JP4633502B2 - Sand separation and cleaning equipment - Google Patents

Description

  The present invention relates to a sand separation and cleaning device, and more particularly, to a sand separation and cleaning device capable of removing odors of dirty sand pumped from a sand basin and the like and highly removing impurities contained in the sand. Is.

  Conventionally, sand that has been pumped from a sand basin such as a sewage treatment plant or water purification plant using a pump is solid-liquid separated by a solid-liquid separation device using specific gravity difference separation, centrifugal separation, etc., and only the sand content is recovered. I am doing so.

By the way, in recent years, regulations regarding wastes have become stricter, and sedimentation sand containing foreign matters is handled as industrial waste, and its disposal cost has become enormous.
On the other hand, in order to dispose (or reuse) the sand sediment as general waste, it is necessary to reliably separate and remove impurities contained in the sand sediment in addition to the heat loss being 10% or less.

Therefore, the applicant of the present invention, according to Patent Document 1 below, removes the odor of the sand that has been pumped from a sand basin and the like, and at the same time, removes impurities contained in the sand to a high degree. A device is proposed.
This sand separation and washing apparatus is a sand separation and washing apparatus comprising a solid / liquid separation tank into which sewage mixed water is introduced and a sedimentation tank installed under the solid / liquid separation tank. A bottom made up of a cylindrical tube wall that generates a swirling flow that descends along the peripheral wall by flowing sewage mixed water in a tangential direction, and an inverted frustoconical sieve disposed at the bottom of the tube wall A wall and a drainage duct for discharging water near the center of the bottom wall to the outside.
This sand separation and cleaning device disperses waste sand and dust by centrifugal force due to swirling flow and separates the specific gravity difference, and also separates the particle size of sand and gravel by the sieve of the bottom wall, thereby, near the center of the bottom wall Collecting waste and gravel with a large specific gravity, and dropping gravel with a large specific gravity into the sedimentation tank from the center of the bottom wall and recovering it together with sand, while discharging waste with a low specific gravity efficiently and selectively together with water through the drainage duct. be able to.

By the way, in the said sand separation washing | cleaning apparatus, as shown in FIG. 5, as a means to clean the sieve of the bottom wall 4, after the completion of the operation of the sand pump, the injection shape is a cone or a fan shape from the back side of the bottom wall 4. The water is jetted by the washing nozzle 13 and backwashed. However, since high pressure is required when water is jetted by the washing nozzle 13, the amount of backwashing water is reduced.
Therefore, there is a demerit that the dust falling from the sieve does not float up from the sieve and is not sucked up by the upward flow of the drainage duct 5, so that the dust fallen from the opening 41 of the sieve is carried out together with the sand.
In addition, in order to clean the screen surface evenly, the number of the cleaning nozzles 13 is increased, which inevitably becomes expensive, and there is a demerit such that the nozzles are clogged with sand.
Japanese Patent Application No. 2004-373323

  In view of the problems of the conventional sand separation and washing apparatus, the present invention cleans the sieve surface uniformly with an inexpensive structure, and retains the dropped dust at the opening of the sieve, so that the upward flow of the drainage duct An object of the present invention is to provide a sand separation and cleaning device that can be sucked and removed by the above.

In order to achieve the above object, the sand separation and washing apparatus of the present invention is a sand separation and washing device comprising a solid-liquid separation tank into which sewage mixed water is introduced and a sedimentation tank installed under the solid-liquid separation tank. In the apparatus, the solid-liquid separation tank has a cylindrical tube wall that generates a swirling flow that descends along the peripheral wall by flowing sewage mixed water in a tangential direction, and an inverted structure disposed at the bottom of the tube wall. It is equipped with a bottom wall made of a frustoconical sieve and a drainage duct that discharges water near the center of the bottom wall to the outside. In addition, the dust adhering to the sieve on the bottom wall is levitated to separate the particle size of sand and gravel by the sieve, and the settling tank is a cylindrical shape provided below the bottom wall of the solid-liquid separation tank Backwash water is allowed to flow in the tangential direction of the cylinder wall and the cylinder wall to generate a swirling flow under the bottom wall. Characterized by comprising a washing water pipe.

  In this case, the reverse washing water pipe can generate a swirling flow in the opposite direction to the solid-liquid separation tank.

