JP2003200185A - Carrier flowing out prevention mechanism for water treatment device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a catchment mechanism for a moving bed type aerobic filtration bed capable of collecting good treated water by inhibiting flowing out of a solid substance to the treated water without inhibiting a flow of a carrier at the time of washing. <P>SOLUTION: Raw water is flowed from an upper part of an aerobic filtration bed tank 10 filled with a carrier and a fine solid substance in the raw water is captured by the carrier during that it descends in the filtration bed tank. After the contaminant dissolved in water is decomposed by microorganisms deposited on a surface of the carrier, the treated water flows out from a catchment area 12 at a lower part of the filtration bed tank to the outside of the tank. Whereas, after the carrier on which the solid substance is deposited by a biological treatment and which descends is raised by an air lift pipe 29 provided at a center of the filtration bed tank 10, the carrier from which the solid substance is separated is circulated into the filtration bed tank. In the filtration bed tank 10, a carrier flowing out prevention mechanism is disposed, which comprises a diffusion umbrella provided on an outer periphery of a protection pipe 25 of the air lift pipe for diffusing the carrier descending into the catchment area 12; a catchment cylinder 30 extending from a small diameter side of the diffusion umbrella to a height arriving at a half part of a central water collecting part 11 at the filtration bed tank; and a treated water flowing out pipe 14 projected from an upper outer wall of the water-collection cylinder to the outside of the tank. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carrier outflow prevention mechanism capable of collecting treated water in a moving bed type aerobic filter which is a downflow type water treatment apparatus without deteriorating the quality of the treated water.

[0002]

2. Description of the Related Art As one of the methods of purifying water polluted by organic substances by the action of microorganisms, the microorganisms are attached to solid particles and contacted with the pollutants in the raw wastewater passing through the solid particles so that the raw wastewater is preferably treated. There is a biofilm purifier that digests and purifies the air. As a representative of this biofilm purification device,
A downflow type water treatment device (aerobic filter) is known. This device blows air from the lower part of an aerobic filter bed tank filled with a carrier (filter medium), allows raw water to flow in from the upper part, and captures fine solid matter in the raw water while descending in the filter bed tank, After being decomposed by microorganisms, the treated water is caused to flow out from the water collecting mechanism at the bottom of the filter bed tank, and the carrier to which solid matter is attached by biological treatment is sucked up by the air lift pipe provided at the center of the filter bed tank and raised to the upper part, The carrier from which the solid matter is separated is circulated in the filter bed tank.

The filter tank is filled with a carrier (for example, anthracite, activated carbon, lightweight aggregate, etc., having a particle size of about 2 to 10 mm), and the lower part of the filter tank is filled with treated water biologically treated in a water treatment chamber. There is a diffusion umbrella to collect water. The water treatment room is equipped with an air diffuser for blowing air necessary for biological treatment into raw water by an aeration blower. Raw water is purified by the action of microorganisms adhering to the surface of the carrier when passing through the carrier in the water treatment chamber. SS component and BO contained in raw water
The component D and the like adhere to and accumulate on the surface of the carrier by biological treatment.
For this reason, clogging occurs between the carriers and the passage resistance of the raw water increases. In this way, washing is performed because it is necessary to remove the solid matter attached to the carrier. That is, the bottom carrier,
It is raised to the upper part through an air lift pipe, and a solid material is separated by a separating device. Generally, in order to obtain treated water of good water quality, in the filter tank, the flow of water during treatment should be uniform to improve treatment efficiency, and the flow of the carrier during washing should not be obstructed and should be gentle. It is necessary to improve the cleaning efficiency, suppress the outflow of solids into the treated water, and evenly collect water at a low flow rate to suppress outflow of the solids and outflow of the carrier into the treated water.

[0004]

The moving-bed aerobic filter bed tank was manufactured from steel plates, but when installing a number of units together, RC construction is more cost effective than steel plate construction. It is advantageous, and the multi-type (multi-tank type) is more advantageous than making a plurality of single tanks. Further, the steel plate aerobic filter bed has a mechanism for collecting water from the periphery of the can body and the lower center part. However, an aerobic filter bed made of RC should have a water collecting mechanism around it. Is difficult, and with only the water collecting mechanism in the lower center, the water collecting area is insufficient and the flow velocity becomes faster.
Outflow of the carrier and deterioration of treated water quality occur, and the above conditions are not satisfied. In order to suppress the outflow of the carrier, it has been attempted to install a screen at the water collection introduction point, but depending on the nature of the raw water, clogging may occur and it is necessary to remove the carrier by stopping the operation. Becomes Therefore, in the present invention, in the filter bed tank satisfying the above, by incorporating a water collecting mechanism having a large water collecting area around the air lift pipe, the flow velocity is uniform,
An object of the present invention is to provide a carrier outflow prevention mechanism for a moving bed type aerobic filter bed tank in which the carrier does not flow out and the treated water quality is good.

