JP2000325703A - Deaeration apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent levering of suction capability of a pump in a vacuum type dreaeration apparatus. SOLUTION: A throttle valve 14 is connected to a liquid tank 11 containing a liquid, and a closed type gas-liquid separation tank 16 for separately storing a liquid and a gas is connected to the throttle valve 14. A suction port 23b of a liquid circulation pump 23 is connected to the liquid storage part 16a of the gas-liquid separation tank 16 and at the same time a delivery port 23b of the liquid circulation pump 23 is connected to the liquid tank 11. Since the suction vacuum pressure of the liquid circulation pump 23 works on the throttle valve 14 through the closed type gas-liquid separation tank 16, the bubbles of a dissolved gas which is deaerated from the liquid between the throttle valve 14 and the gas-liquid separation tank 16 come in the gas-liquid separation tank 16 and are separated and released to a negative pressure space 16b in the upper side relative to the liquid storage part 16a in the lower side and do not reach the liquid circulation pump 23.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deaerator having a throttle means.

[0002]

2. Description of the Related Art As shown in Japanese Patent Application Laid-Open No. 7-328316, in a conventional deaerator, a throttle means is connected to a liquid tank containing a liquid via a filter, and the suction of a liquid feed pump is connected to the throttle means. A gas-liquid separation tank having an open top for separating liquid and gas is connected to a discharge port of the liquid sending pump.

[0005] Then, the liquid is reduced in pressure between the throttle means and the liquid sending pump by the operation of the liquid sending pump, and the dissolved gas in the liquid is separated from the liquid as bubbles. Since these bubbles are coarsened by expansion and bonding while passing through the liquid feed pump, they are quickly floated and separated after being sent to the gas-liquid separation tank.

[0004]

In this conventional apparatus, a liquid feed pump is located between the throttle means and the gas-liquid separation tank, and bubbles generated by the throttle means pass through the liquid feed pump. There is a problem that the pump suction capacity is reduced and the deaeration effect is also reduced.

[0005] Further, there is a problem that the liquid feed pump which is easily affected by cavitation due to passing air bubbles is required to have cavitation resistance.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to solve the problems of reduced pump suction capacity and cavitation in a decompression type deaerator.

[0007]

According to a first aspect of the present invention, there is provided a liquid tank containing a liquid, a throttle connected to the liquid tank, and a liquid and a gas separated from the liquid connected to the throttle. And a liquid circulation pump having a suction port connected to a liquid reservoir of the gas-liquid separation tank and a discharge port connected to the liquid tank. .

[0008] Then, the suction depressurizing force of the liquid circulation pump acts on the throttle means through a closed gas-liquid separation tank.
Bubbles of dissolved gas precipitated from the liquid between the throttle means and the gas-liquid separation tank are separated and released into the upper negative pressure space for the lower liquid reservoir part after entering the gas-liquid separation tank, and the liquid circulation pump Do not reach. For this reason, there is no decrease in pump suction capacity or cavitation problems that occur when bubbles deposited from the liquid pass through the pump.

According to a second aspect of the present invention, in the degassing apparatus according to the first aspect, the liquid circulation pump is provided with a liquid suction pipe for directly sucking the liquid in the liquid tank without passing through the gas-liquid separation tank. A liquid supply pipe for supplying the liquid discharged from the liquid circulation pump to the gas-liquid separation tank, and a liquid for returning the liquid supplied to the gas-liquid separation tank from the upper end of the gas-liquid separation tank to the liquid tank. This is a deaeration device including a return pipe line.

When a large amount of gas has accumulated in the gas-liquid separation tank, each of the above-mentioned pipes is made to function, and a liquid suction pipe and a liquid supply pipe are used by using a common liquid circulation pump during degassing. The liquid in the liquid tank is discharged and supplied to the gas-liquid separation tank through the pipeline for liquid supply, whereby the liquid level in the gas-liquid separation tank is raised, and the liquid is passed into the liquid tank via the liquid return pipe. By discharging the gas, the gas accumulated in the gas-liquid separation tank is exhausted so as to be pushed out.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an embodiment shown in FIG.

