JP2006022652A - Submerged sand pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a submerged sand pump improving reliability by pumping with controlling sand content by a submerged pump constant irrespective of flowing in sand quantity or sinking sand quantity for preventing disablement of pumping due to burying by a large quantity of flowing in earth and sand, and preventing blockage of the pump and improving reliability of a later stage apparatus by sand content control. <P>SOLUTION: A cylindrical burying prevention tank 3 is provided in a lower part of a casing 2. A suction pipe 4 for sucking top clear water and air is connected to the burying prevention tank 3 and a screw 51 generating downward flow in an inside of a tip is provided in a lower part of the burying prevention tank 3 from a rotary shaft of an impeller 1. A stirring pipe 5 provided with an opening 52 communicating to an inside of the casing 2 from the burying prevention tank 3 on a circumference surface is rotatably provided. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a submersible sand pump, and in particular, by controlling so as to keep the sand content rate by pump suction constant, the sand sink is efficiently sucked up so as not to be buried even by a large amount of inflowing earth and sand. The present invention relates to a submersible sand pump designed to prevent pump clogging by rate control and improve the reliability of subsequent equipment.

  Conventionally, underwater sand pumps are frequently used as a method of sanding sand accumulated in a sand basin. This submersible sand pump mixes sand and water by digging and rolling up the accumulated sand by injecting pressure water for digging with a digging nozzle disposed near the suction port of the submersible sand pump. Then, this is sucked from the suction pipe of the submersible sand pump, pressure is generated by a rotating impeller in the submersible sand pump, and the sand is pumped to a predetermined head.

  By the way, the conventional submersible sand pump excavates and rolls up the sand accumulated by the excavating nozzle and sucks the mixture of sand and water from the suction pipe of the submersible sand pump. When the amount of inflow is large, the amount of sand rolled up by the drilling nozzle is inevitably increased, and the mixing ratio (sand content) of the suction water by the submersible sand pump is increased. The rate is low and the sand content is not constant.

For this reason, in this submersible sand pump, the sand content of the submersible sand pump varies greatly depending on the amount of sand inflow or sedimentation, and the sand content cannot be controlled to be constant. There was a problem that it could not be improved.
Further, when the sedimentation sand is cut by the excavation nozzle, the surrounding sand collapses, and there is a problem that a large amount of sand enters the suction portion of the submersible sand pump and closes the suction portion.
Furthermore, when a large amount of earth and sand has flowed into the settling basin at a time, such as during rainfall, the submersible sand pump is buried, making it impossible to lift the sand.

  In view of the problems of the conventional submersible sand pump, the present invention sucks up the sand by controlling the sand content by the submersible pump regardless of the amount of sand inflow or sedimentation, and is also buried by a large amount of inflowing sand. An object of the present invention is to provide a submersible sand pump that improves the reliability by preventing the pump from being sucked up at the same time, prevents blockage of the pump by sand content control, and improves the reliability of the subsequent equipment.

  In order to achieve the above object, the submersible sand pump of the present invention is a submersible sand pump provided with an impeller and its casing. A cylindrical embedding prevention tank is disposed below the casing, and a supernatant water is provided in the embedding prevention tank. And a suction pipe for sucking air, and a screw for generating a downward flow inside the tip from the rotation shaft of the impeller to the inside of the burying prevention tank, and an opening communicating with the casing from the burying prevention tank. A stirring pipe provided on the surface is extended to be rotatable.

  In this case, it is possible to provide a gate that opens the bypass passage when the discharge amount of the pump is reduced while forming a bypass passage that leads from the suction pipe to the casing.

  Further, a check valve can be provided in the discharge pipe of the pump, and a rod that can be raised and lowered by opening and closing the check valve can be provided, and the gate of the bypass path can be opened and closed by raising and lowering the rod.

According to the submersible sand pump of the present invention, in the submersible sand pump including the impeller and its casing, a cylindrical embedding prevention tank is disposed below the casing, and the supernatant water and air are sucked into the embedding prevention tank. Stirring that has a suction pipe connected to the rotation shaft of the impeller and below the embedding prevention tank, a screw that generates a downward flow inside the tip, and an opening that communicates from the embedding prevention tank to the casing. When the impeller is rotated because the pipe is rotatably extended, the supernatant water and air in the pit are drawn into the embedding prevention tank from the suction pipe, and the screw causes a downward flow due to the rotation of the stirring pipe. The sand can be rolled up while stirring and sucked into the casing from the opening of the stirring pipe together with the supernatant water and air, and sanded.
At this time, since air is sucked together with the supernatant water, the apparent specific gravity of the sand-containing water pumped by the pump can be reduced, the power required for sanding can be reduced, and the sand pump cannot be pumped by conventional sand pumps. Even with sand content, the air lift effect helps, and sanding can be done without clogging.
And since it is always forcibly stirred in the pit by the mixed jet water flow of supernatant water and air, it is possible to always carry out sanding at a constant sand content during sanding.

