Gas-liquid separation device

Abstract

A gas-liquid separator having a superior gas-liquid separation function compared to the conventional technology is provided. [Solution] The system comprises a raw water storage chamber of circular cross-section for storing raw water containing a gas-liquid mixture, a raw water supply pipe connected to the upper part of the raw water storage chamber, a degassed water discharge pipe connected to the lower part of the raw water storage chamber, a float chamber arranged above the raw water storage chamber and communicating with the raw water storage chamber via a communication hole, and a float valve arranged within the float chamber which normally closes the float chamber and opens when a predetermined amount of gas accumulates in the float chamber to discharge the gas to the atmosphere, the connection port of the raw water storage chamber to the raw water supply pipe is oriented in the tangent direction of the inner surface of the peripheral side wall of the raw water storage chamber, and the communication hole between the raw water storage chamber and the float chamber is offset from the center of the raw water storage chamber cross-section towards the connection port of the raw water storage chamber to the raw water supply pipe.

Description

[Technical field]

[0001] The present invention relates to a gas-liquid separation device. [Background technology]

[0002] Patent Document 1 discloses a gas-liquid separation device comprising a raw water storage chamber of circular cross-section for storing raw water containing a gas-liquid mixture, a raw water supply pipe connected to the top of the raw water storage chamber, a degassed water discharge pipe connected to the bottom of the raw water storage chamber, a float chamber arranged above the raw water storage chamber and communicating with the raw water storage chamber via a communication hole, and a float valve arranged within the float chamber which normally closes the float chamber and opens when a predetermined amount of gas accumulates in the float chamber to discharge gas to the atmosphere, wherein the connection port of the raw water storage chamber with the raw water supply pipe is oriented in the tangent direction of the inner surface of the peripheral side wall of the raw water storage chamber, and the communication hole between the raw water storage chamber and the float chamber is positioned in the center of the cross section of the raw water storage chamber. In the above gas-liquid separator, the float valve closes when the water level in the float chamber rises and the float rises, and the float valve opens when the water level in the float chamber falls and the float falls. The water level in the float chamber increases or decreases depending on the flow rate of the gas-liquid mixture of raw water flowing into the raw water storage chamber. When the gas-liquid separator is in operation, raw water flowing from the raw water supply pipe into the raw water storage chamber flows in a tangential direction to the inner surface of the peripheral wall of the raw water storage chamber, forming a swirling flow, and air bubbles dispersed in the raw water gather at the center of the cross section of the raw water storage chamber due to the centrifugal force of the swirling flow, forming a bubble group. The bubble group rises in the raw water and flows into the float chamber through the communication hole, and gas accumulates in the float chamber, causing the water level in the float chamber to drop, the float descends, and the float valve opens, allowing the gas separated from the raw water to be discharged to the atmosphere. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 10-202247 Summary of the Invention [Problem to be solved by the invention]

[0004] As a result of extensive research, the inventors of the present application discovered that when the bubbles rise in the center of the cross section of the raw water storage chamber, they are biased toward the connection port of the raw water storage chamber to the raw water supply pipe, as can be seen from Figure 1. It is believed that the ejector effect of the raw water flowing into the raw water storage chamber causes the raw water above the connection port of the raw water storage chamber to the raw water supply pipe to be sucked toward said connection port, and the bubbles rising in the raw water are entrained by the raw water. In view of this knowledge, in the gas-liquid separation device of Patent Document 1, the communication hole between the float chamber and the raw water storage chamber is located at the center of the cross section of the raw water storage chamber, so that the air bubbles that are biased toward the connection port of the raw water storage chamber to the raw water supply pipe rather than the center and rise cannot be guided to the communication hole, and the air bubbles cannot be effectively introduced into the float chamber, gas does not accumulate effectively in the float chamber, and ultimately the gas separation function may not be performed effectively. The present invention has been made in consideration of the above problems, and has an object to provide a gas-liquid separation device which comprises a raw water storage chamber of circular cross section for storing raw water containing a gas-liquid mixture, a raw water supply pipe connected to the upper part of the raw water storage chamber, a degassed water discharge pipe connected to the lower part of the raw water storage chamber, a float chamber arranged above the raw water storage chamber and communicating with the raw water storage chamber via a communication hole, and a float valve arranged within the float chamber which normally closes the float chamber and opens when a predetermined amount of gas accumulates in the float chamber to discharge gas to the atmosphere, and wherein the connection port of the raw water storage chamber to the raw water supply pipe is oriented in the tangential direction of the inner surface of the peripheral side wall of the raw water storage chamber, and which has superior gas-liquid separation function compared to conventional technology. [Means for solving the problem]

