JPS60137404A - Backwashing process for suspended filter - Google Patents

Abstract

PURPOSE:To enhance the effect of air for backwashing and to reduce the time for backwashing by stripping off sludge sticking to a filter by exerting a vibrational external force to the filter at the stage of backwashing in the liquid using air and dispersing the sludge into the liquid. CONSTITUTION:A pressure switch 16 is turned ON, solenoid valves 15, 19, 29 are closed by a controller 28, and solenoid valves 17, 18 are opened to start backwashing when a filter 3 is clogged and filtration pressure exceeds a specified value. Air 30 is blown from a port 6 for filtrate in a housing 2 filled with feed liquid 10 or filtrate 20, etc., thus, sludge in fine pores 3a is stripped off. An external force is exterted to the filter 3 by means of an oscillator 31 or an injecting nozzle 32, and the stripped sludge is dispersed into the liquid in the housing 2. Thereafter, the liquid in the housing 2 is fed to a settling tank 9 together with the sludge from an outlet 8 of the liquid.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD OF THE INVENTION The present invention relates to a method for backwashing a hanging type filter.

Filter to be cleaned In the present invention, a filter in the form of a multi-threaded thin vibrator is to be backwashed. This filter is molded as a hollow fiber porous membrane using polyvinyl alcohol, and its outer diameter is approximately 800 microns, and its inner diameter is approximately 400 microns.
The thickness of the filtration membrane is approximately 200 mm.
It is micron.

The filtration membrane is 0.2 to 0.0 mm along its axial direction.
Continuous fine pores of about 5 microns are evenly formed. These filters are housed inside the casing with their lower ends closed and bundled at their upper ends to form a precision filtration membrane within the casing. The filtration ability of this filter gradually decreases as filtration progresses due to clogging with adulterated substances. Therefore, it is necessary to clean the filter at an appropriate time.

Conventionally, filters have been cleaned by emptying the inside of the casing and backwashing with air or chemical solutions. However, during air backwashing, sludge and the like in the pores are not sufficiently peeled off and dispersed, so sufficient cleaning is not possible and the cleaning cycle is shortened.

However, when chemical cleaning is performed, the filtration ability of the filter is almost restored to its initial state. However, this type of chemical cleaning requires specialized chemical processing equipment.
Furthermore, since the cleaning time is long, the filtration work cannot be performed continuously. Under these circumstances, an effective cleaning method is desired for the filter to be cleaned.

OBJECTS OF THE INVENTION Accordingly, an object of the present invention is to enhance the effect of air backwashing and shorten the backwashing time without using a chemical solution.

Summary of the Invention Therefore, the present invention applies an external force to the filter during air backwashing.
Mainly by applying minute vibrations, suspended substances adhering to the micropores of the filter are removed in a short period of time. Such a vibratory external force is effective in releasing suspended substances from the micropores of the filter, but these free suspended substances are trapped between the bundled filters and are not exposed to the outside. I am in a state where it is difficult to get out. Therefore, in the present invention, a liquid such as an undiluted liquid, a filtrate, or a cleaning liquid is previously stored inside the housing at the time of air reversal, and suspended substances are dispersed in this liquid. That is, this liquid also permeates between the filter bundles, and disperses suspended substances separated by the vibrational external force to the outside of the filter bundles in a suspended state. Therefore, the sludge after peeling is dispersed outside the multi-striped filter and can be easily taken out together with the liquid. With this type of air backwashing,
The filtration capacity of the filter is fully restored in a short period of time, and the separated sludge can be easily discharged and disposed of along with the liquid.

Structure and Function of Filtering Device Hereinafter, one embodiment of the filtering device, which is the premise of the present invention, will be specifically described based on the drawings.

First, FIG. 1 shows an electrolyte filtering device 1 as an example. This filtration device 1 includes, inside a housing 2, a filter 3 to be cleaned, that is, a filter 3 in the form of a multi-thread hanging thin pipe. As already mentioned, this filter'-3 is formed into a hollow shape mainly made of polyvinyl alcohol, is closed at the lower end, and is hung in a bundle inside the housing 2 by the upper holder 4. It is being

The housing 2 has a filtrate inlet 5, a filtrate inlet 6, and an air vent lower in its upper part, and a liquid outlet 8 in its lower part.

The stock solution 10 to be filtered is sent into the settling tank 9 from the electrolytic processing machine 11 . The supernatant of the stock solution 10 in the settling tank 9 crosses the overflow weir 12, enters the stock solution tank 13, and is supplied to the filtrate port 5 by the stock pump 14 via the solenoid valve 15 and the pressure switch 16 of the pointing needle. During this initial supply, the solenoid valve 17 connected to the air vent lower is open, allowing the air inside the housing 2 to exit to the outside.

