JP2007133829A - Fluid control apparatus, pressure regulating valve and control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To control fluid even when a contraction part near a valve seat is frozen in a fluid pressure control apparatus because the temperature of fluid itself rapidly drops by expansion of gas to cause the temperature of a downstream part of a regulating valve drops to be below zero when high pressure fluid is rapidly decompressed by using the regulating valve under a condition of high flow, moisture freezes on the surface of a flow passage of valve seat-valve element-valve seat gap of a valve hole being the contraction part to disturb the movement of the valve element, when moisture is contained in the gas, which causes gas pulsation, abnormal vibrations of the regulating valve, erosion of the valve seat and noises, so that it is difficult to maintain sound operation of a gas supply system. <P>SOLUTION: In this fluid control apparatus, a cutoff valve (2), the regulating valve (3) and a pressure sensor (4) are integrated to be provided along a fluid passage of a control target, and the cutoff valve (2) and the regulating valve (3) are automatically controlled on the basis of a detection pressure signal of the pressure sensor (4). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is used in a high-pressure gas utilization facility represented by a semiconductor manufacturing plant, a liquid crystal manufacturing plant, or the like. It is also used in fuel supply devices for fuel cells that use fluids, analyzers, and medical equipment. In particular, the present invention relates to a fluid pressure and flow rate control device.

  Currently, various fluids used in semiconductor manufacturing apparatuses, liquid crystal manufacturing apparatuses, etc., particularly high-pressure fluids, are first controlled in pressure by a pressure reducing valve, and then flow rate to the manufacturing apparatus is controlled by a flow meter. Further, since the flow meter is usually used under a low pressure condition of 1 MPa (Pascal) or less, the flow meter cannot be used under a high pressure condition by directly connecting a high pressure cylinder.

Usually, the pressure of the gas accommodated in the gas cylinder is too high to be used as it is. The gas pressure varies greatly depending on factors such as the ambient temperature and the remaining amount of gas. Therefore, a supply gas pressure control device is used in a gas supply facility that uses gas. Generally, this control device detects a change in pressure with a diaphragm, and has a control valve that moves in conjunction with the displacement of the diaphragm. The control valve is controlled so that the outlet pressure remains constant even when the supply gas inlet pressure fluctuates. It operates to obtain a predetermined outlet gas pressure (see, for example, Patent Document 1).
JP 2004-318683 A

  Usually, the high-pressure fluid sealed in a cylinder or the like is depressurized by a self-reducing pressure reducing valve in the fluid pressure control device and supplied to the fluid utilization facility. However, in a conventional self-reducing pressure reducing valve, the pressure adjustment accuracy decreases due to a change in upstream pressure or a change in flow rate. In particular, the flow rate change is large and the flow rate becomes large and the tendency is remarkable, and the downstream pressure to be regulated changes by several tens of percent. In addition, when the fluid is a gas, if the pressure is suddenly reduced under a large flow rate condition, the temperature of the fluid itself may rapidly decrease due to the expansion of the gas, and the temperature of the downstream portion of the pressure reducing valve may be below freezing point. In particular, the fluid temperature is often the lowest at the contracted portion near the valve seat, which is the minimum cross-sectional area of the flow path. When moisture is contained in the gas, moisture freezes on the flow path surface of the valve hole-valve-valve-valve seat gap, which is a contraction portion, and hinders the movement of the valve. The driving force of the self-reducing pressure reducing valve makes it impossible to move the valve body, which may hinder fluid control. In particular, when a resin valve seat is used, if the valve seat freezes, the valve seat may be damaged. When the valve seat is damaged, the amount of gas leakage at the valve seat increases, and as a result, the pressure in the downstream side pipe increases, which puts downstream equipment in danger. One problem is that the self-reducing pressure reducing valve does not have a shut-off function. In addition, in the case where the gas to be controlled is easily liquefied, the gas often liquefies in the low temperature region of the pressure reducing valve contraction portion. This causes gas pulsation, abnormal vibration of the pressure reducing valve, valve seat erosion, noise, and the like, making it difficult to maintain a sound operation of the gas supply system. Conventionally, measures such as installing a heater on the outer surface of the valve and heating via a temperature control device have been taken against the problems caused by such low temperatures. In the case of a large flow rate, the valve becomes very large and expensive, and there is an economical problem that a heater and a temperature control device must be prepared for measures against low temperatures. Furthermore, in the structure of a self-powered pressure reducing valve used for a conventional semiconductor manufacturing apparatus, there are many wasted spaces that do not serve as flow paths compared to the structure of a shut-off valve for the same purpose, and the gas replacement characteristics are poor and residual components are not. There are problems such as being easy to remain and easily capturing reaction products and particles.