[0005]

In order to achieve the above-mentioned object, the present invention allows raw water to flow from the upper part of an aerobic filter tank filled with a carrier, and fine particles in the raw water are supplied while descending in the filter bed tank. A solid substance is captured by a carrier, and dirt dissolved in water is decomposed by microorganisms adhering to the surface of the carrier. Therefore, after raising the carrier, the carrier from which the solid matter has been separated is circulated into the filter bed tank, while the carrier outflow prevention mechanism prevents the outflow of the carrier so that the treated water flows out from the catchment area of the filter bed tank. And a diffusing umbrella provided on the outer circumference of a protective pipe of an air lift pipe for diffusing the carrier descending into the catchment area of the filter bed tank, and a diffusing umbrella. From the small diameter side of the Extending to a height reaching the mid-range to the current water bottle capable of preventing the outflow of the carrier, the treated water outlet pipe from the upper outer wall is protruded outside the tank of the condenser water bottle, characterized in that it consists of. Further, the aerobic filter tank is characterized by being a single tank type or a multi-tank type made of steel or reinforced concrete.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION FIG. 1 is a sectional view of a carrier outflow prevention mechanism of the present invention. As shown in the figure, this down-flow type water treatment device comprises a moving-bed aerobic filter bed tank 10 made of RC, a raw water inflow pipe 13 provided at an upper part of the filter bed tank, and a blower for blowing air into the filter tank. Air device 35, an air lift pipe 29 for raising the carrier filled in the filter bed tank, a protective tube 25 with a diffusion umbrella of the air lift tube 29, and a water collecting area 12 in the floor tank near the lower part of the protection tube 25.
A diffusing umbrella 26 which is provided in the diffusing unit and which diffuses the sedimenting carrier;
A carrier separating device 20 provided at the upper end of the air lift pipe 29;
The water collecting mechanism 30 provided around the air lift pipe 29 in the upper part of the diffusion umbrella 26 and the treated water outflow pipe 14 led out of the tank from the water collecting mechanism 30 are the main parts.

The aerobic filter tank 10 is composed of a central water collecting portion 11 which is a reaction area and a lower hopper type water collecting area 12, and a filter layer is formed by a carrier (filter material) filled inside. As the carrier, anthracite having a particle diameter of about 2 to 10 mm, activated carbon, lightweight aggregate or the like is used. Catchment area 12
The air-lift pipe 29 is made into a hopper shape without accumulating the carrier to which the solid matter generated by biological treatment adheres.
Suck it in.

A carrier separating device 20 is provided at the center of the upper lid 16 of the aerobic filter bed tank 10, and a protective pipe 25 with a diffusing umbrella extending to the vicinity of the bottom of the catchment area 12 is provided at the lower part of the separating device 20 by using a hanging metal fitting. It's hanging. The upper end portion of the protection tube 25 is surrounded by a baffle tube 28 for preventing air outflow, and the air tube 18 and an air lift tube 29 for raising the carrier are inserted into the protection tube 25 and diffused by the air supplied from the air tube 18. The carrier that accumulates below the umbrella 26 is lifted by the air lift pipe 29. That is, the solid substance is adsorbed from the lower end of the air lift pipe 29 by the biological treatment of the raw water, and the solid substance and the carrier are simultaneously raised while peeling the solid substance from the carrier in the air lift pipe 29.

At the upper end of the air lift pipe 29, there is a separating device 20 for separating the carrier and solid matter and circulating the carrier in the aerobic filter bed tank 10. As shown in FIG. 1, the separation device 20 includes a carrier dispersion umbrella 23 that disperses and descends a mixture of a carrier and a solid material that has been raised by an air lift pipe 29, and a carrier extraction screen 24 that is provided below the carrier dispersion umbrella 23.
And a tray 21 disposed below the screen 24 for collecting the washing wastewater containing solids, and a washing drainage pipe 15 for draining the drainage received by the washing drainage tray 21 to the outside of the tank. As the screen 24, a slit, a perforated plate, a metal mesh or the like having a mesh that does not allow the carrier to pass therethrough is used. In addition, the amount of solid matter to be discharged can be controlled by adjusting the amount of air in the air tube 18, adjusting the screen inclination angle, and the like.

