JPH0576705A - Small-size tank filter with backwash - Google Patents

Abstract

PURPOSE:To efficiently wash a granulated filter medium with backwash liquid including bubbles by installing a solenoid three-way valve on the raw water supply side and installing a solenoid three-way valve and an ejector sucking air on the treated water takeoff side. CONSTITUTION:In a tank 1 where raw water is supplied from above and treated water is taken out from below, disk filters made of ceramics 2, 2a are installed in the tank 1 on the supply and takeoff sides respectively. In the space between the filters 2, 2a is included ion exchange resin 3. Outside the supply and takeoff ports of the tank 1 are installed solenoid three-way valves 7, 7a respectively. The three-way valve 7 on the supply side provides the route branching off into a feed supply route 8 and a backwash discharge route and the three-way valve on the takeoff side 7a provides the route branching off into a treated liquid takeoff route 9 and an ejector communicating route. The ejector 6 is supplied with backwash clean water to such and mix air and regeneration liquid with the clear water so that the regeneration operation of the ion exchange resin 3 may be performed by the regeneration liquid at a stretch. As a result, a granulated filter medium is efficiently washed with backwash liquid including bubbles.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small filtration tank with backwash.

[0002]

2. Description of the Related Art Generally, in a fixed-bed type filtration device such as a filtration tank, the filtration operation is continuously carried out, and when the clarification level or pressure loss of the passing liquid reaches an allowable value, the filter material is washed or regenerated. To do. The method for cleaning the granular filter medium in this kind of filtration tank includes a back-flow cleaning system in which purified water is poured from the lower part of the filter medium to fluidize and clean the filtration layer, and a surface cleaning system in which purified water is sprayed from a fixed nozzle or a rotating nozzle. There is. In the former method, the backwashing effect can be enhanced by further ejecting air during backwashing.

By the way, the conventional general filtration tank with backwash has a complicated structure and is expensive as described in Japanese Patent Publication No. 2-56125, and the handling operation is complicated and inconvenient. Therefore, while unfamiliar, there is a problem that many operational troubles occur due to operation mistakes caused by them. Further, in order to regenerate (backwash) the ion exchange resin (hereinafter, simply referred to as resin) of the filtration tank with backwash as disclosed in, for example, Japanese Patent Publication No. 1-43933, a desalting column is used. In a filtration tank with backwash that also serves as a recycle column, 1) first, in order to wash out suspensions or ionic solids called “glad” that have precipitated on and inside the resin layer adhered during desalting. ,, demineralize the resin layer that has been compressed by water pressure in the desalting operation, and perform backwashing for the purpose of preventing channeling. 2) Then, set a settling time to set the resin. 3) Next , The ion exchange group is activated by passing an appropriate regenerant solution. 4) Since the regenerant solution remains in the resin layer even after the regenerant solution is passed through it, the regenerant solution remains at about the same speed as the regenerant solution. Perform an extrusion operation of flowing purified water and extruding the regenerated liquid. 5) After the extrusion operation Incidentally residual performing washing operation for washing out the regeneration liquid traces are, 6) then desalting operation, as one cycle process is taken through stock. Therefore, in the desalting tower with backwash for regeneration, there is a problem that the regeneration time is long.

[0004]

Therefore, the present invention was created in order to completely solve various problems in the conventional filtration tank with backwash, and the gist of the invention is from above. In a tank for extracting the treatment liquid from below, plate filters are provided on the supply side and the extraction side, respectively, and a small filtration tank in which a granular filter medium is housed between these plate filters to form a filtration layer, Electromagnetic three-way valves are provided on the outside of the tank supply port and outlet, respectively.The feed-side three-way valve divides the stock solution supply passage and the backwash drainage passage, and the take-out three-way valve connects the treatment liquid outlet and the ejector communication passage. By branching and supplying a backwash solution to the ejector to take in air, a backwash solution containing air bubbles was formed, and the backwash solution was introduced into the tank via the extraction side three-way valve. Characteristic In the filtration tank with a small backwash that.

