JP3138560B2 - Self liquid circulation type canned motor pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a self-liquid circulating type canned motor pump, and more particularly to a self-liquid circulating type canned motor pump for supplying a part of the discharged liquid to a canned motor through a self-liquid circulating pipe and circulating it.

[0002]

2. Description of the Related Art A canned motor pump lubricates a bearing with its own liquid by returning a part of a discharged liquid to a canned motor. That is, as shown in FIG. 2, in the conventional canned motor pump, part of the discharge liquid (handle liquid) discharged from the impeller 2 accommodated in the pump casing 1 is discharged from the discharge port 1a of the pump casing. Is supplied into the canned motor 4 by a self-liquid circulating pipe 3 provided in the motor. The treated liquid supplied into the canned motor 4, after lubricating the bearing 5 on the counter impeller side, passes through the gap between the can 7 fitted on the stator 6 and the rotor 9 supported on the main shaft 8, and After lubricating the bearing 10 on the impeller side, the impeller 2 returns to the suction port from the balance hole 2a of the impeller 2 soon.

[0003]

However, in the canned motor pump shown in FIG. 2, when the handling liquid contains slurry, the life of the bearing is reduced and the peripheral members are worn. In order to solve this problem, a strainer (net / filter) is conventionally provided in the middle of the self-liquid circulation pipe, but this method has the following problems. (1) The strainer is clogged, and it takes time to monitor and maintain the strainer. (2) If the strainer is clogged, the circulating fluid will not flow and the bearing will be damaged in a short time.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a self-liquid circulation type canned motor pump capable of preventing slurry from entering the canned motor without providing a strainer. .

[0005]

In order to achieve the above-mentioned object, a self-liquid circulating canned motor pump according to the present invention takes out a part of the discharged liquid from a circulating liquid outlet on the discharge side of the pump and performs a self-liquid circulation. In a canned motor pump for supplying and circulating in a canned motor by a pipe for use, a cyclone separator is provided in the middle of the self liquid circulation pipe,
The high-concentration slurry liquid discharge port of the cyclone separator was connected to a slurry liquid return port provided downstream of the circulating liquid outlet, and the clean liquid discharge port of the cyclone separator was connected to the self-liquid circulation pipe. It is characterized by the following.

[0006]

According to the present invention having the above-described structure, a part of the discharge liquid taken out from the discharge side of the pump is guided to the cyclone separator by the self-liquid circulation pipe, where the high-concentration slurry liquid and the cleaning liquid are separated. The high-concentration slurry liquid is returned to the pump discharge liquid from the slurry liquid return port, and the cleaning liquid is supplied to the canned motor via the self-liquid circulation pipe. Therefore, the liquid circulating in the canned motor is only the cleaning liquid, and there is no danger of slurry entering the rotor chamber.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a self-liquid circulation type canned motor pump according to the present invention will be described below with reference to FIG. 1, components having the same functions or functions as those of FIG. 2 are denoted by the same reference numerals and description thereof will be omitted.

A discharge port 1a of the pump casing 1 is provided with a circulating liquid outlet 1b, and a circulating liquid pipe 3 is connected to the circulating liquid outlet 1b. The discharge port 1
The discharge pipe 15 is connected to a.

A cyclone separator 11 is provided in the middle of the self liquid circulation pipe 3. The cyclone separator 11 includes a cyclone separator main body 12 having a cylindrical portion 12a and a conical portion 12b extending below the cylindrical portion 12a. An upstream rising pipe 13 is provided in the cyclone separator main body 12. .

In the cyclone separator main body 12, a suction port 12c is opened in a cylindrical portion 12a, and the self liquid circulation pipe 3 is connected to the suction port 12c. At the lower end of the conical portion 12b, a high-concentration slurry liquid outlet 12d is opened, and this outlet 12d is connected to a slurry liquid return port 15a of the discharge pipe 15 by a connection pipe 16.

