JPH0540315Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a residual water drainage pump for draining residual water on the floor of a construction site or the bottom of a tank.

[Conventional technology]

As shown in FIG. 5, a conventional residual water drainage pump of this type has a shaft 2 at the lower end of a vertical shaft submersible motor 1.
The impeller 3 is attached by a blade retaining nut 4 having an airlock prevention blade 4a at its tip. The impeller 3 is installed in the pump casing 5 in which the impeller 3 is built, by retracting the impeller 3 close to the rear wall (upper wall in the figure) 5a of the casing, and leaving a wide gap ( front clearance)
A so-called vortex pump is formed in which impeller wear is reduced by carrying out foreign substances such as sand along with the vortex generated in the gap during pump operation.

On the other hand, a core metal 6 is provided on the bottom of the pump casing 5.
A bottom plate 6 made of an elastic body in which the casing 5 is embedded is tightly pressed by tightening the bolts 7 and nuts 7a that connect the casing 5 with the rear wall 5a. There is. On the bottom surface of the bottom plate 6, there are strainer/pump legs 8.
A large number of them are formed intermittently, maintaining a slight height h,
A fluid passage is formed between these legs 8, and fluid is introduced to the suction portion of the impeller 3 through a pump suction port 9 formed in the center of the bottom plate 6. In addition, in the figure, 10 is a hose coupling.

When the motor pump is operated with the bottom placed on the floor, fluid is sucked in through the gap h between the bottom plate 6 and the floor formed by the strainer/pump legs 8 on the bottom surface of the bottom plate 6, and the fluid is pumped through the suction port of the pump casing 5. It enters the interior, is pressurized by the impeller 3, and is discharged to a predetermined location from the discharge port of the casing 5 through a discharge conduit connected to the hose coupling 10.

[Problem to be solved by the invention] In the conventional residual water treatment pump described above, the strainer of the pump is formed by the low height legs 8 formed on the lower surface of the bottom plate, and the residual water remaining on the floor is removed. The structure is designed to minimize the amount.

However, in this type of pump, () when the water level on the floor decreases and air is sucked in from the pump suction port, aerodynamics often occurs within the casing 5 and the water cannot be pumped; There were problems in that the water could not be drained immediately unless it was submerged to that point, and the water could not be pumped up from a depth of several millimeters.

The present invention solves the above-mentioned problems of the conventional technology, and provides a residual water drainage pump that can immediately drain water even from a water level of several millimeters, has no aerodynamics even in air suction operation, and is easy to handle. It is an object.

[Means to solve the problem]

In order to achieve the above object, the present invention minimizes the space inside the pump casing by making the front clearance, side clearance, and rear clearance between the pump casing containing the impeller and the impeller small. The height of the suction strainer/pump leg, which is formed integrally with the pump casing, is as small as possible from the floor, and the impeller's blade retaining nut is attached to the bottom of the pump casing. The pump casing is positioned so as to extend close to the bottom plate which has a large number of small holes, thereby further reducing the suction space between the pump casing and the floor surface.

The pump casing can be made of a single rust-free material or made of an elastic body.

[Action]

Since the present invention is configured as described above,
When the pump is operated with the bottom placed on a floor surface with residual water, the rotation of the impeller generates negative pressure at the pump suction port, and the suction strainer/pump leg formed integrally with the pump casing generates negative pressure. The water passing through the slight height gap between the floors and remaining on the floor is sucked into the casing from the pump suction port.

At this time, the residual water inlet is formed by a pump leg whose height from the floor is only 1 to 3 mm, so that the inlet can be sealed even with a small amount of residual water. Therefore, the suction pressure at the pump suction port generated by the impeller idling in the air will not be short-circuited with the external atmospheric pressure. Therefore,
Even if there is only a few millimeters of remaining water and the impeller is in the air, the impeller is quickly filled with pumped water, allowing immediate drainage work.

In order to minimize the space inside the casing, we created small front, side, and rear clearances between the impeller and the casing, and created a suction space from the pump suction port to the pump floor.
The blade retaining nut is extended and positioned close to the bottom plate, which has many small holes, making it even smaller, so even with the limited suction air volume due to the impeller, suction pressure can be generated in a short time. be able to.