According to the sand separation and cleaning device of the present invention, the sand and dust are dispersed and separated by specific gravity difference by centrifugal force due to the swirling flow, and the particle size of the sand and gravel is separated by the sieve of the bottom wall. Garbage and gravel with a large specific gravity are collected near the center of the wall, and gravel with a large specific gravity falls from the center of the bottom wall to the settling tank and is collected together with the sand, while garbage with a small specific gravity is efficiently and selectively collected by the drainage duct. Can be discharged with water.
On the other hand, when the shape of the sieve is a conical shape, dust adheres to the outer periphery of the sieve, but the sand separation and cleaning device of the present invention has a sedimentation tank provided below the bottom wall of the solid-liquid separation tank. Since it includes a cylindrical cylindrical wall and a reverse cleaning water pipe that allows reverse cleaning water to flow in a tangential direction of the cylindrical wall and generates a swirling flow under the bottom wall, if water is supplied from the tangential direction, the centrifugal force is generated by the swirling flow. Water exerts a force so that the outer peripheral side swells upward, and the dust adhering to the outer peripheral portion of the sieve floats up and can be sucked and removed by the upward flow of the drainage duct.
In addition, when the opening ratio of the sieve is reduced, the lower surface of the screen becomes stagnation, so most of the water supplied is drained as an upward vortex from the central opening, so that the dust that has fallen off the sieve is opened in this opening. It can be sucked and removed by the upward flow of the drainage duct.

  In this case, the reverse washing water pipe generates a swirling flow in the direction opposite to that of the solid-liquid separation tank, so that dust attached to the sieve surface can be more efficiently removed.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a sand separation and cleaning apparatus of the present invention will be described with reference to the drawings.

1 to 4 show an embodiment of the sand separation and cleaning apparatus of the present invention.
This sand separation and cleaning device includes a solid-liquid separation tank 1 into which dirty sand mixed water is introduced, and a sedimentation tank 2 installed under the solid-liquid separation tank 1.
And this sand separation washing | cleaning apparatus is a cylindrical cylindrical wall 3 which the solid-liquid separation tank 1 produces | generates the swirl | vortex flow which descends along a surrounding wall by injecting waste-sand mixed water in a tangential direction, and this cylindrical wall 3 And a drainage duct 5 for discharging water near the center of the bottom wall 4 to the outside, and the settling tank 2 is a solid tank. A cylindrical tube wall 8 provided below the bottom wall 4 of the liquid separation tank 1 and a reverse flow in which backwash water is introduced in the tangential direction of the tube wall 8 to generate a swirling flow under the bottom wall 4. And a washing water pipe 9.

A separation hopper 6 for allowing an inverted swirl flow to flow is provided at the upper part of the cylindrical wall 3 of the solid-liquid separation tank 1, and dirty sand is mixed so that the swirl flow passes between the separation hopper 6 and the cylindrical wall 3. A water inflow pipe 7 is connected in a tangential direction.
The inflow pipe 7 is pumped with sand mixed water from a sand pump (not shown) such as a jet pump, and an annular overflow trough that receives the overflow water of the separation hopper 6 around the separation hopper 6. 61 is installed.

The bottom wall 4 is formed in a mortar shape having a sieve mesh formed by a punching screen or the like, and an opening 41 is formed at the center.
The bottom wall 4 can also be elastically supported by a coil spring or the like so as to be movable up and down, so that when the sewage mixed water is introduced, it constantly fluctuates due to gravel and dust collision, dust accumulation and swirling flow. The sieve of the bottom wall 4 vibrates (oscillates) due to water pressure and the like, and the gravitational force captured by the sieve surface always acts in the vertical direction, so that gravel is prevented from being caught in the sieve mesh. it can.

  The drainage duct 5 is a pipe that opens above the opening 41 of the bottom wall 4, and the drainage is overflowed by the head difference h of the water surface caused by the height of the side wall above the drainage duct 5. A suction flow is generated so as not to suck in the settling sand, and among the gravel and dust collected near the center of the bottom wall 4, only dust having a small specific gravity is sucked together with water and discharged to the outside.

On the other hand, as shown in FIG. 4, the sedimentation tank 2 is continuously formed below the solid-liquid separation tank 1 with the bottom wall 4 as a boundary, and a cylindrical tube wall 8 is formed at the top. The screw conveyor 10 is integrally disposed in the lower part.
Reverse washing water flows into the cylindrical wall 8 of the settling tank 2 in the tangential direction of the cylindrical wall 8 to generate a swirling flow in the opposite direction to the solid-liquid separation tank below the bottom wall 4 of the solid-liquid separation tank. A cleaning water pipe 9 is connected in the tangential direction of the cylindrical wall 8.
As shown in FIG. 2 (a), 2 to 4 or more reverse washing water pipes 9 are arranged at equal intervals depending on the size of the tank. After the operation of the sand pump is completed, the solid-liquid separation is performed. By supplying water from the tangential direction of the cylindrical wall 8 under the bottom wall 4 of the tank, the sieve surface of the bottom wall 4 can be cleaned.

