Gas-liquid separation device

Abstract

This gas-liquid separation device (1) comprises: a main pump (2) that separates a gas-liquid mixture into a gas and a liquid by using the centrifugal force of an impeller (2e); a first manual valve (12); a vacuum pump (23); and an adjustment valve (31). The adjustment valve (31) has: a valve body (44) that opens and closes a connection port (41a) that connects a first flow path (42) and a second flow path (43); a spring (45) that biases the valve body (44) toward the closed side; and a handle (46) that can adjust the force with which the spring (45) biases the valve body (44).

Description

Gas-liquid separator

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

[0002] Conventionally, gas-liquid separators used for degassing or degassing liquid raw materials or liquid intermediate products have been installed in, for example, liquid food production factories. For example, the gas-liquid separator disclosed in Patent Document 1 includes a pump that separates a gas-liquid mixture introduced into a casing through a fluid suction port into gas and liquid by the centrifugal force of an impeller, discharges the gas through an exhaust port, and discharges the liquid through a liquid discharge port, a suction-side throttle means provided in a suction passage connected to the fluid suction port, a vacuum device provided in an exhaust passage connected to the exhaust port, and a discharge-side throttle means provided in a discharge passage connected to the liquid discharge port.

[0003] International Publication No. 2016 / 121659

[0004] Unlike typical centrifugal pumps, the gas-liquid separator disclosed in Patent Document 1 requires the pump to be vacuumed before it can be started. Therefore, when starting up the gas-liquid separator, a vacuum is created inside the pump using a vacuum device. However, when using the vacuum device to create a vacuum inside the pump, if, for example, a throttling means on the discharge side of the pump's discharge passage is open, backflow of fluid such as air from the discharge passage into the pump can occur, potentially preventing the pump from being properly vacuumed. Furthermore, to prevent this backflow, it is necessary to provide a separate check valve in the discharge passage.

[0005] Furthermore, in the above-described gas-liquid separation device, the optimum conditions differ for each liquid raw material to be degassed, for example. Therefore, it is necessary to adjust the flow rate and pressure of the pump during operation of the gas-liquid separation device. One possible method for adjusting these is, for example, using throttle means provided in the suction passage and discharge passage of the pump. However, when attempting to adjust the flow rate of the pump, the pressure changes along with the flow rate of the pump, and when attempting to adjust the pressure, the flow rate of the pump changes along with the pressure. Therefore, adjusting the flow rate and pressure of the pump requires a lot of effort.

[0006] The present invention has been made in consideration of the above points, and its object is to provide a gas-liquid separation device that can stably draw a vacuum inside the pump using a vacuum device and that makes it easy to adjust the pump flow rate and pressure.

[0007] In order to achieve the above object, the present invention provides a gas-liquid separation device comprising: a pump that separates a gas-liquid mixture introduced into a casing from an intake port into a liquid and a gas by the centrifugal force of an impeller rotating within the casing, and that discharges the gas from an exhaust port and the liquid from a discharge port; an intake path section connected to the intake port; a throttling means provided in the suction path section; an exhaust path section connected to the exhaust port; a vacuum device provided in the exhaust path section; a discharge path section connected to the discharge port; and an adjustment valve provided in the discharge path section, wherein the adjustment valve comprises a fluid inflow path section, a fluid outflow path section provided downstream of the fluid inflow path section, a valve body that opens and closes a connection port that connects the fluid inflow path section and the fluid outflow path section, a biasing section that biases the valve body to a closing side, and an adjustment section that can adjust the force with which the biasing section biases the valve body. According to the present invention configured as described above, when the gas-liquid separation device is started and a vacuum is created inside the pump using a vacuum device, the valve element of the regulating valve is biased to the closed side by the differential pressure between the fluid inlet and outlet channels and the biasing force. As a result, when a vacuum is created inside the pump, the regulating valve can prevent fluid from backflowing from the discharge channel into the pump. Therefore, a stable vacuum can be created inside the pump using a vacuum device. Furthermore, when the gas-liquid separation device is in operation, the biasing force of the biasing unit adjusted by the adjustment unit opens and closes the valve element of the regulating valve. This eliminates the need to adjust the regulating valve when adjusting the throttle means provided in the suction channel, making it easier to adjust the flow rate and pressure of the pump than before.

