JPH06173883A - Submerged pump - Google Patents

Abstract

PURPOSE:To prevent a motor from seizure by cooling the motor with heat exchange by sending low concentration muddy water above a submerged pump into a cooling jacket with the utilization of suction negative pressure while draining high concentration muddy water around the submerged pump to the outside. CONSTITUTION:A submerged pump A has an impeller 13 disposed in an impeller housing 12 having a suction opening 10 in the lower surface and a discharge opening 11 in the peripheral edge. A motor 15 is provided continuously to the upper part of an impeller casing 12 and the output shaft 14 is connected to an impeller 13. Then, the outer periphery of the motor 15 is covered with a cooling jacket 17. Also, to a water inflow port 18 of the cooling jacket 17 connected to one end of a cooling water inflow pipe 20 having a cooling water inflow port 21 opened to the other end. Further, while one end of an outflow pipe 23 for draining water after cooling connected to a water outflow port 22 of the cooling jacket 17, the other end communicates to the suction opening 10. Thus, while high concentration muddy water is drained to the outside, low concentration muddy water wcools the motor 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a submersible pump capable of effectively preventing a motor burnout accident.

[0002]

2. Description of the Related Art Conventionally, a submersible pump has been effectively used for discharging bentonite as a stabilizing solution in, for example, an underground continuous wall construction method.

Here, the underground continuous wall construction method is a method in which a stable liquid is used to excavate the ground with a horizontal multi-axis rotary cutter type excavator while preventing the ground from collapsing, and a rebar cage is inserted to stabilize the ground. It is to build a continuous wall in the ground while exchanging liquid and concrete.

In such a construction method, the excavated earth and sand is sent to the earth and sand separation plant together with the stabilizing liquid by the pumping pump incorporated in the excavator and separated into the earth and the stabilizing liquid, and the high-quality stabilizing liquid is reused.

A submersible pump is effectively used as a pump for pumping mud.

[0006]

However, the submersible pump used for such an application still has the following problems to be solved.

That is, the above-mentioned submersible pump usually has an impeller casing having a suction opening on the lower surface and a discharge opening on the periphery, an impeller arranged in the impeller casing, and an integrally connected upper portion of the impeller casing. The output shaft is connected to the impeller.

On the other hand, in the field where the underground wall construction method is used, the submersible pump is used, for example, at a depth of 90 m, so that the concentration of mud is high and the fluidity is low, so that the cooling of the motor becomes insufficient, The motor temperature rises abnormally,
Eventually, a motor burnout accident occurred.

An object of the present invention is to provide a submersible pump which can solve the above problems.

[0010]

According to the present invention, an impeller casing having a suction opening on a lower surface and a discharge opening on a peripheral edge, an impeller arranged in the impeller casing, and an impeller casing integrally connected to an upper portion of the impeller casing. In a submersible pump including a motor having an output shaft connected to an impeller, a cooling jacket is provided around the outer circumference of the motor, and a cooling water inlet pipe having a cooling water inlet at one end is provided at the water inlet of the cooling jacket. A submersible pump characterized by connecting the ends and connecting one end of the water outlet pipe after cooling to the water outlet of the cooling jacket and communicating the other end of the water outlet pipe after cooling to the suction opening of the impeller casing. It is related.

Further, according to the present invention, the other end of the water outlet pipe after cooling is connected to not only the suction opening of the impeller casing but also a jet nozzle provided at a lower portion of the impeller casing, and the jet nozzle is arranged below the submersible pump. It is also characterized in that it is aimed at the cutter of the excavating cutter device.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A submersible pump A according to the present invention will be specifically described below with reference to the embodiments shown in the accompanying drawings (FIGS. 1 and 2).

As shown in the figure, the submersible pump A basically has an impeller casing 12 having a suction opening 10 at the center of the lower surface and a discharge opening 11 at the periphery, and an impeller 13 arranged in the impeller casing 12. , Is integrally connected to the upper part of the impeller casing 12 to connect the output shaft 14 to the impeller.
It consists of a motor 15 connected to 13.

Further, one end of a discharge pipe 16 is connected to the discharge opening 11, and the other end of the discharge pipe 16 is led to the outside.

