JP2017202454A - Sand removing device of sand basin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sand removing device of a sand basin having proper arrangement of a sand collection nozzle, setting of a jet direction and a basin bottom shape, capable of collecting sand efficiently without a residue of sedimentation sand even when performing sand collection by a low-pressure injection water.SOLUTION: In a sand removing device of a sand basin using a low-pressure type sand collector for collecting and lifting sand after discharging water and drying the sand basin 1, an approximately rectangular loop-shaped sand collection pipe 24 having one sand collection automatic valve 23a and a plurality of sand collection nozzles 24d attached thereto is provided on a position on a water surface of the sand basin 1 in each sand collection area block.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a sand removal device for a sand basin, and more particularly to a sand removal device for a sand basin using a low pressure type sand collection device that collects sand using low-pressure jet water.

Conventionally, in sewage ponds, rainwater settling basins, etc. installed in sewage treatment plants, pumping stations, etc. (collectively referred to as “sedimentation basins” in this specification), they are included in the sewage introduced into the settling basins. Solid matter such as dirty sand is deposited and deposited on the bottom of the pond using natural gravity, and this sediment is collected in a sand pit installed at the bottom of the pond and sucked up and discharged by a sand pump.
In addition, in order to collect sand that settles on the basin, which is almost horizontal, into the sand pit, a large number of jet nozzles are placed near the pond bottom or near the basin, and the nozzle holes are directed toward the sand pit. These jet nozzles are sequentially switched to inject jet water supplied from a high-pressure pump.

  However, the sedimented sand that is precipitated by jetting high-pressure jet water from the jet nozzle moves toward the sand pit by the jet water pressure of the jet water, but the relatively light sand is soared again. In addition, the sand collection rate decreases, the jet nozzle becomes special and expensive, and the pond bottom needs to have a complicated civil engineering shape such as steps and ridges, which increases the construction cost. there were.

  In addition, since the jet nozzle is disposed at or near the pond bottom, it is necessary to dispose this jet nozzle body and a water supply pipe for supplying jet water to the pond bottom or near the pond bottom. Since dust contained in these parts may get caught in these nozzles and pipes, or may be damaged by stone collisions in sewage, it is necessary to provide a protective cover to prevent this, and jet nozzles Since it is necessary to supply the jet water at a high pressure, the feed water pump inevitably has a high pressure. For this reason, there existed a problem that initial cost and running cost became large.

  In addition, when multiple sand basins are deployed at sewage treatment plants, pumping stations, etc., one sand collecting device is required for each sand basin, resulting in an increase in initial cost, and for each sand basin periodically. There was a problem that maintenance was necessary.

  By the way, in view of the problems of conventional sand settling ponds, a low-pressure type sand collecting device that collects sand using low-pressure jet water in a state where the settling basin is drained and dried has been proposed and put into practical use. It has come to be.

However, since this low-pressure type sand collecting device collects sand using low-pressure jet water, it is necessary to consider the arrangement of the appropriate sand collecting nozzle, the setting of the injection direction, the pond bottom shape, etc. However, the conventional low pressure type sand collecting apparatus has the following problems.
1. The sand collecting nozzle was placed near the bottom of the pond on the upstream side of the sand collecting trough on both sides of the water channel and in the center of the water channel, and was submerged under the surface of the water except during the sand collecting operation. During submergence, there was a problem that blockage due to intrusion of foreign matter, progress of corrosion, and nozzle status could not be confirmed from the pond.
2. The sand collecting nozzle was fixed and the jetting direction could not be changed.
3. A submersible pump was used as the sand pump. One unit is required for each pond, and when there are many ponds, the number of units and the motor load increase, and there is a problem that the equipment cost, the repair cost, and the power charge increase.
4). The sand pit that uses a submersible pump was generally shaped like a square frustum inverted. Even if measures were taken to install a sand collecting nozzle toward the bottom of the pond, there was a problem that sedimentation remained.
5. The bottom of the pond has a central trough (made of SUS) in the center of the pond, and a number of small troughs (made of SUS) are provided so as to flow from both sides toward the central trough. It was. For this reason, there existed a problem that a structure was complicated, the construction period was long, and construction cost was also high.
6). The self-priming pump had no automatic backwash method when the sand suction pipe was blocked.

  The applicant of the present application has previously proposed a sand collection device for a sand basin that can collect sand with a low-cost structure and low power (see Patent Document 1). It did not completely eliminate all of the points.

