JP2021181055A - Muddy water treatment system and muddy water treatment method with use thereof - Google Patents

Abstract

To provide a muddy water treatment system which can maintain filtration efficiency for a long time and can achieve reduction in the number of maintenance of a filter medium, and a muddy water treatment method with use of the same.SOLUTION: Soft filter sands 20 are put into a muddy water filtration tank 10. When feeding muddy water into the muddy water filtration tank 10, the soft filter sands 20 are floated and collected upward in the muddy water filtration tank 10 with utilization of water buoyant force. Muddy water is causes to pass through the soft filter sands 20 from below to flow upward, and is filtered. Pure water, which has been obtained by filtration thereof, is discharged to an exterior from the muddy water filtration tank 10 via a pure water drain pipe 15. Since specific gravity of a solid impurity contained in muddy water is larger than specific gravity of water, the solid impurity is naturally separated from the soft filter sands 20, and is precipitated below the muddy water filtration tank 10. When washing the filter sands, the soft filter sands 20 are moved upward by back washing water ejected from a back washing nozzle part 40, and the soft filter sands 20 are moved to a filter sand washing tank 30 through a sand feeding pipe 31.SELECTED DRAWING: Figure 1

Description

The present invention relates to a muddy water treatment system for filtering muddy water and a muddy water treatment method using the same, particularly a reverse muddy water treatment system in which muddy water flows in the direction opposite to the impurity precipitation direction and a muddy water treatment method using the same.

Current muddy water treatment systems include those that filter muddy water using a filter cloth (filter leaf, filter medium) or a centrifugal filter, and those that filter muddy water using a filtered sand sedimentation type or a pressurized type. In the above-mentioned filter cloth (filter leaf, filter medium) filtration method, muddy water is passed through the filter cloth and flows downward, and impurities and harmful substances contained in the muddy water are collected on the surface of the filter cloth (filter leaf, filter medium). The collected impurities become mud. Once the mud on its surface becomes thick, the mud directly affects the filtration efficiency of the muddy water treatment system. For this reason, it is always necessary to replace or clean the filter cloth (filter leaf, filter medium) with a new one, which requires time and effort for maintenance work and increases the cost. The filtered sand settling type requires the construction of a settling tank, requires a large area of the site, and has the disadvantage that it takes time to build the settling tank. A large amount of flocculant is used to further accelerate precipitation. The centrifugal filter filtration method and the pressurized filtration method require power equipment, the cost of the equipment is high, and the amount of muddy water treatment is limited, so that the total cost is too high.

Japanese Unexamined Patent Publication No. 2002-219471

In these current muddy water treatment systems, impurities removed from the muddy water inevitably settle in the filter medium as mud. And it is necessary to frequently clean the filter media and remove mud (impurities). It is a problem that the present invention positively tries to solve by making it possible to individually clean the filter material and remove mud (impurities) and to reduce the frequency of doing so as much as possible.

Considering the above-mentioned problems with the conventional methods and techniques, the present inventor felt the insufficiency of the current muddy water treatment system and conducted research and development with all his heart. After many years of experience in this industry, he has invented a backwashable floating reverse muddy water treatment system and a muddy water treatment method using the same. As a result, the objectives of maintaining filtration efficiency for a long period of time, reducing the number of times of filtration material maintenance, saving energy, simplifying maintenance work, reducing costs, and easily treating mud have been achieved.

A main object of the present invention is to provide a backwashable floating reverse muddy water treatment system capable of solving the above-mentioned problems and a muddy water treatment method using the same. In this backwashable floating reverse muddy water treatment system, mainly when the muddy water is passed through the muddy water filtration tank, the muddy water is flowed in the direction opposite to the impurity precipitation direction by using light filtered sand, and the impurities are settled on the filter material. Avoid that. As a result, it is possible to maintain the filtration efficiency for a long time, reduce the number of times of maintenance of the filter material, save energy, simplify the maintenance work, reduce the cost, and further easily treat the mud.

In order to achieve the above object, the present inventor provides a backwashable floating reverse muddy water treatment system. The backwashable floating reverse muddy water treatment system of the present invention is used for the purpose of filtering muddy water to purify water, and includes the following. :
One muddy water filtration tank. This muddy water filtration tank is a closed container whose inside is a muddy water filtration chamber. A muddy water supply pipe for supplying muddy water to the muddy water filtration chamber is provided at a predetermined position below the center of the muddy water filtration tank. A purified water drainage pipe is provided at a predetermined position above the center of the muddy water filtration tank to discharge purified water obtained by filtering muddy water to the outside from the muddy water filtration chamber. ;
A large amount of light filtered sand. A large amount of light filtered sand is placed in the muddy water filtration chamber, and when the muddy water is supplied to the muddy water filtration chamber, it is floated in the muddy water filtration chamber using the buoyancy of the water and collected upward. Here, the amount of the lightly filtered sand put into the muddy water filtration chamber is the amount so that the lowermost portion of the lightly filtered sand is located below the purified water drainage pipe when the muddy water is supplied into the muddy water filtration tank. In the present invention, the muddy water filtration treatment is performed by floating the light filtered sand on muddy water (floating) and flowing the muddy water in the direction opposite to the impurity precipitation direction (from bottom to top) and passing it through the light filtered sand. ;
One filtered sand cleaning tank. The filtered sand cleaning tank is connected to the upper part of the muddy water filtration tank via a sand supply pipe, and the bottom of the filtered sand cleaning tank is connected to the muddy water filtration tank via a sand drain pipe. Filtered sand cleaning tanks are used for cycle cleaning of light filtered sand. The sand supply pipe is for supplying the lightly filtered sand in the muddy water filtration chamber from the muddy water filtration chamber to the filtered sand washing tank, and the sand draining pipe is for supplying the lightly filtered sand washed in the filtered sand washing tank from the filtered sand washing tank. It is for discharging to the muddy water filtration chamber. ;
One backwash nozzle part. This backwash nozzle portion is arranged at a position above the purified water drainage pipe in the upper part of the muddy water filtration chamber. Water for backwashing is injected from the outside through the backwash nozzle into the muddy water filtration chamber, and the flow of this backwashing water removes dirt adhering to the lightly filtered sand and lightly filters using the water pressure of the backwashing water. The sand is transferred to the filtered sand cleaning tank via the sand supply pipe. ;
One mud discharge device. This mud discharge device is installed at the bottom of the mud filtration tank and is connected to the mud filtration chamber. The mud discharge device is a device used to discharge the mud generated during the filtration process of mud water.

