JP2004108169A - Seal device for horizontal shaft pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a seal device for a horizontal shaft pump capable of maintaining a stand-by state for a long time. <P>SOLUTION: In starting a horizontal shaft pump A, a three-way valve 11 is opened toward a communication tube 7, and closed toward a supply tube 13, and a three-way valve 8 is opened toward a vacuum pump 4. In this state, the vacuum pump 4 is operated, priming is sucked up from a lower end of a drain tube 5 to fill a supply tank 3. The vacuum pump 4 is stopped, and the three-way valve 8 is closed toward the vacuum pump 4, and opened toward atmospheric air. Simultaneously at this time, the three-way valve 11 is closed toward the communication tube 7, and opened toward the supply tube 13, and water in the supply tank 3 is introduced to the seal device 10. Water film of this water is formed on a seal surface of the seal device 10 to improve seal performance in the seal device 10. Leak of air into a space 6 is thus reduced, and lowering of the water level in the space 6 is restricted, thereby a stand-by state can be maintained for a long time. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a sealing device for a horizontal shaft pump.
[0002]
[Prior art]
Since the horizontal axis pump used for water pumping equipment has a long distance from the liquid level to the pump propeller, when starting the pump, priming water is introduced into the space from the liquid level to the pump using a vacuum pump or the like. There is a need. However, the atmosphere leaks from the seal around the rotation axis of the horizontal pump, and the level of the priming water drops before the pump is started. For this reason, an auxiliary tank is usually provided to introduce priming water in consideration of the drop in the water level.
[0003]
[Problems to be solved by the invention]
However, in the conventional pump, there is a problem called a so-called water drop phenomenon, in which the sealing portion around the shaft is incomplete and the amount of air leaking is large, so that the water level drops.
Therefore, it is necessary to operate the vacuum pump every time the water level drops, or to increase the capacity of the auxiliary tank and the capacity of the vacuum pump.This causes problems and shortens the life of the vacuum pump, and also increases the size and cost of the equipment. There was a problem that led to an increase.
An object of the present invention is to solve the above-mentioned problems of the prior art.
[0004]
[Means for Solving the Problems]
In order to achieve the above object, a sealing device for a horizontal shaft pump of the present invention includes a vacuum pump for filling a space from a water suction portion to a propeller portion of the horizontal shaft pump with an auxiliary tank communicating with the space, A seal portion provided around the axis of the horizontal axis pump, and at least the auxiliary tank is provided on the seal portion during a period from the time when the vacuum pump is started to fill the space and the auxiliary tank with water to the time when the horizontal axis pump is started. And a supply device for supplying water.
In the above configuration, since water is supplied to the seal portion from the auxiliary tank and a water film is formed on the seal surface, suction of air from the seal portion is reduced. Therefore, there is an effect that the operation time and capacity of the vacuum pump can be reduced or the capacity of the auxiliary tank can be reduced.
It is desirable that the seal portion mainly includes a segment seal.
The seal portion has a first seal to which the water of the auxiliary tank is supplied, and a lip seal mounted on the shaft on the atmosphere side of the first seal and abutting on a casing of the first seal. Such a configuration is also possible. The lip seal comes into contact with the casing of the first seal during operation of the vacuum pump, and has an effect of preventing suction of air.
Further, in the invention according to claim 5, a vacuum pump for filling the space from the water suction part to the propeller part of the horizontal shaft pump with water, a seal chamber provided around the shaft of the horizontal shaft pump, and An opening / closing valve that opens and closes with respect to the shaft, a segment seal mounted on a shaft in the seal chamber, and a lip seal mounted on the shaft on the atmosphere side of the seal chamber and abutting against a side wall of the seal chamber. Then, between the time when the vacuum pump is started to make the space full and the horizontal axis pump is started, the open / close valve is closed, and after the start, the open / close valve is opened to communicate the seal chamber with the atmosphere. . According to this configuration, there is an effect that the water drop phenomenon can be suppressed without using an auxiliary tank or the like.
[0005]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In FIG. 1, the horizontal axis pump A is provided with an L-shaped drain pipe 5, and the lower end of the drain pipe 5 is located below the water surface W to pump up water and discharge it from the other end.
[0006]
The propeller 1 is provided in the drain pipe 5, and the shaft 2 of the propeller 1 extends out of the drain pipe 5 in a horizontal direction, and is connected to a driving source (not shown) such as a motor to rotate. I have. The seal device 10 seals the space between the shaft 2 and the drain pipe 5.
[0007]
The replenishment tank 3 is provided above the drain pipe 5, and communicates with the space 6 inside the drain pipe 5 through the communication pipe 7.
Further, a vacuum pump 4 is connected to the replenishing tank 3 to make the inside of the replenishing tank 3 and the space 6 negative pressure, so that the space 6 and the inside of the replenishing tank 3 can be filled with water.