[0005] In order to solve the above problems, the present invention provides a gas-liquid separation device comprising a raw water storage chamber of circular cross-section for storing raw water containing a gas-liquid mixture, a raw water supply pipe connected to the upper part of the raw water storage chamber, a degassed water discharge pipe connected to the lower part of the raw water storage chamber, a float chamber arranged above the raw water storage chamber and communicating with the raw water storage chamber through a communication hole, and a float valve arranged within the float chamber which normally closes the float chamber and opens when a predetermined amount of gas accumulates in the float chamber to discharge the gas to the atmosphere, wherein the connection port of the raw water storage chamber to the raw water supply pipe is oriented in the tangent direction of the inner peripheral side wall of the raw water storage chamber, and the communication hole between the raw water storage chamber and the float chamber is offset from the center of the cross section of the raw water storage chamber toward the connection port of the raw water storage chamber to the raw water supply pipe. In the present invention, the communication hole between the raw water storage chamber and the float chamber is offset from the center of the cross section of the raw water storage chamber toward the connection port of the raw water storage chamber to the raw water supply pipe, so that a group of air bubbles rising in the raw water while being offset toward the connection port of the raw water storage chamber to the raw water supply pipe can be guided to the communication hole and effectively introduced into the float chamber, allowing gas to be effectively accumulated in the float chamber, the float valve to be effectively opened, and gas separated from the raw water to be effectively discharged to the outside air while suppressing water leakage from the float valve.

[0006] In a preferred embodiment of the present invention, float guide projections extending in the longitudinal direction are disposed on the inner surface of the peripheral side wall of the float chamber, the float guide projections being distributed at intervals in the circumferential direction. The float guide protrusion allows the float to move smoothly, improving the gas discharge function. In a preferred embodiment of the present invention, the communicating hole between the raw water storage chamber and the float chamber is rectangular in shape. By making the communication hole rectangular, the gas discharge function is improved compared to when the communication hole is circular. In a preferred embodiment of the present invention, the edge line of the communication hole between the raw water storage chamber and the float chamber, which is closely opposed to the inner surface of the peripheral side wall of the float chamber, is an arc. By making the edge line of the communication hole between the raw water storage chamber and the float chamber, which is close to and faces the inner surface of the peripheral side wall of the float chamber, into an arc, the gas discharge function is improved compared to when the edge line is a straight line. In a preferred embodiment of the present invention, the arcuate edge line of the communication hole between the raw water storage chamber and the float chamber, which is adjacent to and faces the inner surface of the peripheral side wall of the float chamber, does not contact the inner surface of the peripheral side wall of the float chamber. If the edge line of the communication hole between the raw water storage chamber and the float chamber, which is close to and faces the inner surface of the peripheral side wall of the float chamber, comes into contact with the inner surface of the peripheral side wall of the float chamber, the gas discharge function will be reduced. In a preferred embodiment of the present invention, the ratio of the area of ​​the communication hole between the raw water storage chamber and the float chamber to the inner diameter area of ​​the upper part of the raw water storage chamber, i.e., communication hole area / inner diameter area of ​​the upper part of the raw water storage chamber, is 6.5% to 12.7%. By setting the ratio of the area of ​​the communication hole between the raw water storage chamber and the float chamber to the inner diameter area of ​​the upper part of the raw water storage chamber, i.e., communication hole area / inner diameter area of ​​the upper part of the raw water storage chamber, to 6.5% to 12.7%, good water leakage prevention function and gas discharge function can be obtained. [Brief description of the drawings]