JP 2008-126145 A

  The present invention solves the problems of sand removal basin sand removal devices using conventional low pressure type sand collection devices, has an appropriate arrangement of sand collection nozzles, setting the injection direction and pond bottom shape, It is an object of the present invention to provide a sand removal apparatus for a sand basin that can collect sand efficiently without sand remaining even when sand collection is performed using jet water.

  In order to achieve the above object, the sand removal apparatus for a sand basin according to the present invention is a sand removal apparatus for a sand basin using a low pressure type sand collection apparatus that drains and dries the sand basin, and collects sand. For each sand collecting area block, a sand collecting pipe having a substantially rectangular loop shape, to which one automatic sand collecting valve and a plurality of sand collecting nozzles are attached, is provided on the water surface of the sand basin.

  In this case, a sand collecting nozzle can be attached to the straight pipe portion of the substantially rectangular loop-shaped sand collecting pipe, and a rotation mechanism can be provided on both sides of the straight pipe portion.

  In addition, a sand collecting nozzle can be provided on the sand collecting trough at the center of the pond of a substantially rectangular loop shaped sand collecting pipe.

  Moreover, the self-priming type sand pump which combined the extraction pump and the vortex pump can be used for the sand pump.

  Further, the sand pit can be formed into a cylindrical shape, and the intersecting line portion between the side surface and the bottom surface of the sand pit can be finished in a haunch shape or an arc shape.

  In addition, a sand collecting trough having a gradient so as to flow into the sand pit can be provided in the center of the pond width direction, and a slope can be provided so as to flow into the sand collecting trough from both sides of the water channel.

  Moreover, the pond bottom can be formed by placing unreinforced concrete and mortar.

  Further, a backwash pipe can be connected between the suction port of the sand suction pipe and the automatic sand lift valve via a backwash automatic valve so that water can be supplied.

  According to the sand removal device for a sand basin of the present invention, in the sand removal device for a sand basin using a low pressure type sand collection device that drains and dries the sand basin, and collects and lifts sand, In addition, a sand collecting pipe with a generally rectangular loop shape with a single sand collecting automatic valve and a plurality of sand collecting nozzles installed at the position above the water surface of the sand basin enables automatic sand collection even in a sand basin with a long pond length. By switching the valves and injecting sequentially, sand can be collected efficiently up to the sand pit. Moreover, by installing on the water surface, it is possible to prevent obstruction due to intrusion of foreign matter, progress of corrosion, and the like.

  In addition, the sand collection nozzle is attached to the straight pipe section of the generally rectangular loop-shaped sand collection pipe, and the rotation direction is provided on both sides of the straight pipe section, so that the injection direction of the sand collection nozzle can be easily changed to the optimum direction. can do.

  In addition, by installing a sand collection nozzle on the sand collection trough at the center of the pond of a rectangular collection pipe with a rectangular loop shape, the sand collection trough's transfer force is increased, and the sand is collected to the pumping pit without residual sand. be able to.

  Further, by using a self-priming sand pump that combines a bleed pump and a centrifugal pump as the sand pump, even if the number of sand basins is large, sand can be pumped by one unit. The number of units and the motor load are smaller than when submersible pumps are used, and the equipment costs, repair costs, and power charges can be reduced. In addition, since the pump body is on the floor, inspection is easy, and even when repairing, it is not necessary to pull up from the pond like a submersible pump, and it can be performed easily. Self-priming pumps include a pump that leaves water in the casing or injects exhaled water for self-priming. However, the self-priming force is weak, and there is one pumping sand suction pipe for one pump. It is not possible to divide multiple sand suction pipes and switch the automatic sand suction valve to self-prime. In addition, from the use of the present invention, the target is sewage containing sand and cannot be retained in the casing for a long time. Equipment such as piping is necessary to inject fresh water. The self-priming pump combined with the bleed pump used in the present invention has higher self-priming performance than the self-priming pump and can be used even when the sand basin is deep. Further, a plurality of suction pipes can be branched, and the self-priming can be performed by switching the automatic sanding valve.

  In addition, the sand pit has a cylindrical shape, and the intersecting line between the side and bottom of the sand pit is finished in a haunch or arc shape, so that sand remains in the corner of the sand pit where it is particularly likely to remain. Can be prevented.

  In addition, a sand collection trough with a gradient to flow into the sand pumping pit is provided in the center of the pond width direction, and slopes are provided to flow into the sand collection trough from both sides of the channel so that no sediment remains. Sand collection can be performed efficiently.

  In addition, by forming the pond bottom by placing unreinforced concrete and mortar, the pond bottom structure is simple, the construction period is short, and the construction cost can be reduced.

