JP2010058044A - Sand pumping apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sand pumping apparatus (jet pump) which improves pumping efficiency of sedimentary sand as compared with the conventional apparatus while suppressing the use amount of pressurized water. <P>SOLUTION: The jet pump 1 includes a suction pipe 2 disposed at the center of a sedimentary sand pit 3; a tank 4 with a circular inner periphery 4c formed at the bottom of the sedimentary sand pit 3; a drive water pipe 5 disposed below the bottom face 4e of the tank 4 and having a discharge port 5a facing the suction port 2a of the suction pipe 2; and a jet nozzle 6 jetting pressurized water along the inner periphery 4c of the tank 4. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a sand pumping device for sanding a sand settling in a sewage treatment plant or a pumping plant and sinking to the bottom of the pond. In particular, the present invention relates to a jet pump type sand raising device.

  Bucket conveyor systems have been used frequently for sand collection from sand settling basins such as sewage treatment plants, but in recent years, odor countermeasures, simplified maintenance, and equipment cost reduction measures have been used. From the point of view, the adoption of jet pump type sand raising devices is increasing. The jet pump type sand raising device refers to a type of sand raising device that ejects water at a high pressure from a nozzle and sucks and discharges sand using the negative pressure generated at this time.

  Here, as a technique related to the jet pump type sand raising apparatus, for example, there is a technique described in Patent Document 1. The sand raising device (jet pump) described in Patent Document 1 is characterized in that an injection nozzle that injects pressure water and generates a swirling flow around the suction port is provided in the sand pit. And in patent document 1, it is called that sand collection can be gathered together in the center part of a sand settling pit by the swirl flow from an injection nozzle, and, as a result, the sand pumping efficiency of a jet pump can be improved. .

JP 2005-246272 A

  On the other hand, in a jet pump type sand pumping device, the suction force of the settling sand located in a place other than the vicinity of the suction port arranged in the settling pit is small, and only a part of the settling sand accumulated in the settling pit can be removed. There is a problem that it cannot be done. Here, according to the technique described in Patent Document 1, this problem is improved to some extent. However, the jet pump described in Patent Document 1 relies on the injection nozzle to generate a swirling flow, and requires a large amount of pressure water. When the required amount of pressurized water increases, there are cases where the specifications of the supply pump must be raised to the next level, which affects the initial cost and operating cost. Moreover, in an actual site, it is difficult to arrange nozzles and to operate them so as not to leave as much sand as possible in the sand pit. That is, as a measure for preventing as much sedimentation as possible from being left, it is not a sufficient measure at present to simply provide an injection nozzle for injecting pressure water in the sedimentation pit.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a sand raising device (jet pump) capable of improving the sand-carrying efficiency of the settling sand while suppressing the amount of pressure water used. Is to provide.

Means and effects for solving the problems

  As a result of intensive studies to solve the above-mentioned problems, the inventors of the present invention form a tank having a circular inner peripheral surface at the bottom of the sand settling pit, and dispose a driving water pipe below the bottom of the tank. As a result, it has been found that a dead zone in which sedimentation tends to accumulate compared to the prior art is less likely to be formed and a swirl flow is likely to occur, thereby finding that the above problems can be solved, and the present invention has been completed based on this finding. is there.

  That is, in order to solve the above-mentioned problem, the present invention relates to a suction pipe disposed in the center of the sand pit, a tank having a circular inner peripheral surface formed at the bottom of the sand pit, and the bottom surface of the tank. Provided is a sand raising device provided with a drive water pipe disposed below the bottom surface and having a discharge port facing the suction port of the suction pipe, and an injection nozzle for jetting pressure water along the inner peripheral surface of the tank. To do.

  According to this configuration, the swirling flow is generated by injecting the pressure water from the injection nozzle along the inner peripheral surface of the circular tank formed at the bottom of the sand pit. Here, a tank having a circular inner peripheral surface is formed at the bottom of the sand settling pit, and a driving water pipe is disposed below the bottom of the tank, thereby making it difficult to form a dead zone in which sand settling easily accumulates. A swirling flow tends to occur at the bottom of the sand pit. For this reason, even if the number of injection nozzles is reduced, that is, the amount of pressure water used is suppressed, the sand-carrying efficiency of the settling can be improved as compared with the prior art.