[0007] [Figure 1] The photographs show the operating state of a conventional gas-liquid separator made of transparent material. (a) is an external view of the entire device, and (b) is an external view focusing on air bubbles. [Diagram 2] 1 is a structural diagram of a gas-liquid separation device according to an embodiment of the present invention, in which (a) is a front view, (b) is a view taken along the arrow bb in (a), (c) is a cross-sectional view taken along the cutting line cc in (a), (d) is a view taken along the arrow dd in (a), and (e) is a view taken along the arrow ee in (a). [Diagram 3] FIG. 1 is a block diagram of a test device for a gas discharge rate confirmation test. [Figure 4] 1 is a top view of the bottom wall of the float chamber of a gas-liquid separator, where (a) shows the structure of a conventional product, and (b) to (l) show the structures of improved products. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] A gas-liquid separation device according to an embodiment of the present invention will be described below. As shown in Figure 2, the gas-liquid separation device 1 comprises a raw water storage chamber 2 of circular cross section for storing raw water containing a gas-liquid mixture, a raw water supply pipe 3 connected to the upper part of the raw water storage chamber 2, a deaerated water discharge pipe 4 connected to the lower part of the raw water storage chamber 2, a float chamber 5 disposed above the raw water storage chamber 2 and communicating with the raw water storage chamber via a communication hole 5a, and a float valve 6 having a float 6a and a valve mechanism 6b and disposed within the float chamber 5, which normally keeps the float chamber 5 closed and opens when a predetermined amount of gas has accumulated in the float chamber 5 to discharge the gas to the atmosphere. The connection port 2a to the raw water supply pipe 3 of the raw water storage chamber 2 is directed in the tangent direction of the inner surface of the side wall surrounding the raw water storage chamber 2, and the connection port 2b to the deaerated water discharge pipe 4 of the raw water storage chamber 2 is directed in the tangent direction of the inner surface of the side wall surrounding the raw water storage chamber 2. A communication hole 5a between the raw water storage chamber 2 and the float chamber 5 is offset from the center C of the cross section of the raw water storage chamber toward the connection port 2a of the raw water storage chamber 2 with the raw water supply pipe 3.

[0009] The operation of the gas-liquid separator 1 will now be described. As shown in Figures 2(c) to 2(e), raw water flowing from the raw water supply pipe 3 into the raw water storage chamber 2 flows tangentially to the inner surface of the peripheral wall of the raw water storage chamber 2, forming a swirling flow SF, and air bubbles dispersed in the raw water gather near the center of the cross section of the raw water storage chamber due to the centrifugal force of the swirling flow SF, forming an air bubble group. As shown by the white arrow A1 in Figure 2(c), the air bubble group rises in the raw water near the center of the cross section of the raw water storage chamber. Due to the ejector effect of the raw water flowing from the raw water supply pipe 3 into the raw water storage chamber 2, the raw water above the connection port 2a of the raw water storage chamber 2 to the raw water supply pipe 3 is sucked toward the connection port 2a, and the raw water entrains the group of air bubbles rising in the raw water near the center of the cross section of the raw water storage chamber, and the ascending flow of the group of air bubbles is biased toward the direction of the connection port 2a, as shown by the white arrow A2 in Figure 2(c). Since the communication hole 5a between the raw water storage chamber 2 and the float chamber 5 is biased away from the center C of the raw water storage chamber cross section toward the connection port 2a of the raw water storage chamber 2 to the raw water supply pipe 3, the rising air bubbles biased toward the connection port 2a accumulate directly below the communication hole 5a and enter the float chamber 5 through the communication hole 5a. The gas accumulated in the float chamber 5 pushes down the water level in the float chamber 5, causing the float 6a to descend. When the amount of gas accumulated in the float chamber 5 reaches a predetermined value, the float valve 6 opens by the operation of the valve mechanism 6b, and the gas is discharged into the outside air. As can be seen from the above explanation, in the gas-liquid separation device 1, the communication hole 5a between the raw water storage chamber 2 and the float chamber 5 is offset from the center C of the raw water storage chamber cross section toward the connection port 2a of the raw water storage chamber 2 with the raw water supply pipe 3, so that the air bubbles rising in the raw water are guided to the communication hole 5a and effectively introduced into the float chamber 5, effectively accumulating gas in the float chamber 5 and effectively opening the float valve 6, thereby effectively discharging the gas separated from the raw water to the outside air while suppressing water leakage from the float valve 6.

