JPH09150015A - Moving bed type filtration device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to increase/decrease the feed rate of a cleaning water (filtrate) automatically in accordance with an increase/a decrease in the quantity of cleaning water effluent and thereby facilitate an operating control by extracting a contaminated granular filter medium from the lower part of a filtration bed, and taking out a water for transporting the filter medium and the cleaning water effluent separately. SOLUTION: Foreign matter contained in an untreated liquor supplied from a supply port 3 into a filtration tank 1 is captured while the foreign matter ascends through a granular filter medium 2 layer, and a filtrate is overflown from the upper part of the filtration tank 1 to be taken out of a drain port 4 to an area outside this floating bed filtration device. In this case, the ascending current of the filtrate and the reflective ascending current of water for transporting the filter medium 2 are generated in a cleaning cylinder 11 submerged in the internal upper part of the filtration tank 1. Further, the ascending current separated from the filter medium 2 carrying the foreign matter is drained from a drain pipe 14 as waste water to be cleaned. On the other hand, the filtrate is taken out of an extraction cylinder 21 as water for transporting the contaminated filter medium 2 extracted from the lower part of a filtration bed. This filtrate is circulated through a circulating water pipe 9, a pump 8, an ejector 7 and a transport pipe 10 in that order. Thus it is made possible to easily perform an operating control even when the pollution load of the untreated liquor is varied.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of clarifying a suspension of tap water, sewage, industrial wastewater, etc. by filtering, and at the same time, a particulate filter medium moves from the top to the bottom to remove contaminated filter medium from the filter bed under a filter bed. The present invention relates to an improvement of a moving bed type filtration device in which a filter medium that has been taken out from a cleaning unit and washed is returned to the upper part of the filter bed.

[0002]

2. Description of the Related Art There are many known techniques relating to an upflow moving bed type filtration apparatus in which a filter medium constituting a filter bed moves, the filter medium is taken out, washed, and returned to an upper part of the filter bed. For example,
In Japanese Patent Laid-Open No. 56-51808, a transportation pipe of an air lift pump that operates dirty sand with compressed air is mounted vertically on the central axis of a filtration tank, and a cleaning device is provided around the transportation pipe. This cleaning device is immersed in the treated water zone above the filtration tank, and the inlet of the cleaning water is connected to the treated water zone. Further, as another example, Japanese Patent Laid-Open Publication No. 64-64-
In 10246, a moving bed type filtration device for transporting dirty sand by a water ejector is provided with a separation device provided with a transportation water inlet connecting a cleaning drainage discharge port and a transportation pipe on the outside of the filtration tank, and a counter flow is provided. A cleaning device for secondary cleaning of the filter medium separated by the separation device is provided by being immersed in the treated water zone,
The upper part of the washing tower is shown as a device connected to the lower part of the separation device through a control valve. A washing water outlet is provided above the washing device, and is connected to a circulation pump.

As another example, Japanese Patent Application Laid-Open No. 7-2044 discloses
In a moving bed type filtration device 21 for transporting dirty sand by a water jet, a transportation drainage separation pipe for separating contaminants and filter media is provided at the upper part of the cleaning device, and the transportation drainage pipe is provided outside the transportation drainage separation pipe. A discharge device is provided, and a guide hole to the cleaning device is provided below the transportation wastewater separation cylinder, and the filter medium that has been mostly cleaned is dropped from the guide hole into the cleaning device, and the filter medium is washed with the cleaning water in a counterflow. An apparatus in which a zigzag slit for cleaning is provided and a cleaning drainage device is provided outside the slit is shown.

