JP3698297B2 - Filter media cleaning and recycling equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement in a filtration apparatus using a floatable filter medium and an apparatus for cleaning and regenerating a filter medium layer of a biofilm filtration apparatus.
[0002]
[Prior art]
Conventionally, a filtering device using a floatable filter medium having a specific gravity of 1.0 or less and close to 1.0 is provided with a filter medium support part in the upper part of the filtration tank, and a filter medium with a floatable material is loaded on the lower side thereof. A method is well known in which a layer is formed, raw water is passed in an upward flow or a downward flow for filtration, and cleaning water and air are supplied from the bottom of the filter medium layer when the filter medium is washed. The invention described in Japanese Patent Application Laid-Open No. 11-114319 is an example thereof, and this method allows a draft tube to be installed concentrically in the center of the filtration tank as a means for turning the mixture of the filter medium and the washing water up and down, Further, an aeration nozzle for stirring is provided eccentrically from the center at the bottom of the filtration tank. Further, the invention of Japanese Patent Laid-Open No. 10-85515 includes a partition member extending downward so as to divide a region where air is diffused during cleaning and a region where air is not diffused along the lower surface of the upper filter medium support. It is provided and switched alternately to perform aeration and change the direction of the swirl flow.
[0003]
[Problems to be solved by the invention]
However, in the invention of Japanese Patent Application Laid-Open No. 11-114319, the shape of the filtration tank is limited to the lower cone type cylindrical tank. And, for example, in a large-capacity filter tank made of concrete, there is a problem that it is difficult to sufficiently stir by causing a swirling flow to the entire filter medium layer only by installing a draft tube or attaching an aeration nozzle eccentrically. is there. Further, in the invention of Japanese Patent Laid-Open No. 10-85515, a partition member is provided on the lower surface of the filter medium support portion, and the method of dividing and agitating alternately by dividing into a region where air is diffused during cleaning and a region where air is not diffused is as follows. Although it is excellent as a cleaning and regeneration method for floating filter media, there is a problem that it takes time for cleaning.
[0004]
[Means for Solving the Problems]
The present invention solves the above-mentioned problems of the prior art, and the gist of the invention is a filtration tank provided with a filter medium outflow prevention net on the top, a lower surface of the filter medium outflow prevention net, and an intermediate part of the filtration tank A flow guide plate is arranged in the vertical direction, a filter medium layer is formed by a floating filter medium below the filter medium outflow prevention net, a means for supplying raw water and cleaning water for the filter medium to the lower part of the filter tank, and a filter medium at the time of cleaning construed layer, a diffuser for pivoting the filter material is provided, in an upper portion of the filtration tank is provided with a take-out tube and detergent drain take-out pipe of the treated water.
[0005]
The filter medium to be loaded into the filtration tank is a heat-fusible composite fiber with a polypropylene core and polyethylene sheath, and a first filament with a fineness of 18 to 65 denier and a polypropylene fiber with a fineness of fine. Needle punching a web consisting of 3 to 10 denier second filament and a heat-fusible composite fiber with a core of polypropylene and a sheath of polyethylene, and a third filament with a fineness of 1.5 to 6 denier The cloth is made into a cloth by the method, and heat treatment is carried out without smoothing the web raised state on both sides to produce a cloth-like plate-like body having a weight of 200 to 800 g / m 2 and a thickness of 2 to 8 mm. When the shaped plate was cut into a 5-30 mm rectangle and this filter medium was loaded into a filtration tank, the ratio of the height of the filter medium layer to the height of the water layer was 65: 5-50: with is loaded as a 50, a portion of the treated water was made to circulate in the raw water supply port.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
The present invention is configured as described above. For example, when a filter medium layer loaded in a large concrete filter tank is clogged, the filter medium layer is first deposited at the bottom of the filter tank in order to wash and regenerate the filter medium layer. After discharging the precipitate, the filter medium is stirred and washed by supplying air and washing water from below the filter medium layer, and the washing waste water is taken out from the upper part of the filtration tank. At this time, the diffused air is supplied from the left and right wall surfaces or from the vicinity of the center of the filtration tank. A filter medium outflow prevention net is provided at the upper part of the filtration tank, and a plate-like or substantially wedge-shaped water flow guide plate is provided in the vertical direction at the lower surface of the filter medium outflow prevention net and in the middle part of the filter tank. The mixture of water and filter media that has risen along the left and right wall surfaces is converted into a flow toward the center of the filtration tank by the filter medium outflow prevention net, and further to a downward flow by the water flow guide plate. Produces a swirling flow in the clockwise direction and the other half in the counterclockwise direction, and the entire filter medium in the tank can be stirred and washed. When air is sent from the center of the filtration tank, the mixture of filter medium and water rises near the center and is divided into right and left by the water flow guide plate. It becomes the flow which goes to, and is changed into the flow which goes to the downward direction by the left and right wall surfaces, and the vertical swirl flow is generated.