  In a fluid pressure control device, a contracted part near the valve seat that is the minimum cross-sectional area of the fluid flow path to be controlled, which maintains the downstream pressure constant according to the set pressure against changes in upstream pressure and flow It is extremely important to devise measures such as preventing freezing, preventing a loss of control even if freezing occurs in a constricted portion near the valve seat, and being sufficiently adaptable for use in semiconductor manufacturing equipment. It is also an important issue to provide a fluid pressure control device that satisfies these requirements at a low cost.

In order to achieve the above object, a shut-off valve, a regulating valve, and a pressure sensor are provided along a fluid flow path to be controlled according to claim 1, and based on a detected pressure signal of the pressure sensor. A fluid control device that automatically controls a shutoff valve and a regulating valve.
The fluid control device according to claim 1, wherein the shutoff valve, the regulating valve, and the pressure sensor are integrated.
A shutoff valve, a control valve, a temperature sensor disposed downstream of the control valve, a heater, and a pressure sensor are provided along the fluid flow path to be controlled according to claim 3, and the pressure sensor Based on the detected pressure signal, the shut-off valve and the control valve are automatically controlled, and at the same time, the amount of heat generated by the heater is automatically controlled based on the signal from the temperature sensor. A fluid control apparatus characterized by preventing exposure to the following low temperature.
5. The fluid control device according to claim 3, wherein the shutoff valve, the regulating valve, a temperature sensor disposed downstream of the regulating valve, a heater, and a pressure sensor are integrated.
6. A fluid control apparatus according to claim 5, wherein an orifice mechanism is arranged upstream or downstream of the control valve, or upstream and downstream.

A fluid control device according to claim 6, wherein a purge and vent flow path is provided in the bellows portion of the regulating valve according to any one of claims 1, 2, 3, 4, and 5. .
The filter according to any one of claims 1, 2, 3, 4, 5, and 6, wherein the filter is disposed on the downstream side of the control valve. Fluid control device.
The pressure sensor according to any one of claims 1, 2, 3, 4, 5, 6, and 7 according to claim 8 is provided between the shutoff valve and the regulating valve. A fluid control device additionally provided.
Claim 9, Claim 2, Claim 3, Claim 3, Claim 4, Claim 5, Claim 7, Claim 8, Equally arranged in the control valve drive section A fluid control device comprising a plurality of drive shaft urging means and a rubber diaphragm, wherein the fluid control device is of a multistage type.
Claim 10, Claim 2, Claim 3, Claim 3, Claim 4, Claim 5, Claim 7, Claim 8, Equally arranged in the control valve drive section A fluid control device comprising a plurality of drive shaft urging means and a rubber diaphragm, wherein the fluid control device is a reverse-acting multistage type.

The control valve for controlling a fluid by adjusting the gap flow path between the valve seat and the valve body according to claim 11, wherein the flow path control unit formed by the gap flow path between the valve seat and the valve body is a multistage type. A control valve characterized in that the flow path cross-sectional area of the downstream flow path control section is larger than the flow path cross-sectional area of the upstream flow path control section.
13. The control valve according to claim 12, wherein the control valve controls the fluid by adjusting the gap flow path between the valve seat and the valve body, and has a structure in which the valve seat and the gasket are integrated.

  The flow rate measurement result of the flow meter provided along the fluid flow path of the fluid control device according to claim 13, and the pressure measurement result of the pressure gauge similarly disposed along the fluid flow path of the fluid control device, A fluid control method comprising feeding back an electrical signal to a controller of the fluid control device.