In the backwashable floating reverse muddy water treatment system of the present invention, the light filtered sand is filtered granules having a lower specific density than water.

In the backwashable floating reverse muddy water treatment system of the present invention, an electric valve may be provided in each pipe in order to enable automatic control of the system. In this case, specifically, a first valve for adjusting the inflow of muddy water is installed in the muddy water supply pipe. A second valve is installed in the purified water drain pipe to regulate the outflow of purified water. A third valve is installed in the sand supply pipe to regulate the inflow of light filtered sand. A fourth valve is installed in the sand drain pipe to regulate the outflow of light filtered sand. A fifth valve for adjusting the inflow of backwash water is installed in the backwash water supply pipe connected to the backwash nozzle portion.

In the backwashable floating reverse muddy water treatment system of the present invention, a large number of holes, for example, mesh holes, which allow only purified water to pass through the pipe wall of the purified water drainage pipe drawn into the muddy water filtration chamber and prevent the intrusion of light sand. Is desirable to be formed.

In the backwashable floating reverse muddy water treatment system of the present invention, it is desirable that the backwash nozzle portion is formed with a large number of holes, for example, mesh holes, which allow only water to pass through and prevent the intrusion of light sand.

In the backwashable floating reverse direction mud treatment system of the present invention, the mud discharge device may include the following. That is, a mud carrier installed at the bottom of the muddy water filtration tank for carrying out the mud accumulated at the bottom of the muddy water filtration chamber, and mud carried out by the mud carrier connected to the muddy water filtration chamber via the mud carrier. It is a mud discharge pipe for discharging to the outside.

In the backwashable floating reverse muddy water treatment system of the present invention, it is desirable that the muddy water filtration tank is provided with a water level gauge that indicates the water level of the muddy water in the muddy water filtration chamber.

In the backwashable floating reverse muddy water treatment system of the present invention, the above water level gauge is a water level visual window formed on the side surface of the muddy water filtration tank so that the water level of the muddy water in the muddy water filtration chamber can be visually observed, or muddy water filtration. It may be a transparent water level tube connected to a muddy water filtration tank so that indoor muddy water can freely flow.

In order to achieve the above-mentioned object, the present inventor provides a muddy water treatment method using the above-mentioned backwashable floating reverse muddy water treatment system. The muddy water treatment method of the present invention includes a muddy water filtration step in which muddy water is filtered in a muddy water filtration chamber using light filtered sand and then converted into purified water and discharged to the outside, and filtered sand in which the light filtered sand is washed in a filtered sand washing tank. It has a cleaning step and a mud discharge step of discharging the mud accumulated at the bottom of the muddy water filtration chamber to the outside using a mud discharge device. Of these, the muddy water filtration step includes the procedures shown in the following (a)-(e) as the procedure for the muddy water filtration treatment.
(A) Open the valve of the purified water drain pipe connected to the muddy water filtration tank, close each valve of the sand supply pipe and sand drain pipe connected to the filtered sand washing tank, and open the valve of the backwash water supply pipe connected to the backwash nozzle part. Close and close the outlet of the mud drainer.
(B) Open the valve of the muddy water supply pipe connected to the muddy water filtration tank, and put the external muddy water into the muddy water filtration tank through the muddy water supply pipe.
(C) By continuing to put the muddy water in the muddy water filtration tank, the muddy water is made to flow upward with the purified water drain pipe by the water pressure.
(D) At this time, the light filtered sand collects in the upper part of the muddy water filtration chamber due to the buoyancy of the muddy water, and the muddy water flowing upward through the light filtered sand is filtered by the light filtered sand, and solid impurities are separated from the muddy water. The purified water obtained by filtering the muddy water is discharged to the outside through a purified water drainage pipe. On the other hand, solid impurities trapped in the lightly filtered sand settle to the bottom of the muddy water filtration chamber and become mud.
(E) When the muddy water filtration process is completed, close the valves of the muddy water supply pipe and the purified water drainage pipe.