  Moreover, in this invention, it is preferable that the center part of the bottom face of the said tank inclines diagonally upward toward the discharge outlet of the said drive water pipe. According to this configuration, the sedimentation is easily guided to the pressure water ejected from the drive water pipe, and the sedimentation efficiency of the sedimentation can be further improved.

  Furthermore, in this invention, it is preferable that the bottom face of the said tank and the discharge port front-end | tip of the said drive water pipe | tube are flush. According to this configuration, the sedimentation is more easily guided to the pressure water ejected from the drive water pipe, and the sedimentation efficiency of the sedimentation can be further improved.

  Further, in the present invention, an introduction part for introducing the sand sediment into the tank is formed on the inner peripheral surface of the tank, and the introduction part is provided at a position facing the sand collecting direction where the sand sediment flows into the tank. It is preferable that

  According to this configuration, by providing the sand sediment introduction portion at a position facing the sand collecting direction on the inner peripheral surface of the tank, a swirling flow of the fluid containing the sand sediment is more likely to occur.

  Furthermore, in the present invention, it is preferable that the injection nozzle is provided in the vicinity of the introduction portion. According to this configuration, a swirling flow of a fluid containing sand is more likely to occur.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In the following description, a jet pump type sand pumping device is referred to as a “jet pump”.

(Configuration of jet pump)
FIG. 1 is a side view of a jet pump 1 (sand raising apparatus) according to an embodiment of the present invention. FIG. 2 is a plan view of the jet pump 1 shown in FIG. FIG. 3 is an enlarged view of a portion A in FIG. 1 does not show the sand collecting device 14 shown in FIG.

  As shown in FIG. 1 and FIG. 2, the jet pump 1 of the present embodiment includes a suction pipe 2 disposed at the center of the sand settling pit 3, a tank 4 formed at the bottom of the sand settling pit 3, and a bottom surface of the tank 4. 4e includes a drive water pipe 5 disposed below the bottom surface 4e, an injection nozzle 6 for injecting pressure water along the inner peripheral surface 4c of the tank 4, and a sand collecting device 14.

  Here, the sand pit 3 is formed at the bottom of a sand basin 100 provided in a sewage treatment plant or a pumping station. The sand settling basin 100 is a concrete pond into which sewage that reaches a sewage treatment plant or a pumping station first flows, and is provided to remove sand and impurities contained in the sewage. Sand having a specific gravity greater than that of water sinks to the bottom of the settling basin 100 by slowly flowing sewage, and is poured into the settling pit 3 by the sand collecting device 14.

  The sand settling pit 3 is made of concrete, and as shown in FIG. 1, is composed of a quadrangular pyramid shaped portion 3a and a quadrangular prism shaped portion 3b. The quadrangular pyramid-shaped portion 3a has a shape that becomes narrower as the upper surface is opened and the surface is lowered. Further, the quadrangular prism-shaped portion 3 b is provided so as to extend downward from the lower portion of the quadrangular pyramid-shaped portion 3 a and forms the bottom portion of the sand settling pit 3.

(Sand collector)
As shown in FIG. 2, the sand collecting device 14 has a plurality of spray nozzles 12 arranged at predetermined intervals, and a water supply pipe 13 connected to the spray nozzles 12. Arranged. The water supply pipe 13 is connected with a pressure water pump (not shown). Water is supplied to the injection nozzle 12 from the pressure water pump through the water supply pipe 13. Sand is poured into the sand pit 3 by the jet from the injection nozzle 12. A sand collection direction X shown in FIG. 2 indicates a direction in which the sand settling on the bottom of the sand settling basin 100 is caused to flow (moved) together with sewage by the sand collecting device 14. Moreover, the sand collecting apparatus 14 is not limited to what is provided in one row as shown in FIG. 2, and may be provided in a plurality of rows.

(Suction pipe)
The suction pipe 2 disposed in the center of the sand settling pit 3 sucks the sand settling into the sand settling pit 3 from the suction port 2a at the tip thereof, and passes through a sand settling transfer pipe (not shown) connected to the suction pipe 2. This is to discharge the sand to a sand set separator (not shown). The suction pipe 2 is a cylindrical steel product, and is arranged in the center of the sand settling pit 3 with its longitudinal direction aligned with the vertical direction.

