JPH0218121B2 - - Google Patents

Description

Detailed Description of the Invention [Industrial Application Field] The present invention provides a pump device for use in gasoline metering machines, etc., in which first and second gas-liquid separators and a pump are housed in a casing. Regarding.

[Prior Art] As is well known, in a refueling system at a refueling station that handles volatile liquids such as gasoline, a pump device is provided with a device for separating gas mixed in the liquid as bubbles.

By the way, in a conventional gas-liquid separation device, a large filter chamber is formed to reduce the flow rate, and the gas, that is, the liquid containing bubbles, is floated upward, and the liquid flows into the gas-liquid separation chamber, and then the gas-liquid separation is performed. The chamber was designed to separate gas and liquid. In this way, conventional gas-liquid separation devices utilize the natural floating of air bubbles, so in order to improve the separation effect, it is necessary to reduce the liquid flow rate, which increases the size of the filter chamber. The drawback was that the entire pump device became larger. In addition, since the air bubbles are allowed to float naturally, it is difficult for the air bubbles to completely separate from the liquid, and as a result, the liquid mixed with air bubbles may flow out from the discharge side of the pump device.To prevent this, the filter chamber must be made larger. Alternatively, the amount of outflow to the gas-liquid separation chamber must be increased, which further increases the size of the pump and reduces its efficiency.

The present applicant has proposed a pump device that eliminates the various drawbacks mentioned above in Japanese Patent Application No. 190829/1982. This separation device has a vortex chamber on the pump discharge side, and a separation pipe with an open tip at the center of the vortex chamber. Therefore, the liquid that flows into the swirl chamber from the inlet swirls, and since the liquid has a high specific gravity, it flows radially outward due to centrifugal force, and the air bubbles have a low specific gravity, so they are centered in the radial direction. It is only necessary to separate the liquid containing bubbles collected in the central part using a separation pipe and allow it to flow out into the gas-liquid separation chamber, thus eliminating the above-mentioned drawbacks of the prior art.

[Problems to be Solved by the Invention and Objectives of the Invention] As mentioned above, the separation device for a pump device proposed by the present applicant consists of a volute chamber and a separation pipe arranged in the vortex chamber, so it is small in size. However, although the separation of gas and liquid is reliable and the amount of liquid flowing out from the gas-liquid separator to the gas-liquid separation chamber is small, it has been found that there is room for further improvement. In other words, the above-mentioned separation device proposed by the present applicant has a small hole on the downstream side of the separation pipe, so that the flow resistance of the liquid when flowing from the volute chamber to the separation chamber and collecting into the separation pipe is relatively low. Therefore, if a large amount of air temporarily flows in, for example, air bubbles will accumulate in the vortex chamber until the liquid present in the separation pipe flows out from the small hole, and will flow out with the liquid without being separated. However, it could not necessarily be said that it was efficient.

Further, in a conventional pump device used in a gasoline metering machine, etc., in which the first and second gas-liquid separators and the pump are housed in a casing, the first gas-liquid separator is A method has been used in which the cross-sectional area of a channel (gas-liquid separation channel) through which a liquid mixture flows is widened and the flow rate is slowed, so that the gas in the liquid rises while flowing through the channel. Therefore, there was a problem in that the chamber constituting the first gas-liquid separation device had to be made larger, and the casing had to be made larger.

Furthermore, the cross-sectional area of the flow path communicating the first gas-liquid separator and the second gas-liquid separator is determined assuming that the amount of gas mixed in the liquid (degree of gas mixing) is a normal value. Therefore, when a large amount of gas is mixed, the flow rate of the gas to be separated is large, and there is a problem that the gas cannot be transferred to the second gas-liquid separation device via the flow path. be. As a result, most of the gas does not flow into the channel that communicates the first gas-liquid separator and the second gas-liquid separator, and cannot be sent to the second gas-liquid separator. There was an inconvenience that the flow rate of the gas was measured at the time of the measurement.

Other conventional techniques include, for example, JP-A-58-
No. 36606 proposes a technique in which a mixture of gas and liquid flows into a gas-liquid separator through a small hole, is swirled there, and the separated gas is discharged from the center of the swirl. However, with this technique, it was not possible to deal with the above-mentioned problems when a large amount of gas is mixed.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a pump device which has low flow resistance to the flow of gas from the volute chamber to the separation chamber, and therefore has low resistance to gas flowing into the separation chamber, and has high separation efficiency.