  In addition, if a backwash pipe is connected between the suction port of the sand suction pipe and the automatic sand pump valve via a backwash automatic valve so that water can be supplied, automatic backwash is possible if the sand suction pipe is blocked. can do.

It is explanatory drawing which shows one Example of the sand removal apparatus of the sand basin of this invention. It is a top view of FIG. It is a BB arrow longitudinal cross-sectional view of FIG. It is CC sectional view taken on the line of FIG. FIG. 3 is a cross-sectional view taken along the arrow D-D in FIG. 2. It is a top view which shows the pond bottom of the sand basin of the sand removal apparatus of the sand basin. It is an AA arrow longitudinal cross-sectional view of FIG. It is a BB arrow cross-sectional view of FIG. It is CC sectional view taken on the line of FIG. It is a finishing drawing of the side and bottom intersection part of the sand pit of the sand removal device of the sand basin. It is detail drawing of the rotation mechanism of the sand collection nozzle of the sand removal apparatus of the sand basin. It is a skeleton figure of the backwashing mechanism of the sand collection nozzle of the sand removal apparatus of the sand basin.

  DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment of a sand removal apparatus for a sand basin according to the present invention will be described with reference to the drawings.

  FIGS. 1-12 shows the example which applied the sand removal apparatus of the sand basin of this invention to the rainwater sand basin.

  This sand removal basin removal device uses a low pressure type sand collection device that collects and lifts sand after the sedimentation basin 1 is drained and dried.

  In the sand basin 1, an inflow gate 12 and a fine screen 13 (preferably having a mesh width of 25 mm or less are desirable) are disposed on the inflow side, and an outflow gate 14 and a rainwater pump 15 are disposed on the discharge side. Yes.

A sand pit 4 is formed near the inflow side from the center in the flow direction of the sand basin 1.
The sand pit 4 has a cylindrical shape, and its diameter D4 is about 800 to 2000 mm, preferably about 1000 mm.

As shown in FIG. 10 (a), the intersecting portion between the side surface and the bottom surface of the sand pit 4 is a haunch 41 (C50 to 200 mm, preferably about C100 mm) or as shown in FIG. 10 (b). An arc shape 42 (R50 to 200 mm, preferably about R100 mm) is used.
Thereby, it is possible to prevent the sand sediment from remaining in the corner portion of the sand lifting pit 4 where the sand sediment is particularly likely to remain.

  In addition, it is desirable that the intersecting line portion where the inclined surface and the vertical surface for guiding sand to the sand lifting pit 4 intersect with each other is finished in a haunch shape or an arc shape by eliminating the corners of the cross section.

  The sand collecting trough 5 having a bottom slope of about 1/50 to 1/200, preferably about 1/100 as the gradient α5 so as to flow into the sand pit 4 is the center in the pond width direction on the inflow side and the outflow side. To form.

  A slope is formed so as to flow into the sand collecting trough 5 at the center of the pond width direction from both sides. The angle α11 of the slope is 10 to 20, preferably about 13 °.

  The bottom 11 of the settling basin 1 is formed by placing unreinforced concrete and mortar finishing.

  The flow direction of the settling basin 1 is No. 1-No. Divided into 5 blocks (the number of blocks is not limited to this, but is determined by the length of the pond), and each block has a rectangular loop-shaped sand collecting pipe 2A to 2E (rectangular loop-shaped sand collecting pipes). Collectively, the sand collecting pipe 24 is provided.

  Among the sand collecting tubes, No. The sand collecting pipes 2A, 2C to 2E, excluding the sand collecting pipe 2B arranged in the two blocks, are installed at a high water level (HWL) or higher, and on both pond wall sides and the sand collecting trough 5 A required number of sand collecting nozzles 24d are attached.

  No. The sand collecting pipes 2B arranged in the two blocks are installed above the water level (W.L) of the sand collecting operation (slightly higher than the upper end of the sand pit 4). A necessary number of sand collecting nozzles 24d are mounted on the top.

  In order to collect sand by spraying low pressure jet water from the sand collecting nozzle 24d to the sand collecting pipes 2A to 2E (24) of each block, a sand collecting water pipe 22 and one piece are collected from the sand collecting water pump 21. The sand collection water is selectively supplied through the branched sand collection pipe 23 provided with the automatic sand collection valve 23a.