[0004]

The conventional moving bed filter has the following problems. In the case of using the air lift pump, the transportation wastewater that has risen in the transportation pipe is discharged together with the cleaning wastewater that has risen in the counterflow to the outside of the filtration tank through the same wastewater adjusting device. For this reason, if the sand transport volume increases, the water level in the washing tank rises,
There is no difference between the filtered water level and the counter flow for washing, and contaminants are mixed in the filtered water. Therefore, when increasing the amount of sand, it is necessary to adjust the washing and drainage adjusting device (weir, orifice, etc.) each time. For this purpose, it is necessary to always keep the washing and drainage adjusting device at maximum load,
Normally, wastewater must be discharged more than necessary, a large amount of washing water is used, and filtration efficiency is poor. Further, the efficiency of the air lift pump is low, the power consumption is large, and the noise of the air compressor is also large. In addition, even when the filter medium is transported by a water ejector, the flush water valve must be adjusted as the amount of lifted sand increases and decreases.

[0005]

SUMMARY OF THE INVENTION The present invention is provided to solve the above-mentioned problems, in which the transportation wastewater of the filter medium and the cleaning wastewater of the filter medium are separately discharged, and the amount of lifted sand is increased. When the amount of filter medium increases, the filtrate is used as circulating water for transporting the contaminated filter medium, and if the transport amount of the filter medium is increased, the amount of washing water is increased to automatically obtain sufficient water.

In order to achieve the above-mentioned object, the present invention is constructed as follows. That is, it comprises a filter tank having a filter bed constituted by a filter medium inside, a transportation device for taking out and transporting dirty filter medium from the filter tank, and a washing device for separating and washing the filter medium and foreign matters, and the washing device The treated wastewater is used to remove the cleaning wastewater and to transport the filter medium, and part of the treated water is used as cleaning water in the cleaning device.

Further, in the cleaning cylinder forming the cleaning device,
The stirring dish is installed facing upward, and the upper end opening of the circulating water transport pipe faces the inside of the stirring dish. Then, the cleaning drainage of the filter medium overflows from the upper edge of the cleaning cylinder above the stirring dish.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Since the apparatus according to the present invention is configured as described above, the raw water supplied to the lower part of the filter bed has its impurities trapped while rising in the filter bed, The filtrate is taken out of the tank from the upper filtrate take-out section. At the same time, by operating the filter medium transport device, the filter medium is pulled out from the bottom of the filter bed, and the filter medium gradually moves downward. Then, the filter medium with the contaminants extracted from the filter bed is transported to the upper cleaning device by the transport water.

When the filter medium transported to the cleaning device falls into the stirring dish, the adhering contaminants are peeled off, and at the same time, the contaminants are stirred and the light contaminants are floated up, and only the heavy filter medium from which the contaminants are peeled off is separated. The inside of the filtrate rising in the tube settles and is distributed on the upper surface of the filtration bed. Then, the floating contaminants are carried on the filtrate and the transport water rising in the separation cylinder to become cleaning drainage, overflowing from the upper part of the separation cylinder and taken out of the system.

On the other hand, a part of the filtrate rising in the guide cylinder is
The overflow of the transport water overflows from the upper edge of the guide tube. Then, the overflowed filtrate is sent to the water ejector by the transportation water pump, sucks the contaminated filter medium from the bottom of the filtration tank, and conveys it to the above-mentioned cleaning device. At this time, since the transport water is drained from the lower part of the take-out tube, it is not drained even if contaminants are mixed.

As is clear from the above description, in the device according to the present invention, the washing device is submerged in the filtration tank so that the ascending flow of the filtrate and the ascending flow of the transport water of the filter medium are caused in the washing cylinder. The contaminants separated from the filter medium are placed on this ascending flow and discharged to the outside of the system as cleaning drainage.In addition to this cleaning drainage, the filtrate is taken out from the extraction cylinder and circulated as transport water for the contaminated filter medium. The amount of water transported by the filter medium (transported amount of the filter medium) can be controlled according to the amount of washing and drainage of the filter medium discarded outside the system, and operation control is easy even when the pollution load of the stock solution changes. Is. The present invention will be described below with reference to the drawings.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, reference numeral 1 is a filtration tank, 2 is a granular filter material such as sand, 3 is a supply port for a stock solution to be filtered, 4 is a discharge port for a filtrate, and 5 is a supply pump for the stock solution.