In this case, by forming a bypass passage that leads from the suction pipe to the casing and providing a gate that opens the bypass passage when the pump discharge amount is reduced, the inside of the embedding prevention tank is buried with sedimentation, so that the supernatant water and air Even if it becomes impossible to suck the water, it is possible to introduce the supernatant water and the air into the casing by opening the gate of the bypass passage according to the decrease in the pump discharge amount.
As a result, even if sand-containing water having a high sand content is sucked, the supernatant water can be supplied into the casing before the discharge pipe is compacted and closed with sand, and the sand concentration is automatically diluted and closed. There is nothing.
When the pump discharge amount is recovered by opening the gate, the gate is closed and the normal operation can be resumed.
Further, while supplying the supernatant water, the sand settling in the embedding prevention tank can be forcibly discharged by the stirring by the rotation of the stirring pipe and the downward flow by the screw.

  In addition, a check valve is provided in the discharge pipe of the pump, a rod that is raised and lowered by opening and closing the check valve, and a gate of the bypass passage is opened and closed by raising and lowering the rod, thereby preventing a decrease in pump discharge amount. Transmission is performed by the operation of the valve and rod, and the gate of the bypass path can be automatically opened and closed.

  Hereinafter, embodiments of the submersible sand pump of the present invention will be described with reference to the drawings.

1 to 5 show an embodiment of the submersible sand pump of the present invention.
This submersible sand pump includes an impeller 1 and its casing 2. A cylindrical embedding prevention tank 3 is disposed below the casing 2, and supernatant water and air (shown as bubbles A) are provided in the embedding prevention tank 3. ) And a screw 51 for generating a downward flow inside the tip from the rotating shaft of the impeller 1 to the inside of the tip, and from the embedding prevention tank 3 into the casing 2. The stirring pipe 5 provided with a communication opening 52 on its peripheral surface is extended to be rotatable.

The impeller 1 is rotationally driven by a submersible motor 6 and sands water and sand sucked from an integrally rotating stirring pipe 5 to the ground via a discharge pipe 7.
Below the casing 2 of the impeller 1, a burying prevention tank 3 having a diameter slightly smaller than that of the casing 2 is coaxially installed, and a stirring pipe 5 is rotatably fitted in the lower wall 21 of the casing 2. ing.
In the present embodiment, the impeller 1 is slowed down to 400 to 500 rpm to reduce the wear of the impeller 1 and, as shown in FIG. By providing 22, the wear state of the impeller 1 can be confirmed. Further, as shown in FIG. 5B, the impeller 1 is bolted, and the lower portion of the casing 2 is disassembled, so that only the impeller 1 can be removed and easily replaced.

The embedding prevention tank 3 has a cylindrical shape and prevents the surrounding sand pool from collapsing and the opening 52 of the stirring pipe 5 from being buried.
A suction pipe 4 is connected to the embedding prevention tank 3 so as to penetrate the peripheral wall, and a supernatant water inlet 43 and an air inlet 44 are provided on the upper part of the suction pipe 4.

The suction pipe 4 is formed with a bypass path 41 that leads to the casing 2, and the bypass path 41 is provided with a gate 42 that opens the bypass path 41 when the pump discharge amount is reduced.
As shown in FIGS. 3 to 4, the gate 42 is provided so as to be opened and closed by a check valve 8 disposed in the discharge pipe 7 of the pump. That is, a rod 82 that moves up and down by the rotation of the shaft 81 of the check valve 8 is provided, and the gate 42 is fixed to the tip of the rod 82. When the pump discharge amount is normal and the check valve 8 is fully opened, the gate is fixed. The gate 42 is configured to open when the valve 42 is closed, the pump discharge amount is greatly reduced, and the check valve 8 is closed.
The rod 82 is connected to the shaft 81 of the check valve 8 via a link mechanism 83 and is urged downward by a weight 84.

As shown in FIGS. 1 to 2, the stirring pipe 5 extends from the rotating shaft of the impeller 1 below the embedding prevention tank 3, and rotates in the same direction at the same rotational speed as the impeller 1 by the underwater motor 6. The inside of the embedding prevention tank 3 is agitated.
A screw 51 that generates a downward flow by rotation of the stirring pipe 5 is disposed inside the hollow tip of the stirring pipe 5, and a portion from the embedding prevention tank 3 to the casing 2 has a stirring pipe 5. An opening 52 communicating with the inside of the casing 2 from the embedding prevention tank 3 through the inside is formed.
As shown in FIG. 2, the screw 51 of the stirring pipe 5 sucks the sand sediment S from the lower portion of the opening 52 of the stirring pipe 5 and forcibly discharges it from the tip when the burying prevention tank 3 is buried with the sand sediment S. can do.