[Structure, operation, and effect of the invention] The pump device of the present invention includes a rotary pump that includes a casing having an inlet and an outlet, and that sucks liquid from the inlet, and a rotary pump that is provided in a discharge flow path of the rotary pump. The second gas-liquid separator includes a first gas-liquid separator and a second gas-liquid separator that communicates with the gas outflow hole of the first gas-liquid separator, and the second gas-liquid separator has a second gas-liquid separator formed above and communicates with the atmosphere. 1 opening, a second opening that communicates with the small hole of the first gas-liquid separator, and a third opening that is formed below and communicates with the flow path on the suction side of the rotary pump. In the pump device, the first gas-liquid separation device separates the gas-liquid by swirling the liquid in which the gas is mixed. a volute chamber, the vortex chamber is provided in a position parallel to the rotation axis of the rotary pump and so as to tangentially guide the liquid from the discharge side channel of the rotary pump, and the second gas-liquid separation Consists of a valve biased by a spring that controls the opening surface to open wide in order to avoid interfering with the transfer of a large amount of gas and liquid when a large amount of gas exists in the small hole communicating with the device. A gas-liquid outflow control mechanism is provided.

According to the present invention having such a configuration, when a large amount of gas exists in the small hole communicating with the second gas-liquid separation device, the valve constituting the gas-liquid outflow control mechanism is activated by the spring. This biases the opening area in the direction of increasing the opening area, making it possible to transfer all of the large amount of gas to the second gas-liquid separation device.
On the other hand, if there is not a large amount of gas at the small hole, the spring will not bias the valve in the direction of increasing its opening area. Therefore, all the gas separated by the first gas-liquid separator is transferred to the second gas-liquid separator, regardless of the amount of gas mixed into the liquid. Therefore, the inconvenience of measuring the gas flow rate when measuring the flow rate is completely prevented.

Further, a small hole for gas-liquid outflow is provided at the upstream end of the separation pipe, and the downstream side of the separation pipe is substantially at atmospheric pressure. Therefore, the liquid flowing into the swirl chamber from the discharge side of the pump swirls, but due to this swirl, the liquid flows radially outward due to the centrifugal force because of its high specific gravity, and the air bubbles flow inward due to their small specific gravity. The liquid containing bubbles collected in the center flows out into the gas-liquid separation chamber through the small hole. The flow resistance when the liquid flows out is small because the downstream side of the separation pipe is at atmospheric pressure, so the liquid flows out easily and air bubbles can escape easily. Since air bubbles can escape easily, the small diameter of the hole can be small.
Therefore, only a small amount of liquid is required to flow out into the gas-liquid separation chamber, improving pump efficiency and reducing the size of the pump.

An embodiment of the present invention will be described below with reference to the accompanying drawings, but it is clear that the pump device embodying the present invention can be applied to pumps other than the illustrated internal gear pump. In addition, the small hole in the separation pipe can also be designed to be a valve type. Regarding other configurations, the present invention is not limited to the illustrated embodiments.

[Example] FIG. 1 is a schematic diagram of a pump device embodying the present invention, and FIG. 2 is a sectional view of the same pump device. Referring to these figures, the pump device P includes a casing C, and the casing C is provided with an inlet I and an outlet O for liquid. A check valve 1 is provided at the inner end of the inlet I, and opens into a chamber 2 provided with a strainer 2a on the inlet side. As shown in the figure, the check valve 1 is of the type that closes by gravity, and a stopper 50 is provided above it to prevent the valve from coming off during transportation or operation of the pump device.
has been established. A pump 3 is provided approximately in the center of the casing C. In the illustrated embodiment, the pump 3 is a known internal gear pump. This pump 3 has a suction port 3a and a discharge port 3b, and a liquid path 10 is formed in the casing C to connect the chamber 2 and the suction port 3a. A discharge port 3b of the pump 3 communicates with a gas-liquid separation device 4, which will be described later. A liquid path is configured such that the liquid flowing outside in the radial direction of the gas-liquid separator 4, that is, the liquid that does not contain bubbles, flows into a chamber 5 provided with a strainer 5a on the outflow side, and a strainer chamber 5 on the outflow side. A control valve 6 is provided between the outlet O and the outlet O. When the pump is driven, this control valve 6 opens against the spring 6a to allow the liquid to flow out and after the oil supply is stopped.
Although not shown, when the pressure inside the pipe connected to the outlet increases due to a rise in temperature, etc., a small valve is opened against the spring 6b provided on the valve 6 to allow the liquid to flow backwards. It's getting old. A bypass valve 12 is provided in a liquid passage 11 for liquid flowing radially outward of the gas-liquid separation device 4, and this liquid passage 11 communicates with the suction port 3a of the pump 3.