As shown in the figure, the diffusing umbrella 26 has a conical shape and is attached to the lower end of the water collecting cylinder 31. The treated water outflow pipe 14 penetrates the filter bed tank 10 from the upper part of the water collecting cylinder 31 and is led to the outside. The treated water collected by the diffusing umbrella 26 rises to the treated water tank due to the difference in water level. The air diffuser 35 is provided on the upper part of the diffusing umbrella. Therefore, oxygen is supplied to the carrier evenly, and microorganisms adhere to and grow on the surface of the carrier. The air lift pipe 29 has its lower end located at the bottom of the aerobic filter bed tank 10 and its upper end located at the upper part of the filter bed tank 10.

The aerobic filter tank 10 is filled with a carrier (filter material) for biologically treating raw water, and air is supplied from the air diffuser 35. The air diffuser 35 is the air header tube 3
A plurality of air diffusing pipes 37, 37 are arranged between the pipes 6, 36 to blow the air from the process air supply pipe 38 into the tank to enhance the action of aerobic microorganisms.

The carrier outflow prevention mechanism 30 is, as shown in the figure, a diffusing umbrella 2 provided on the outer periphery of a protective pipe 25 of an air lift pipe for diffusing the carrier descending into the catchment area 12 of the filter bed tank.
6 and from the small diameter side of the diffusion umbrella 26 to a height reaching the middle of the central water collecting part (reaction area) 11 in the filter bed tank, and preventing the outflow due to the sedimentation of the carrier, and uniformly collecting the treated water at a low flow rate. It is composed of a water collecting cylinder 31 for water and a treated water outflow pipe 14 protruding from the upper outer wall of the water collecting cylinder 31 to the outside of the tank.
In FIG. 1, reference numeral 32 is a support provided at a connection position between the water collecting cylinder 31 and the diffusing umbrella 26, 17 is a tank upper mount, and 40 is an air header drain pipe.

Next, the operation of the present invention will be described. When air is blown from the raw water inflow pipe 13 while blowing air from the air diffuser 35 below the filter bed filled with the carrier (filter medium), numerous aerobic microorganisms propagate on the surface of the carrier. Fine solids in the raw water are captured by the carrier while flowing from the top to the bottom in the tank. The dirt dissolved in the water is decomposed by the microorganisms adhering to the surface of the carrier, and clean water (treated water) is discharged from the water collecting mechanism 30 below. Since the filter bed is gradually closed, water and air are periodically blown from the lower part to operate the air lift, and the carrier is washed and circulated in the air lift pipe. Air for aeration is supplied to the carrier filled in the aerobic filter bed tank 10 by the air diffuser 35, and microorganisms are attached and grown on the surface of the carrier. The raw water supplied by the raw water inflow pipe 13 passes through the filtration layer formed in the filter bed tank. The SS component and BOD component contained in the raw water are oxidatively decomposed by the aerobic treatment of microorganisms, and as a result, solid matter is attached and accumulated on the surface of the carrier. The solid matter in the raw water and the solid matter generated by biological treatment are collected on the surface of the carrier or between the carriers, and while being collected, move to the lower layer of the filtration layer, and are separated from the air lift pipe 29 to the separation device 20. Be led to. Therefore, the solid content in the treated water is small, and the sedimentation basin in the usual corrosive oxidation method, activated sludge method, sprinkling filter method, etc. becomes unnecessary. The raw water is purified when it encounters the filter layer, and flows downward from the upper part of the aerobic filter bed tank 10 by the gravity force and the suction force to the lower end of the air lift pipe 29 generated by the air lift device.

The treated water purified by the filtration layer flows toward the bottom of the aerobic filter tank, but since the hopper-shaped catchment area 12 having the diffusion umbrella 26 is formed in the lower part of the filter bed tank 10, A part of the treated water is sucked into the lower end of the air lift pipe 29, but most of the treated water is sucked into the water collecting mechanism 30 and introduced into the treated water tank (not shown) through the treated water outflow pipe 14. The water collecting mechanism 30 has the diffusion umbrella 26 and a relatively long water collecting cylinder 31, and the treated water outlet pipe inlet 14 is set near the upper part of the water collecting cylinder 31, so that the flow of water during treatment is It is possible to obtain uniform treated water by increasing the treatment efficiency, suppressing the outflow of solid matters and carriers into the treated water, and obtaining good treated water.