Next, reference numeral 6 is a filter material storage pit provided at the bottom of the filtration tank 1. The pit 6 is a water ejector 7.
It is in communication with. Reference numeral 8 denotes a filter medium circulating pump provided in the circulating water pipe 9 of the filter medium 2, and is connected to the ejector 7 and the suction portion is connected to a filter medium cleaning device described later.

A transport pipe 10 for the filter medium 2 is connected to the water ejector 7 described above, and the other end of the transport pipe 10 is connected to a cleaning device provided in the upper part of the filtration tank 1 submerged in water. This cleaning device, the circulating water pipe 9 and the transport pipe 10 described above.
It constitutes a circulation system for cleaning the filter media.

Next, the structure of the cleaning device for the filter medium 2 will be described. FIG. 2 shows the details of the configuration of the cleaning device.
It consists of an agitation washing section at the top and a transport water take-out section connected to the bottom. A bowl-shaped stirring dish 12 is provided in the cleaning cylinder 11 at the upper part thereof, and the tip of the transport pipe 10 is opened downward in the stirring dish 12. In addition, the upper surface of the cleaning cylinder 11 is opened to form the overflow portion 13,
The overflow portion 13 is provided with a wash water discharge pipe 14. Reference numeral 15 is a dam plate provided on the cleaning cylinder 11.

Below the cleaning cylinder 11, there is provided a filter material distribution umbrella 16 that is exposed to the lower surface opening of the cleaning cylinder 11, and a filter material guide cylinder 18 that surrounds a support column 17 of this distribution umbrella 16. Is provided, and a sand chute 19 is provided so as to face the lower opening of the guide cylinder 18. The sand chute 19 is fixed to the support column 17 and is supported by the support frame 20 fixed to the filtration tank 1. Incidentally, reference numeral 17a
Is a piece of baffle.

The peripheral portion of the guide cylinder 18 is surrounded by a take-out cylinder 21 for transport water. The lower edge of the washing cylinder 11 is connected to the upper surface of the take-out cylinder 21, and the upper edge of the guide cylinder 18 is connected. A clearance is provided between the inner surface of the discharge tube 21 and the inner surface of the discharge tube 21 to serve as an outlet for the transport water. Then, a take-out pipe 22 for the transport water is connected to the lower side of the take-out pipe 21. Reference numeral 18 a is a baffle piece provided on the inner surface of the guide cylinder 18.

In FIG. 2, reference numeral 23 is an air vent pipe, the lower end of which is opened in the flow dividing plate 24 of the raw water in FIG. Further, in FIG. 1, reference numeral 25 is a distribution plate of the descending filter medium.

The apparatus according to the present invention is configured as described above, and the stock solution supplied to the filter tank 1 traps impurities during the ascent in the filter layer, and the filtrate is filtered. 1 can be collected in the upper part, overflowed from the upper part, and taken out of the system.

On the other hand, by operating the pump 8, the water ejector 7 is actuated so that the contaminated filter medium at the bottom of the filter medium layer can be sucked and transported to the cleaning device via the transport pipe 10. Contaminants in the undiluted solution are attached to the filter medium extracted by the ejector 7, but they are peeled off while being sent through the transport pipe 10 and when discharged into the cleaning cylinder 11 of the cleaning device, they are further stirred there and completely. Is peeled off and washed.

Then, in the cleaning device, light contaminants float up and overflow from the cleaning cylinder 11, and are taken out of the system through the discharge pipe 14 together with the cleaning drainage. Further, the heavy filter medium is settled and diffused in the guide cylinder 18 by the distribution umbrella 16, settled while touching the baffle plates 17a and 18a, and distributed by the sand dividing chute 19 to the surface of the filtration bed.

For this reason, the amount of water in the delivery water take-out pipe 21 is reduced by the amount of water discharged from the discharge pipe 14 as cleaning waste water and the amount of water extracted by the pump 8 for transporting the filter medium. The filtrate above the filtration bed is replenished from the opening at the bottom of the guide cylinder 18. Therefore, an ascending flow of the filtrate is generated in the guide cylinder 18 and the washing cylinder 11, but the filter medium from which the foreign substances have been separated to increase the specific gravity is settled in the ascending flow.