[0010] If the communication hole 5a is too small, the inflow of gas into the float 5 chamber is restricted, and the amount of gas discharged is reduced. On the other hand, if the communication hole 5a is too large, the float 6a becomes unstable due to the influence of the turbulent flow of raw water in the raw water storage chamber 2, the operation of the float valve 6 becomes unstable, the closed float valve 6 opens, and raw water leaks through the float valve 6. Therefore, in order to select the optimal communication hole 5a that achieves both gas discharge efficiency and water leakage prevention, multiple gas-liquid separators 1 with different areas, positions, and shapes of the communication hole 5a were prototyped, and the gas discharge efficiency and the maximum raw water flow rate that can prevent water leakage were measured. The test conditions are as follows.

[0011] 1. Leakage confirmation test (1) Test method Water was supplied to the raw water inlet pipe 3 of the prototype gas-liquid separation device 1 for 150 seconds at a predetermined water pressure and various flow rates, and the water flow rate when leakage from the float valve 6 occurred was measured. (2) Test conditions (a) Applied water pressure: 300 kPa (taking into consideration that the maximum value of the internal pressure of the circulation path connecting the heat source unit having a heat pump of the hot water storage type hot water heater in which the gas-liquid separation device 1 is planned to be used and the hot water storage unit having a hot water storage tank is expected to be less than 300 kPa) (b) Water flow rate: The water flow rate is increased in increments of 5 L / min from 45 L / min to 70 L / min, and the presence or absence of water leakage is detected at each water flow rate. (Taking into consideration that the hot water flow rate of the above-mentioned circulation path is 50 to 65 L / min.) (c) Judgment criteria: The maximum water flow rate at which leakage can be prevented (hereinafter referred to as the allowable water flow rate) must be 65 L / min or more. (Taking into consideration that the maximum hot water flow rate of the aforementioned circulation path is 65 L / min.)

[0012] 2. Gas emission rate confirmation test (1) Test equipment Figure 3 shows a block diagram of the test equipment. (2) Test method Gas-liquid mixed water was supplied to the raw water inlet pipeline 3 of the prototype gas-liquid separation device 1 at a specified water pressure, water flow rate, and air inlet flow rate, and the flow rate of air discharged from the float valve 6 was measured to calculate the air discharge rate (air discharge flow rate / air inlet flow rate). (3) Test conditions (a) Gas used: Air (b) Applied water pressure: 300 kPa (c) Water flow rate: 50L / min (d) Air inflow flow rate: 30NL / min (taking into consideration that the maximum flow rate of the refrigerant gas that may be mixed into the hot water in the aforementioned circulation path is expected to be less than 30NL / min) (e) Judgment criteria: Air exhaust rate must be 90% or more.

[0013] 3. Test Results (1) Leakage confirmation test The ratio of the communication hole area to the inner diameter area of ​​the upper part of the raw water storage chamber, that is, the communication hole area / the inner diameter area of ​​the upper part of the raw water storage chamber (hereinafter referred to as the communication hole area in the following text) of a conventional gas-liquid separation device (the structure is the same as that of the gas-liquid separation device 1, but the circular communication hole between the raw water storage chamber and the float chamber is positioned at the center of the cross section of the raw water storage chamber. More specifically, the center, which is the center of gravity of the area of ​​the circular communication hole, is positioned at the center of the cross section of the raw water storage chamber) installed in the circulation path of a heat pump type storage water heater is Considering that the through hole area ratio (hereinafter referred to as the through hole area ratio) was about 12%, a conventional product (Fig. 4(a)) was prototyped in which the communication hole 5a of the gas-liquid separator 1 was positioned at the center C of the raw water storage chamber cross section and the communication hole area ratio was set to 12% (circular hole with a hole diameter of 20 mm) and a leakage confirmation test was conducted. As a result, the allowable water flow rate was 45 L / min, which did not reach the lower limit of 50 L / min of the hot water flow rate in the circulation path of the heat pump type hot water storage water heater in which the gas-liquid separator 1 is to be used. Therefore, an improved product 1 (Fig. 4(b)) was prototyped in which the communication hole was positioned at the center of the raw water storage chamber cross section and the communication hole area ratio was set to 8.7% (circular hole with a hole diameter of 17 mm) and a leakage confirmation test was conducted. As a result, the allowable water flow rate increased to 55 L / min, which was within the range of 50 to 65 L / min of the hot water flow rate in the circulation path of the heat pump type hot water storage water heater in which the gas-liquid separator 1 is to be used.