Therefore, even if the suction air volume is small, even if there is only a few millimeters of water remaining on the floor and the impeller is in the air, the remaining water can be immediately guided into the pump impeller and water pumping can be started in a short time. Also, drainage work can be carried out continuously without aerodynamics.

Furthermore, even once the pump sucks in air and starts discharging gas and liquid, the impeller has the ability to suck up the remaining water by itself and fill the impeller with water, as described above, The discharged air is appropriately discharged through the discharge pipe, and gas-liquid drainage is performed continuously until there is no remaining water.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional side view of essential parts of a residual water drainage pump showing an embodiment of the present invention, and in the figure, the same reference numerals as those shown in FIG. 5 indicate the same or similar parts. shall be.

In the figure, an impeller 3 is attached to the lower end of a shaft 2 of a vertical shaft type submersible motor 1 by a blade retaining nut 4. It is made of an inexpensive material with no rust, and is attached to the intermediate casing 12 via a bottom plate 13 with bolts 14. The bottom plate 13 is provided with a large number of small holes 16 near the pump suction port 15, as shown in FIG.

The impeller 3 is located inside the pump casing 11.
The pump is installed with the front clearance a, the side clearance b, and the back clearance c all kept small, thereby creating a pump casing space shown by diagonal lines in Figure 2A. It is configured to make A as small as possible.

In addition, on the bottom periphery of the pump casing 11,
A large number of strainer/pump legs 17 are formed integrally with the casing 11, maintaining a slight height d of 1 to 3 mm, and between each of these legs 17, a large number of inlets 18 for residual water are provided. Further, the blade retaining nut 4 of the impeller 3 described above is installed so as to extend to the vicinity of the bottom plate 13 having a large number of small holes 16 attached to the bottom surface of the pump casing 11. Therefore, the structure is such that the suction space B indicated by diagonal lines in FIG. 2B is made even smaller. Accordingly, the distance (width) f between the impeller 3 and the floor surface is made as short as possible.

Further, as shown in FIG. 3, a pump outlet 19 is provided in the intermediate casing 12 which is tightened by bolts 14 on the rear surface (upper side in the figure) of the pump casing 11. teeth,
A discharge pipe 20 with a large contact area with outside air is attached to serve as a steam/water separation chamber 20a, and a hose coupling 10 connected to a discharge conduit (not shown) is attached to the upper part of the discharge pipe 20. In the figure, 3a indicates a blade, 21 indicates a shaft sealing device, and e indicates a distance between the bottom plate 13 and the floor surface.

Next, the effect will be explained.

When the pump is operated with the bottom placed on a floor surface with residual water, the rotation of the impeller 3 generates negative pressure at the pump suction port 15, and the pump casing 11
Suction strainer/pump leg 1 integrally formed with
7 and the floor surface, the remaining water on the floor surface is removed from the pump suction port 15 to the casing 1.
Inhale into 1.

At this time, a residual water inlet 18 is formed by a strainer/pump leg 17 whose height from the floor is only 1 to 3 mm, so that the inlet 18 can be sealed even with a small amount of residual water. Therefore, the suction pressure of the pump suction port 15 generated by the impeller 3 idling in the air will not be short-circuited with the external atmospheric pressure. Therefore, even if the remaining water is only a few mm and the impeller 3 is in the air, the impeller 3 can be quickly removed.
Since the water is filled with pumped water, drainage work can be carried out immediately.

In addition, the space A (second
In order to minimize the difference in Figure A), the front, side, and rear clearances a, b, and c between the impeller 3 and the casing 11 are slightly formed, and the suction space from the pump suction port 15 to the floor is B (Figure 2B)
is made even smaller by extending and positioning the vane retaining nut close to the bottom plate, which has many small holes, so even with the limited suction air volume by the impeller 3, the suction pressure can be reduced in a short time. can occur.

