JPH06235394A - Self circulation type canned motor pump - Google Patents

Abstract

PURPOSE:To provide a self liquid circulation type canned motor which can at least prevent the intrusion of slurry into a canned motor without installing a strainer. CONSTITUTION:A canned motor pump which takes out a portion of the liquid discharged from a circulation liquid taking-out part 1b on the discharge side of the pump and supplies the liquid into a canned motor 4 through a pump 3 for self liquid circulation and allows the liquid to circulate, and a cyclone separator 11 is installed midway in the pipe 3 for self liquid circulation, and the high concentration slurry liquid discharge port 12d of the cyclone separator 11 is connected with a slurruy liquid return port 15a formed on the backwash side from the circulation liquid taking-out port, and the clean liquid discharge port 12e of the cyclone separator 11 is connected to the pipe 3 for self liquid circulation.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art In a canned motor pump, a part of discharged liquid is returned to the canned motor to lubricate a bearing with its own liquid. That is, as shown in FIG. 2, in the conventional canned motor pump, a part of the discharge liquid (handled liquid) discharged from the impeller 2 housed in the pump casing 1 is partially discharged from the discharge port 1a of the pump casing. It is supplied into the canned motor 4 by the self-liquid circulation pipe 3 provided in the. The treated liquid supplied into the canned motor 4 lubricates the bearing 5 on the side opposite to the impeller, and then passes through the gap between the can 7 fitted to the stator 6 and the rotor 9 supported by the main shaft 8, and further, After lubricating the impeller-side bearing 10, it eventually returns from the balance hole 2a of the impeller 2 to the suction port.

[0003]

However, in the canned motor pump shown in FIG. 2, when the liquid to be handled contains slurry, the life of the bearing is shortened and the peripheral members are abraded. In order to solve this, a strainer (mesh / filter) is conventionally provided in the middle of the self-liquid circulation pipe, but this method has the following problems. (1) The strainer becomes clogged, which requires time and effort for monitoring and maintenance. (2) If the strainer is clogged, the circulating fluid will not spread and the bearing will be damaged in a short period of time.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a self-liquid circulation type canned motor pump capable of preventing the intrusion of slurry into the canned motor without providing a strainer. .

[0005]

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

[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 mixed. The high-concentration slurry liquid is returned to the pump discharge liquid from the slurry liquid return port, and the clean liquid is supplied to the canned motor through the self-liquid circulation pipe. Therefore, the liquid that circulates in the canned motor is only the cleaning liquid, and there is no risk that the slurry will enter the rotor chamber.

[0007]

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

A circulating liquid outlet 1b is provided at the discharge port 1a of the pump casing 1, and a self-liquid circulation pipe 3 is connected to the circulating liquid outlet 1b. In addition, the discharge port 1
The discharge pipe 15 is connected to a.

A cyclone separator 11 is installed in the middle of the self-liquid circulation pipe 3. The cyclone separator 11 includes a cyclone separator body 12 having a cylindrical portion 12a and a conical portion 12b extending downward from the cylindrical portion 12a, and an upstream ascending pipe 13 is arranged in the cyclone separator body 12. .

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

A clean liquid discharge port 12e is opened at the upper end of the cylindrical portion 12 of the cyclone separator body 12, and the clean liquid discharge port 12e is connected 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 installed in the discharge pipe 15, and a differential pressure is generated before and after the orifice 17 by the orifice 17.

Next, the operation of the self-liquid circulation type canned motor pump constructed as described above will be described. A part of the discharge liquid (handled 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 through 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 the particles in the liquid are collected by the centrifugal force toward the peripheral wall portion and along the conical surface. It flows down and continuously flows out from the high-concentration slurry liquid outlet 12d as a downstream, and the connecting pipe 16
Is returned to the pump discharge liquid from the slurry liquid return port 15a. At this time, since a negative pressure is formed in the vicinity of the slurry liquid return port 15a by the orifice 17,
It is possible to prevent backflow of the high-concentration slurry liquid.

On the other hand, the cleaning liquid from which the particles have been separated rises in the rising vortex portion near the center, passes through the upstream rising pipe 13 and enters the upper cylindrical portion 12a, and then flows out through the cleaning liquid discharge port 12e. After that, the clean 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 side opposite to the impeller, 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 side of the impeller. The balance hole 2a of the impeller 2 returns to the suction port.

[0015]

As described above, according to the present invention,
Protects the canned motor from the slurry because the high-concentration slurry liquid and the clean liquid can be separated by the cyclone separator into the discharge liquid taken out by the self-liquid circulation pipe, and only the clean liquid can be supplied as the circulating liquid of the canned motor. You can Therefore, according to the present invention,
Unlike protection of the canned motor by a strainer, no cleaning maintenance is required. Also, since no strainer is used, there is no risk of the bearing being damaged by clogging.

Further, according to the present invention, since the entire apparatus has a non-sealed structure, there is no fear that the handled liquid will leak to the 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 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 cross-sectional view showing a conventional self-liquid circulation type canned motor pump.

[Explanation of symbols]

 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 Rise Pipe 15 Discharge Pipe 17 Orifice

Claims (2)

[Claims] 1. A canned motor pump in which a part of the discharged liquid is taken out from a circulating liquid outlet on the discharge side of the pump and is supplied into a canned motor by a self liquid circulation pipe to circulate in the middle of the self liquid circulation pipe. A cyclone separator is provided, the high-concentration slurry liquid outlet of the cyclone separator is connected to a slurry liquid return port provided on the downstream side of the circulating liquid outlet, and the clean liquid outlet of the cyclone separator is the self-liquid A self-liquid circulation type canned motor pump characterized by being 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. .