[0008] In the present invention, preferably, the biasing portion is an elastic body, and the adjustment portion is configured to be able to manually adjust the degree of compression of the elastic body. According to the present invention configured in this manner, since the adjustment portion is configured to be able to manually adjust the degree of compression of the elastic body, costs can be reduced compared to a configuration in which the degree of compression of the elastic body is adjusted using an actuator or the like.

[0009] In the present invention, preferably, the regulating valve includes a valve box that houses the valve element and the elastic body, and further includes a diaphragm fixed to the valve box and the valve element and separating the fluid outflow path portion from the accommodation portion for the elastic body, the diaphragm being configured to isolate the fluid inflow path portion upstream of the valve element from the pressure therein when the regulating valve is in a fully closed state. According to the present invention configured in this manner, the diaphragm separates the accommodation portion for the elastic body from the fluid outflow path portion, thereby preventing liquid flowing through the fluid outflow path portion from adhering to the elastic body. This eliminates the need for cleaning the elastic body. Furthermore, when the regulating valve is in a fully closed state, the diaphragm is isolated from the pressure in the fluid inflow path portion. This prevents the diaphragm from being excessively deformed by the reduced pressure in the fluid inflow path portion that occurs when a vacuum is created inside the pump using a vacuum device.

[0010] As described above, according to the present invention, it is possible to provide a gas-liquid separation device that can stably draw a vacuum inside a pump using a vacuum device and that allows easy adjustment of the pump flow rate and pressure.

[0011] It is a schematic cross-sectional view showing a state in which a regulating valve is fully closed, and a schematic cross-sectional view showing a state in which a regulating valve is open, in accordance with an embodiment of the present invention.

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the following description of the preferred embodiments is merely exemplary in nature.

[0013] 1 shows a gas-liquid separator 1 according to an embodiment of the present invention. The gas-liquid separator 1 is used, for example, to degas or defoam liquid raw materials or liquid intermediate products in a manufacturing process in a food factory.

[0014] 1 and 2, the gas-liquid separation device 1 includes a main pump 2. The main pump 2 includes a casing 2a, an inlet 2b, an outlet 2c, and a discharge port 2d provided in the casing 2a, an impeller 2e rotatably supported within the casing 2a, and a motor (not shown) connected to the impeller 2e via a drive shaft (not shown) and for driving the impeller 2e to rotate.

[0015] The downstream end of a suction pipe 3 is connected to the suction port 2b of the main pump 2. The upstream end of the suction pipe 3 is connected to a tank (not shown) in a previous process. When the main pump 2 is started, a gas-liquid mixture, which is a mixture of a liquid (e.g., a liquid raw material or a liquid intermediate product) and a gas (gas bubbles or foam) stored in the tank, is introduced into the main pump 2 via the suction pipe 3.

[0016] The suction pipe 3 is also provided with a first manual valve 12 .

[0017] The first manual valve 12 is, for example, a butterfly valve, a globe valve, or a ball valve. In this embodiment, the opening degree of the first manual valve 12 can be manually changed.

[0018] A gas-liquid mixture introduced into the casing 2a of the main pump 2 from the suction pipe 3 is centrifuged in the main pump 2 to separate the liquid and the gas. In this embodiment, the gas-liquid mixture introduced into the casing 2a is forcibly centrifuged into the gas and the liquid by the rotation of the impeller 2e. The centrifuged gas accumulates near the center of the impeller 2e, creating a cavity. The cavity (gas) is discharged into the exhaust pipe 4 from an exhaust port 2c provided near the rotation center on one end face of the casing 2a. Meanwhile, the liquid centrifuged in the main pump 2 travels along the inner circumferential wall of the casing 2a and is then discharged into the discharge pipe 5 from a discharge port 2d connected tangentially to the inner wall surface of the casing 2a. The discharge pipe 5 is provided with a regulating valve 31. The regulating valve 31 will be described in detail later. In this embodiment, the discharge pipe 5 is not provided with a check valve.