[0008]
The seal device 10 is provided with a supply pipe 13 for supplying water from the refill tank 3. The supply pipe 13 is connected to the replenishing tank 3 via the three-way valve 11, and is configured to receive the supply of water by opening and closing the three-way valve 11. 12 is an orifice.
[0009]
A three-way valve 8 is also provided between the replenishing tank 3 and the vacuum pump 4, so that it is possible to select whether to connect the replenishing tank 3 to the vacuum pump 4 or open it to the atmosphere.
[0010]
FIG. 2 shows the configuration of the sealing device 10. In this embodiment, a segment seal is used. A casing 21 and a casing 22 connected to the drain pipe 5 are provided to form a seal chamber, in which segment rings 20 and 20 to be fitted to the shaft 2 are provided. The segment rings 20, 20 are pressed against the side wall of the casing 21 by a spring 23, and form a sealing surface S1 between the segment rings 20, 20 and the casing 21 and a sealing surface S2 between the segment rings 20, 20 and the outer periphery of the shaft 2. Is formed, and the inside of the drain pipe 5 and the atmosphere side are sealed by the seal surface S1 and the seal surface S2.
[0011]
An injection hole 24 is formed in the casing 22, and the injection hole 24 is connected to the supply pipe 13 so as to supply water to the segment rings 20, 20. A liquid film is formed on the seal surface S1 and the seal surface S2 by the moisture, so that the suction of air is shut off and the sealing performance is improved.
[0012]
In the embodiment of FIG. 2, a V-ring 30 is further provided on the atmosphere side of the casing 22 to improve the sealing performance. The V ring 30 is mounted on the shaft 2 and rotates with the shaft 2. The V-ring 30 has a lip 31, which comes into contact with the end face of the casing 22 to seal.
[0013]
As shown in FIG. 3 (A), when priming water is introduced into the space 6, the space 6 has a negative pressure and the shaft 2 is not rotating. 22 and seal the inside of the machine.
On the other hand, when the shaft 2 rotates, the lip 31 separates from the casing 22 due to the centrifugal force as shown in FIG. Therefore, no abrasion occurs.
[0014]
In the above configuration, when starting the horizontal pump A, an operation of filling the space 6 with priming is first performed. That is, the three-way valve 11 is opened on the communication pipe 7 side and closed on the supply pipe 13 side. Further, the three-way valve 8 is opened to the vacuum pump 4 side. If the vacuum pump 4 is operated in this state, the space 6 becomes negative pressure, and water is sucked from the lower end of the drain pipe 5. At this time, the lip 31 of the V-ring 30 of the sealing device 10 is pressed by the atmospheric pressure as shown in FIG. 3 (A) and closely adheres to the outer wall of the casing 22, so that the sealing property of the sealing device 10 is improved. Therefore, the air is less likely to leak into the space 6, and the priming water can be filled efficiently. When the priming water is filled up to the replenishing tank 3, the vacuum pump 4 is stopped, and the three-way valve 8 is closed on the vacuum pump 4 side and opened on the atmosphere side.
[0015]
At this time, the three-way valve 11 is simultaneously opened to the supply pipe 13 side, and water in the replenishment tank 3 is introduced into the sealing device 10. The water forms a film of water on the seal surface S1 and the seal surface S2, and the sealing performance of the seal device 10 is improved. Therefore, the leakage of the air into the space 6 is small, the decrease in the water level of the space 6 is reduced, and the standby state can be maintained for a long time.
The three-way valve 8 is of an electromagnetic type, and the above operation is automated.
This state is a standby state for starting the horizontal pump A, and is a standby state unless the water level in the space 6 decreases.
Therefore, there is an effect that the capacity of the refill tank 3 or the vacuum pump 4 or the operation time of the vacuum pump 4 can be reduced.
[0016]
Note that various types of seal devices can be used instead of the segment seals, and for example, a gland packing or the like may be used.
[0017]
Another embodiment will be described with reference to FIGS.
In this embodiment, no auxiliary tank is provided, and only the vacuum pump 4 and the on-off valve 32 are provided. Further, water is not supplied to the sealing device 10, and an opening / closing valve 15 is provided.
As shown in FIG. 5, the sealing device 10 ′ has a casing 21 and a casing 22, which form a sealing chamber, in which segment rings 20, 20 to be fitted to the shaft 2 are provided. The segment rings 20, 20 are pressed against the side wall of the casing 21 by a spring 23, and form a sealing surface S1 with the casing 21 and also form a sealing surface S2 with the outer periphery of the shaft 2 to form a sealing surface S1. The seal surface S2 seals the inside of the drain pipe 5 from the atmosphere.
[0018]
A V-ring 30 is mounted on the shaft 2 on the atmosphere side of the casing 22, and is configured to rotate together with the shaft 2. The V-ring 30 has a lip 31, which comes into contact with the end face of the casing 22 to seal.
