JPH08144990A - Liquid discharge device - Google Patents

Abstract

PURPOSE: To provide a liquid discharge device to automatically discharge gases accumulated in a vacuum tank for preventing a pumping-up failure from occurring, regarding a liquid discharge device equipped with a vacuum pump at the intake side of a pump. CONSTITUTION: Regarding a liquid discharge device equipped with a vacuum tank 2 at the intake side of a pump 1, the height of piping at the delivery side of the pump 1 is made larger than the height of the top of the tank 2, and deaeration piping 7 is laid on the top of the tank 2. Also, the device features that the piping 7 is fitted with a check valve 8 for preventing a flow toward the tank 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drainage device having a vacuum tank on the suction side of a pump.

[0002]

2. Description of the Related Art FIG. 2 shows an example of a conventional drainage device provided with a vacuum tank on the suction side of a pump. In FIG.
1 is a pump, 2 is a vacuum tank, 3 is a replacement liquid valve, 4 is an exhaust valve, 5 is a check valve, and 6 is a pit.

Before starting the pump, the replenishment valve 3 and the exhaust valve 4 are opened, the liquid is supplied from the replenishment valve 3 to the vacuum tank 2, and the gas in the vacuum tank 2 is exhausted from the exhaust valve 4. When the vacuum tank 2 is filled with the liquid, the replenishment valve 3 and the exhaust valve 4 are closed, and the pump 1 is started. When the pump 1 discharges the liquid in the vacuum tank 2, the inside of the vacuum tank 2 becomes below atmospheric pressure, and the liquid in the pit 6 moves into the vacuum tank 2 through the check valve 5.

[0004]

However, in the above-described drainage device, when gas enters the vacuum tank 2 due to leakage from the gland packing of the pump 1 or the like, the pressure in the vacuum tank 2 rises and the vacuum tank 2 goes from the pit 6 to the vacuum tank. It happens that it becomes impossible to pump to 2. In such a case, the apparatus was stopped and the liquid replacement valve 3 and the exhaust valve 4 were manually opened to supply the liquid into the vacuum tank 2 so that the gas could be extracted and the liquid could be pumped up. Also takes.

The present invention has been made in order to solve such a problem, and in a drainage device having a vacuum tank on the pump suction side, the gas that has entered the vacuum tank is automatically discharged and the pumping is performed. The purpose is to prevent disability.

[0006]

SUMMARY OF THE INVENTION In the drainage device having a vacuum tank on the suction side of the pump, the height of the pipe on the discharge side of the pump is made higher than the height of the upper surface of the vacuum tank. The gas discharging pipe is provided in the gas discharging pipe, and the gas discharging pipe is provided with a check valve for blocking the flow toward the vacuum tank side.

[0007]

In the drainage device having the vacuum tank on the pump suction side, if the height of the pipe on the pump discharge side is higher than the height of the upper surface of the vacuum tank, the pressure difference when the pump is stopped causes the pump discharge side. Also, the liquid in the suction side pipe flows backward and returns to the inside of the vacuum tank, so that the gas accumulated in the vacuum tank can be discharged.
At this time, a gas can be automatically discharged by providing a check valve in the gas release pipe provided on the upper surface of the vacuum tank to prevent the gas from flowing into the vacuum tank.

As described above, since the gas in the vacuum tank is automatically discharged when the pump is stopped, it is possible to prevent the pumping failure.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a drainage device having a vacuum tank on the suction side of a pump according to an embodiment of the present invention. Descriptions of the same reference numerals as those in FIG. 2 are omitted. In FIG. 1, 7
Is a gas vent pipe, 8 is a check valve, and 9 is a tank.

When the liquid stored in the pit 6 is discharged by the pump 1, the liquid exiting the pit 6 passes through the check valve 5, is sent to the vacuum tank 2, and is then discharged by the pump 1. The pump 1 is repeatedly started and stopped as necessary for drainage, but as shown in the figure, the piping on the discharge side of the pump 1 is higher than the height of the upper surface of the vacuum tank. The liquid in the discharge-side and suction-side pipes flows back to the vacuum tank 2.
Therefore, the gas or liquid in the vacuum tank 2 cannot be returned to the pit 6 by the check valve 5, and thus is guided to the gas vent pipe 7 provided with the check valve 8. Then, at least the gas in the vacuum tank 2 is discharged to the outside.

It is desirable that the tip of the gas vent pipe 7 is immersed in the liquid filled in the tank 9 so that the outside air does not flow back into the vacuum tank 2 when the check valve 8 is opened and closed.
However, the liquid in the tank 9 may also flow back into the vacuum tank 2 when the check valve 8 is opened and closed. Therefore, a device for supplementing the tank 9 may be provided, or the liquid in the tank 9 may not flow back into the vacuum tank 2. It is necessary to install the tank 9 at the position.

In this embodiment, the check valve 5 prevents the liquid from backflowing from the vacuum tank 2 to the pit 6. However, if the check valve 5 is not provided, the vacuum tank 2 can be used.
By setting the highest point of the height of the inlet side pipe to be higher than the highest point of the gas vent pipe 7, the purpose of the present invention to vent the air in the vacuum tank 2 can be achieved.

By using this apparatus, stable drainage was possible without the possibility of pumping failure.

[0014]

Since the present invention is configured as described above, in a drainage device provided with a vacuum tank on the pump suction side, the gas accumulated in the vacuum tank is automatically discharged without human intervention. It is possible to prevent the pumping failure.

[Brief description of drawings]

FIG. 1 is a diagram showing a drainage device in which a vacuum tank is provided on a pump suction side according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example of a conventional drainage device provided with a vacuum tank on the suction side of a pump.

[Explanation of symbols] 1 pump 2 vacuum tank 7 gas venting pipe 8 check valve 9 tank

Claims (1)

[Claims] 1. A drainage device provided with a vacuum tank on the pump suction side, wherein the height of the pipe on the pump discharge side is made higher than the height of the upper surface of the vacuum tank, and a gas vent pipe is provided on the upper surface of the vacuum tank. A drainage device characterized in that a check valve for blocking the flow to the vacuum tank side is provided in the gas vent pipe.