In the muddy water treatment method using the backwashable floating reverse muddy water treatment system of the present invention, the filtered sand washing step and the mud discharge step include the procedures shown in (f)-(l) below.
(F) Close each valve of the muddy water supply pipe and the purified water drain pipe connected to the muddy water filtration tank, and close the valve of the sand drain pipe connected to the filtered sand washing tank. Then, open the valve of the sand supply pipe connected to the filtered sand washing tank.
(G) Open the valve of the backwash water supply pipe connected to the backwash nozzle and put the backwash water into the muddy water filtration chamber.
(H) After starting the supply of the backwash water in this way, the backwash water is continuously supplied to the muddy water filtration chamber, and the lightly filtered sand is washed with the backwash water. In addition, the light filtered sand is moved upward by the water pressure of the backwashing water, and put into the filtered sand washing tank through the sand supply pipe.
(I) Wash the light filtered sand in the filtered sand washing tank.
(J) Close the valve of the sand supply pipe connected to the filtered sand washing tank and the valve of the backwash water supply pipe connected to the backwash nozzle, and open the valve of the sand drain pipe.
(K) After opening the valve of the sand discharge pipe, the mud discharge device is driven to discharge the mud settled at the bottom of the muddy water filtration chamber. When the mud is discharged, the light filtered sand in the filtered sand washing tank is passed through the sand drain pipe and returned to the muddy water filtration chamber by utilizing the fact that the muddy water filtration chamber is in a negative pressure state.
(L) After the mud discharge treatment and the treatment of returning the lightly filtered sand to the muddy water filtration chamber are completed, the mud discharge from the mud discharge device is stopped and the valve of the sand drain pipe is closed.

The backwashable floating type reverse muddy water treatment system of the present invention and the muddy water treatment method using the same can achieve the effects shown in the following (1)-(3).

(1) In the present invention, lightly filtered sand is used, and a reverse muddy water treatment structure (that is, a structure in which muddy water flows from bottom to top) is adopted, and muddy water is filtered according to a predetermined muddy water filtration treatment procedure. That is, since the specific gravity of the light filtered sand is smaller than the specific gravity of water, the light filtered sand can be floated and collected in the upper part of the muddy water filtration tank, and the muddy water flowing from the bottom to the top can be filtered by the light filtered sand. Since the specific gravity of the solid impurities in the muddy water is larger than the specific gravity of the water, the solid impurities can be reliably separated from the lightly filtered sand, and the solid impurities are automatically settled to the bottom in the muddy water filtration tank. .. Since it is possible to prevent impurities from settling on the filter material in this way, it is possible to achieve the effects of maintaining the filtration efficiency for a long time and reducing the number of maintenance times of the filter material.

(2) In the present invention, a backwash nozzle portion and a filtered sand washing tank are provided, and light filtered sand is washed according to a predetermined procedure of filtered sand washing treatment and mud discharge treatment. That is, the light filtered sand can be moved upward by the backwashing water ejected from the backwash nozzle portion, and the light filtered sand can be easily put into the filtered sand washing tank through the sand supply pipe. Then, the light filtered sand can be washed in the filtered sand washing tank. Further, by discharging the mud settled at the bottom of the muddy water filtration chamber with the mud discharge device, the muddy water filtration chamber can be put into a negative pressure state. Therefore, by utilizing the negative pressure, the light filtered sand contained in the filtered sand washing tank can be automatically taken out from the filtered sand washing tank to the muddy water filtering tank through the sand drain pipe, so that the light filtered sand is pumped. There is no need to send it out. As a result, the effects of energy saving and maintenance cost reduction can be achieved.

(3) In the present invention, the mud discharge device is used to discharge the mud that has settled at the bottom of the muddy water filtration chamber. As a result, mud can be easily treated, so that maintenance work can be simplified.

FIG. 1 is a schematic perspective view of a backwashable floating type reverse muddy water treatment system according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view for explaining a muddy water filtration step in a muddy water treatment method using the backwashable floating reverse muddy water treatment system of the present embodiment. FIG. 3 is a schematic cross-sectional view for explaining a filtered sand cleaning step and a mud discharge step in a muddy water treatment method using the backwashable floating reverse muddy water treatment system of the present embodiment.

In order to fully understand the features and effects of the present invention, the contents of the present invention will be described in detail with reference to the accompanying drawings and the following specific embodiments. FIG. 1 is a schematic perspective view of a backwashable floating type reverse muddy water treatment system according to an embodiment of the present invention. Here, in FIG. 1, a part of the system is cut out and shown.

As shown in FIG. 1, the backwashable floating reverse muddy water treatment system according to the embodiment of the present invention is for filtering the supplied muddy water (raw water) and converting it into purified water (treated water) for discharging. used. More specifically, the backwashable floating reverse muddy water treatment system of the present embodiment includes the following components. That is, as shown in FIG. 1, this backwashable floating type reverse muddy water treatment system has one muddy water filtration tank 10, a large amount of light filtered sand 20, one filtered sand washing tank 30, and one reverse. A washing nozzle portion 40 and one mud discharging device 50 are provided.