[0005]

Embodiments of the present invention will be described in detail with reference to the embodiments shown in the accompanying drawings. FIG. 1 is a flow chart of an embodiment of the present invention,
2A is a cross-sectional view of a main part of FIG. 1, and FIG. 2B is a plan view of FIG.

This embodiment is suitable for a backwashing filtration tank, which uses an ion exchange resin as a granular filter medium to purify raw water for desalting or salt conversion, and the diameter of the tank is 2
It is suitable for small ones with a diameter of 00 to 500 mmφ. In FIG. 1, reference numeral 1 denotes a tank housing which supplies raw water from above and takes out treated water from below, and is provided with a reverse funnel-shaped upper portion and a funnel-shaped lower portion on the body of the tank housing. A rough ceramic disk-shaped filter 2 is provided near the boundary between the upper portion and the body, and a finer ceramic disk-shaped filter 2a is provided near the boundary between the lower portion and the body. .. These filters 2, 2a
Is composed of a porous integrated body in which foamable ceramic filaments are swirled to form multiple layers, and a granular filter medium is housed in the space between these filters 2 and 2a so as not to flow out.
This granular filter medium is a filter layer formed of Na type resin 3, H type resin 4 or OH type resin 5.
Electromagnetic three-way valves 7 and 7a are provided respectively on the upper supply port side and the lower outlet side of the tank housing 1, and the ejector 6 having two suction ports is connected to the three-way valve 7a on the outlet side. ing.

Therefore, in this embodiment, when the stock solution is desalted, the three-way valve 7 on the supply port side is set so that the stock solution supply passage 8 and the tank housing 1 communicate with each other, and the three-way valve on the take-out port side is set. The valve 7a is set so that the processing liquid outlet 9 and the tank housing 1 communicate with each other. Therefore, the stock solution is supplied to the stock solution supply passage 8 at a water pressure of 1.2 to 5 kgf / cm ² . As a result, after the fine solids are captured by the filter 2, desalting is performed by the resin 3 or 4 or 5, and then,
The processing liquid flows out of the processing liquid outlet 9 via the three-way valve 7a on the outlet side. After desalting the stock solution in this way,
When the resin 3 or 4 or 5 loses the filter desalting performance, the following regeneration operation is performed.

That is, the three-way valve 7 on the supply port side is set so that the tank housing 1 communicates with the backwash drainage channel 11, and the three-way valve 7a on the outlet side communicates with the tank housing 1 and the ejector 6. Set to. The air ejector 6 is supplied with an air supply passage 12 for air ratio, a regenerant supply passage 13 for supplying a saline or 10% hydrochloric acid or a regenerant of caustic soda, and desalted purified water. The backwash water supply passage 10 is communicated with each other. Of course, these supply paths 10, 12, and 13 are provided with solenoid valves, and their opening / closing operations are performed by electric control. Therefore, if a portion of the desalted purified water is supplied to the backwash water supply passage 10 by a pump (not shown), the air and the regenerated liquid are sucked into the purified water by the action of an ejector, and then the tank housing 1 Will be introduced to. Then filter 2,
The resin 3 or 4 or 5 held between 2a flows violently and contacts well (scrubbing action). Therefore, the above-mentioned backwashing, regenerating liquid, extrusion, water washing and desalting operations proceed simultaneously, but after the lapse of a predetermined backwashing time, the supply of air and the regenerating liquid is stopped and only purified water is supplied. After that, the supply of purified water is also stopped and the regeneration operation is completed. Therefore, according to the experiment, a reduction of about 30 minutes was achieved as compared with the conventional 5-step regeneration operation.