  Claim 14, Claim 1, Claim 2, Claim 3, Claim 4, Claim 5, Claim 6, Claim 7, Claim 8, Claim 9, or Claim 10 In addition, because it is composed of a shut-off valve using a metal diaphragm and a control valve using a bellows seal, it has a structure that minimizes the retention of fluid, and the entire surface of the flow path in contact with the fluid is mirror-polished. A fluid control apparatus comprising:

  According to the first, second, third, and fourth aspects of the invention, the fluid pressure control device includes the electromechanical automatic control mechanism, so that it depends on the increase or decrease in the fluid pressure on the primary side (fluid supply side) or the flow rate of the supply fluid. The pressure on the secondary side (fluid demand side) can always be kept constant. Further, if the pressure sensor is arranged on the most upstream side in the control device, not only the pressure control on the fluid demand side but also the pressure control on the fluid supply side becomes possible. Further, the valve box of the control device may be an integrated type, but may be divided into a valve box having a shut-off valve and a control valve and a flow path having a pressure sensor, and may be used by being connected via a gasket. Usually, since the pressure sensitive part of the pressure sensor is designed to be further away from the joint connecting part of the pressure sensor, the internal flow path is often a dead end. This is because when the joint is connected, the member near the gasket is distorted and easily affected. If the valve box and pressure sensor flow path are separated, it is easy to calibrate the pressure sensor even after the pressure sensor is installed in the pressure sensor flow path. Also, replace the pressure sensor while it is installed in the pressure sensor flow path. It becomes possible. As a result, the pressure sensing part of the pressure sensor can be designed close to the joint connection part of the pressure sensor, so that the portion of the internal flow path that becomes a bag path is minimized and the gas replacement characteristics are improved.

  According to the inventions of claims 1 and 2, when the shutoff valve is arranged upstream of the control valve, the differential pressure upstream and downstream of the control valve is higher than that of the shutoff valve. Even if the control valve is exposed to a low temperature, the shutoff valve is not exposed to a low temperature, and the fluid shutoff function can be maintained healthy in the fluid supply system. Moreover, even if the control valve is exposed to low temperatures, it has a stronger electromechanical driving force than a self-reducing pressure reducing valve, so even if the valve body freezes, the valve body can be moved easily to control the fluid. Is possible. In addition, if only a metal valve seat is used as the valve seat of the control valve, it is possible to keep the flow rate deterioration and the amount of fluid leakage when the valve seat portion is shut off to a minimum.

  According to the second and third aspects of the present invention, even if the downstream portion of the fluid pressure control device of the present invention is once exposed to a low temperature state, it is provided with a temperature adjustment function using a temperature sensor such as a thermocouple and a heater such as a heating wire. Accordingly, it is possible to avoid a problem in a low temperature state by heating a temperature lowering part such as a fluid contraction part. In particular, it becomes possible to protect the devices arranged downstream from low temperatures. Further, there is no need to prepare a new temperature control device, which is economical.

  Further, according to the inventions of claims 2 and 4, the fluid control device can be reduced in size, and the degree of freedom of the installation location of the fluid control device is increased.

  According to the fifth aspect of the present invention, the control valve is provided with the multistage pressure reducing mechanism that arranges the orifices upstream and downstream of the control valve, reduces the fluid differential pressure applied to the control valve, and distributes the differential pressure to the orifice part. The rapid pressure drop and temperature drop in the fluid contraction part can be suppressed, and troubles due to freezing of water in the fluid and liquefaction of the fluid in the fluid contraction part can be avoided.

  According to the sixth aspect of the present invention, when a bellows seal is used for the control valve, the portion becomes a fluid passageway, so that the gas replacement characteristic is deteriorated. By providing purge and vent flow paths in the bellows seal portion, gas replacement characteristics (high speed and high purity) can be improved.