The muddy water filtration tank 10 is a closed container having one muddy water filtration chamber 11 inside. In the present embodiment, the central portion of the muddy water filtration tank 10 is formed in a cylindrical shape, and the muddy water filtration tank 10 is arranged so that its central axis is perpendicular to the ground. At the top of the muddy water filtration tank 10, there is an upper conical portion 12 whose apex is located on the upper side, and the upper conical portion 12 is arranged above the central portion of the muddy water filtration tank 10. At the bottom of the muddy water filtration tank 10, there is a lower conical portion 13 whose apex is located on the lower side, and this lower conical portion 13 is arranged below the central portion of the muddy water filtration tank 10. A muddy water supply pipe 14 is attached to a predetermined location below the center of the muddy water filtration tank 10, for example, a location near the lower conical portion 13 in the central portion thereof. A purified water drain pipe 15 is attached to a predetermined location above the center of the muddy water filtration tank 10, for example, a location near the upper conical portion 12 in the central portion thereof. The tip of the purified water drainage pipe 15 is drawn into the muddy water filtration chamber 11. The muddy water supply pipe 14 is for supplying muddy water (raw water) to the muddy water filtration chamber 11, and the purified water drain pipe 15 is for purifying water (treated water) obtained by filtering muddy water (raw water) from the muddy water filtration chamber 11. It is for discharging to the outside.

The light filtered sand 20 is light filtered granules (specific gravity <1) whose specific gravity is smaller than the specific density (≈1) of water. A large amount of light filtered sand 20 is placed in the muddy water filtration chamber 11. The lightly filtered sand 20 contained therein is floated and collected on the upper side in the muddy water filtration chamber 11 by the buoyancy of water. Here, in the present embodiment, the amount of the light filtered sand 20 put into the muddy water filtration chamber 11 is such that the lowermost portion of the light filtered sand 20 is lower than the purified water drain pipe 15 when the muddy water is supplied into the muddy water filtering tank 10. It is the amount that comes to be located in. That is, in the state where the light filtered sand 20 is floated, the light filtered sand 20 is collected above the muddy water supply pipe 14, but completely covers the purified water drain pipe 15. In this way, the light filtered sand 20 filters the muddy water by floating the light filtered sand 20 on the muddy water (floating) and flowing the muddy water in the direction opposite to the impurity precipitation direction (from bottom to top) and passing it through the light filtered sand 20. Then, the impurities and harmful substances contained in it are separated from the muddy water. As the light filtered sand 20, for example, sand having a particle size smaller than 1 mm can be used.

The filtered sand cleaning tank 30 is for storing the light filtered sand 20 and cleaning the light filtered sand 20. As the filtered sand washing tank 30, a tank having a capacity capable of accommodating all of the light filtered sand 20 is used. The lightweight filtered sand 20 is washed in the filtered sand washing tank 30 by a predetermined method. In the present embodiment, the filtered sand washing tank 30 is arranged at a position higher than the muddy water filtering tank 10. One end of the sand supply pipe 31 is connected to the side of the filtered sand cleaning tank 30, and the other end of the sand supply pipe 31 is the top of the muddy water filtration tank 10, specifically, muddy water. It is connected to the apex of the upper conical portion 12 of the filtration tank 10. Further, one end of the sand drain pipe 32 is connected to the bottom of the filtered sand washing tank 30, and the other end of the sand drain pipe 32 is connected to the muddy water filtration chamber 11 of the muddy water filtration tank 10. There is. The sand supply pipe 31 is for supplying the light filtered sand 20 in the muddy water filtration chamber 11 from the muddy water filtration chamber 11 to the filtered sand cleaning tank 30, and the sand drain pipe 32 is the light quality washed in the filtered sand cleaning tank 30. This is for discharging the filtered sand 20 from the filtered sand washing tank 30 to the muddy water filtration chamber 11. By moving the light filtered sand 20 between the muddy water filtering tank 10 and the filtered sand washing tank 30 via the sand supply pipe 31 and the sand draining pipe 32, the light filtered sand 20 can be circulated and washed. In the present embodiment, the filtered sand cleaning tank 30 is arranged at a position higher than the muddy water filtration tank 10, but in general, the filtered sand cleaning tank 30 is arranged at a position lower than the muddy water filtration tank 10. You may.

The backwash nozzle portion 40 is provided in the upper part of the muddy water filtration chamber 11. Here, the backwash nozzle portion 40 is arranged on the upper side of the purified water drain pipe 15. The backwash nozzle portion 40 is connected to a backwash water supply pipe for supplying water for backwash from the outside. The backwash water is sent into the muddy water filtration chamber 11 via the backwash nozzle portion 40, and the dirt adhering to the light filtered sand 20 is removed by the flow of the sent backwash water, and the water pressure of the backwash water is reduced. It can be utilized to move the light filtered sand 20 upward and lead it to the filtered sand cleaning tank 30. Then, the light filtered sand 20 is washed in the filtered sand washing tank 30.

The mud discharge device 50 is installed at the bottom of the muddy water filtration tank 10 and is connected to the muddy water filtration chamber 11. The mud discharge device 50 is for discharging the mud 80 that has settled at the bottom of the muddy water filtration chamber 11 during the muddy water filtration process.