[0019] As shown in FIG. 2, the exhaust pipe 4 is provided with a second manual valve 21, a drain separator 22, and a vacuum pump 23 in this order in the gas flow direction.

[0020] The second manual valve 21 is, for example, a gate valve. In this embodiment, the second manual valve 21 is configured to be manually switchable between a closed state and an open state. The second manual valve 21 can be switched between a state in which communication between the main pump 2 and the vacuum pump 23 is blocked by closing the second manual valve 21, and a state in which communication between the main pump 2 and the vacuum pump 23 is opened by opening the second manual valve 21.

[0021] An inlet 22b of the drain separator 22 is connected to the exhaust port 2c of the main pump 2 via an exhaust pipe 4. This allows gas and the like (including liquid that could not be completely separated in the main pump 2) discharged from the exhaust port 2c of the main pump 2 to be introduced into the drain separator 22.

[0022] The inlet 22b is connected tangentially to the inner wall surface of the case 22a. This allows gas or the like introduced into the case 22a through the inlet 22b to be separated into gas and liquid within the case 22a by centrifugation. The centrifuged gas is then discharged from the outlet 22c. Meanwhile, the centrifuged liquid accumulates in the lower part of the case 22a. The liquid accumulated in the lower part of the case 22a is then discharged from the drain port 22d.

[0023] The vacuum pump 23 is, for example, a liquid ring vacuum pump. The vacuum pump 23 is capable of drawing a vacuum inside the main pump 2 by sucking gas from the main pump 2 through the exhaust pipe 4.

[0024] In this embodiment, a pressure gauge and a flow meter (not shown) are provided at appropriate positions on the piping of the gas-liquid separation device 1 .

[0025] Next, the regulating valve 31 will be described with reference to Figures 3 and 4. For convenience, in Figures 3 and 4, the discharge pipe 5 upstream of the regulating valve 31 is referred to as the upstream discharge pipe 5a, and the discharge pipe 5 downstream of the regulating valve 31 is referred to as the downstream discharge pipe 5b.

[0026] The regulating valve 31 has a valve body 41. The valve body 41 is provided with a first flow path 42, a second flow path 43, a valve element 44, a spring 45, a handle 46, and a diaphragm 47.

[0027] The upstream end of the first flow path 42 is connected to the downstream end of the upstream discharge pipe 5 a, so that the liquid discharged from the discharge port 2 d of the main pump 2 is introduced into the first flow path 42.

[0028] The first flow path 42 is connected to the second flow path 43 via the connection port 41 a. The upstream end of the second flow path 43 is connected to the downstream end of the first flow path 42. The downstream end of the second flow path 43 is connected to the upstream end of the downstream discharge pipe 5 b.

[0029] A valve seat 41b is provided at a connection port 41a between the first flow path 42 and the second flow path 43.

[0030] The valve element 44 is housed in the valve box 41. The valve element 44 is configured to open and close the connection port 41a.

[0031] The spring 45 is, for example, a coil spring, and is housed in the valve box 41. In this embodiment, the spring 45 is disposed on the back side of the valve body 44.

[0032] The spring 45 is configured to bias the valve element 44 toward the valve seat 41b (closed side).

[0033] A handle 46 is provided on the opposite side of the spring 45 from the valve body 44, allowing the degree of compression of the spring 45 to be changed. The handle 46 includes a gripping portion 46a that can be gripped when an operator manually rotates the handle 46, a pressing portion 46b that presses the spring 45, and a shaft portion 46c that connects the gripping portion 46a and the pressing portion 46b. A screw thread (not shown) is provided on the outer surface of the shaft portion 46c. The screw thread is adapted to thread into a screw hole (not shown) provided in the valve box 41. The screw thread and the screw hole form a screw mechanism.