Next, the operation of this sand separation and cleaning apparatus will be described.
As shown in FIG. 1 (a), a swirl flow is generated by flowing in the tangential direction of the cylindrical solid-liquid separation tank 1 with the sewage mixed water introduced from a sand pump such as a jet pump.
Sand, gravel, and dust are dispersed by centrifugal force generated by the swirling flow generated here and separated by specific gravity, and sand and dust are separated by a conical sieve on the bottom wall 4.
The sand that has passed through the conical sieve due to the water sieve effect settles in the settling tank 2 and is carried out by the screw conveyor 10.

On the other hand, the separated dust and gravel naturally gather near the center of the bottom wall 4 due to the synergistic effect of the conical shape of the sieve and the swirl effect caused by the swirling flow.
Then, the dust is caused to overflow with the drainage by the suction flow generated at the center of the bottom wall 4, and the gravel is dropped from the opening 41 of the bottom wall 4 to the settling tank 2 and carried out together with the sand.
Since the conventional sand washer separates the specific gravity in a state where sand, dust and gravel are mixed, the suction flow velocity of the drainage duct 5 could not be increased in order to suppress the outflow of sand. In this case, since the gravel and garbage are greatly different in weight, it is possible to increase the suction flow velocity as compared with the conventional case, and it is possible to increase the efficiency of removing the dust.
Moreover, by causing a flow in the sedimentation tank 2 by the suction flow of the drainage duct 5, the passing flow rate of the sieve can be increased, and the sieving effect can be enhanced.

On the other hand, after the operation is completed, as shown in FIG. 1 (b), the bottom wall 4 is back-washed to remove residue and gravel attached to the sieve surface.
When the shape of the sieve is a conical shape, dust adheres to the outer peripheral portion of the sieve, but when water is supplied from the tangential direction of the cylindrical wall 8, the force acts so that the outer peripheral side swells upward due to the centrifugal force caused by the swirling flow, The dust adhering to the outer peripheral portion of the sieve floats up and is removed by the upward flow of the drainage duct 5.
Further, when the opening ratio of the sieve is reduced, the lower surface of the screen becomes stagnation, and most of the supplied water is drained as the rising vortex 11 from the central opening 41, and thus the dust that has fallen from the sieve is It stays in the vicinity of the opening 41 and is removed by suction by the upward flow of the drainage duct 5.
At this time, in order to ensure the flow velocity of the swirling flow, it is desirable that the amount of water supplied from the backwash water pipe 9 is equal to or greater than the amount of sand flow.

In this case, when a jet pump system is employed as the sand pumping system, high-pressure water from the drive water pump can be supplied as backwash water from the backwash water pipe 9.
At this time, after stoppage of backwashing, it is necessary to consider the installation of a check valve or the like in order to prevent water from flowing back due to the siphon phenomenon and flowing into the pump and tank (FIG. 3A).

On the other hand, a backwash water pump can be installed separately from the sand pump.
At this time, the washing water pipe 12 provided separately from the inflow pipe 7 is used as a backwash water pump and a washing water pump for the solid-liquid separation tank, as shown in FIG. Thus, the washing water can be introduced from the tangential direction of the solid-liquid separation tank 1.
Thereby, the stirring ability in the tank at the time of sand sanding becomes large, and it is possible to further improve the odor removing property.
Further, after completion of the sanding, when the valve is switched and backwashed, the valve is switched again and the cleaning water is introduced from above the sieve surface, the cleaning effect of the sieve surface is increased.
This is performed in order to wash away the fibers, etc., which stay below the screen surface, because the fibers adhere again on the screen surface by backwashing.
At this time, after the backwash is stopped, it is necessary to consider the installation of a check valve in order to prevent water from flowing back due to the siphon phenomenon and the inflow of dust into the pump and the storage tank (FIG. 3B). ).
The treated water is preferably treated water, but in pump stations where it is difficult to secure a treated water source, it is also possible to supply sewage from which dust has been removed by way of an automatic strainer (FIG. 3 (c)). ).