Further, as shown in FIG. 1, in order to realize automatic control of the muddy water filtration treatment and the cleaning treatment of the light filtered sand 20, the backwashable floating type reverse muddy water treatment system of the present embodiment has the following configuration. It is adopted. That is, a first valve 16 for adjusting the inflow of muddy water is installed in the muddy water supply pipe 14 connected to the muddy water filtration tank 10, and a second valve 17 for adjusting the outflow of purified water is installed in the purified water drain pipe 15. Further, a third valve 33 for adjusting the inflow of the light filtered sand 20 is installed in the sand supply pipe 31 connected to the filtered sand washing tank 30, and a fourth valve for adjusting the outflow of the light filtered sand 20 is installed in the sand drain pipe 32. 34 is installed. Further, a fifth valve 41 for adjusting the inflow of backwash water is installed in the backwash water supply pipe connected to the backwash nozzle portion 40. Electric valves are used as these five valves 16, 17, 33, 34, 41. Therefore, the plug passages of the valves 16, 17, 33, 34, and 41 can be automatically opened and closed by a signal from the control device (not shown).

Further, on the pipe wall at the tip of the purified water drain pipe 15 drawn into the muddy water filtration chamber 11, a large number of light filtered sands 20 can be prevented from entering the pipe and only purified water can enter the purified water drain pipe 15. Holes are formed. For example, as these a large number of holes, a sorting means such as a mesh hole 151 or a net can be used. Similarly, the backwash nozzle portion 40 is also formed with a large number of holes that prevent the light filtered sand 20 from entering the pipe and allow only water to enter and exit the muddy water filtration chamber 11. Also in this case, as a large number of holes, a sorting means such as a mesh hole 42 or a net can be used. In particular, when the particle size of the light filtered sand 20 is smaller than 1 mm, a sorting means using a filtering material may be used as the large number of holes.

As the mud discharge device 50 described above, the one having the following configuration can be used. That is, the mud discharge device 50 is installed at the apex of the lower conical portion 13 of the mud filtration tank 10 via a mud transporter 51 for carrying out the mud accumulated at the bottom of the mud filter chamber 11 and the mud transporter 51. It is provided with a mud discharge pipe 52 for discharging the mud carried out by the mud transporter 51 to the outside, which is connected to the mud filter chamber 11, and an electric motor 81 for driving the mud transporter 51. Specifically, a mechanism capable of taking out the mud 80 to the outside, such as a screw conveyor and a pumping tube conveyor, can be applied to the mud transporter 51. In FIGS. 2 and 3 described later, a mud transporter 51 using a screw conveyor is shown. Further, the discharge port between the mud discharge device 50 and the mud discharge pipe 52 is configured to be openable and closable by a signal from a control device (not shown). Here, this outlet is designed to withstand water pressure of, for example, 5 atm or more.

In the muddy water filtration tank 10, a water level gauge 60 indicating the water level of the muddy water in the muddy water filtration chamber 11 can be installed. Specifically, as the water level gauge 60, a water level visual window formed on the side surface of the muddy water filtration tank 10 for visually observing the water level of the muddy water in the muddy water filtration chamber 11 or a muddy water in the muddy water filtration chamber 11 can freely flow. A transparent water level pipe connected to the muddy water filtration tank 10 can be used so as to be possible. Here, the transparent water level pipe is connected to the muddy water filtration chamber 11 and indicates the water level in the muddy water filtration chamber 11. Further, the water level visual window can be used not only to show the water level in the muddy water filtration chamber 11 but also to show the height of the light filtered sand 20. In the present embodiment, a case where the water level visual window 61 is used as the water level meter 60 will be considered.

Next, a muddy water treatment method using the backwashable floating type reverse muddy water treatment system of the present embodiment will be described. This muddy water treatment method includes a muddy water filtration step in which muddy water is filtered in the muddy water filtration chamber 11 using the light filtered sand 20 and discharged to the outside in the form of purified water, and the light filtered sand 20 is washed in the filtered sand washing tank 30. It includes a filtered sand cleaning step and a mud discharging step of discharging the mud accumulated at the bottom of the muddy water filtering chamber 11 to the outside by using the mud discharging device 50.

First, the procedure of the muddy water filtration step in the muddy water treatment method using the backwashable floating reverse muddy water treatment system of the present embodiment will be described. FIG. 2 is a schematic cross-sectional view for explaining a muddy water filtration step in a muddy water treatment method using the backwashable floating reverse muddy water treatment system of the present embodiment. Specifically, the procedure of the muddy water filtration step is as shown in (a)-(e) below.

(A) First, the second valve 17 of the purified water drain pipe 15 connected to the muddy water filtration tank 10 is opened, and the third valve 33 of the sand supply pipe 31 and the fourth valve 34 of the sand drain pipe 32 connected to the filtered sand washing tank 30. Close. Then, the fifth valve 41 of the backwash water supply pipe connected to the backwash nozzle portion 40 is closed, and the discharge port of the mud discharge device 50 is closed. Here, in the present embodiment, the opening and closing of the discharge ports of these valves 17, 33, 34, 41 and the mud discharge device 50 is automatically controlled by a signal from the control device (not shown).

(B) Next, the supply of muddy water is started. That is, the first valve 16 of the muddy water supply pipe 14 connected to the muddy water filtration tank 10 is opened, and the external muddy water is put into the muddy water filtration chamber 11 through the muddy water supply pipe 14.