[0007]
In addition, the filter medium to be loaded in the filtration tank is preferably lightweight, has a large gap, has pressure resistance / corrosion resistance, and has strength. To satisfy these conditions, a filter medium made of the following synthetic resin is used. ing. That is, a heat-fusible conjugate fiber with a polypropylene core and polyethylene sheath and a first filament with a fineness of 18 to 65 denier and a second filament with a polypropylene fiber and a fineness of 3 to 10 denier And a material made of polypropylene with a core and polyethylene with a sheath and a heat-fusible conjugate fiber, and a cotton blended with a third filament with a fineness of 1.5 to 6 denier is made into a cloth by the needle punching method. The raised state is heat-treated without smoothing, and a cloth-like plate-like body having a web weight of 200 to 800 g / square meter and a thickness of 2 to 8 mm is produced. This cloth-like plate-like body is 5 to 30 mm. It is cut into rectangles.
[0008]
When the filter medium configured as described above is loaded into the filtration tank, the ratio of the height of the filter medium layer to the height of the water layer in the filter tank is 65:35 to 50:50 in consideration of the fluidity during washing and stirring. If the loading amount is adjusted so that, the filter medium can be efficiently agitated and washed at the time of washing the filter medium. The present invention will be specifically described below with reference to the drawings.
[0009]
【Example】
FIG. 1 is a longitudinal side view of a filtration apparatus according to the present invention, and the operation of a filter medium cleaning and regenerating method will be described based on this figure. A filter medium outflow prevention net 3 is provided at the upper part of the filtration tank 2, and a filter medium layer 1 is formed by loading a floatable filter medium below the filter medium outflow prevention net 3, and raw water is supplied from the raw water supply port 10 at the lower part of the filter tank 2. The filtered water layer 1 is supplied and filtered through the filter medium layer 1, and the treated water is collected in a water collection trough 4 provided in the upper part of the filtration tank 2, and a treated water pipe 12 connected to the water collection trough 4 is connected to the treated water pipe 12. It flows into the treated water tank 14 through. When the treated water tank 14 becomes full, it overflows from the treated water take-out pipe 15 and is taken out to the outside.
[0010]
When the filter medium is clogged by solid matter or sludge collected by the filter medium layer 1 by the above operation, the raw water supply is stopped, the treated water valve 11 is closed, and the sediment deposited on the bottom of the filter tank 2 Is extracted from the drawing tube 16. Next, air is injected into the filtration tank 2 from the air diffuser 6 connected to the blower 5. In FIG. 1, the air diffuser 6 is provided near the left and right wall surfaces of the filtration tank 2. Further, plate-shaped or substantially wedge-shaped water flow guide plates 7 a and 7 b are arranged in the vertical direction on the lower surface of the filter medium outflow prevention net 3 and the middle portion of the filtration tank 2. The water flow guide plate 7a in FIG. 3 is provided on the lower surface of the filter medium outflow prevention net 3, and has a substantially wedge shape, but is curved inward on the left and right sides. The air injected from the air diffuser 6 becomes bubbles and rises along the left and right wall surfaces of the filtration tank 2, and the bubbles that hit the lower part of the filter medium layer 1 and the filter medium outflow prevention net 3 are in the center of the filter tank 2. In the center, the flow is changed downward by the water flow guide plates 7a and 7b, and a swirling flow in the vertical direction is generated. In the left half of FIG. 1, the swirl flow is clockwise, and in the right half, the swirl flow is counterclockwise. By continuing this operation for 3 to 10 minutes, the clogged and hardened filter medium layer 1 is loosened and sufficiently stirred. Next, while continuing the aeration stirring, the cleaning water pump 9 is driven to pass the processing water stored in the processing water tank 14 through the cleaning water pipe 8 and into the filtering tank 2 from the lower part of the filtering tank 2. Supply. The washing water supplied into the filtration tank 2 becomes a swirl flow together with the filter medium, and the filter medium is washed to remove clogged substances such as solids and sludge collected in the filter medium, and together with the clogged substances. Then, it passes through the filter medium outflow prevention network 3, overflows into the water collection trough 4, and is discharged to the outside through the washing drain pipe 13. If the washing water speed at this time is too high, the swirling filter medium is pressed against the filter medium outflow prevention net 3, and the washing becomes insufficient. If it is too slow, it takes time to wash and regenerate the filter medium. From experimental data, it has been found that 10-30 m / Hr is the optimum value for the cleaning speed of the filter medium.