  The regulating valve regulates the flow rate by regulating the gap area between the valve body and the valve hole. Due to the structure, minute wear foreign matter is inevitably generated. According to the seventh aspect of the present invention, by arranging the filter downstream of the regulating valve, it is possible to prevent foreign matters generated by the regulating valve or the like from flowing into the fluid demand side.

  According to the eighth aspect of the present invention, by providing a pressure sensor between the shutoff valve and the control valve, it is possible to accurately measure the flow rate characteristic of the control valve, and the shutoff of the fluid pressure control device of the present invention. When a leak occurs in one of the valve seat and the control valve, it is possible to identify which valve seat is causing the leak, and this can be used as a self-diagnosis means for device abnormality. Further, the high-pressure fluid or the like is often supplied by a cylinder and can be used as a residual pressure monitoring means for the high-pressure fluid packed in the cylinder.

  According to the ninth aspect of the present invention, the control valve is provided with the positively actuated multi-stage type drive unit, so that the shape of the drive unit becomes compact, and the pressure change in the fluid chamber for operating the drive unit is small with high output and small hysteresis. The difference can be converted into the valve opening of the control valve, enabling high-precision control of high-pressure fluid. In addition, when the power is shut off or the operating fluid pressure of the drive unit disappears, it is effective when the valve body is fully opened and the upstream pressure is released.

  According to the invention of claim 10, by providing the control valve with a reverse-acting multi-stage drive unit, the shape of the drive unit becomes compact, and the pressure change in the fluid chamber for operating the drive unit is small with high output and small hysteresis. The difference can be converted into the valve opening of the control valve, enabling high-precision control of high-pressure fluid. In addition, when the power is shut off or the operating fluid pressure of the drive unit disappears, the valve body is fully closed, which is effective when the upstream pressure is shut off.

  According to the eleventh aspect of the present invention, since the flow path control unit of the control valve is a multistage type, the fluid pressure difference applied to the control valve is divided into a plurality of parts as in the third aspect of the invention. Is equipped with a multistage pressure reduction mechanism that reduces the differential pressure of the control valve, so that rapid pressure drop and temperature drop in the fluid constriction part of the control valve are suppressed, and freezing of water in the fluid and fluid liquefaction in the fluid constriction part Trouble caused by can be avoided.

  According to the invention of claim 12, since the valve seat and the gasket are integrated, it is possible to realize a control valve that is small in size and excellent in airtightness. Further, it is possible to use a cobalt base alloy (Co—Cr—W alloy: for example, Stellite (registered trademark)), which is expensive and wear resistant, at least on the surface of the valve seat that comes into contact with the valve body. Compared to the case of using a valve seat made of a general metal material such as synthetic resin, etc., the valve seat is less deteriorated, and the deterioration of the flow control characteristic of the control valve can be reduced.

  According to the invention of claim 13, when pressure control is mainly performed and the flow meter exceeds a value set in advance by the controller, the flow rate is limited, or conversely, when the flow rate is lower than the set value, The flow rate can be controlled to some extent together with the pressure control, such as increasing the flow rate. In addition, when the flow control is mainly performed and the fluid pressure exceeds the value preset by the controller, the flow rate is limited so that the pressure decreases, or conversely, if the fluid pressure falls below the set value, the pressure As the flow rate is increased so as to increase, the pressure can be controlled to some extent along with the flow rate control.

  According to the fourteenth aspect of the present invention, since the shut-off valve using the metal diaphragm and the adjusting valve using the bellows seal are configured, the structure has a structure that minimizes the retention of the fluid, and the fluid contacts. Since the entire surface of the flow path is mirror-polished, gas residual components, reaction products, particles, and the like do not remain in the flow path, and an optimal fluid control apparatus for a semiconductor manufacturing apparatus can be provided.

  Embodiments of the present invention will be described with reference to the drawings. The present invention is not limited by the following examples as long as it does not depart from the spirit of the present invention.

  FIG. 1 is a conceptual diagram of the configuration of a fluid control apparatus according to claim 2 which is a first embodiment. A shut-off valve (2), a regulating valve (3), and a pressure sensor (4) are integrally provided along the fluid flow path to be controlled, based on the pressure detection signal of the pressure sensor (4). The shut-off valve (2) and the control valve (3) are automatically controlled according to instructions from the controller (9).