On the other hand, the carrier to which the solid matter is attached is the air tube 1
Air for air lift blown from 8 is sucked from the lower end of the air lift pipe 29 and rises in the pipe. Since the carrier, part of the treated water, and air rise in the air lift pipe 29, the solid matter is agitated and separated from the carrier. The dirty carrier is scrubbed with air and continuously operated without backflow. The separated solid matter, carrier, and part of the treated water rise in the air lift pipe 29, and are separated from the upper end of the separation device 2
It is discharged to 0. At this time, the solid matter, the carrier, and part of the treated water (usually this treated water is called backwash water) are separated by the separator 20.
It is blocked by the shield plate and flows along the inclined surface. The carrier washed in the air lift pipe 29 is hung on the inclined screen 24 of the separator and circulated in the filter bed tank 10.
The solid matter enters the hollow structure of the separating device 20 together with the backwash water. This solid matter becomes backwash drainage together with backwash water.
The backwash drainage is received by the wash drainage tray 21 and the drain pipe 1
Discharged by 5.

[0016]

As described above, according to the present invention, since there is no screen, there is no fear of clogging, and the application to the raw water state is widened. There are few welding points on the tank body, the structure is simplified and the workability is improved. In addition, the carrier outflow prevention mechanism
A diffusing umbrella provided on the outer periphery of the protective tube of the air lift pipe for diffusing the carrier descending into the catchment area of the filter bed tank, and extending from the small diameter side of the diffusing umbrella to a height reaching the middle of the reaction area in the filter bed tank. Since it is composed of a water collection tube that uniformly collects the treated water at a low flow rate while preventing the outflow due to the sedimentation of the carrier, and a treated water outflow pipe protruding from the upper outer wall of the water collection tube to the outside of the tank, It is possible to obtain good treated water by uniformly collecting water without disturbing the movement of the carrier at the flow rate to improve the treatment efficiency and suppressing the outflow of the carrier and solids into the treated water. Further, by using a single tank type or multi-type aerobic filter bed tank made of steel plate or reinforced concrete, it is possible to reduce the installation cost.

[Brief description of drawings]

1 is a cross-sectional view of an apparatus for carrying out the method of the present invention.

[Explanation of symbols]

10 Aerobic filter tank 11 Central water collecting part 12 Lower hopper type water collecting area 13 Raw water inflow pipe 14 Treated water outflow pipe 15 Washing drainage pipe 16 Upper lid 17 Tank upper mount 18 Air pipe 20 Separation device 21 Washing drainage tray 22 Collecting tray Bracket 23 carrier dispersion umbrella 24 screen 25 protective tube with diffuser umbrella 26 diffuser umbrella 29 air lift tube 28 air outflow prevention baffle tube 30 water collecting mechanism 31 water collecting tube 32 support 35 air diffuser 36 air header tube 37 air diffuser 38 process air Supply pipe 40 Air header drain pipe

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Claims (2)

[Claims] 1. Raw water is introduced from the upper part of an aerobic filter bed filled with a carrier, and fine solids in the raw water are captured by the carrier while descending in the filter bed tank to remove solid matter by biological treatment. The carrier that has adhered and descended is raised by an air lift pipe provided in the center of the filter bed tank, and then the carrier from which solids have been separated is circulated into the filter bed tank, while the carrier outflow prevention mechanism prevents the carrier from flowing out. While being a downward flow type water treatment device configured to allow treated water to flow out of the catchment area of the filter bed tank, the carrier outflow prevention mechanism diffuses carriers descending into the catchment area of the filter bed tank. A diffusing umbrella provided on the outer periphery of the protective tube of the air lift pipe, a water collecting cylinder that can prevent the outflow of the carrier by extending from the small diameter side of the diffusing umbrella to a height reaching the middle of the reaction area in the filter bed tank, and a water collecting cylinder With the treated water outflow pipe protruding from the upper outer wall of the Carrier outflow preventing mechanism of the water treatment apparatus characterized by comprising a. 2. The carrier outflow prevention of a downflow type water treatment device according to claim 1, wherein the aerobic filter bed tank is a single tank type or a multi-tank type made of steel plate or reinforced concrete. mechanism.