[0019]
A communication hole 16 is formed in the casing 22, and an opening / closing valve 15 is mounted in the communication hole 16, and the inside of the casing 22 can be opened or closed to the atmosphere by opening / closing the opening / closing valve 15.
[0020]
In the above configuration, when starting the horizontal axis pump A, the vacuum pump 4 is first operated to make the space 6 a negative pressure, and water is sucked from the lower end of the drain pipe 5 to fill the space 6 with priming water.
At this time, the opening / closing valve 15 is closed, and the inside of the casing 22 is closed to the atmosphere. As shown in FIG. 5A, the lip 31 of the V-ring 30 is pressed by the atmospheric pressure and closely adheres to the side wall of the casing 22, so that the leakage of air into the casing 22 is small, and the priming water can be filled efficiently. When the priming water is filled up to the replenishing tank 3, the vacuum pump 4 is stopped, the on-off valve 32 is closed, and the horizontal axis pump A is set in a standby state. Even in the standby state, the opening / closing valve 15 is closed and the sealing by the lip 31 is effective, so that the leakage of the air is small, the water level in the space 6 is suppressed, and the standby state can be maintained for a long time.
[0021]
When the horizontal pump A is started, the open / close valve 15 is opened to open the inside of the casing 22 to the atmosphere. As a result, the pressing by the atmosphere is lost, and the lip 31 is separated from the casing 22 and does not contact as shown in FIG. 5B due to the centrifugal force due to the rotation of the shaft 2. Therefore, no abrasion occurs. Even when the lip seal 31 is separated, the internal seal is performed by the segment seals 20 and 20.
[0022]
When the V ring 30 is used in the above configuration, if the V ring 30 deteriorates during use and needs to be replaced, it is cut and removed, and a new V ring 30 is cut and wound around a shaft. It is also possible to use the cut surfaces integrally with an adhesive.
In addition, the segment seals 20 and 20 are constituted by divided ring pieces, and can be easily replaced without disassembling the device.
[0023]
【The invention's effect】
As described above, the sealing device for a horizontal shaft pump according to the present invention includes a vacuum pump for filling a space from a water suction portion to a propeller portion of the horizontal shaft pump, an auxiliary tank communicating with the space, and a horizontal shaft pump. The seal portion provided around the axis of the, and at least the vacuum pump is activated to fill the space and the auxiliary tank with water until the horizontal axis pump is started. And a supply device for supplying the water, a water film is formed on the sealing surface, and suction of air from the sealing portion is reduced. Therefore, there is an effect that the operation time and capacity of the vacuum pump can be reduced or the capacity of the auxiliary tank can be reduced.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing one embodiment of the present invention.
FIG. 2 is a partially enlarged view showing an embodiment of the present invention.
FIG. 3 is an explanatory diagram showing the operation of the embodiment of the present invention.
FIG. 4 is a schematic view showing an embodiment of the present invention.
FIG. 5 is an explanatory diagram showing the operation of the embodiment of the present invention.
[Explanation of symbols]
1: propeller, 2: shaft, 3: refill tank, 4: vacuum pump, 5: drain pipe, 6: space, 7: communication pipe, 8: 3-way valve, 10: sealing device, 11: 3-way valve, 12 : Orifice, 13: supply pipe, 15: open / close valve, 16: communication hole, 20: segment ring, 21: casing, 22: casing, 23: spring, 24: injection hole, 30: V ring, 31: lip, 32 : On-off valve.

Claims (4)

A vacuum pump to fill the space between the water suction part of the horizontal axis pump and the propeller part with priming water,
An auxiliary tank communicating with the space;
A seal portion provided around the rotation axis of the horizontal pump,
A supply device that supplies water in the auxiliary tank to the seal portion during at least the vacuum pump is activated and the space and the auxiliary tank are filled with water and before the horizontal axis pump is started.
A sealing device for a horizontal shaft pump, comprising: The seal portion has a segment seal,
The sealing device for a horizontal shaft pump according to claim 1. A first seal to which the seal portion is supplied with water from the auxiliary tank; and a lip seal mounted on the shaft on the atmosphere side of the first seal and abutting on a casing of the first seal. Have,
The sealing device for a horizontal shaft pump according to claim 1. A vacuum pump to fill the space between the water suction part of the horizontal axis pump and the propeller part with priming water,
A seal chamber provided around the axis of the horizontal axis pump,
An on-off valve for opening and closing the seal chamber with respect to the atmosphere;
A segment seal mounted on a rotating shaft in the seal chamber;
A lip seal mounted on the shaft on the atmosphere side of the seal chamber and in contact with a side wall of the seal chamber;
From the time when the vacuum pump is started to fill the space to the full state until the start of the horizontal axis pump, the on-off valve is closed, and after the start, the seal chamber is opened to communicate with the atmosphere.
A sealing device for a horizontal pump.

Images