On the other hand, the liquid containing bubbles flowing inside the gas-liquid separator 4 in the radial direction flows into the liquid path 13 through the gas-liquid outflow control mechanism 7. This liquid path 13 is formed in the side cover of the casing. This liquid path 13 communicates with a gas-liquid separation chamber 8, which will be described later. The gas separated in the gas-liquid separation chamber 8 is discharged from the air vent 14, and the liquid from which the gas has been separated flows into the liquid path 15. A check valve 9 is provided in this liquid passage 15, and this liquid passage 15 communicates with the strainer chamber 2 on the inflow side.

Therefore, when the pump 3 is rotated by a suitable prime mover, the liquid flows from the inlet I to the check valve 1, the strainer chamber 2 on the inlet side, the pump 3, the gas-liquid separator 4, the strainer chamber 5 on the outlet side, and the control valve 6. It passes through the outlet O and is discharged from the outlet O. Also, the gas-liquid separator 4
A portion of the liquid is bypassed to the pump 3 through the bypass valve 12. This is to cope with changes in the discharge amount since the discharge amount is determined by the rotational speed of the gear pump 3. On the other hand, in the gas-liquid separator 4, the liquid containing gas flows through the gas-liquid outflow control mechanism 7 to the gas-liquid separation chamber 8, where the gas is released from the air vent 14, and the liquid passes through the check valve 9 on the inflow side. It is returned to the strainer chamber 2.

Next, a pump device embodying the present invention will be described.

As shown in FIG. 3, a liquid path 18 from the pump discharge port 3b leading to the gas-liquid separator 4 is communicated with a swirl chamber S configured to introduce the liquid tangentially to the gas-liquid separator 4. . This spiral chamber S is extended by an outer cylinder 20, and its end 20a is open, and the strainer chamber 5 and flow path 11 on the outflow side are extended.
It communicates with

Therefore, the gas-free liquid flowing out from the end 20a of the outer cylinder 20 flows from the outside to the inside of the strainer 5, flows into a chamber formed at the axial end of the strainer 5, and then passes through the control valve 6. Then, it flows out from the outlet O.

A separation pipe, that is, an inner cylinder 21 provided approximately concentrically with the outer cylinder 20 of the gas-liquid separator 4 separates and collects the liquid containing bubbles from the liquid that does not contain the gas-liquid separation chamber 8 (the first 2), and a small hole 40 for gas and liquid outflow is bored at the inlet end thereof. The other outlet end 41 communicates with the gas-liquid separation chamber 8 via a flow path 43 formed in the side cover 42 and the flow path 13 . Since the gas-liquid separation chamber is at atmospheric pressure via the air vent 14, the inside of the flow path 43 and the inside of the inner cylinder 21 are also at approximately atmospheric pressure. In addition, the outer cylinder 20 of the separation device
If spiral grooves or protrusions are provided on the inner wall of the membrane, a stronger swirl will be created and the separation efficiency will be increased.

As mentioned above, when the pump 3 is driven, liquid is sucked in from the inlet I of the pump device P and discharged from the outlet O, but the liquid discharged from the discharge port of the pump 3 is transferred to the gas-liquid separation device 4. flows tangentially into the spiral chamber S of. In the swirl chamber S, the liquid swirls,
During this swirling, the liquid with a high specific gravity that does not contain air bubbles gathers radially outward of the outer cylinder 20, and the liquid that contains air bubbles and has a low specific gravity gathers at the center in the radial direction. Most of the liquid that does not contain air bubbles is in the outer cylinder 20.
is forced into the strainer 5 through the control valve 6 and flows out from the outlet O. The remainder passes through the flow path 11 and the bypass valve 12 to the pump 3.
Return to the suction side.

The liquid containing air bubbles and having a low specific gravity is collected in the inner cylinder 21 through the small hole 40 of the inner cylinder 21, and flows out to the gas-liquid separation chamber 8 through the channels 43 and 13.
A buffer member is provided in the gas-liquid separation chamber 8 at a position facing the flow path 13, and the liquid is guided to the gas-liquid separation chamber 8 without bubbling.