Next, the operation of the submersible sand pump of this embodiment will be described.
When the impeller 1 is rotated by the submersible motor, as shown in FIG. 1, the supernatant water and air in the pit are drawn into the burying prevention tank 3 from the suction pipe 4, and the screw 51 is caused to flow downward by the rotation of the stirring pipe 5. Then, the sand is rolled up while stirring in the pit, sucked into the casing 2 through the opening 52 of the stirring pipe 5 together with the supernatant water and air, and sanded.
At this time, since air is sucked together with the supernatant water, the apparent specific gravity of the sand-containing water pumped by the pump can be reduced, the power required for sanding can be reduced, and the sand pump cannot be pumped by conventional sand pumps. Even with sand content, the air lift effect helps, and sanding can be done without clogging.
And since it is always forcibly stirred in the pit by the mixed jet water flow of supernatant water and air, it is possible to always carry out sanding at a constant sand content during sanding.

The conventional sand pump has an apparent specific gravity of about 1.3 with sand-containing water with a sand content of 10%, and the power is 10-15% larger than that of fresh water with a specific gravity of 1.0. By putting air into the water, it becomes possible to reduce the apparent specific gravity of the sand-containing water due to the air lift effect even at the same sand content rate, and the increase in power is less than that during clean water.
In addition, since the conventional sand pump pumps up the water by generating a vortex flow in the casing 2 by increasing the number of rotations, if air is sucked as in this embodiment, it will stay in the casing 2. Since the suction side does not become negative pressure, pumping becomes impossible, but the pump of this embodiment does not stay in the casing 2 even if air is sucked by reducing the rotation speed, and pumping is not disabled. .

In addition, the submersible sand pump of the present embodiment has a structure in which it is difficult to be buried by sedimentation by attaching the embedding prevention tank 3, but as shown in FIG. Even if the embedding prevention tank 3 is buried with the sedimentation sand S and the supernatant water and air cannot be sucked from the suction pipe 4, the reduction of the pump discharge acts in the closing direction of the check valve 8 and the gate 42 of the bypass passage 41. The supernatant water and air can be introduced into the casing 2.
Thereby, even if the sand-containing water having a high sand content is sucked, the supernatant water can be supplied into the casing 2 before the discharge pipe 7 is closed with the sand and closed, and the sand concentration is automatically reduced. There is no blockage.
When the pump discharge amount is recovered by opening the gate 42, the check valve 8 is opened, the gate 42 is closed, and the normal operation can be automatically resumed.
Further, while the supernatant water is being supplied, the sand sediment S in the embedding prevention tank 3 can be forcibly discharged by the stirring by the rotation of the stirring pipe 5 and the downward flow by the screw 51.

  In addition, the outline | summary of the pump blockage | prevention prevention mechanism by the submersible sand pump of this invention is shown in FIG.6 and FIG.7.

  As mentioned above, although it explained based on the example about the submersible sand pump of the present invention, the present invention is not limited to the composition described in the above-mentioned example, the composition described in the example is suitably combined, etc. The configuration can be changed as appropriate without departing from the spirit of the invention.

  The submersible sand pump of the present invention has a characteristic that the sand content rate is controlled and sucked up at the same time, and has the property of preventing the incapability of sucking up due to burial, so it is suitable for the use of a submersible sand pump installed in a sand basin. Besides being used, it can also be used for applications such as sludge pumping, ocean dredging, factory waste liquid transportation, residual waste processing, and river mud discharge.

It is a partial cross section front view which shows one Example of the submersible sand pump of this invention. It is sectional drawing which shows operation | movement when the inside of an embedding prevention tank is buried with sedimentation. It is sectional drawing which shows the opening / closing operation | movement of the gate of a bypass path. (A) is a cross-sectional view showing the bypass path and the vicinity of the gate, (b) is a cross-sectional view showing the vicinity of the check valve for opening and closing the gate. A casing is shown, (a) is the top view, (b) is sectional drawing of the principal part. It is a flowchart which shows the pump blockage | prevention prevention mechanism by the submersible sand pump of this invention. It is a flowchart which shows the pump blockage | prevention prevention mechanism by the submersible sand pump of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Impeller 2 Casing 21 Lower wall 3 Buried prevention tank 4 Suction pipe 41 Bypass path 42 Gate 43 Supernatant water intake 44 Air intake 5 Stirring pipe 51 Screw 52 Opening 6 Underwater motor 7 Discharge pipe 8 Check valve 81 Shaft 82 Rod 83 Link mechanism 84 Weight A Bubble S Sedimentation

Claims (3)

  In an underwater sand pump provided with an impeller and its casing, a cylindrical embedding prevention tank is disposed below the casing, and a suction pipe for sucking supernatant water and air is connected to the embedding prevention tank, and the impeller A stirring pipe provided with a screw for generating a downward flow inside the tip from the rotating shaft and provided with an opening communicating with the inside of the casing from the embedding prevention tank is rotatably extended. Features a submersible sand pump.   2. The submersible sand pump according to claim 1, wherein a bypass passage is formed from the suction pipe to the casing, and a gate is provided for opening the bypass passage when a discharge amount of the pump is reduced.   3. A pump according to claim 2, wherein a check valve is provided in the discharge pipe of the pump, a rod that is raised and lowered by opening and closing the check valve is provided, and a gate of the bypass passage is opened and closed by raising and lowering the rod. Submersible sand pump.

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