In the take-out cylinder 21, the pump 8 is
Although a descending flow is generated because the cleaning filter material is pulled out by the above, the contaminants are levitated by the ascending flow in the guide cylinder 18 even if they are accompanied by contaminants, and do not flow into the extraction cylinder on the side. is there. Even if it flows in, the water in the take-out cylinder 21 is washing water, which is removed during recirculation, and does not mix with the filtrate. In this respect, as shown in FIG. 2, if the transport water outlet pipe 22 is provided on the lower side of the outlet pipe 21,
Since the contaminants are light, they do not settle and are efficient in separation.

Further, in the present invention, the washing device is provided submerged in the filtrate, and the weir plate 15 is provided at the overflow portion of the washing cylinder 11.
Since the water level H1 of the washing cylinder 11 is set lower than the water level H2 of the filtrate in the filtration tank 1, the filtrate can be attracted into the take-out cylinder 21 and the cleaning cylinder 11 as transport cleaning water. Can be effective.

[0025]

As described above, the moving bed type filtration device according to the present invention can automatically increase or decrease the supply amount of cleaning water (filtrate) according to the increase or decrease of the cleaning drainage, and the conventional filter medium circulation. This is easier to control than water (transport water) that is adjusted according to the amount of washing waste water.

[Brief description of the drawings]

FIG. 1 is a schematic vertical cross-sectional view of a filtration device according to the present invention.

FIG. 2 is likewise an enlarged vertical sectional view of a cleaning device portion.

[Explanation of symbols]

 1 Filtration Tank 2 Filter Material 3 Supply Port 4 Discharge Port 10 Transport Pipe 11 Cleaning Cylinder 12 Stirring Dish 15 Weir Board 16 Distributing Umbrella 17 Support Pillar 18 Guide Cylinder 19 Sand Chute 21 Extracting Cylinder

Claims (4)

[Claims] 1. A filter bed is formed from granular filter media 2, and a raw water supply port 3 for supplying raw water to the lower part of the filter bed is provided in the lower part of the filter bed.
A filtering device provided with a treated water discharge port 4 on the upper part, a transportation means for extracting the contaminated filter medium from the lower part of the three beds and transporting it to the cleaning device, and separating the contaminated filter medium by stirring, and then separating the above-mentioned filter bed. In the moving bed type filtering device provided with a means for distributing on the upper surface of the above, a moving bed type filtering device is characterized in that the transportation drainage and the cleaning drainage of the granular filter medium 2 are taken out separately. 2. The means for separating and washing contaminants from the contaminated filter medium 2 has an upper surface opened by being immersed in the filtrate of the filtration tank 1 and having an overflow portion, and a lower surface is opened. The washing cylinder 11 and the stirring cylinder 12 provided in the cleaning cylinder 11 having a U-shaped cross section and the transport pipe 10 for the filter medium 2 inserted into the stirring dish 12 with its opening facing downward. Item 2. A moving bed type filtration device according to item 1. 3. The means for distributing the filter medium 2 from which the contaminants have been separated to the upper surface of the filter bed is a distributing umbrella 16 arranged toward the lower surface opening of the washing cylinder 11, and the lower end of a supporting column 17 of the distributing umbrella 16. A sand chute 19 provided in the above, a guide cylinder 18 that is provided to surround the support column 17 of the distribution umbrella 16 and that is open at the top and bottom,
2. The moving bed type filtration device according to claim 1, further comprising a transport water take-out tube 21 which surrounds the guide tube 18 and integrally connects an upper end edge of the guide tube 18 to the cleaning tube 11 and a lower side portion of the guide tube 18. 4. The moving bed type filtration device according to claim 1, wherein an adjustable weir plate 15 is provided at an upper surface overflow portion of the washing cylinder.