[0014] (2) Water leakage improvement and gas discharge rate improvement test 1 Taking into consideration the results of the leakage confirmation test, in order to improve Improved Product 1 (Figure 4(b)) based on the present invention, the connecting hole area ratio was fixed at 8.7% (circular hole with a hole diameter of 17 mm), and Improved Product 2 (Figure 4(c)) was prototyped in which the connecting hole position was shifted 3 mm from the center C of the raw water storage chamber cross section toward the connection port 2a between the raw water storage chamber 2 and the raw water flow pipe 3, and Improved Product 3 (Figure 4(d)) was prototyped in which the connecting hole position was shifted 10 mm from the center C of the raw water storage chamber cross section toward the connection port 2a between the raw water storage chamber 2 and the raw water flow pipe 3, and the allowable water flow rate and air discharge rate were measured. As a result, for improved product 1, the allowable water flow rate was 55 L / min and the air discharge rate was 62.9%, for improved product 2, the allowable water flow rate was 60 L / min and the air discharge rate was 65.2%, and for improved product 3, the allowable water flow rate was 65 L / min and the air discharge rate was 68.5%. Furthermore, in order to smooth the movement of the float 6a, an improved product 4 (Figure 4(e)) was prototyped in which the float guide protrusions 5b extending longitudinally on the inner surface of the side wall surrounding the float chamber 5 of improved product 3 were distributed at equal intervals circumferentially.The allowable water flow rate and air discharge rate were measured, and the allowable water flow rate was maintained at 65 L / min and the air discharge rate increased to 73.4% compared to improved product 3.

[0015] (3) Leakage Improvement and Discharge Rate Improvement Test 2 Taking into consideration the results of the leakage improvement and discharge rate improvement test 1, in order to further improve the improved product 4 (Figure 4(e)), the float guide protrusions 5b are fixed in a dispersed arrangement on the inner surface of the side wall around the float chamber, the position of the communication hole 5a is shifted 10 mm from the center C of the cross section of the raw water storage chamber toward the connection port 2a between the raw water storage chamber 2 and the raw water flow pipe 3, and the communication hole area ratio is increased to 9.8% (a circular hole with a hole diameter of 18 mm). The following prototypes were manufactured: Improved Product 5 (Fig. 4(f)), Improved Product 6 (Fig. 4(g)), which has a communicating hole area ratio of 10%, roughly the same as Improved Product 5, and the communicating hole position (area center of gravity position) is roughly the same as Improved Product 5 with the communicating hole shape being made roughly square; and Improved Product 7 (Fig. 4(h)), which has a communicating hole area ratio of 9.9%, in which the edge line facing closely to the inner surface of the peripheral side wall of the float chamber of Improved Product 6 has been changed from a straight line to an arc. And the allowable water flow rate and air discharge rate were measured. As a result, compared to improved product 4, the allowable water flow rate was maintained at 65 L / min for improved products 5, 6, and 7, and the air discharge rate increased to 85.4% for improved product 5 and to 95.0% for improved products 6 and 7. Furthermore, a 3D-CAD fluid analysis conducted in parallel with the leakage improvement and discharge rate improvement test 2 revealed that the water flow velocity in the raw water storage chamber 2 at the communication hole position was slower for Improved Product 6 than for Improved Product 5, and that the water flow velocity at the communication hole position was slower for Improved Product 7 than for Improved Product 6. It is believed that a slower water flow velocity makes it easier for air bubbles to enter the float chamber through the communication hole. Therefore, the fluid analysis confirmed that Improved Product 6 is superior to Improved Product 5, and Improved Product 7 is superior to Improved Product 6, in terms of improving the gas discharge rate. Furthermore, the above fluid analysis revealed that when the arc-shaped edge of Improved Product 7 comes into contact with the inner surface of the float chamber peripheral side wall, the water flow velocity at the communication hole increases. It is believed that if the water flow velocity is high, it becomes difficult for the air bubble group to enter the float chamber via the communication hole. Therefore, from the perspective of improving the gas discharge rate, it is desirable for the arc-shaped edge of the communication hole not to come into contact with the inner surface of the float chamber peripheral side wall.