[0034] In this embodiment, when the screw mechanism is screwed forward and backward by rotating the handle 46, the handle 46 moves in a first direction toward the valve body 44 and in a second direction away from the valve body 44. When the handle 46 moves in the first direction, the gap between the pressing portion 46b and the valve body 44 becomes relatively small, so the degree of compression of the spring 45 becomes relatively large. On the other hand, when the handle 46 moves in the second direction, the gap between the pressing portion 46b and the valve body 44 becomes relatively large, so the degree of compression of the spring 45 becomes relatively small.

[0035] The greater the degree of compression of the spring 45, which is adjusted by the handle 46, the greater the force with which the spring 45 presses the valve element 44 toward the valve seat 41b, i.e., the greater the biasing force of the spring 45 on the valve element 44. The greater the biasing force of the spring 45, the higher the pressure in the first flow path 42.

[0036] The diaphragm 47 has an annular shape, and its inner periphery is fixed to the valve element 44, while its outer periphery is fixed to the valve box 41. This allows the diaphragm 47 to function as a partition member that separates the second flow path 43 from the space S in which the spring 45 is disposed within the valve box 41. Therefore, the diaphragm 47 can prevent the liquid flowing through the second flow path 43 from adhering to the spring 45.

[0037] Furthermore, the diaphragm 47 is configured to be isolated from the pressure in the first flow path 42 upstream of the valve element 44 when the adjustment valve 31 is in a closed state (fully closed state). In other words, when the valve element 44 is in a closed state, the pressure in the first flow path 42 upstream of the valve element 44 does not act on the diaphragm 47. As a result, even if the pressure in the first flow path 42 decreases due to suction by the vacuum pump 23, the decreased pressure in the first flow path 42 does not act on the diaphragm 47. Therefore, the diaphragm 47 can be prevented from being excessively deformed by the pressure in the first flow path 42.

[0038] When the pressure in the first flow path 42 exceeds the pressure corresponding to the compression degree of the spring 45 and the opening of the valve body 44 increases, the liquid in the first flow path 42 flows through the connection port 41 a into the second flow path 43. This allows the pressure in the first flow path 42 to be released to the second flow path 43 side. Therefore, the pressure in the first flow path 42 is maintained at the pressure corresponding to the compression degree of the spring 45.

[0039] In this embodiment, when the gas-liquid separation device 1 is started, the vacuum pump 23 is used to draw a vacuum inside the main pump 2. The pressure difference between the negative pressure in the first flow path 42 and the positive pressure in the second flow path 43 and the atmospheric pressure in the space S presses the valve element 44 strongly against the valve seat 41b, tightly sealing the connection port 41a. The biasing force of the spring 45 also presses the valve element 44 against the valve seat 41b. Therefore, when the main pump 2 is being vacuumed and when the main pump 2 is stopped, the regulating valve 31 can prevent backflow of fluid from the discharge pipe 5 into the main pump 2. This allows the vacuum pump 23 to stably draw a vacuum inside the main pump 2 without providing a check valve in the discharge pipe 5. During operation of the gas-liquid separation device 1, the opening of the valve element 44 of the regulating valve 31 is adjusted according to the biasing force of the spring 45, which is adjusted using the handle 46. This eliminates the need to adjust the regulating valve 31 when adjusting the first manual valve 12 provided in the suction pipe 3, making it possible to adjust the flow rate and pressure of the main pump 2 more easily than before.

[0040] Furthermore, since the handle 46 is configured to allow manual adjustment of the compression degree of the spring 45, costs can be reduced compared to a configuration in which the compression degree of the spring 45 is adjusted using an actuator or the like.