The stock solution 10 inside the housing 2 receives the supply pressure from the stock solution pump 14, that is, under the external pressure filtration method, from the outside of the hollow filter 3 through the micropores 3a as shown in FIG.
through the filtrate port 6 as the filtrate 20.
sent to. There are two solenoid valves 18 at this filtrate port 6.
19 is connected, but during this filtration process, the solenoid valve 18
is closed, the filtrate 20 flows through the solenoid valve 1 which is open.
9 and an integrated water meter 21, and is housed inside a filtrate tank 22. The filtrate 20 in the filtrate tank 22 is sent to the electrolytic processing machine 11 as a new electrolyte by the pump 23. The concentrated liquid 24 at the bottom of the settling tank 9 is discharged to the outside as a cake by, for example, a filter press 25, and the filtrate at that time is sent into the settling tank 9 again. Further, the sludge at the bottom of the housing 2 is sent to the settling tank 9 via the liquid outlet 8 by the electromagnetic valve 29. And these solenoid valves 15, 17, 18, 19, 29 are connected to the pressure switch 16
The relationship is controlled by a controller 28 which receives the signal as input.

Through such a filtration cycle, the stock solution 1o, that is, the electrolytic solution, is recycled and used while removing suspended substances such as processing waste from the solution under an external pressure filtration method.

Backwashing process When such filtration is performed continuously, suspended substances contained inside the stock solution 10 clog the micropores 3a of the filter 3, resulting in a so-called clogging state, and the filtration ability decreases.
The filtration pressure will gradually increase. When the filtration pressure exceeds a certain value, the pressure switch 16 turns on and sends a signal to the controller 28. The controller 28 then closes the solenoid valves 15, 19, 29 and opens the other solenoid valves 17, 18 in order to carry out backwashing.

Now, the backwashing method of the present invention is performed by air backwashing. Air 30 for backwashing is set at a predetermined pressure by a regulator 27 from a pressurized air source 26, and is supplied to the filtrate port 6 through a solenoid valve 18 that is open during backwashing. At this time, the air 30 is sent into the inside of each filter 3, and the floating matter in the micropores 3a, that is, sludge, is peeled off from the filter 3 by pressure in a direction opposite to the filtration direction. Inside the housing 2, the undiluted solution 10, the filtrate 20, or special cleaning water is stored in advance. , they become bubbles and rise in the liquid inside the housing 2, and are released into the atmosphere through the air vent lower.

During or after this air blowing, filter 3
An external force is applied to the This external force is applied, for example, by the vibrator 31 or the injection nozzle 32.

FIG. 3 shows an example in which the vibrator 31 is fixed to the upper surface of the holder 4. This holder 4 is fixed inside the housing 2 by a vibrating damper 33. This vibrator 31 applies ultrasonic vibration to the filter 3 during or after blowing the air 30, so that suspended substances, that is, sludge released from the micropores 3a of the filter 3 pass through the gaps between the bundled filters 3. , is dispersed in the liquid inside the housing 2 while being energized by the vibration of the filter 3. Thereafter, the liquid inside the housing 2 passes through the liquid outlet 8 together with the sludge and is supplied to the inside of the settling tank 9 P4.

Next, FIG. 4 shows an example in which a vibrator 31 is attached to the lower end portion of the filter 3 in a non-contact manner. This vibrator 31 applies direct ultrasonic vibrations to the internal liquid of the housing 2, but also indirectly applies ultrasonic vibrations to the filter 3 through the liquid. Note that the vibrator 31 may be an electromagnetic vibrator, and its vibration frequency is
Not limited to ultrasound.

Next, FIG. 5 shows an example in which a plurality of injection nozzles 32 are provided inside the housing 2 at positions facing the filter 3. This injection nozzle 32 injects water or air from the nozzle opening during backwashing, and applies a vibrational external force to the filter 3.

Further, the embodiment shown in FIG. 6 shows an example in which a large number of injection nozzles 32 are placed directly inside the multi-filter filter 3. In this case, the injection nozzle 32 applies a direct vibrational external force to the sludge interposed between the filters 3 using air or water, and disperses the sludge to the outside.

In this way, in the present invention, the air 30 for backwashing is sent into the filter 3 from the direction opposite to the filtration direction,
The sludge is separated from the micropores 3a, and at the same time or afterwards, the vibrator 31 and the injection nozzle 32 directly or indirectly apply a vibrating external force to the filter 3, so that the separated sludge is released from between the filters 3 to the outside. It is discharged and dispersed in the liquid inside the housing 2. In this way, during the backwashing process, the jet of air 30 in the opposite direction and the external force acting on the filter 3 act, so a high cleaning ability can be obtained in a short time due to the synergistic function of both in the liquid. Although this cleaning effect is not as good as that of chemical cleaning, it is useful in that a practically sufficient function can be obtained in a short time.