(A tank formed at the bottom of the sand pit)
The tank 4 formed at the bottom of the sand settling pit 3 is a concrete cylindrical tank whose inner peripheral surface 4c is formed in a circular shape. As shown in FIG. 2, the tank 4 is formed with a sand sink (sewage containing sand settle) introduction part 4a as a recess in a part of its inner peripheral surface 4c. The introduction portion 4 a is formed on the inner peripheral surface 4 c at a position facing the sand collection direction X in which sand flows into the sand settling pit 3. Further, the introduction portion 4 a is formed on the inner peripheral surface 4 c between the sand collecting device 14 and the suction pipe 2. In addition, as shown in FIG. 2, the introduction portion 4 a is formed with a predetermined width so as to be connected to the circular inner peripheral surface 4 c of the tank 4 and the flat surface in a plan view, and has flowed in. Sedimented sand is formed to flow along the inner peripheral surface 4c. As shown in a side view of the introduction portion 4a in FIG. 1, the introduction portion 4a is formed on the inner peripheral surface 4c as a slope portion having a predetermined width.

  Further, as shown in FIG. 3A, the central portion of the bottom surface 4e of the tank 4 is formed in a conical shape having an inclined surface 4d inclined obliquely upward toward the tip of the discharge port 5a of the drive water pipe 5. Has been. Furthermore, in the center of this center part, the bottom face 4e of the tank 4 and the front-end | tip of the discharge outlet 5a of the drive water pipe 5 are made flush. Here, the term “equal” means that either one does not protrude and both are set to substantially the same height (level). In addition, the boundary part of the bottom face 4e of the tank 4 and the internal peripheral surface 4c is diagonally chamfered.

  In this embodiment, the inner peripheral surface 4c is circular. However, the inner peripheral surface 4c may be a polygonal shape such as an octagon or a hexagon, or a complete circle. It may be oval. Further, in the present embodiment, only one settling portion 4a for sand settling is provided. However, for example, when sand settling flows from two different directions with respect to the sand settling pit 3 (when there are two sand collecting directions X). ) May be provided with two introduction portions 4a so as to face each sand collecting direction X, and the number of introduction portions 4a is not limited to one. That is, a plurality of introduction portions 4a may be provided on the inner peripheral surface 4c.

  The tank 4 is not limited to concrete. For example, a tank formed of a resin material such as vinyl chloride may be used. As an example of a tank made of a resin material, a so-called pre-swirl tank can be cited. When the tank 4 is made of concrete as in the present embodiment, the tank 4 is formed by on-site construction. For example, when a pre-swirl tank made of a resin material is used, the tank 4 is manufactured in advance at the factory ( It is only necessary to install the pre-swivel tank formed on site, and the construction time can be shortened. Moreover, since the resin surface is generally smoother than the concrete surface (the friction coefficient is small), it is easier to generate a swirling flow in the tank 4 and to prevent sedimentation of sand.

(Drive water pipe)
The drive water pipe 5 is for injecting high-pressure water toward the suction port 2a of the suction pipe 2, and is connected to a pressure water pump (not shown). The pressure water pump (not shown) connected to the sand collecting device 14 and the drive water pipe pressure water pump (not shown) connected to the drive water pipe 5 may be a common pump or another pump. It may be. The pressure water pump (not shown) is one of the devices constituting the jet pump 1.

  The drive water pipe 5 is embedded in the tank 4 (see FIG. 3B), and is piped in parallel along the bottom surface 4e to the center of the tank 4. And in the central part of the tank 4, the direction is changed vertically upward, the pipe diameter is narrowed, and the discharge port 5a faces the suction port 2a of the suction pipe 2 with a predetermined distance between the suction port 2a The drive water pipe 5 is disposed with an interval.

  In addition, this drive water pipe 5 may be arrange | positioned below the bottom face 4e of the tank 4 in the aspect as shown in FIG. Here, FIG. 4 is a view for showing a modification of the arrangement of the drive water pipe 5 with respect to the tank 4 formed at the bottom of the sand pit 3.