Then, the impeller is driven by driving the motor 15.
When 13 is rotated, muddy water flows into the impeller casing 12 through the suction opening 10 and is then discharged to the outside through the discharge opening 11 and the discharge pipe 16.

However, since the above-mentioned muddy water has a high concentration and a small fluidity, it hardly performs the motor cooling action and the motor 15
When driving in such a state, the temperature of the motor 15 will be abnormally increased.

Therefore, in the present invention, as shown in FIGS. 1 and 2, a pair of semicircular dividing plates 17a, 17a,
It is covered with a cooling jacket 17 consisting of 17b, and the rotational force of the motor 15 is used to forcibly flow in the mud with low fluidity and high fluidity above it, effectively
Is configured to be cooled.

That is, the cooling jacket 17 has one end of a cooling water inflow pipe 20 connected to a water inflow port 18 provided at the upper portion thereof, and the other end of the cooling water inflow pipe 20 serves as a cooling water inflow port 21 above the submersible pump A. It is open to mud water with low concentration and high fluidity located at (Fig. 3).

The cooling jacket 17 has one end of the after-cooling water outflow pipe 23 connected to the water outlet 22 provided at the lower portion thereof, and the other end of the after-cooling water outflow pipe 23 is connected to the suction opening 11 of the impeller casing 12. Is in communication with.

With this structure, when the motor 15 is driven, the high-concentration muddy water around the submersible pump A can be discharged to the outside through the impeller casing 12 and the discharge pipe 15 as described above, and the suction opening of the impeller casing 12 can be discharged. Utilizing suction negative pressure generated in 10, submersible pump A
It is possible to effectively cool the motor 15 by heat exchange by flowing a low-concentration muddy water having a high fluidity located above the inside of the cooling jacket 17 into the cooling jacket 17. By such cooling, the motor
It is possible to reliably prevent a burnout accident or the like due to the temperature rise of 15.

After that, the muddy water after cooling is cooled by the water outflow pipe.
It flows into the suction opening 11 of the impeller casing 12 through 23, is mixed in high-concentration mud water with low fluidity, and is discharged to the outside through the impeller casing 12 and the discharge pipe 16 integrally.

However, since the mud water flowing into the impeller casing 12 from the water outflow pipe 23 after cooling is a low-concentration mud water having high fluidity, the above-mentioned high-concentration operation of the submersible pump A and the submersible pump A are When it is operated in a state of being buried in, the concentration can be adjusted and the motor 15 of the submersible pump A can be prevented from being burned.

Since the post-cooling water outflow pipe 23 is piped along the discharge opening 11 formed of a large-diameter pipe in this embodiment, it is possible to effectively prevent a damage accident during transportation and installation of the submersible pump A. It can be prevented.

The other construction of the illustrated embodiment will be described. Reference numeral 30 is an opening / closing valve attached to the lower end of the cooling water inflow pipe 20, 31 is an inspection window attached to the side surface of the cooling jacket 17, and 32 is an opening / closing window. A power supply cable to the motor 15 and 33 are support legs attached to the peripheral edge of the bottom of the impeller casing 13.

Further, another embodiment of the submersible pump A according to the present invention is shown in FIGS.

The embodiment shown in FIG. 4 is characterized in that the cooling water inlet 21 forming the upper end of the cooling water inflow pipe 20 is provided with a cooling water pumping device 40 comprising a small submersible pump.

When the negative pressure generated in the impeller casing 13 is not sufficient, the cooling water is forcibly flown into the cooling jacket 17 by the cooling water pump 40.
Can be cooled.

The embodiment shown in FIG. 5 is characterized in that the submersible pump A described above is attached to the suspension frame 50 arranged in the excavation hole H, and the excavation cutter device B is attached below the submersible pump A. It is what

With this configuration, after cooling the motor 15 of the submersible pump A, part of the water can be sucked into the impeller casing 15, and the remaining post-cooling water is radially mounted below the submersible pump A. It is supplied to the jet nozzle 51, and the cutter of the excavating cutter device B is supplied from the jet nozzle 51.
By ejecting toward the cutter 52, it is possible to prevent clods from adhering to the cutter 52 and maintain a good excavation capability.

The embodiment shown in FIG. 6 is a cooling water pressure-feeding device 60.
Is composed of a land pump installed on the ground F.