Next, the details of the edge ejector 6 will be described. In FIG. 2, a tube body 1 having an inner diameter of about 20 mmφ
4, a pair of inhalation branch pipes 14a, 14a are projected and communicate with each other. Inside the pipe body 14, a space forming projection 15 having a height of 2 mm is provided upstream of the branch pipe 14a. It is set up. A first check valve 16 communicating with the air supply passage 12 and a second check valve 17 communicating with the regeneration liquid supply passage 13 are connected to these branch pipes 14a, respectively. Further, in the pipe body 14, a negative pressure forming pin 18 is provided laterally on the downstream side of the branch pipe 14a passing through the pipe center point. Also,
The first and second check valves 16 and 17 are composed of a ball 19, a spring 20 for pressing the ball 19, and a joint collar 21 for holding them. ..

Therefore, when purified water is supplied to the backwash water supply passage 10 in the direction of the arrow in FIG.
Inside, a water flow having a diameter regulated by the protrusion 15 comes into contact with the pin 18 and flows out, but unexpectedly, a negative pressure is generated on the pipe wall on the upstream side of the pin 18, and the negative pressure causes a pair of pairs. Branch pipe 1
From 4a and 14a, the air and the regenerant liquid which are slightly pressurized to make the supply amount constant are sucked. And, the air bubbles of the inhaled air are different from those of the ordinary Ejector, and the tube body 1
Since it is not squeezed, it is contained as extremely fine and uniform bubbles, and when this purified water is introduced into the tank housing 1, it is not sprayed in a nozzle shape, so that channeling does not occur and the resin 3 Or 4 or 5
The water will flow evenly. In addition, this negative pressure is generated
If a blade is set toward the water flow in the water flow conduit, a lift force is generated in this blade due to a negative pressure equal pressure difference, and it is considered that this negative pressure has changed.

Needless to say, the desalting apparatus of the present embodiment uses Na-type ion exchange resin, H-type ion exchange resin and OH.
It consists of a series of desalting towers, each containing a separate type ion-exchange resin. In addition, if activated carbon is used for the granular filter medium, the backwashing of activated carbon can be performed more effectively by ultrasonic wave generation or ion adsorption, and it can also be applied to a biodenitrator filtration device. You can Furthermore, if ozone gas is supplied to the backwash drainage channel 11 and the air supply channel 12, it can be useful for purification of raw water, removal of deposits of the activated carbon, and sterilization.

[0012]

According to the present invention, basically, an electromagnetic three-way valve is provided on the raw liquid supply side of the filtration tank, an electromagnetic three-way valve is provided on the treatment liquid take-out side, and an ejector for sucking air is provided.
The backwashing liquid containing air bubbles can efficiently wash the granular filter medium, and the structure is extremely simple and inexpensive, which in turn facilitates operation and prevents erroneous operation, which is convenient for a small filtration tank. Further, since the backwashing liquid containing air bubbles is used for washing, the granular filtration layer can be uniformly washed by scrubbing.

[Brief description of drawings]

FIG. 1 is a flow chart of an embodiment of the present invention.

2A is a cross-sectional view of a main part of FIG. 1, and FIG. 2B is a plan view of FIG.

[Explanation of symbols]

1 ... Tank housing, 2, 2a ... Disc filter,
3, 4, 5 ... Ion exchange resin, 6 ...
a ... Electromagnetic three-way valve, 8 ... Undiluted solution supply path, 9 ... Treatment solution extraction path, 10 ... Backwash water supply path, 12 ... Air supply path

Claims (1)

[Claims] 1. A tank in which a stock solution is supplied from above and a treatment solution is taken from below is provided with plate-like filters on the supply side and the take-out side, respectively, and a granular filter medium is housed between these plate-like filters to form a filter layer. In the formed small filtration tank, electromagnetic three-way valves are provided on the outside of the inlet and outlet of the tank, respectively, the stock solution supply passage and the backwash drain passage are branched by the supply-side three-way valve, and the treatment liquid is provided by the take-out three-way valve. By branching the extraction passage and the ejector communication passage, and supplying air to the backwash liquid to the ejector to form air, a backwash liquid containing air bubbles is formed, and the backwash liquid is supplied to the extraction side three-way valve. Small filtration tank with backwash, which is introduced into the tank via