  First, as shown in FIG. 4A, grooves 4 b (pipe pits) are formed in the bottom surface 4 e of the tank 4. The support member 10 is fixed to the bottom of the groove 4b, and the drive water pipe 5 is attached to the support member 10. A receiving frame member 9 (angle material) is embedded in the upper part on both sides of the groove 4b, and a steel lid 8 is placed on the receiving frame member 9. The top surface of the lid 8 and the bottom surface 4e of the tank 4 are flush with each other. Thus, by disposing the drive water pipe 5 in the groove 4b formed in the bottom surface 4e of the tank 4, the drive water pipe 5 can be easily attached and detached as necessary. Moreover, since the upper part of the groove | channel 4b is covered by the same level as the bottom face 4e level of the tank 4, the swirl | vortex flow in the tank 4 is not disturbed at all. As shown in FIG. 4B, it is not always necessary to cover the groove 4b. This is because the disturbance of the swirling flow can be prevented more than in the prior art by disposing the hydrodynamic pipe 5 below the bottom surface 4e of the tank 4.

(Injection nozzle installed in the sand settling pit)
As shown in FIG. 2, one injection nozzle 6 is attached to the inner peripheral surface 4 c of the tank 4 formed at the bottom of the sand settling pit 3. The injection nozzle 6 is for generating a swirling flow along the inner peripheral surface 4 c of the tank 4. Further, the injection nozzle 6 is attached in the vicinity of the sand sink introduction portion 4a and is adjusted so that the injection direction of the pressure water is obliquely downward. A water supply pipe 7 is connected to the injection nozzle 6, and a pressure water pump (not shown) is connected to the water supply pipe 7. This pressure water pump (not shown) may be a pump common to the pressure water pump (not shown) for the driving water pipe connected to the driving water pipe 5, or may be a separate pump. Note that the number of injection nozzles 6 need not be one, and may be plural. Moreover, it is preferable that the injection nozzle 6 is provided in the vicinity of the introduction part 4a at least for each introduction part 4a of the settling sand. Thereby, it becomes easier to generate a swirling flow at the bottom of the tank 4.

(Jet pump operation)
Next, the operation of the jet pump 1 will be described. In the following description, a pressure water pump (not shown) supplies pressure water to all of the drive water pipe 5, the injection nozzle 12 of the sand collecting device 14, and the injection nozzle 6 provided in the sand settling pit 3. A description will be given assuming that the pumps are common. In addition, switching of the supply of the pressure water to the drive water pipe 5, the injection nozzle 12, and the injection nozzle 6 is performed by opening and closing an electric valve (not shown) provided on the upstream side of each of these devices.

  First, a pressure water pump (not shown) of the jet pump 1 is activated, pressure water is jetted from the jet nozzle 12 of the sand collecting device 14, and sand is poured into the sand settling pit 3 (tank 4) together with sewage. Thereby, as indicated by the arrows in FIG. 2, the sand settling at the bottom of the sand settling basin 100 flows down along the quadrangular pyramid shaped portion 3 a of the sand settling pit 3, and the introduction portion 4 a formed on the inner peripheral surface 4 c of the tank 4. Into the tank 4.

  Further, it is provided in the sand settling pit 3 (tank 4) at the same time as the pressure water is jetted from the jet nozzle 12 of the sand collecting device 14 or after a while after jetting the pressure water from the jet nozzle 12. The pressure water is jetted from the jet nozzle 6 along the inner peripheral surface 4 c of the tank 4. Due to the jet flow from the injection nozzle 6, the sand flow flowing into the tank 4 from the introduction portion 4 a becomes a swirling flow.

  Next, pressure water is supplied to the drive water pipe 5 of the jet pump 1, and the pressure water is jetted from the discharge port 5 a toward the suction port 2 a of the suction pipe 2. The jetted pressure water is sucked into the suction pipe 2 from the suction port 2 a together with the sand settling in the tank 4. The sand settling into the suction pipe 2 in this manner is discharged to a sand settling machine (not shown) via a sand settling pipe (not shown) connected to the suction pipe 2.

  Here, by making the inner peripheral surface 4c of the tank 4 formed at the bottom of the sand settling pit 3 into a circular shape, a swirling flow is easily generated at the bottom of the sand settling pit 3 (the tank 4). Further, by disposing the drive water pipe 5 below the bottom surface 4e of the tank 4, it becomes difficult to form a dead zone in which sedimentation tends to accumulate. Moreover, since it becomes difficult to form a dead zone at the bottom of the tank 4, sedimentation of sand is prevented and a swirl flow is more likely to occur. And in the center part of the bottom of the tank 4, since the settling sand is sucked into the suction pipe 2 from the suction port 2a together with the pressure water, the flow of the settling sand turning in the tank 4 gradually reduces the turning diameter. It will be guided to the center of the tank 4. Therefore, even if only one injection nozzle 6 is installed as in the present embodiment and the amount of pressure water used is reduced, the generation of swirling flow can be promoted, so that the sand-carrying efficiency of sand settling is improved as compared with the prior art. Can be made.