Modifications of the Invention Although the above embodiments use the vibrator 31 or the injection nozzle 32 alone, they may be used in combination. Therefore, in addition to the direct application of external force by the vibrator 31,
It can also be obtained indirectly by injection of air or liquid.

Effect of the invention .

In the present invention, the function of the filter can be restored in a short time by air backwashing in the liquid and application of a vibrational external force. The sludge is separated from the micropores of the filter, and the separated sludge is dispersed in the liquid by the subsequent vibrational external force, so a sufficient backwashing effect can be achieved in a short time, and the filtration process can be temporarily stopped. You can do it just by doing this.

Further, the method of the present invention can be implemented without making any major structural changes to conventional filtration devices, so it can be easily implemented in existing devices.

[Brief explanation of drawings]

Figure 1 is a piping diagram of the filtration device, Figure 2 is an enlarged sectional view of a part of the filter, Figure 3 is a side view of a part of the mounting of the vibrator and filter, and Figure 4 is a view of the housing. FIG. 5 is a cross-sectional view of a portion showing the attachment of the vibrator, FIG. 5 is a partial cross-sectional view of the portion showing the attachment of the injection nozzle, and FIG. 6 is a horizontal sectional view of the portion showing the other attachment of the injection nozzle. 1...filtration device, 2...housing, 3...filter, 4...holder, 5...filtrate port, 6...filtrate port, 7
...Air vent, 8.Liquid outlet, 9.Sedimentation tank, 10
・・Undiluted solution, 11.・Electrolytic processing machine, 12.・Overflow weir, 13.・Undiluted solution tank, 14.・Undiluted solution pump, 15.
Solenoid valve, 16... Pressure switch, 17.18.19...
・Solenoid valve, 20...filtrate, 21...integrating water meter, 22
・・Filtrate tank, 23・・Pump, 24・・Concentrate liquid,
25... Filter press, 26... Pressure air source, 27
...Regulator, 28...Controller, 30...Air,
31... Vibrator, 32... Injection nozzle, 33... Damper. Figure 7: Kazuo Wakasugi, Commissioner of the Patent Office 1. Indication of the incident 1982 Patent Application No. 24j781'i! 2. Name of the invention Method for back cleaning hanging filters 3. Relationship with the case of the person making the amendment Patent applicant address 5329 Shimosuwa-cho, Suwa-gun, Nagano Prefecture Name (
223) Sankyo Seiki Seisakusho Co., Ltd. Representative Kubo 1) Minoru 4, Agent Tatami 160 Address 708 Shinjuku Seven Building, 2-8-1 Shinjuku, Shinjuku-ku, Tokyo Telephone 03 (350) 0255 Name (8377) Benrito Kunio Chuyo 5, Date of amendment order None 6, Claims of the specification to be amended and detailed description of the invention 7, Contents of the amendment (1) The claims of the specification are corrected as shown in the attached sheet. . (2) "Reverse destination" in the second line of page 4 of the specification is corrected to "backwash." (3) On page 4, line 7 of the specification, "suspended substances remain suspended" is corrected to "substances". (4) "Dispersion" on page 4, line 8 of the specification is corrected to "dispersion fall." (5) “Dispersion” on page 4, line 10 of the specification is “dispersion falling”
I am corrected. (6) "Supernatant" on page 5, line 11 of the specification is corrected to "supernatant." (7) "Disperse" in the first line of page 9 of the specification is corrected to "disperse and fall to the bottom." (8) "Dispersion" in the first line of page 10 of the specification is corrected to "dispersion and falling." (9) "Dispersion" on page 1, line 10 of the specification is corrected to "dispersion fall.""Dispersion" on page 11, line 10 of the specification is corrected to "dispersion fall." Above 2, Claims + 1) Filtration using a filtration device comprising a housing having a filtrate port and a filtrate port, and these filtration ports and the filtrate port are communicated through a filter in the form of a multi-wire hanging pipe. In this method, fill the housing with a liquid such as filtrate, filtrate, or washing water, blow air for backwashing from the filtrate port, and apply an external force to the filter using an additional means.
A method for backwashing a hanging filter, which is characterized by peeling off sludge adhering to the filter. (2) The method for backwashing a hanging filter according to claim 1, wherein an external force is applied after blowing air for backwashing.

Claims (2)

[Claims] (1) A filtration method using a filtration device consisting of a housing that has a filtrate port and a filtrate port, and these filtrate ports and filtrate port are connected through a filter in the form of a multi-thread hanging thin pipe. Fill the filter with a liquid such as filtrate, filtrate, or washing water, blow air for backwashing from the filtrate port, and apply external force to the filter using a bed means.
A method for backwashing a hanging filter, which is characterized by peeling off sludge adhering to the filter. (2) The method for backwashing a hanging filter according to claim 1, wherein an external force is applied after blowing air for backwashing.