Thus, the sand separation and washing apparatus of the present embodiment is a sand separation and washing apparatus provided with a solid / liquid separation tank 1 into which dirty sand mixed water is introduced and a sedimentation tank 2 installed under the solid / liquid separation tank 1. The solid-liquid separation tank 1 is disposed at a cylindrical cylindrical wall 3 that generates a swirling flow that descends along the peripheral wall by flowing sewage mixed water in a tangential direction, and at the bottom of the cylindrical wall 3. In addition, a bottom wall 4 made of an inverted frustoconical sieve and a drainage duct 5 for discharging the water near the center of the bottom wall 4 to the outside are provided. While separating and separating the specific gravity difference, the sand and gravel are separated by the particle size by the sieve of the bottom wall 4, thereby collecting garbage and gravel having a large specific gravity difference near the center of the bottom wall 4. While dropping from the center of the bottom wall 4 into the sedimentation tank 2 and collecting it with sand, it efficiently selects trash with a low specific gravity. It can be discharged together with water by to drainage duct 5.
That is, conventionally, since the specific gravity difference separation is performed in a state where sand, waste, and gravel are mixed, the suction flow velocity of the drainage duct 5 cannot be increased in order to suppress the outflow of sand. In the embodiment, gravel and waste having different specific gravities are separated by specific gravity difference, so that it is possible to increase the suction flow velocity as compared with the conventional case, and the dust removal efficiency can be increased.
Moreover, by sucking the water in the sedimentation tank 2 with a strong suction flow of the drainage duct 5, the flow rate of the sieve wall passing through the bottom wall 4 can be increased, thereby enhancing the sieving effect.

On the other hand, when the shape of the sieve is a conical shape, dust adheres to the outer periphery of the sieve. However, in the sand separation and washing apparatus of the present invention, the sedimentation tank 2 is provided below the bottom wall 4 of the solid-liquid separation tank. Since the cylindrical cylindrical wall 8 is provided, and the reverse cleaning water pipe 9 for flowing back cleaning water in the tangential direction of the cylindrical wall 8 and generating swirling flow under the bottom wall 4, When water is supplied, the centrifugal force generated by the swirling flow causes the water to swell upward on the outer periphery, and the dust adhering to the outer periphery of the sieve floats up and can be sucked and removed by the upward flow of the drainage duct. .
Further, when the opening ratio of the sieve is reduced, the lower surface of the screen is in a stagnation state. Therefore, most of the supplied water is drained as the rising vortex 11 from the central opening 41, so that the dust that has fallen from the sieve is It stays in the vicinity of the opening 41 and can be sucked and removed by the upward flow of the drainage duct 5.
And since the said reverse washing water pipe | tube 9 generate | occur | produces the swirling flow of a reverse direction with the solid-liquid separation tank 1, the dust adhering to a sieve surface can be removed still more efficiently.

  As mentioned above, although the sand separation washing | cleaning apparatus of this invention was demonstrated based on the Example, this invention is not limited to the structure described in the said Example, The structure is suitably comprised in the range which does not deviate from the meaning. Can be changed.

  The sand separation and cleaning apparatus of the present invention can remove the odor of the sand that has been pumped up from a sand basin and the like, and can highly remove impurities contained in the sand. Since it is cleaned evenly, the dropped garbage stays at the opening of the sieve and is sucked and removed by the upward flow of the drainage duct. It can be suitably applied to the case of exclusion.

One Example of the sand separation washing | cleaning apparatus of this invention is shown, (a) is sectional drawing at the time of the normal use, (b) is sectional drawing at the time of backwashing. (A) is an A arrow equivalent figure of FIG.1 (b), (b) is an arrow B equivalent figure. (A)-(c) is explanatory drawing which shows the usage example of the pump of the sand separation washing | cleaning apparatus of the Example. It is a general view which shows the sand separation washing | cleaning apparatus. It is sectional drawing which shows the conventional sand separation washing | cleaning apparatus.

1 Solid-liquid separation tank 2 Sedimentation tank 3 Cylinder wall (solid-liquid separation tank)
4 Bottom wall 41 Opening 5 Drain duct 6 Separation hopper 61 Overflow trough 7 Inflow pipe 8 Cylindrical wall (sedimentation tank)
9 Backwash water pipe 10 Screw conveyor 11 Ascending vortex 12 Wash water pipe

Claims (2)

In a sand separation and washing apparatus comprising a solid / liquid separation tank into which sewage mixed water is introduced and a sedimentation tank installed under the solid / liquid separation tank, the solid / liquid separation tank is mixed with sewage sand in a tangential direction. A cylindrical tube wall that generates a swirling flow descending along the peripheral wall by flowing water, a bottom wall formed of an inverted frustoconical sieve disposed at the bottom of the tube wall, and A drainage duct that discharges water near the center to the outside, separates the specific gravity difference between the sewage sand and the dust by using only the centrifugal force generated by the swirling flow, and floats the dust adhering to the bottom wall sieve. The particle size separation of sand and gravel is performed by the above, and the settling tank has a cylindrical cylindrical wall provided under the bottom wall of the solid-liquid separation tank, and backwash water flows in the tangential direction of the cylindrical wall. And a reverse cleaning water pipe for generating a swirling flow under the bottom wall.   The sand separation and washing apparatus according to claim 1, wherein the reverse washing water pipe generates a swirling flow in a direction opposite to that of the solid-liquid separation tank.

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