The sand collecting pipes 2A to 2E (24) of each block are formed by a straight pipe portion 24a and an elbow-shaped bent pipe portion 24b in a generally rectangular loop shape, and the straight pipe portion 24a includes a sand collecting nozzle. A rotating mechanism, in this embodiment, a loose flange 24c, is provided on both sides of the straight pipe portion 24a to which the sand collecting nozzle 24d is attached.
As shown in FIG. 11, the loose flange 24c is configured to tighten the flange portion of the loose flange 24c with a tightening bolt 24e with the packing 24f interposed therebetween.
Thus, by providing the loose flange 24c as a rotation mechanism on both sides of the straight pipe portion 24a, the injection direction of the sand collecting nozzle 24d can be easily changed to the optimum direction.

A sand suction pipe 31 is provided in the center of the sand pit 4.
The sand raising suction pipe 31 is provided with a sand raising automatic valve 31 a and is connected to the collective sand raising pipe 32.
The aggregated sand pipe 32 is connected to the sand suction pipes 31 of a plurality of other sand basins 1 and is provided with a self-priming sand pump 33.

A backwash pipe 25 is connected to the sand suction pipe 31 of each sand basin 1 on the suction port side of the sand sand automatic valve 31a.
The backwash pipe 25 is connected to the sand collecting water pipe 22 via a backwash automatic valve 25a.
Thus, as shown in FIG. 12, with the automatic sand lifting valve 31a closed, the backwash automatic valve 25a is opened, and backwash water (water supplied from the sand collecting water pipe 22) is supplied from the backwash pipe 25. By supplying to the sand suction pipe 31, the blockage of the sand suction pipe 31 can be automatically resolved.

As the sand pump, a self-priming sand pump 33 comprising a centrifugal pump 34 and a centrifugal pump 33 connected to the centrifugal pump 34 is used. To do.
Thereby, even when the number of sand basins 1 is large, it is possible to carry out sanding by one.

The sedimentation separation mechanism 6 is connected to the downstream side of the collective sandpump 32, that is, the discharge side of the self-priming sandpump 33.
In this embodiment, the sand settling mechanism 6 includes a sand settling separator 61, a sand settling hopper 62, and a sewage settling basin 63. However, the present invention is not limited to this, and a sand settling equipment comprising a sand settling machine or the like. Can also be provided.

Next, the sand driving operation of the sand removal device of the sand basin will be described.
The sand pumping operation is sequentially performed for each sand basin 1 after the inflow of rainwater is completed after the end of rain.
First, the rainwater pump 15 drains to a low water level (LWL), closes the inflow gate 12 and the outflow gate 14 of the sand basin 1, opens the automatic sand pump valve 31a of the sand basin 1, and is self-priming. The sand pump 33 is operated and drained to the level of the sand driving operation.

No. The sand collecting automatic valve 23a of the sand collecting pipe 2B disposed in the two blocks is opened, and the sand in the sand pit 4 is sanded.
The sand settling mechanism 6 is activated in advance and continuously operates during the subsequent sand collection operation.
When the operation of the sand pit 4 is completed within the set time of the operation timer, The automatic sand collection valve 23a of the sand collection pipe 2B arranged in 2 blocks is closed.

  Next, no. Open the sand collection automatic valve 23a of the sand collection pipe 2A arranged in one block, and Collect 1 block of sand. The operation of the self-priming sand pump 33 is continued. It is the set time of the operation timer. When 1 block of sand collection is completed, The automatic sand collection valve 23a of the sand collection pipe 2A arranged in one block is closed.

  Hereinafter, in the same procedure, no. 3 blocks → No. 4 blocks → No. Collect 5 blocks of sand.

Thereafter, sand collection in the pit 4 is performed again.
No. After closing the automatic sand collection valve 23a of the sand collection pipe 2B arranged in 2 blocks, the self-priming sand pump 33 drains to the lowest level of the sand pit 4 and the self-priming pump at the set water level of the water level gauge. After the sand pump 33 is stopped, the automatic sand lifting valve 31a is closed, and the sand settling mechanism 6 is stopped.
As a result, the sand collecting and sanding operation of the sand basin 1 is completed.
Thereafter, the sand removal operation of the sand removal device of the other sand basin 1 is performed in the same procedure.

Here, the wall-side sand collecting nozzle 24d is sprayed so as to reach the vicinity of the corner where the wall and the inclined bottom surface are in contact (at this time, at least a part of the spray water is sprayed on the wall surface by the spray water). It can also be sprayed so as to be washed.), The sand collection state after operation is confirmed, and the rotation mechanism provided in the straight pipe portion 24a of the sand collection pipe 24, in this embodiment, through the loose flange 24c, By rotating the straight pipe portion 24a to which the sand collecting nozzle 24d is attached, the angle of the sand collecting nozzle 24d can be set to an optimum angle.
Similarly, the sand collecting nozzle 24d provided on the sand collection pit 4 and the sand collecting trough 5 is rotated by rotating the straight pipe portion 24a to which the sand collecting nozzle 24d is attached via the loose flange 24c. The angle of 24d can be set to the optimum angle.