[0041] Furthermore, because the diaphragm 47 separates the space S (the accommodation portion for the spring 45) from the second flow path 43, it is possible to prevent the liquid flowing through the second flow path 43 from adhering to the spring 45. This makes it possible to omit the cleaning work for the spring 45. Furthermore, when the adjustment valve 31 is in a fully closed state, the diaphragm 47 is isolated from the pressure in the first flow path 42. This prevents the diaphragm 47 from being excessively deformed by the reduced pressure in the first flow path 42 that occurs when the pressure in the first flow path 42 is reduced when the vacuum pump 23 is used to create a vacuum inside the main pump 2.

[0042] In this embodiment, the second manual valve 21 is manually switched between a closed state and an open state, but it may be of a type other than manual (for example, electrically operated).

[0043] Furthermore, in this embodiment, an example in which the drain separator 22 is provided in the exhaust pipe 4 has been described, but the drain separator 22 may not be provided.

[0044] In addition, in this embodiment, an example of the vacuum pump 23 has been described as the vacuum device, but means other than a vacuum pump (for example, a negative pressure generator) may be used as long as it is possible to create a vacuum inside the main pump 2. Also, a check valve may be provided in the discharge pipe 5.

[0045] Furthermore, in this embodiment, an example of the spring 45 being a coil spring has been described, but as long as it is capable of biasing the valve body 44 to the closing side, it may be a spring other than a coil spring (for example, a leaf spring), or an elastic body other than a spring (for example, rubber).

[0046] In addition, in this embodiment, an example has been described in which the degree of compression of the spring 45 (the set pressure of the adjustment valve 31) is adjusted using the handle 46, but a configuration other than the handle 46 (for example, a dial, an adjustment screw) may be used, or an actuator such as a hydraulic, pneumatic, or electric actuator may be used.

[0047] The present invention is suitable for a gas-liquid separator.

[0048] REFERENCE SIGNS LIST 1 Gas-liquid separator 2 Main pump (pump) 2a Casing 2b Suction port 2c Exhaust port 2d Discharge port 2e Impeller 3 Suction pipe (suction path section) 4 Exhaust pipe (exhaust path section) 5 Discharge pipe (discharge path section) 12 First manual valve (throttling means) 23 Vacuum pump (vacuum device) 31 Adjusting valve 41 Valve box 41a Connection port 42 First flow path (fluid inflow path section) 43 Second flow path (fluid outflow path section) 44 Valve element 45 Spring (biasing section, elastic body) 46 Handle (adjusting section) 47 Diaphragm S Space (accommodating section for elastic body)

Claims

1. A gas-liquid separation device comprising: a pump which separates a gas-liquid mixture introduced into a casing from a suction port into a liquid and a gas by the centrifugal force of an impeller rotating inside the casing, discharges the gas through an exhaust port and discharges the liquid from a discharge port; a suction path section connected to the suction port; a throttling means provided in the suction path section; an exhaust path section connected to the exhaust port; a vacuum device provided in the exhaust path section; a discharge path section connected to the discharge port; and an adjustment valve provided in the discharge path section, wherein the adjustment valve comprises a fluid inflow path section, a fluid outflow path section provided downstream of the fluid inflow path section, a valve body which opens and closes a connection port which connects the fluid inflow path section and the fluid outflow path section, a biasing section which biases the valve body to the closing side, and an adjustment section which can adjust the force with which the biasing section biases the valve body.

2. A gas-liquid separator as claimed in claim 1, wherein the biasing portion is an elastic body, and the adjustment portion is configured to manually adjust the degree of compression of the elastic body.

3. A gas-liquid separation device as described in claim 2, wherein the regulating valve has a valve box that houses the valve body and the elastic body, and further has a diaphragm fixed to the valve box and the valve body and separating the fluid outflow path portion from the housing portion for the elastic body, the diaphragm being configured to separate the pressure of the fluid inflow path portion upstream of the valve body from the pressure of the fluid inflow path portion upstream of the valve body when the regulating valve is in a fully closed state.

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