  In the present embodiment, since the sand settling part 4 a is provided at a position facing the sand collecting direction X of the inner peripheral surface 4 c of the tank 4, a swirl flow is more likely to occur at the bottom of the tank 4. Further, the central portion of the bottom surface 4e of the tank 4 is formed in a conical shape inclined obliquely upward toward the discharge port 5a of the drive water pipe 5, and the bottom surface 4e of the tank 4 and the discharge port 5a tip of the drive water pipe 5 are connected to each other. Since the surfaces are flush with each other, the sand is easily guided to the pressure water ejected from the drive water pipe 5, and the sand-carrying efficiency of the sand can be further improved.

  Moreover, when the sand basin 100 is used as a sand basin for rainwater in a sewage treatment plant, the sand basin 100 is normally emptied. That is, after using the sand basin 100 during rain, the sand basin 100 must be dried each time. When the sand basin 100 is dried, if sand remains in the sand pit 3, it is not preferable because odor is generated or the sand is fixed to the pit. According to the jet pump 1 of the present embodiment, the lower the water level of the sand settling basin 100, the stronger the swirling flow. Therefore, the sand settling basin 100 can be dried by removing the settling sand without leaving the settling pit 3.

(Modification of tank formed at the bottom of the sand pit)
FIG. 5 is a side view of a jet pump for illustrating a modified example of the tank formed at the bottom of the sand settling pit 3.

  Here, the tank 4 shown in FIG. 1 had a cylindrical shape. On the other hand, as shown in the side view in FIG. 5, the tank 41 according to the modification has a conical shape. This conical form is a conical shape that becomes narrower as it goes downward. That is, the inner peripheral surface 41 c of the tank 41 is an inclined surface that inclines toward the center of the tank 41 from the upper side to the lower side. In plan view, the inner peripheral surface 41c of the tank 41 is circular. Further, the shape of the bottom surface 41 e of the tank 41 is the same shape as the bottom surface 4 e of the tank 4. Furthermore, although not shown in the figure, as in the case of the tank 4, the introduction portion of the sand sink is formed as a recess in a part of the inner peripheral surface 41 c, and the sand sinks into the sand settling pit 3. It is formed on the inner peripheral surface 41c at a position facing the coming sand collecting direction X. By making the tank formed at the bottom of the sand settling pit 3 into a conical shape as in this modification, the capacity of the tank is smaller than in the case of a columnar shape, but the settling of sand is the suction pipe 2 It becomes easy to be guided to the suction port 2a.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims. .

It is a side view of the sand raising apparatus which concerns on one Embodiment of this invention. It is a top view of the sand raising apparatus shown in FIG. It is the A section enlarged view and BB sectional drawing of FIG. It is a figure for showing the modification of arrangement | positioning of the drive water pipe with respect to the tank formed in the bottom part of the sand settling pit. It is a side view of the sand raising apparatus for showing the modification of the tank formed in the bottom part of a sand settling pit.

Explanation of symbols

1: Jet pump (sanding device)
2: Suction pipe 2a: Suction port 3: Sand pit 4: Tank 5: Drive water pipe 5a: Discharge port 6: Injection nozzle

Claims (5)

A suction pipe placed in the center of the sand pit;
An inner circumferential surface formed at the bottom of the sand pit is a circular tank,
A drive water pipe disposed below the bottom surface of the tank and having a discharge port facing the suction port of the suction pipe;
An injection nozzle for injecting pressure water along the inner peripheral surface of the tank;
A sand raising device, comprising:   2. The sand raising apparatus according to claim 1, wherein a central portion of the bottom surface of the tank is inclined obliquely upward toward the discharge port of the drive water pipe.   The sand raising device according to claim 1 or 2, wherein a bottom surface of the tank and a discharge port tip of the driving water pipe are flush with each other.   An introduction part for guiding the settling sand into the tank is formed on the inner peripheral surface of the tank, and the introduction part is provided at a position facing the sand collecting direction in which the settling sand flows into the tank. The sand raising device according to any one of claims 1 to 3, wherein the sand raising device is characterized.   5. The sand raising apparatus according to claim 4, wherein the spray nozzle is provided in the vicinity of the introduction portion.

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