JPH0536090U - Vertical pump - Google Patents

Abstract

(57) [Summary] [Purpose] Lubricate the upper bearing (submersible bearing) in the dry state by using part of the pumped water. [Structure] A hole 21 for collecting the dynamic pressure of pumping water is formed in the discharge bowl 3 (or the pumping pipe 4), and a pipe 22 extending from this hole 21 is connected to the hole 13 of the packing box 10,
The hole 21 communicates with the chamber 14 between the upper bearing 7 and the gland packing 9. When the upper bearing 7 is in a dry state, the valve (solenoid valve or check valve) 24 provided in the pipe 23 branched from the pipe 22 is closed, and the pumping water in the suction bowl 3 (or the pumping pipe 4) under positive pressure is at atmospheric pressure or The upper bearing 7 is lubricated by being introduced into the chamber 14 under negative pressure through the pipe 22.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a vertical shaft pump used as, for example, a large-scale circulating water pump for cooling turbine condensate in a thermal power plant or a nuclear power plant, and more specifically, when the upper bearing supporting the main shaft is dry, This is related to the technique of injecting lubricating water into the upper bearing.

[0002]

[Prior Art]

 FIG. 2 shows a conventional vertical shaft pump, in which an impeller 2 integrated with a main shaft 1 is located in a discharge bowl 3, and pumped water by this impeller 2 is a discharge bowl 3, a pump pipe 4, a discharge elbow 5 and a discharge pipe. Water is sent via 6. The upper and lower parts of the main shaft 1 are supported by an upper bearing 7 and a lower bearing 8 each made of a Teflon (registered trademark) -based or ceramic-based underwater bearing. Further, a shaft seal device 12 including a gland packing 9, a packing box 10 and a packing retainer 11 is provided at a portion where the main shaft 1 extends inside the pumping pipe 4 and discharges the elbow 5. The upper bearing 7 supports the main shaft 1 at a lower portion.

By the way, this type of pump lowers the water level in the discharge elbow 5 and the discharge pipe 6 at the time of starting the low head, when the discharge pipe system is filled with water, or when the discharge pipe system is siphon-shaped. To do. Therefore, the upper bearing 7 is in a dry state as shown in FIG. 2, and the bearing portion is burned out as it is. In FIG. 2, A is the suction water level, B is the discharge water level, and C is the air layer from atmospheric pressure to negative pressure.

In order to prevent this, conventionally, pressure water is injected from the hole 13 of the packing box 10 into a chamber 14 formed between the upper bearing 7 and the gland packing 9 and a valve (electromagnetic valve). Or, it is injected through a check valve 16 to lubricate the upper bearing 7 and prevent its burnout. In this case, the pressure water is sent after being properly adjusted in pressure by a separate pressure water injection system.

[0005]

[Problems to be solved by the device]

 As described above, in the conventional vertical shaft pump, the pressure water supplied to lubricate the upper bearing in the dry state is supplied from the other system, so that various devices equipped with an interlock are required as the system. As a result, the cost and maintenance cost are high, and the operation is complicated.

The present invention has been made in order to solve the problems of the prior art as described above. Lubrication of the upper bearing in a dry state is performed by utilizing a part of the pumped water, and An object of the present invention is to provide a vertical shaft pump that is prevented from burning.

[0007]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, the present invention provides a gland packing in a portion where a main shaft integrally having an impeller located in a discharge bowl extends in a pumping pipe and penetrates a discharge elbow. In a vertical shaft pump in which a dry state occurs in the upper bearing that supports the main shaft at the lower part, a hole for collecting the dynamic pressure of pumping water is bored in the discharge bowl or pumping pipe, and this hole is used as the upper bearing. It is connected by piping to a room formed between it and the gland packing.

[0008]

[Action]

 In a vertical shaft pump, the chamber between the upper bearing and the gland packing is under atmospheric pressure or negative pressure when the low head is started, when the discharge pipe is filled with water, or when the discharge pipe is siphoned. Therefore, by collecting the dynamic pressure of the pumped water by the above means and installing a pipe with low resistance, the pumped water in the discharge elbow or pump pipe under positive pressure is introduced into the above chamber, and the water in the upper bearing is Lubricate.

[0009]

【Example】

 Hereinafter, an embodiment of the present invention will be described in detail with reference to FIG. FIG. 1 shows a vertical shaft pump according to the present embodiment. The same parts as those shown in FIG. 2 are designated by the same reference numerals, and duplicated description will be omitted.

According to the present embodiment, as shown in FIG. 1, the discharge bowl 3 of the vertical shaft pump is provided with a hole 21 for collecting the dynamic pressure of the pumping water, and a pipe 22 extending from the hole 21. Is connected to the hole 13 of the packing box 10, so that the hole 21 is communicated with the chamber 14 between the upper bearing 7 and the gland packing 9. A branch pipe 23 is branched from the middle of the pipe 22, and a valve (electromagnetic valve or check valve) 24 is provided in the branch pipe 23. The hole 21 for collecting the dynamic pressure of the lifting pressure may be formed in the pumping pipe 4 instead of the discharge bowl 3.

In the vertical shaft pump, however, the chamber 14 between the upper bearing 7 and the gland packing 9 is operated when the low head is started, when the discharge pipe system is filled with water, or when the discharge pipe system is siphoned. Atmospheric or negative pressure. Therefore, as in this embodiment, the discharge bowl 3 (or the pumping pipe 4) is provided with a hole 21 for effectively collecting the dynamic pressure of the pumping water, and this hole 21 is connected to the upper bearing 7 by the pipe 22 having a low resistance. By communicating with the chamber 14 between the gland packing 9 and the gland packing 9, the pumped water in the discharge elbow 3 (or the pumping pipe 4) under positive pressure is introduced into the chamber 14 and the upper bearing 7 is lubricated with water. In this case, the valve 24 of the branch pipe 23 is closed.

Then, when the pump starts normal operation and the upper bearing 7 is normally lubricated, the valve 24 is opened by a timer (not shown) so that the upper bearing 7 and the gland packing 9 are separated from each other. Excess overflow water from the chamber 14 is discharged through the branch pipe 23 and the valve 24. If necessary, the pipe 22 may be incorporated with other pressure water pipes or backwash pipes.

[0013]

[Effect of the device]

 As described above, according to the present invention, in the vertical shaft pump, when the upper bearing is in a dry state, the upper bearing is lubricated by utilizing a part of the pumped water, which is, so to speak, self-pressure lubrication. As a result, there is no need for a separate pressure water injection system, thus reducing costs and maintenance costs, and simplifying operation.

[Brief description of drawings]

FIG. 1 is a vertical sectional view for explaining the configuration of a vertical shaft pump according to an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view for explaining the configuration of a conventional vertical shaft pump.

[Explanation of symbols]

 1 main shaft 2 impeller 3 discharge bowl 4 pumping pipe 5 discharge elbow 6 discharge pipe 7 upper bearing 8 lower bearing 9 gland packing 10 packing box 11 packing retainer 12 shaft sealing device 13 hole 14 chamber 21 hole 22 pipe 23 branch pipe 24 valve

Claims (1)

[Scope of utility model registration request] 1. A gland packing is provided at a portion where a main shaft integrally having an impeller located in a discharge bowl extends inside a pumping pipe and penetrates a discharge elbow, and the main shaft is supported at a portion below the gland packing. In a vertical shaft pump in which a dry state occurs in the upper bearing, a hole is formed in the discharge bowl or the pumping pipe to collect the dynamic pressure of the pumping water, and the hole is formed between the upper bearing and the gland packing. Vertical shaft pump characterized by communicating with the pipe by.