Also in this case, muddy water having a low concentration and a high fluidity is sucked into the cooling water pumping device 60 through the suction pipe 61, and then the cooling jacket 17 is passed through the cooling water inflow pipe 20.
To cool the motor 15. And,
As in the embodiment of FIG. 5, the cooled water is pressure-fed to the impeller casing 15 and the ejection nozzle 51, and the cooled water is ejected from the ejection nozzle 51 toward the cutter 52 of the excavating cutter device B, whereby the cutter A good excavation capacity can be maintained by preventing clods from adhering to 52.

In some cases, the cooling jacket 17
It is also possible to release the communication connection with the impeller casing 15 and supply all the cooled water after being fed from the cooling water pressure-feeding device 60 to the cooling jacket 17 to prevent clogging of the cutter 52 with clods.

[0033]

According to the present invention, an impeller casing having a suction opening on the lower surface and a discharge opening on the peripheral edge,
In an underwater pump including an impeller arranged in the impeller casing and a motor integrally connected to an upper portion of the impeller casing and having an output shaft connected to the impeller,
The outer circumference of the motor is covered with a cooling jacket, the water inlet of the cooling jacket is connected to the other end of a cooling water inlet pipe having a cooling water inlet at one end, and the water outlet of the cooling jacket is connected to the post-cooling water outlet pipe. While connecting one end,
It is characterized in that the other end of the water outlet pipe after cooling is communicated with the suction opening of the impeller casing.

With this configuration, when the motor is driven, the high-concentration muddy water around the submersible pump can be discharged to the outside through the impeller casing and the discharge pipe, and the suction negative pressure generated at the suction opening of the impeller casing can be used. As a result, mud having a high fluidity and a low concentration located above the submersible pump can flow into the cooling jacket to effectively cool the motor by heat exchange. By such cooling, it is possible to reliably prevent a burnout accident or the like due to the temperature rise of the motor.

Further, since the mud water flowing into the impeller casing from the water outflow pipe after cooling is a low concentration mud water having high fluidity, the submersible pump is operated at a high concentration and the submersible pump is operated in a state of being buried in the earth and sand. In this case, the concentration can be adjusted and the motor of the submersible pump can be prevented from being burned.

[0036]

[Brief description of drawings]

FIG. 1 is a front view of a submersible pump according to the present invention.

FIG. 2 is a plan view of the same.

FIG. 3 is an enlarged cutaway view of the relevant part.

FIG. 4 is a front view of another submersible pump according to the present invention.

FIG. 5 is a front view of a submersible pump according to another embodiment of the present invention.

FIG. 6 is a front view of a submersible pump according to another embodiment of the present invention.

[Explanation of symbols]

 A Submersible pump 10 Suction opening 11 Discharge opening 12 Impeller casing 13 Impeller 14 Output shaft 15 Motor 17 Cooling jacket 18 Water inlet 20 Cooling water inlet pipe 21 Cooling water inlet 22 Water outlet 23 Water outlet pipe after cooling

Claims (2)

[Claims] 1. An impeller casing (12) having a suction opening (10) on the lower surface and a discharge opening (11) on the periphery, and an impeller (13) arranged in the impeller casing (12).
In a submersible pump that is integrally connected to the upper part of the impeller casing (12) and has a motor (15) that connects the output shaft (14) to the impeller (13), a cooling jacket around the outer periphery of the motor (15). The cooling water inlet (18) of the cooling jacket (17) is connected to the other end of the cooling water inflow pipe (20) provided with the cooling water inlet (21) at one end, and the cooling jacket (17) is covered with the cooling jacket (17). ) Of the water outlet pipe (23) after cooling is connected to one end, and the other end of the water outlet pipe (23) after cooling is connected to the suction opening (10) of the impeller casing (12).
Submersible pump characterized by communicating with. 2. The after-cooling water outflow pipe (23) is connected at the other end thereof not only to the suction opening (10) of the impeller casing (12) but also to a jet nozzle (51) provided in the lower portion of the impeller casing (12). The submersible pump characterized in that the jet nozzle (51) is directed to the cutter (52) of the excavating cutter device (B) arranged below the submersible pump.