(C) After starting the supply of muddy water in this way, when the muddy water is continuously injected into the muddy water filtration chamber 11, the muddy water is discharged into the muddy water filtration chamber as shown by the solid arrow in FIG. 2 due to the water pressure of the injected muddy water. It flows from the bottom to the top in 11 and above the purified water drain pipe 15, and the water level of muddy water gradually rises.

(D) Further, when the muddy water is injected into the muddy water filtration chamber 11 in this way, the light filtered sand 20 floats on the muddy water due to the buoyancy of the muddy water and collects on the upper part of the muddy water filtration tank 10 as shown in FIG. When the muddy water fills the muddy water filtration tank 10, the light filter sand 20 is collected in the upper part of the muddy water filtration chamber 11, and the backwash nozzle portion 40 and the purified water drain pipe 15 are buried in the light filter sand 20. Then, the light filtered sand 20 filters and purifies impurities and harmful substances contained in the muddy water flowing from the bottom to the top of the muddy water filtration chamber 11. In this way, the muddy water flowing in the upper part of the muddy water filtration chamber 11 becomes purified water and is discharged to the outside through the purified water drain pipe 15.

On the other hand, since the specific gravity of the solid impurity 70 adsorbed by the light filtered sand 20 is larger than the specific gravity of water, as shown by the dotted arrow in FIG. 2, it precipitates at the bottom of the muddy water filtration chamber 11 and becomes mud 80. The mud 80 will be discharged using the mud discharge device 50 described above in the mud discharge step.

(E) When the muddy water filtration process is completed, the first valve 16 of the muddy water supply pipe 14 and the second valve 17 of the purified water drainage pipe 15 are closed.

As described above, in the backwashable floating reverse muddy water treatment system of the present embodiment and the muddy water treatment method using the same, the specific gravity of the light filtered sand 20 is smaller than the specific gravity of water, so that the light filtered sand 20 is used in the muddy water filtration tank. It can be floated on the top of 10 and collected, and the muddy water flowing upward through the light filtered sand 20 can be filtered from below. Further, since the specific gravity of the solid impurities 70 contained in the muddy water is larger than the specific gravity of the water, the solid impurities 70 naturally separate from the light filtered sand 20 and settle below the muddy water filtration tank 10. As a result, it is possible to prevent the solid impurities 70 from settling on the filter material, so that it is possible to achieve the effects of maintaining the filtration efficiency for a long time and reducing the number of maintenance times of the filter material.

Next, the filtered sand washing step and the mud discharge step in the muddy water treatment method using the backwashable floating type reverse muddy water treatment system of the present embodiment will be described. FIG. 3 is a schematic cross-sectional view for explaining a filtered sand cleaning step and a mud discharge step in a muddy water treatment method using the backwashable floating reverse muddy water treatment system of the present embodiment. The work of this filtered sand washing step is performed in a state where the muddy water filtering tank 10 is filled with water. Specifically, the filtered sand washing step and the mud discharging step are as shown in (f)-(l) below.

(F) First, the first valve 16 of the muddy water supply pipe 14 connected to the muddy water filtration tank 10, the second valve 17 of the purified water drain pipe 15, and the fourth valve 34 of the sand drain pipe 32 connected to the filtered sand washing tank 30 are closed. The third valve 33 of the sand supply pipe 31 connected to the filtered sand cleaning tank 30 is opened. Here, in the present embodiment, the opening and closing of these valves 16, 17, 33, 34 is automatically controlled by a signal from a control device (not shown).

(G) Next, the injection of backwash water is started. That is, the fifth valve 41 of the backwash water supply pipe connected to the backwash nozzle portion 40 is opened, and the backwash water is put into the muddy water filtration tank 10 through the backwash nozzle portion 40.

(H) After starting the supply of the backwash water in this way, by continuously supplying the backwash water into the muddy water filtration chamber 11, the dirt adhering to the light filtered sand 20 in the muddy water filtration chamber 11 due to the flow of the backwash water. Can be dropped. Further, since the specific gravity of the light filtered sand 20 is smaller than the specific gravity of water, the light filtered sand 20 floats upward due to the water pressure of the backwashing water and moves to the filtered sand washing tank 30 through the sand supply pipe 31.

(I) At this point, the fourth valve 34 of the sand removal pipe 32 is closed. In this state, the light filtered sand 20 contained therein is washed in the filtered sand washing tank 30, and the washed light filtered sand 20 is stored in the filtered sand washing tank 30.

(J) Next, the first valve 16 of the muddy water supply pipe 14 and the second valve 17 of the purified water drainage pipe 15 are kept closed, and the backwash connected to the third valve 33 of the sand supply pipe 31 and the backwash nozzle portion 40. Close the fifth valve 41 of the water supply pipe. Then, the discharge port of the fourth valve 34 of the sand discharge pipe 32 and the mud discharge device 50 is opened.

(K) After that, the mud discharge device 50 is driven to discharge the mud 80 accumulated at the bottom of the muddy water filtration chamber 11 to the outside. Due to the action of the mud discharge device 50 to discharge the mud 80, the inside of the muddy water filtration chamber 11 is in a vacuum negative pressure state. Therefore, the light filtered sand 20 stored in the filtered sand washing tank 30 naturally enters the muddy water filtration chamber 11 through the sand drain pipe 32.