Reference numeral 11 denotes a liquid tank containing a liquid to be degassed. An on-off valve 12 and an electromagnetic 3
A throttle valve 14 as throttle means is connected via the one-way switching valve 13. Although the throttle valve 14 is a variable throttle, a fixed orifice may be used as the throttle means.

A conduit 15 having the throttle valve 14 is connected to a lower part of a gas-liquid separation tank 16 of a closed type for storing a liquid and a gas separately.

The gas-liquid separation tank 16 is compared with a liquid level sensor 17 for controlling the liquid level of the liquid L contained in a liquid reservoir 16a located relatively lower in the tank. A vacuum gauge 18 for measuring the pressure in a negative pressure space 16b formed in the target upper portion.

The gas reservoir 16a of the gas-liquid separation tank 16
The suction port 23a of the liquid circulating pump 23 is connected through an electromagnetic on-off valve 22 in the pipe 21. As the liquid circulation pump 23, for example, a vortex pump is used.

The discharge port 23b of the liquid circulation pump 23 includes a check valve 24, an electromagnetic three-way switching valve 25, a pipe 26, and an on-off valve 27.
Is connected to the upper part of the liquid tank 11 via the

Between the electromagnetic three-way switching valve 13 and the suction port 23a of the liquid circulation pump 23, the liquid circulation pump 23 transfers the liquid in the liquid tank 11 without passing through the gas-liquid separation tank 16. A liquid suction pipe line 31 for directly sucking liquid is provided.

A liquid supply line 32 for supplying the liquid discharged from the liquid circulation pump 23 to the gas-liquid separation tank 16 is provided between the electromagnetic three-way switching valve 25 and the line 21. It is arranged.

In addition, between the upper end of the gas-liquid separation tank 16 and the pipe 26, the liquid supplied into the gas-liquid separation tank 16 is supplied from the upper end of the gas-liquid separation tank 16 to the liquid tank 11. A conduit 33 for returning the liquid to the inside is provided, and an electromagnetic on-off valve 34 is provided in the conduit 33.

In FIG. 1, two electromagnetic three-way switching valves are used.
13 and 25 indicate that the side of the white triangle is open,
The black triangle indicates the closed state, and the two electromagnetic on-off valves 22 and 34 indicate that the white line indicates the line communication state and the black mark indicates the line closed state.

Next, the operation of the illustrated embodiment will be described.

First, as shown in FIG. 1, the valve state during the deaeration operation is such that the suction port 23a of the liquid circulation pump 23 is connected to the electromagnetic on-off valve 22, the liquid reservoir 16a of the gas-liquid separation tank 16, It communicates with the lower part of the liquid tank 11 through a throttle valve 14, an electromagnetic three-way switching valve 13 and an on-off valve 12, and a discharge port 23b of a liquid circulation pump 23 is a check valve.
24, which communicates with the upper part of the liquid tank 11 via an electromagnetic three-way switching valve 25, a pipe 26 and an on-off valve 27. At this time, the liquid return pipeline 33 is in a pipeline closed state by the electromagnetic on-off valve 34.

Thus, during the deaeration operation, the liquid circulation pump
Since the suction pressure reducing force of 23 acts on the throttle valve 14 via the electromagnetic on-off valve 22 and the closed gas-liquid separation tank 16, the throttle valve 14
Dissolved gas is precipitated as bubbles from the liquid between the gas and the gas-liquid separation tank 16. That is, it is defoamed.

The bubbles of the dissolved gas enter the gas-liquid separation tank 16 and then enter the upper negative pressure space 16b with respect to the lower liquid reservoir 16a.
And does not reach the liquid circulation pump 23. For this reason, there is no decrease in pump suction capacity or cavitation problems that occur when bubbles deposited from the liquid pass through the pump.

On the other hand, when the liquid level falls as the gas accumulates in the gas-liquid separation tank 16 and the liquid level sensor 17 operates at the lower limit of the liquid level due to the accumulation of a large amount of gas, the two electromagnetic signals are generated by the sensor signals. The three-way selector valves 13 and 25 automatically switch directions, respectively. At the same time, the electromagnetic on-off valve 22 automatically switches to the line closed state, and the electromagnetic on-off valve 34 automatically switches to the line communication state. Switch.