  In FIG. 1, the high-pressure fluid stored in a high-pressure gas cylinder or the like flows into the fluid control device from the fluid inlet (1), and the flow path of each part of the shutoff valve (2), the regulating valve (3), and the pressure sensor (4). , The pressure is reduced to a predetermined pressure and flows out from the fluid outlet (5). The main parts of the fluid inlet (1), the shutoff valve (2), the control valve (3), the pressure sensor (4), and the fluid outlet (5) are shown in cross-sectional views so that the fluid flow path can be easily understood. ing.

  The desired fluid outlet (5) pressure is initially set by the controller (9). First, the pressure sensor (4) measures the pressure at the fluid outlet (5) and transmits the measured value to the controller (9). Depending on the deviation between the measured value of the pressure sensor (4) and the pressure set value of the fluid outlet (5), the controller (9) is connected to an electromagnetic valve (7) and an electropneumatic (hereinafter abbreviated as electropneumatic) converter ( In step 8), the electric control signal calculated by the control program is transmitted. The shut-off valve (2) is mechanically opened by the electromagnetic valve (7) that has received the control signal, and then the electric control signal is converted into a change in air pressure by the electropneumatic converter (8), so that the pressure control valve drive unit (6 ), The valve body (3A) of the control valve (3) is mechanically moved up and down, and the valve body (3A) and the valve seat ( 3B) is automatically adjusted by feedback control.

FIG. 2 is a conceptual diagram of the configuration of the fluid control apparatus according to claim 4 as the second embodiment. A cutoff valve (22), a regulating valve (23), a temperature sensor (29) disposed downstream of the regulating valve, a heater (28), and a pressure sensor (24) along the fluid flow path to be controlled. ) And the shutoff valve (22) and the control valve (23) are automatically controlled based on the pressure detection signal of the pressure sensor (24), and at the same time, the signal of the temperature sensor (29) Based on the above, the heating value of the heater (28) is automatically controlled. The temperature detection point of the temperature sensor (29) may be placed in the fluid flow path.
2 has a structure in which a temperature sensor (29) and a heater (28) are additionally arranged in the control device shown in FIG. A temperature sensor (29) measures the temperature in the vicinity of the control valve and automatically controls the amount of heat generated by the heater (28) to prevent the downstream of the control valve from being exposed to a low temperature below the condensation temperature. Have.

FIG. 3 is a conceptual diagram for explaining the operation of the fluid control apparatus according to claim 5 which is the third embodiment. An orifice mechanism is arranged upstream or downstream of the control valve, or upstream and downstream.
As shown in FIG. 3, orifices (38, 39) are arranged upstream and downstream of the control valve (33) to reduce the fluid differential pressure applied to the control valve (33) and distribute the differential pressure to the orifice section. By providing the pressure reducing mechanism, a rapid pressure drop and temperature drop in the fluid contraction portion of the control valve are suppressed.

FIG. 4 shows a cross section of the bellows part (41) and the vent and purge flow path (42) of the control valve (43) according to the sixth embodiment of the present invention. By using the replacement fluid vent and purge ports (44, 45), the fluid stagnating in the bellows portion is exhausted.
When a bellows seal is used for the control valve, a part of the fluid that has flowed in through the gap formed by the valve body and the valve seat of the control valve is stagnated in the bellows portion that is a bag path, so that the gas replacement characteristic is deteriorated. By providing purge and vent flow paths in this portion, the gas replacement characteristics can be improved.

  FIG. 5 shows a conceptual diagram of a fluid control apparatus according to claim 7, wherein a filter (58) is arranged on the downstream side of the regulating valve (53) of the fifth embodiment. For the purpose of making the fluid flow path easier to see, the main part is shown in a sectional view. Foreign matter is removed from the fluid whose pressure is adjusted by the control valve (53) by the filter (58), and the fluid is sent from the fluid outlet (55) to the fluid demand side.