(L) After the mud discharge treatment and the treatment of returning the light filtered sand 20 to the muddy water filtration chamber 11 are completed, the drive of the mud discharge device 50 is stopped, the discharge port of the mud discharge device 50 is closed, and the sand discharge pipe is closed. The fourth valve 34 of 32 is closed. By repeating the above treatments (f)-(l) a predetermined number of times, the entire light filtered sand 20 is washed.

In the backwashable floating reverse muddy water treatment system of the present embodiment, the backwash nozzle portion 40, the filtered sand washing tank 30 connected to the muddy water filtration tank 10, and the mud discharge provided at the bottom of the muddy water filtration tank 10. It is equipped with a device 50. In the muddy water treatment method of the present embodiment, the filtered sand washing treatment and the mud discharge treatment can be easily performed by using this backwashable floating type reverse direction muddy water treatment system. That is, the light filtered sand 20 can be moved upward by the backwashing water ejected from the backwash nozzle portion 40, and the light filtered sand 20 can be put into the filtered sand washing tank 30 through the sand supply pipe 31 for washing. As described above, it is not necessary to take out the light filtered sand 20 in the washing process, and it is not necessary to suck up the light filtered sand 20 by using another pump. Therefore, the effects of energy saving and reduction of maintenance cost can be obtained. Further, in the cleaning treatment of the light filtered sand 20, the mud discharge device 50 is used to discharge the mud 80 that has settled at the bottom of the muddy water filtration chamber 11. Since the inside of the muddy water filtration chamber 11 can be brought into a negative pressure state by performing this mud discharge treatment, the light filtered sand 20 washed and accumulated in the filtered sand washing tank 30 can be made to use the negative pressure. It can be returned to the muddy water filtration chamber 11. As a result, the effects of energy saving, simplification of mud discharge treatment, and simplification of maintenance work can be obtained.

The present invention is not limited to the above embodiment, and various modifications can be made within the scope of the gist thereof.

As described above, according to the muddy water treatment system of the present invention and the muddy water treatment method using the same, light filtered sand is floated and collected in the upper part of the muddy water filtration tank, and the muddy water flowing from the bottom to the top is collected by the light filtered sand. By filtering with, the solid impurities in the muddy water and the light filtered sand can be separated and the solid impurities can be settled to the bottom of the muddy water filtration chamber, so that the filtration efficiency can be maintained for a long time and the maintenance of the filter material can be maintained. The number of times can be reduced. Further, when washing the light filtered sand, the light filtered sand can be moved upward by the backwashing water ejected from the backwash nozzle portion, so that the light filtered sand can be easily transferred to the filtered sand washing tank through the sand supply pipe. Can be put in. Furthermore, by utilizing the fact that the muddy water filtration chamber can be put into a negative pressure state by discharging the mud that has settled at the bottom of the muddy water filtration chamber with the mud discharge device, the light filtered sand contained in the filtered sand washing tank is discharged. Since it can be automatically taken out from the filtered sand washing tank to the muddy water filtration tank through the sand pipe, energy saving and maintenance cost reduction can be achieved. Therefore, the present invention is suitable for use in performing a treatment for filtering muddy water.

10 Muddy water filtration tank 11 Muddy water filtration chamber 12 Upper conical part 13 Lower conical part 14 Muddy water water supply pipe 15 Purified water drain pipe 151 Mesh hole 16 First valve 17 Second valve 20 Lightly filtered sand 30 Filtered sand cleaning tank 31 Sand supply pipe 32 Discharge Sand pipe 33 Third valve 34 Fourth valve 40 Backwash nozzle 41 Fifth valve 42 Mesh hole 50 Mud discharge device 51 Mud transporter 52 Mud discharge pipe 60 Water level gauge 61 Water level visual window 70 Solid impurities 80 Mud 81 Electric motor

Claims (10)