[0011]
The filter medium loaded in the filtration tank 2 is a heat-fusible composite fiber whose material is polypropylene and whose sheath is polyethylene, the first filament whose fineness is 18 to 65 denier and the material is polypropylene fiber, and the fineness. Needle with a second filament of 3 to 10 denier and a heat-fusible conjugate fiber with a core of polypropylene and a sheath of polyethylene, and a third filament with a fineness of 1.5 to 6 denier Fabricated by punching method, heat-treated without smoothing the web brushed state on both sides, producing a cloth-shaped plate-like body having a weight of 200 to 800 g / m2 and a thickness of 2 to 8 mm. Fabricated plate is cut into a 5-30mm rectangle, and this synthetic resin fiber filter is lightweight, has large gaps, and has pressure and corrosion resistance. , Since it has a strength, without wear and deformation by stirring, it is suitable as a filter material.
[0012]
The amount of the filter medium to be loaded into the filtration tank 2 is that if the filter medium layer 1 is clogged and a swirling flow is generated by a washing and stirring operation, and the fluidity when unraveling the filter medium layer 1 is taken into consideration, the filtration medium 2 is filtered. By adjusting the loading so that the ratio of the height of the filter medium layer to the height of the water layer in the tank 2 is 65:35 to 50:50, the filter medium can be efficiently stirred and washed.
[0013]
FIG. 2 is a vertical side view of a filtration device according to another embodiment of the present invention, and the air diffuser 6 is disposed on the left and right sides with a perpendicular extending from the water flow guide plates 7a and 7b. In the embodiment of No. 1, a swirling flow of reverse rotation is generated. In the case of a large filtration tank 2 having a rectangular plane, water flow guide plates 7a, 7b... May be provided at a plurality of locations, and the wall surface of the filtration tank 2, the first water flow guide plates 7a, 7b, and the first water flow guide plate. 7a, 7b and the second water flow guide plates 7a, 7b... To the nth water flow guide plates 7a, 7b, the (n + 1) th water flow guide plates 7a, 7b and the (n + 1) th water flow guide plates 7a, 7b and the wall surface. The interval is set to 1 to 3 m, and preferably 2 m is optimal from experimental data.
[0014]
【The invention's effect】
The filter medium layer clogged by the cleaning and regenerating method of the filter medium in the filtration device of the present invention is stirred with a swirling flow by aeration, sufficiently loosened, and then supplied with cleaning water to remove solids, sludge, etc. from the filter medium. The clogging material can be easily peeled off, the cleaning effect can be improved, the amount of cleaning water can be reduced by shortening the cleaning time, and even in a large-scale filtration tank, the filter media can be cleaned and regenerated efficiently at once. It solves the problem at the time of filter medium cleaning of the conventional seed filtration device.
[Brief description of the drawings]
FIG. 1 is a longitudinal side view of a filtration device according to the present invention.
FIG. 2 is a longitudinal side view of a filtration device according to another embodiment of the present invention.
FIG. 3 is a side view showing an example of an upper water flow guide plate.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Filter medium layer 2 Filtration tank 3 Filter medium outflow prevention network 4 Catchment trough 5 Blower 6 Air diffuser 7a, 7b Water flow guide plate 8 Washing water piping 9 Washing water pump 10 Raw water supply port 11 Treating water valve 12 Treating water piping 13 Washing drainage Pipe 14 Treated water tank 15 Treated water take-out pipe 16 Pull-out pipe

Claims (3)

A filtration tank (2) provided with a filter medium outflow prevention net (3) at the top, and a water flow guide plate (7a, 7b) perpendicular to the lower surface of the filter medium outflow prevention net (3) and the middle part of the filter tank (2) disposed of, the filter media outflow prevention network (3) filter media layer (1) formed by floating filter media under the, means for supplying wash water of the raw water and filter material at the bottom of the filtration tank (2), washed An air diffuser (6) for loosening the filter medium layer (1) and swirling the filter medium is sometimes provided, and a treated water discharge pipe (12) and a washing drainage discharge pipe (13) are provided above the filtration tank (2). An apparatus for cleaning and regenerating a filter medium layer, comprising: A heat-fusible conjugate fiber with a polypropylene core and polyethylene sheath, and a first filament whose fineness is 18 to 65 denier and a second filament whose material is polypropylene fiber and whose fineness is 3 to 10 denier; A heat-fusible conjugate fiber with a core of polypropylene and a sheath of polyethylene, and a web blended with a third filament with a fineness of 1.5 to 6 denier is made into a cloth by the needle punching method, and the web is raised on both sides The fabric is made into a rectangular plate having a weight of 200 to 800 g / square meter and a thickness of 2 to 8 mm. The apparatus for washing and regenerating a filter medium layer according to claim 1 , wherein the filter medium is loaded as a filter medium. When the filter medium is loaded into the filtration tank (2), the ratio of the height of the filter medium layer (1) to the height of the water layer is 65:35 to 50:50, and a part of the treated water is supplied to the raw water supply port. The apparatus for washing and regenerating a filter medium layer according to claim 1 , wherein the apparatus is circulated in (10).

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