FIG. 6 is a conceptual diagram of a fluid control apparatus according to claim 8, wherein a pressure sensor (64B) according to a sixth embodiment is additionally arranged between the shutoff valve (62) and the regulating valve (63). Indicates. For the purpose of making the fluid flow path easier to see, the main part is shown in a sectional view.
A pressure sensor (64B) was also provided between the shutoff valve (62) and the control valve (63), and the pressure upstream of the control valve (63) was measured to enable accurate measurement of the flow characteristics. In addition, when a leak occurs in either the shut-off valve or the control valve of the fluid pressure control device of the present invention, it is possible to identify which valve seat is causing the leak, and the device malfunction It can be used as a self-diagnosis means. In addition, the high pressure fluid or the like is often supplied by a cylinder, and the pressure sensor (64B) can be used as a means for monitoring the residual pressure of the high pressure fluid packed in the cylinder.

  FIG. 7 is a cross-sectional view of the control valve drive unit of the fluid control apparatus according to claim 9, wherein the control valve drive unit according to the seventh embodiment is a two-stage forward operation type. It comprises a plurality of drive shaft biasing means, rubber diaphragms (72A, 72B), and a plurality of control air chambers (73A, 73B) that are evenly arranged. In this figure, a two-stage control valve drive unit having two diaphragms for converting air pressure into mechanical force is shown, but three or more diaphragms may be used. The control valve drive unit is a multistage type, the drive unit shape is compact, and high output can be realized. Also, by providing a plurality of drive shaft biasing means and rubber diaphragms that are evenly arranged, the pressure change in the fluid chamber can be converted into the valve opening of the control valve with a small hysteresis difference, and high-precision fluid control is possible. it can.

  Air, which is an automatic control signal generated by an electropneumatic converter (not shown), moves back and forth through the control air intake port (71) to the control air chamber (73A, 73B), and the diaphragm (72A, 72B). Is moved up and down by air pressure. Accordingly, the control valve drive shaft (75) fixed to the diaphragm (72A, 72B) moves up and down. Since the control valve drive shaft is connected to a valve body (not shown), the gap between the valve body and the valve seat (not shown) is automatically adjusted. In this embodiment, the diaphragms (72A, 72B) are moved up and down by air pressure, but an inert gas such as carbon dioxide or nitrogen gas may be used instead of air.

  FIG. 8 is a cross-sectional view of the regulating valve driving unit of the fluid control apparatus according to claim 10, wherein the regulating valve driving unit according to the eighth embodiment is a two-stage reverse operation type. It comprises a plurality of drive shaft biasing means, rubber diaphragms (82A, 82B), and a plurality of control air chambers (83A, 83B) that are evenly arranged. In this figure, for the sake of simplicity, a two-stage control valve drive unit having two diaphragms for converting air pressure into mechanical force is shown, but three or more diaphragms may be used. The control valve drive unit is a multistage type, the drive unit shape is compact, and high output can be realized. Also, by providing a plurality of drive shaft biasing means and rubber diaphragms that are evenly arranged, the pressure change in the fluid chamber can be converted into the valve opening of the control valve with a small hysteresis difference, and high-precision fluid control is possible. it can.

  Air, which is a control signal generated by an electropneumatic converter (not shown), travels through the control air chamber (83A, 83B) via the control air intake port (81), and passes through the diaphragm (82A, 82B). Move up and down by air pressure. Accordingly, the control valve drive shaft (85) fixed to the diaphragm (82A, 82B) moves up and down. Since the regulating valve drive shaft (85) is connected to the valve body (not shown), the gap between the valve body and the valve seat (not shown) is automatically adjusted. Instead of air, an inert gas such as carbon dioxide gas or nitrogen gas may be used.

  An embodiment of a control valve having a two-stage flow path control unit according to claim 11 will be described below. 9A and 9B are main cross-sectional views of the flow control unit of the control valve in which the flow control unit of the control valve has a two-stage type for the sake of simplicity, but the number of stages may be three or more.

  In FIG. 9A, the valve seat and the gasket are integrated (96) with the valve seat holder, whereas in FIG. 9B, the valve seat holder (96B) having a structure in which the gasket is integrated is made of synthetic resin or metal. A valve seat (97) is attached. 9A and 9B are the same in other structures.

