied to the vacuum forming chamber 4 via the bypass pipe 20. .

(3) The stock solution in the vacuum forming chamber 4 is at a certain level.
When the MWL is reached, the air vent valve 8 and the bypass valve 19 are closed.

(4) At this point, the pump 23 may be operated continuously or may be stopped.

2 Generation of vacuum (see Figure 2) (1) When the on-off valve 9 is opened, the stock solution in the vacuum forming chamber 4 flows out from the atmospheric leg forming pipe 10 to the discharge pit 11, and the water level in the vacuum forming chamber 4 decreases. descend, e.g.
An atmospheric leg of hm is formed from the water level of the discharge pit 11 at the BWL position. That is, the inside of the vacuum forming chamber 4 becomes a vacuum of -hm in the water column (assuming the pressure is -Ph).

(2) At this time, since the vacuum forming chamber 4 and the overchamber 5 are communicated through the communication pipe 13, the inside of the liquid chamber 5 also becomes a vacuum of -hm (-Ph), and the liquid pit 1
Similarly, the atmospheric leg of hm is formed from the water level of 7.

(3) As a result, the stock solution in the liquid chamber 6 is vacuum filtered through the filter element 18 by the negative pressure of -Ph, and the liquid passes through the liquid chamber 6 into the liquid outlet pipe 16.
The liquid flows out from the liquid into the liquid pit 17. At this time, the height Hm from the open end of the liquid outflow pipe 16 in the liquid chamber 5 to the water level of the liquid pit 17 is H≧
It is h.

(4) Note that when the pump 23 is operating at pressure P, the differential pressure ΔP between the inside and outside of the filter element 18 is passed at a pressure of ΔP=P−(−Ph)=P+Ph.

3. Overflow completion (see Figure 3) (1) When the suspended matter in the stock solution is captured in the form of a cake on the surface of the filter element 18 and a predetermined overresistance is exhibited, the on-off valve 9, the communication valve 12, and the liquid outflow valve are closed. 15 is closed, and if the pump 23 is operating, it is stopped and the stock solution inflow valve 21 is closed.

(2) Next, open the compressed air inlet valve 14 and air vent valve 8, and open the bypass valve 19 while slowly allowing compressed air to flow in. Then, the remaining stock solution in the overchamber 6 flows into the vacuum forming chamber 4 through the bypass pipe 20 by the compressed air, and when the water level in the vacuum forming chamber 4 reaches a predetermined HWL, the on-off valve 9 is opened. The undiluted solution flows out into the sludge pit 11 by opening and closing, and the water level in the vacuum forming chamber 4 is adjusted to maintain HWL, and the water level in the overchamber 6 is adjusted.
The on-off valve 9 and the bypass valve 19 are closed when the LWL is reached.

(3) Next, open the drain valve 22, blow the filter element 18 with compressed air from the compressed air inflow valve 14, peel off the cake captured by the filter element 18, and discharge it from the drain valve 22 to the outside of the tank. do. In this way, the cake is peeled off from the filter element 18 by air blowing, but if a telescopic support such as a coil spring is used as the support for the filter element 18, the cake can be peeled off more effectively.

4. Restart (see Figure 4) (1) Close the drain valve 22, open the bypass valve 19, and guide the stock solution in the vacuum forming chamber 4 into the excess chamber 6 under natural flow. At this time, it is preferable to leave the communication valve 12 open in order to vent air from the vacuum forming chamber 4.

(2) When the overchamber 6 is filled with the stock solution or the water level in the vacuum forming chamber 4 reaches LWL,
Bypass valve 19 is closed. (LWL needs to be above the upper end of the atmospheric leg formation tube 10) (3) Next, operate the pump 23 and return to the first stock solution supply step.

〔Effect of the invention〕

As described above, the filtration device of the present invention has a compact structure and uses an atmospheric leg to perform depressurization without using a vacuum pump, etc., and can also simultaneously pressurize undiluted solution, thereby improving the filtration efficiency. In addition, there is almost no need to remove the untreated stock solution during peeling off the cake trapped in the filter element and backwashing, making it possible to shorten one cycle time, increase processing capacity, and facilitate automation. It is possible.

[Brief explanation of drawings]

The drawings are structural explanatory diagrams showing one embodiment of the present invention.
1 to 4 show an example of the order of operations. DESCRIPTION OF SYMBOLS 1... Sealed tank, 2... Upper partition plate, 3... Lower partition plate, 4... Vacuum forming chamber, 5... Liquid chamber, 6...
...Overchamber, 7...Water level gauge, 8...Air vent valve, 9...
...Opening/closing valve, 10... Atmospheric leg forming pipe, 11... Discharge pit, 12... Communication valve, 13... Communication pipe, 14
... Compressed air inflow valve, 15 ... Liquid outflow valve, 16
...Liquid outflow pipe, 17...Liquid pit, 18...
Filter element, 19...Bypass valve, 20
... Bypass pipe, 21 ... Raw solution inflow valve, 22 ...
Drain valve, 23...pump.

Claims (1)

[Claims] 1 The inside of the sealed tank 1 is divided into a vacuum forming chamber 4, a liquid chamber 5, and a liquid chamber 6 in order from the top by partition plates 2 and 3; the water level in the vacuum forming chamber 4 is detected in the vacuum forming chamber 4. Equipped with a water level gauge 7, an air vent valve 8 is connected, and the vacuum forming chamber 4 and the lower discharge pit 11 are communicated with the atmosphere in a state that can be shut off through an atmospheric leg forming pipe 10 equipped with an on-off valve 9; A communication pipe 13 with a valve 12 communicating between the formation chamber 4 and the upper part of the liquid chamber 5
The opening end of the communication pipe 13 in the vacuum forming chamber 4 is set at a position above the set high water level in the vacuum forming chamber 4; the compressed air inflow valve 14 is connected to the liquid chamber 5, and 5 is communicated with the atmosphere in a shut off manner through a liquid outflow pipe 16 equipped with a liquid outflow valve 15 to a liquid pit 17 located below the atmospheric leg formed by the atmospheric leg forming pipe 10; A cylindrical filter element 18 with a support provided on the side is provided, and the liquid side of the filter element 18 is connected to the liquid chamber 5.
The overchamber 6 and the vacuum forming chamber 4 are connected to each other through a bypass pipe 20 equipped with a bypass valve 19, and the overchamber 6 is connected to an undiluted solution inflow valve 21 and a drain valve 22.
connected;