In a muddy water treatment system that filters muddy water
A muddy water filtration tank whose inside is a muddy water filtration chamber where the process of filtering the muddy water is performed, and
A muddy water supply pipe for supplying the muddy water to the muddy water filtration chamber provided at a predetermined position below the center of the muddy water filtration tank, and
A purified water drainage pipe provided at a predetermined position above the center of the muddy water filtration tank for discharging purified water obtained by filtering the muddy water from the muddy water filtration chamber to the outside.
A large amount of light filtered sand that is placed in the muddy water filtration chamber and floats in the muddy water filtration chamber and collected upward by utilizing the buoyancy of water when the muddy water is supplied to the muddy water filtration chamber.
A filtered sand cleaning tank in which the process for cleaning the light filtered sand is performed, and
The light filtered sand in the muddy water filtration chamber, one end connected to the filtered sand washing tank and the other end connected to the upper part of the muddy water filtering tank, is washed from the muddy water filtering chamber by the filtered sand. A sand supply pipe for supplying to the tank and
The light filtered sand washed in the filtered sand washing tank, one end connected to the bottom of the filtered sand washing tank and the other end connected to the muddy water filtering tank, is connected to the filtered sand washing tank. And a sand drain pipe for discharging to the muddy water filtration chamber,
By injecting backwash water provided in the upper part of the muddy water filtration chamber and above the purified water drain pipe into the muddy water filtration chamber, the light filtered sand is injected through the sand supply pipe at the water pressure. The backwash nozzle for moving to the filtered sand washing tank,
A mud discharge device provided at the bottom of the muddy water filtration tank and discharging mud accumulated in the lower part of the muddy water filtration chamber during the muddy water filtration process to the outside.
Equipped with
The amount of the light filtered sand put into the muddy water filtration chamber is an amount such that the lowermost portion of the light filtered sand is located below the purified water drain pipe when the muddy water is supplied into the muddy water filtration tank. It is characterized by being. The muddy water treatment system according to claim 1, wherein the light filtered sand is filtered granules having a specific gravity smaller than that of water. The muddy water supply pipe is provided with a first valve for adjusting the inflow of the muddy water, the purified water drain pipe is provided with a second valve for adjusting the outflow of the purified water, and the sand supply pipe is provided with the light filtered sand. A third valve for adjusting the inflow of water is provided, a fourth valve for adjusting the outflow of the lightly filtered sand is provided in the sand discharge pipe, and the reverse washing water supply pipe connected to the backwash nozzle portion is in reverse. The muddy water treatment system according to claim 1 or 2, wherein a fifth valve for adjusting the inflow of wash water is provided. The wall of the purified water discharge pipe drawn into the muddy water filtration chamber is formed with a large number of holes capable of preventing the inflow of the light filtered sand, although the purified water can flow into the purified water discharge pipe. The muddy water treatment system according to claim 1, 2 or 3. 15. The muddy water treatment system according to 2, 3 or 4. The mud discharge device is a mud transporter installed at the bottom of the mud filtration tank to carry out mud accumulated at the bottom of the mud filtration chamber, and the mud connected to the mud filtration chamber via the mud transporter. The muddy water treatment system according to any one of claims 1 to 5, further comprising a mud discharge pipe for discharging the mud carried out by the transporter to the outside. The muddy water treatment system according to any one of claims 1 to 6, wherein a water level gauge indicating the water level of the muddy water in the muddy water filtration chamber is installed in the muddy water filtration tank. The water level gauge is a water level visual window formed on the side surface of the muddy water filtration tank so that the water level of the muddy water in the muddy water filtration chamber can be visually recognized, or the muddy water in the muddy water filtration chamber can be freely flowed. The muddy water treatment system according to claim 7, wherein the water level tube is connected to a muddy water filtration tank. The muddy water treatment method using the muddy water treatment system according to any one of claims 1 to 8 is
A muddy water filtration step of filtering the muddy water in the muddy water filtration chamber using the lightly filtered sand, converting it into purified water, and discharging it to the outside.
In the filtered sand cleaning step of cleaning the light filtered sand in the filtered sand cleaning tank,
A mud discharge process in which the mud accumulated at the bottom of the muddy water filtration chamber is discharged to the outside using the mud discharge device, and
Have,
The muddy water filtration step is
The first step of opening the valve of the purified water drain pipe and closing each valve of the sand supply pipe, the sand drain pipe, and the backwash water water supply pipe connected to the backwash nozzle portion.
The second step of opening the valve of the muddy water supply pipe and starting the process of supplying the muddy water to the muddy water filtration chamber, and the second step.
After starting the supply of the muddy water in the second step, by continuously supplying the muddy water to the muddy water filtration chamber, the muddy water is flowed from the bottom to the top in the muddy water filtration chamber, and the light filtered sand is used as the muddy water. A third that floats in the muddy water filtration chamber by buoyancy, collects it on the upper part thereof, filters the muddy water through which the lightly filtered sand flows upward, and discharges the purified water obtained by the filtration to the outside through the purified water drain pipe. Process and
The fourth step of closing each valve of the muddy water supply pipe and the purified water drainage pipe when the filtration process of the muddy water is completed, and
A muddy water treatment method comprising. The filtered sand washing step and the mud discharging step
The first step of opening the valve of the sand supply pipe and
The second step of opening the valve of the backwash water supply pipe connected to the backwash nozzle portion and starting the process of putting the backwash water into the muddy water filtration chamber, and the second step.
After starting the supply of the backwash water in the second step, the backwash water is continuously supplied to the muddy water filtration chamber, so that the light filtered sand is supplied to the sand by utilizing the water pressure of the backwash water. The third step of moving to the filtered sand washing tank via a pipe, and
The fourth step of cleaning the light filtered sand placed in the filtered sand washing tank, and
The fifth step of closing each valve of the sand supply pipe and the backwash water supply pipe connected to the backwash nozzle portion and opening the valve of the sand drain pipe.
After opening the valve of the sand drain pipe in the fifth step, the mud discharge device is driven to discharge the mud accumulated in the muddy water filtration chamber to the outside, and when the mud is discharged, the muddy water filtration is performed. The sixth step of returning the light filtered sand accumulated after cleaning in the filtered sand cleaning tank to the muddy water filtration chamber via the sand drain pipe by utilizing the negative pressure state of the chamber.
After the mud discharge treatment and the treatment of returning the light filtered sand to the muddy water filtration chamber are completed in the sixth step, the mud discharge from the mud discharge device is stopped and the valve of the sand drain pipe is closed. Process and
9. The muddy water treatment method according to claim 9.

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