  The fluid flowing in from the fluid inflow port (91) is depressurized by the first stage flow path control unit (G1) and the second stage flow path control unit (G2), which are fluid contraction parts, and the fluid outflow port (92). To leak. The flow passage cross-sectional area of the second-stage flow path control unit (G2) is made larger than the flow-path cross-sectional area of the first-stage flow path control unit (G1), and the first-stage flow path control unit (G1) The second stage flow path control unit (G2) is devised so that the pressure is further reduced and not suddenly reduced. This structure is particularly effective for gases, since the volume of the gas expands with reduced pressure when the fluid is a gas.

  FIG. 10A schematically shows how the flow velocity, pressure, and temperature of the fluid constriction portion and the fluid flow change before and after the fluid flow control portion when the flow path control portion is a single stage. When the flow path control unit is of a three-stage type, the fluid flow rate, pressure, and temperature change as shown in FIG. From this figure, it can be understood that if the number of stages of the flow path control unit is increased, rapid changes in the flow rate, pressure, and temperature of the fluid can be prevented.

  In this embodiment, when the control valve in which the valve seat and the gasket of claim 12 are integrated (96) is used, cobalt, chromium, tungsten, etc., such as expensive and wear-resistant Stellite (registered trademark) is used for the valve seat. It can be used by welding only a small amount of alloy made of, and there is less deterioration of the valve seat compared to the case of using a valve seat made of a general metal material such as stainless steel or synthetic resin, and the flow control characteristics of the control valve Degradation can be reduced.

  The flow measurement result of the flow meter (15) provided downstream of the fluid control device and the pressure measurement result of the pressure gauge (14) disposed downstream of the control valve (13) of the fluid control device are used as the electrical signal. FIG. 11 is a conceptual diagram showing a fluid flow rate control method according to claim 13, which is fed back to the controller (19) of the fluid control device.

  The pressure measurement result of the pressure gauge (14) is fed back to the controller (19) to control the pressure, and the flow rate measured by the flow meter (15) installed on the fluid demand side is preset by the controller (19). If it is out of the range, the controller (19) monitoring the flow rate can adjust the opening of the control valve (13) to limit or increase the flow rate.

  The flow rate measurement result of the flow meter (15) is fed back to the controller (19) to control the flow rate, and the controller (19) adjusts when the fluid pressure is out of the range previously set by the controller (19). It is possible to control the pressure to some extent by adjusting the opening of the valve (13).

  A flow path that has a structure that minimizes the retention of fluid by being constituted by the shut-off valve using a metal diaphragm and the control valve using a bellows seal according to claim 14, and that is in contact with the fluid A fluid control apparatus characterized in that the entire surface is mirror-polished will be described with reference to FIG.

  As shown in the sectional view of the gasket seal portion at the upper end of the bellows in FIG. 6, a bellows seal having a structure that minimizes the retention of fluid is used and the entire wall surface of the flow path is mirror-polished. The surface roughness after mirror polishing is preferably such that the center line average roughness is 0.1 μm or less.

Since the entire surface of the flow path in contact with the fluid has a structure that minimizes fluid retention and the entire wall surface of the flow path is mirror-polished, residual gas components, reaction products, particles, etc. remain in the flow path. In addition, an optimum fluid control apparatus for a semiconductor manufacturing apparatus can be provided.
[Operating characteristics of nitrogen gas supply system]
The conceptual diagram of the nitrogen gas supply system using the control apparatus of Claim 1 is shown in FIG. The liquid nitrogen accommodated in the high-pressure nitrogen gas cylinder is depressurized by the fluid control device of the present invention and supplied to the nitrogen gas demand side (the flow meter side in this figure). A gas tank (capacity: 6.7 liters) for temporarily storing nitrogen gas is disposed in a flow path downstream of the pressure control valve and upstream of the flow control valve.