Further, the backwash pipe 25 is connected to the sand suction pipe 31 on the suction port side of the sand raising automatic valve 31a. It detects that there is no flow in the suction pipe 31, and performs automatic backwashing.
In this automatic backwashing, the automatic sandwashing valve 31a of the corresponding sanding suction pipe 31 is closed, the backwashing automatic valve 25a is opened, and the backwashing water is supplied from the backwashing pipe 25 (water supplied from the sand collecting water pipe 22). Is supplied to the sand suction pipe 31 to release the blockage of the sand suction pipe 31. After a certain period of time (by timer setting), the backwash automatic valve 25a is closed, the sanding automatic valve 31a is opened, and sanding is resumed. If the blockage is not released, the automatic backwash operation is repeated several times (the number depends on the setting). If the blockage is still not released, a failure signal is generated and the devices after the self-priming sand pump 33 are stopped. .

  As mentioned above, although the sand removal apparatus of the sand basin of this invention was demonstrated based on the Example, this invention is not limited to the structure described in the said Example, In the range which does not deviate from the meaning, the The configuration can be changed.

  The sand removal apparatus of the sand basin of the present invention has an appropriate arrangement of the sand collecting nozzle, setting of the injection direction and the shape of the pond bottom, and even when sand collection is performed with low-pressure jet water, there is no residual sand, and it is efficient. Because it has the property of collecting sand, it is suitable for sand basin sand removal equipment using a low pressure type sand collecting device that collects and lifts sand after draining and drying the sand basin. Can be used.

DESCRIPTION OF SYMBOLS 1 Sedimentation basin 11 Pond bottom 12 Inflow gate 13 Fine screen 14 Outflow gate 15 Rainwater pump 21 Sand collection water pump 22 Sand collection water pipe 23 Branch collection sand water pipe 23a Sand collection automatic valve 24 (2A-2E) Sand collection pipe 24a Straight pipe part 24b Curved pipe section 24c Loose flange (rotating mechanism)
24d Sand collection nozzle 25 Backwash pipe 25a Automatic backwash valve 31 Sand suction pipe 31a Automatic sand suction valve 32 Collecting sand pipe 33 Spiral pump (self-priming sand pump)
34 Extraction pump 4 Sand pumping pit 5 Sand collection trough 6 Sand settling mechanism 61 Sand settling machine 62 Sand settling hopper 63 Sewage settling basin

Claims (8)

  In a sand removal basin sand removal device that uses a low-pressure sand collection device that collects and raises sand after draining and drying the sand collection basin, each sand collection area block has one automatic sand collection valve and multiple collection tools. A sand removal device for a sand settling basin, characterized in that a sand collecting pipe having a generally rectangular loop shape with a sand nozzle is provided on the water surface of the settling basin.   The sand removal device for a sand basin according to claim 1, wherein a sand collecting nozzle is attached to a straight pipe portion of a substantially rectangular loop-shaped sand collecting pipe, and a rotation mechanism is provided on both sides of the straight pipe portion.   The sand removal device for sand settling basin according to claim 1 or 2, wherein a sand collecting nozzle is provided on a sand collecting trough at the center of the pond of a substantially rectangular loop shaped sand collecting tube.   The sand removal device for a sand basin according to claim 1, 2 or 3, wherein a self-priming sand pump that combines a bleed pump and a centrifugal pump is used as the sand pump.   The sand removal basin sand removal device according to claim 1, 2, 3 or 4, wherein the sand pit has a cylindrical shape, and the intersection line between the side surface and the bottom surface of the sand pit is finished in a haunch shape or an arc shape. .   A sand collecting trough having a slope so as to flow into the sand pit is provided in the center of the pond width direction, and a slope is provided so as to flow into the sand collecting trough from both sides of the water channel. A sand removal device for a sand basin according to 3, 4 or 5.   The sand removal apparatus for a sand basin according to claim 1, 2, 3, 4, 5 or 6, wherein the bottom of the pond is formed by placing unreinforced concrete and mortar.   A backwash pipe is connected between the suction port of the sand suction pipe and the automatic sand lift valve via a backwash automatic valve so that water can be supplied. Or the sand removal apparatus of the sand basin of 7.

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