The cylindrical portion 12 of the cyclone separator main body 12 has a cleaning liquid discharge port 12e opened at the upper end thereof. The cleaning liquid discharge port 12e is opposite to the canned motor 4 by the self liquid circulation pipe 3. It is connected to the end on the impeller side. An orifice 17 is provided in the discharge pipe 15, and a differential pressure is generated by the orifice 17 before and after the orifice 17.

Next, the operation of the self-liquid circulation type canned motor pump configured as described above will be described. A part of the discharge liquid (handling liquid) is taken out from the circulating liquid outlet 1b of the pump casing 1, and the handled liquid is sucked into the cyclone separator 11 from the suction port 12c through the self liquid circulation pipe 3. The handling liquid sucked into the cyclone separator 11 advances to the conical portion 12b while rotating the portion near the wall of the cylindrical portion 12a, and particles in the liquid are collected toward the peripheral wall portion by centrifugal force and along the conical surface. It flows down and flows out continuously from the high-concentration slurry liquid discharge port 12d as a downstream, and the connection pipe 16
Thus, the slurry is returned into the pump discharge liquid from the slurry liquid return port 15a. At this time, since a negative pressure is formed near the slurry liquid return port 15a by the orifice 17,
The backflow of the high concentration slurry liquid can be prevented.

On the other hand, the cleaning liquid from which the particles have been separated rises in the rising vortex near the center, enters the upper cylindrical portion 12a through the upstream rising pipe 13, and then flows out through the cleaning liquid discharge port 12e. Thereafter, the cleaning liquid flows into the canned motor 4 through the self liquid circulation pipe 3.

The handling liquid flowing into the canned motor 4 is:
After lubricating the bearing 5 on the non-impeller side, it passes through the gap between the can 7 fitted to the stator 6 and the rotor 9 supported on the main shaft 8, and further lubricates the bearing 10 on the impeller side. The impeller 2 returns from the balance hole 2a to the suction port.

[0015]

As described above, according to the present invention,
Protect the canned motor from the slurry because the discharged liquid taken out by the self-liquid circulation pipe is separated by the cyclone separator as a high-concentration slurry liquid and a cleaning liquid, and only the cleaning liquid can be supplied as a circulating liquid for the canned motor. Can be. Thus, according to the present invention,
Unlike the protection of the canned motor by the strainer, there is no need for cleaning maintenance. Further, since no strainer is used, there is no possibility that the bearing is damaged due to clogging.

Further, according to the present invention, since the entire apparatus has a non-sealing structure, there is no possibility that the handling liquid leaks outside. By providing a differential pressure generating mechanism such as an orifice, backflow can be prevented, and the cyclone separator can be used more effectively.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a self-liquid circulation type canned motor pump according to the present invention.

FIG. 2 is a sectional view showing a conventional self-liquid circulation type canned motor pump.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 pump casing 2 impeller 3 self-liquid circulation pipe 4 canned motor 5, 10 bearing 6 stator 7 can 9 rotor 11 cyclone separator 12 cyclone separator main body 13 upstream rising pipe 15 discharge pipe 17 orifice

Continuation of front page (56) References JP-A-6-221291 (JP, A) JP-A-6-221293 (JP, A) JP-A-4-42292 (JP, U) JP-A 54-35361 (JP) , Y1) (58) Field surveyed (Int. Cl. ⁷ , DB name) F04D 13/06 F04D 29/70

Claims (2)

(57) [Claims] In a canned motor pump, a part of the discharged liquid is taken out from a circulating liquid outlet on a discharge side of the pump and supplied to and circulated in a canned motor by a self-liquid circulating pipe. A cyclone separator, a high-concentration slurry liquid discharge port of the cyclone separator is connected to a slurry liquid return port provided downstream of the circulating liquid outlet, and a cleaning liquid discharge port of the cyclone separator is connected to the self-liquid. A self-liquid circulation type canned motor pump connected to a circulation pipe. 2. The self-liquid circulation type canned motor pump according to claim 1, wherein a differential pressure generating mechanism is provided upstream of the slurry liquid return port and downstream of the circulating liquid outlet. .