[0016] (4) Leakage Improvement and Discharge Rate Improvement Test 3 Taking into consideration the results of leakage improvement and discharge rate improvement test 2, in order to further improve improved product 7 (Fig. 4(h)), the following were prototyped: improved product 7-A (Fig. 4(i)), which retains the same communicating hole position and shape as improved product 7, but with the communicating hole area ratio reduced to 6.1%, improved product 7-B (Fig. 4(j)), which has the communicating hole area ratio reduced to 6.5%, improved product 7-C (Fig. 4(k)), which has the communicating hole area ratio increased to 12.7%, and improved product 7-D (Fig. 4(l)), which has the communicating hole area ratio increased to 13.3%, and the allowable water flow rate and air discharge rate were measured. As a result, compared to Improved Product 7, the allowable water flow rate of Improved Product 7-A increased to 70 L / min but the air discharge rate decreased to 84.7%; the allowable water flow rate of Improved Product 7-B increased to 70 L / min but the air discharge rate decreased to 90.0; the allowable water flow rate of Improved Product 7-C was maintained at 65 L / min and the air discharge rate was also maintained at 95.0%; and the allowable water flow rate of Improved Product 7-D decreased to 60 L / min and the air discharge rate was maintained at 95.0%. From the leakage improvement and discharge rate improvement test 3, it was found that the improved products 7, 7-B, and 7-C met the judgment criteria of the air discharge efficiency confirmation test and the judgment criteria of the leakage confirmation test, and achieved both gas discharge efficiency and elimination of leakage. [Industrial Applicability]

[0017] The present invention can be widely used in gas-liquid separation devices. [Explanation of symbols]

[0018] 1 Gas-liquid separator 2 Raw water storage room 2a Connection port between raw water storage chamber and raw water supply line 2b Connection port between raw water storage chamber and deaerated water discharge line 3 Raw water supply pipeline 4 Deaerated water discharge pipe 5 Float Chamber 5a Communication hole 5b Float guide protrusion 6 Float Valve 6a Float 6b Valve mechanism A1, A2 Bubbly flow C Center of raw water storage chamber cross section SF swirl flow

Claims

1. a raw water storage chamber having a circular cross section for storing raw water containing a gas-liquid mixture; a raw water supply pipe connected to the upper part of the raw water storage chamber; a deaerated water discharge pipe connected to the lower part of the raw water storage chamber; a float chamber arranged above the raw water storage chamber and communicating with the raw water storage chamber through a communication hole; and a float valve arranged within the float chamber which normally closes the float chamber and opens when a predetermined amount of gas accumulates in the float chamber to discharge the gas to the atmosphere, wherein the connection port of the raw water storage chamber to the raw water supply pipe is oriented in the tangent direction of the inner peripheral wall of the raw water storage chamber, and the communication hole between the raw water storage chamber and the float chamber is offset from the center of the cross section of the raw water storage chamber toward the connection port of the raw water storage chamber to the raw water supply pipe.

2. 2. The gas-liquid separator according to claim 1, wherein float guide projections extending in the longitudinal direction are disposed on the inner surface of the peripheral wall of the float chamber at intervals in the circumferential direction.

3. 2. The gas-liquid separator according to claim 1, wherein the shape of the communication hole between the raw water storage chamber and the float chamber is rectangular.

4. 4. A gas-liquid separator according to claim 3, wherein an edge line of the communication hole between the raw water storage chamber and the float chamber, which is adjacent to and faces an inner surface of the peripheral side wall of the float chamber, is an arc.

5. 5. A gas-liquid separator according to claim 4, wherein an arcuate edge line of the communication hole between the raw water storage chamber and the float chamber, which is adjacent to and faces the inner surface of the peripheral side wall of the float chamber, does not contact the inner surface of the peripheral side wall of the float chamber.

6. A gas-liquid separation device as described in claim 5, characterized in that the ratio of the area of ​​the connecting hole between the raw water storage chamber and the float chamber to the inner diameter area of ​​the upper part of the raw water storage chamber, i.e., connecting hole area / inner diameter area of ​​the upper part of the raw water storage chamber, is 6.5% to 12.7%.

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