That is, the suction port 23a of the liquid circulation pump 23
Communicates with the lower part of the liquid tank 11 through a liquid suction line 31, an electromagnetic three-way switching valve 13 and an on-off valve 12, and a discharge port 23b of a liquid circulation pump 23 is connected to a check valve 24, an electromagnetic type. 3-way switching valve
25. It communicates with the lower part of the gas-liquid separation tank 16 via a liquid supply line 32.

Further, the upper end of the gas-liquid separation tank 16 communicates with the upper portion of the liquid tank 11 via a liquid return pipe 33 having an electromagnetic on-off valve 34 switched to a pipe communication state and an on-off valve 27. I do.

Thus, a common liquid circulation pump is used during deaeration.
23, the liquid in the liquid tank 11 is discharged and supplied to the gas-liquid separation tank 16 through the liquid suction pipe 31 and the liquid supply pipe 32, so that the liquid level in the gas-liquid separation tank 16 is reduced. Is raised, and the liquid is discharged into the liquid tank 11 through the liquid return pipe 33, thereby exhausting the gas accumulated in the negative pressure space 16b of the gas-liquid separation tank 16 so as to push it out, and sealing it. The gas-liquid separation tank 16 is returned to the initial operation state.

The liquid L is, for example, a cleaning liquid when the liquid tank 11 is an ultrasonic cleaning tank, but is not limited thereto. For example, a liquid that needs to reduce dissolved oxygen or the like may be used. .

[0030]

According to the first aspect of the present invention, the suction depressurizing force of the liquid circulating pump acts on the throttle means via the closed gas-liquid separation tank, so that the pressure between the throttle means and the gas-liquid separation tank is reduced. Bubbles of dissolved gas precipitated from the liquid between the liquids enter the gas-liquid separation tank and are separated and released in the upper negative pressure space for the lower liquid reservoir, and do not reach the liquid circulation pump, so the air bubbles pass through the pump It is possible to solve the problem of cavitation and deterioration of the pump suction capacity that occurs when performing, and to use an existing liquid circulation pump that does not require high cavitation resistance while obtaining an excellent deaeration effect with strong pump suction capacity. it can.

According to the second aspect of the invention, when a large amount of gas has accumulated in the gas-liquid separation tank, the liquid suction pipe, the liquid supply pipe, and the liquid return pipe are changed. Let it work,
The liquid in the liquid tank is discharged and supplied to the gas-liquid separation tank by using the common liquid circulation pump during degassing to raise the liquid level in the gas-liquid separation tank, and the gas accumulated in the gas-liquid separation tank Can be evacuated through a liquid return line so as to extrude, and the closed gas-liquid separation tank can be easily returned to the initial operation state.

[Brief description of the drawings]

FIG. 1 is a piping diagram showing one embodiment of a deaerator according to the present invention.

[Explanation of symbols]

 11 Liquid tank 14 Throttle valve as throttling means 16 Gas-liquid separation tank 23 Liquid circulation pump 23a Suction port 23b Discharge port 31 Pipe for liquid suction 32 Pipe for liquid supply 33 Pipe for liquid return

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Yukio Hashimoto 843-5 Kuji, Takatsu-ku, Kawasaki-shi, Kanagawa F-term in Nikuni Co., Ltd. (Reference) 4D011 AA02 AA14 AA16 AB10 AC01 AC04 AC06 AD06

Claims (2)

[Claims] 1. A liquid tank containing a liquid, a restrictor connected to the liquid tank, a sealed gas-liquid separation tank connected to the restrictor and separating and storing a liquid and a gas. A degassing apparatus comprising: a liquid circulation pump having a suction port connected to a liquid reservoir of a gas-liquid separation tank and a discharge port connected to the liquid tank. 2. A liquid suction pipe in which the liquid circulation pump sucks the liquid in the liquid tank directly without passing through the gas-liquid separation tank, and a liquid for supplying the liquid discharged from the liquid circulation pump to the gas-liquid separation tank. 2. The liquid supply apparatus according to claim 1, further comprising a supply pipe, and a liquid return pipe for returning the liquid supplied to the gas-liquid separation tank from the upper end of the gas-liquid separation tank into the liquid tank. Degassing device.