Therefore, even if the suction air volume is small, even if the remaining water on the floor is only a few mm and is in the air above the impeller, the impeller 3
This combined with the fact that the distance f between the surface and the floor surface is made as short as possible, the remaining water can be immediately guided into the pump impeller, water pumping can be started in a short time, and each area around the impeller can be Since the clearances a, b, and c are made small to make the space A inside the casing as small as possible, a self-priming effect occurs, allowing continuous drainage work without air locking.

Further, even once the pump sucks air and starts discharging gas and liquid, the impeller 3 has the ability to suck up the remaining water by itself and fill the impeller 3 with water, as described above, and the intermediate casing 12 A discharge pipe 20 provided above has a chamber 2 that temporarily stores the pumped water and increases the contact area with the outside air to serve as a gas-liquid separation chamber.
0a is formed, the air-water mixture discharged to the discharge pipe 20 together with the pumped water is subjected to a gas-liquid separation action here, the air is discharged to the outside via the hose coupling 10, and a portion of the water is is returned into the pump casing 11 as needed and used for continuous air and water drainage.

In addition, since a large number of small holes 16 are bored in the center of the bottom plate 13, the residual water inlet 18 with a slight height d formed by the pump leg 17 with a low height constitutes a strainer. Together with this, it is possible to prevent sand, dirt, etc. from entering, and the impeller 3 can be prevented from clogging.

Furthermore, since the pump casing 11 is made of a rust-free material such as rubber, it is possible to prevent the impeller from locking due to rust after the pump is stopped and left unattended.

In the above-mentioned embodiment, the structure in which the strainer/pump leg 17 is provided on the bottom periphery of the pump casing 11 has been described, but the shape of the pump leg 17 is not limited to this, and it is also possible to provide it intermittently radially, for example. It is. Furthermore, the pump casing 11 can be made of an elastic material, which is resistant to shocks in handling, prevents wear of the impeller due to encroachment of sand, and provides good stability with respect to the floor.

[Effect of idea]

As explained above, according to the present invention, the front, side, and rear clearances between the impeller and the pump casing are minimized to minimize the pump casing space, and the suction strainer and pump leg are integrated with the pump casing. The height from the floor of the impeller is made small, and the impeller's blade retaining nut is
The suction space is made even smaller by extending the pump casing close to the bottom plate, which has many small holes attached to the bottom of the pump casing, so that only a few millimeters of water remains and the impeller is not submerged in water. Even if the water is drained, residual water can be immediately drained, and airlock during draining can be prevented, allowing continuous draining of gas and liquid. As a result, work such as draining residual water from pits during drainage of residual water at a construction site can be carried out efficiently.

Furthermore, by constructing the pump casing from a single material that does not rust, it is possible to prevent the impeller from locking due to rust after the pump is stopped or left unused.

Moreover, by constructing the pump casing from an elastic body, it is possible to prevent shocks during handling, and it is possible to prevent wear of the impeller due to sand entrapment.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional side view of essential parts of a residual water drainage pump showing an embodiment of the present invention, Figs. 2A and 2B are explanatory drawings, and Fig. 3 is a top view of the pump casing with the intermediate casing removed. FIG. 4 is a bottom view, and FIG. 5 is a sectional side view of a main part showing a conventional example. DESCRIPTION OF SYMBOLS 1... Submersible motor, 2... Motor shaft, 3... Impeller, 11... Pump casing, 12... Intermediate casing, 13... Bottom plate, 15... Pump suction port, 16... Small hole, 17... ... Strainer/pump leg, 18... Inflow port for residual water, 19... Pump discharge port, 20... Discharge pipe, a, b, c... Clearance, A... Pump casing space, B... Suction space.

Claims (1)

[Scope of utility model registration request] In a motor pump with an impeller attached to the shaft of a vertical shaft type electric motor, the front clearance, side clearance, and rear clearance between the pump casing containing the impeller and the impeller are all set to small gaps within the pump casing. In addition, the suction strainer/pump leg, which is formed integrally with the pump casing, has a small height from the floor. A residual water drainage pump characterized in that the suction space between the pump casing and the floor surface is further reduced by extending the pump to the vicinity of a bottom plate having a large number of small holes attached to the pump casing.