The gas-liquid separation chamber 8 is provided with a float valve, etc., and when liquid accumulates, the float valve opens and the liquid returns to the strainer chamber 2 through the check valve 9. The gas separated in the gas-liquid separation chamber is transferred to air vent 1.
Leave from 4.

By the way, according to the present invention, the inner cylinder 21 of the gas-liquid separator 4 is formed with a small hole 40 for gas-liquid outflow at its upstream end, and the downstream side has a large diameter and is at approximately atmospheric pressure. This allows the liquid containing air bubbles to escape efficiently.

Now, the small hole 40 of the inner cylinder 21 constitutes the gas-liquid outflow control mechanism 7, but this gas-liquid outflow control mechanism can also be configured as shown in FIG. 4. That is, a valve body 24 and a valve seat 25 are provided on the upstream side of the inner cylinder 21, the valve body 24 is pressed in the opening direction by a spring 26, and an opening 22 is provided in the center of the valve body 24.
It is also possible to provide an opening 28 on the side. When the amount of gas contained in the liquid increases, the pressure on the inlet side of the valve body 24 decreases, and when there is little gas, the pressure on the inlet side of the valve body 24 increases. Therefore, when the amount of air contained in the liquid increases, the valve body 24 moves to the left in the drawing due to the pressure difference between the front and rear, and a large amount of liquid (including air bubbles) flows from the openings 22 and 28 to the valve seat 25. It flows into the liquid path 43 through the passage. When the content of bubbles decreases, the valve body 24 is moved to the right by the pressure of the inflowing liquid, and the liquid flows out only from the central opening 22. When a valve mechanism is provided in this way, the flow path becomes large when there are many bubbles, and becomes small when there are a small amount of bubbles, so that the bubble removal efficiency and liquid recovery efficiency are improved.

[Effects of the Invention] As described in detail above, according to the pump device of the present invention, the gas-liquid outflow control mechanism Since the opening area of the valve constituting the valve is controlled to be changed, even if a large amount of gas exists in the small hole, the opening area of the valve is increased and all of the large amount of gas is transferred to the second gas. It becomes possible to transfer to a liquid separation device. Therefore, even when the amount of mixed gas is large, a large amount of gas can be efficiently separated. Moreover, since all the gas separated by the first gas-liquid separator is transferred to the second gas-liquid separator, the gas does not flow into the main flow path. Therefore, the inconvenience of measuring the gas flow rate when measuring the flow rate is completely prevented.

Furthermore, since the structure is such that gas and liquid are separated by the swirling flow of liquid, the separation efficiency is high.
Moreover, the device can be made smaller.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing an example of a pump device embodying the present invention, Fig. 2 is a sectional view of the same as above, Fig. 3 is a sectional view showing one embodiment of a gas-liquid separation device, and Fig. 4 is a flow rate control FIG. 3 is a cross-sectional view showing one embodiment of the mechanism. 3... pump, 4... gas-liquid separation device, 20...
Outer cylinder, 21... Inner cylinder, 40... Small hole for gas and liquid outflow.

Claims (1)

[Claims] 1 A rotary pump including a casing having an inlet and an outlet and sucking liquid from the inlet, a first gas-liquid separator provided in the discharge flow path of the rotary pump, and a first gas-liquid separator. a second gas-liquid separator communicating with the gas outflow small hole, the second gas-liquid separator having a first opening formed above and communicating with the atmosphere; It is composed of a chamber having a second opening communicating with the small hole and a third opening formed below and communicating with the flow path on the suction side of the rotary pump. In a pump device having a float valve that opens and closes, the first gas-liquid separation device has a swirl chamber that separates gas and liquid by swirling a liquid in which gas is mixed, and the swirl chamber rotates when the rotary pump rotates. When a large amount of gas exists at the location of the small hole, which is parallel to the axis and is located at a position where the liquid from the discharge side flow path of the rotary pump is guided in the tangential direction, and which communicates with the second gas-liquid separation device. The device is characterized by being equipped with a gas-liquid outflow control mechanism consisting of a valve biased by a spring that controls the opening surface to be wide open so as not to impede the transfer of a large amount of gas and liquid. pump equipment.