  FIG. 13 shows measured values of operating characteristics of the nitrogen gas supply system of FIG. When the valve opening degree of the flow control valve arranged downstream of the gas tank is changed rapidly, the gas tank pressure tends to decrease or increase rapidly. On the other hand, the fluid control apparatus of the present invention operates so as to suppress and keep the gas tank pressure constant. It can also be seen that the gas tank pressure is kept almost constant in any flow range.

1 is a conceptual diagram of a configuration of a fluid control apparatus according to a first embodiment. Configuration conceptual diagram of fluid control apparatus according to second embodiment Configuration conceptual diagram of fluid control apparatus according to third embodiment Sectional view of the vicinity of the purge and vent parts provided in the bellows part of the control valve Conceptual diagram of the configuration of a fluid control device characterized by arranging a filter downstream of the control valve Conceptual diagram of the configuration of a fluid control device, wherein a pressure sensor is additionally arranged between the shutoff valve and the control valve Conceptual diagram of the configuration of a fluid control device characterized in that the control valve drive section is a multi-stage forward operation type Configuration conceptual diagram of fluid control device characterized in that control valve drive unit is reverse-acting multi-stage type A control valve having a structure in which a valve seat, a valve seat holder and a gasket are integrated, having a two-stage flow path control unit A control valve having a two-stage flow path control unit and a structure in which the valve seat is independent from the valve seat holder in which the gasket is integrated. Schematic diagram showing changes in pressure, temperature, and flow rate of a control valve with a single-stage flow control unit Schematic diagram showing changes in pressure, temperature, and flow rate of control valve with three-stage control valve The conceptual diagram which shows the control method of the fluid flow rate described in Claim 11 Conceptual diagram of a nitrogen gas supply system using the fluid control device of the present invention Operating characteristics of nitrogen gas supply system using fluid control device of the present invention (actually measured values)

Explanation of symbols

1, 21, 31, 51, 61, 91 ............... Fluid inlet 2, 12, 22, 32, 52, 62 ............... Shutoff valves 3, 13, 23, 33, 43, 53, 63 ............ Control valves 3A, 23A, 33A ........................... Valve body 3B, 23B, 33B ……………………………… Seats 4, 14, 24, 34, 54, 64A, 64B ..... Pressure sensors 5, 25, 35, 55, 65, 92 ........... Fluid outlets 6, 26, 36, 46, 56 , 66, 70, 80 ... Control valve drive unit 7, 17 ... ………………………………………… Solenoid valve 8, 18 ……………………………… ………………… Electropneumatic converters 9, 19 ………………………………………………… Controller 15 ……………………………………… ……………… Flow meter 2 ……………………………………………………… Heater 29 ……………………………………………………… Temperature Sensors 38, 39 ……………………………………………… Orifice 41 ……………………………………………………… Bellows 42 ………………… …………………………………… Vent and purge channels 44, 45 ……………………………………………… Vent and purge ports 47 …………… ………………………………………… Bonnet 58 ……………………………………………………… Filter 71, 81 ………………… …………………………………………………………………………………………………………………………………………… Control Air Intake 72A, 72B, 82A, 82B ………………… Diaphragms 73A, 73B, 83A, 83B …………………… Control Air Chamber 74A 74 B, 84A, 84B ........................... Vent holes 75, 85 ……………………………………………… Control valve drive shaft 96 ……………………… … Valve seat holder 96B with a structure that integrates the valve seat and gasket …………………………… The gasket integrated valve seat holder 97 with a structure that the valve seat is independent from the valve seat holder …………… ………………………………………… Valve seat 98 ……………………………………………………… Valve G1 ………………… …………………………………… First stage flow path control unit G2 ……………………………………………………… Second stage flow path Control part S ……………………………………………………… Gap between bonnet and bellows

Claims (14)

A shut-off valve, a control valve, and a pressure sensor are provided along the fluid flow path to be controlled, and the shut-off valve and the control valve are automatically controlled based on the detected pressure signal of the pressure sensor. A fluid control device. 2. The fluid control device according to claim 1, wherein the shutoff valve, the control valve, and the pressure sensor are integrated. A shut-off valve, a control valve, a temperature sensor, a heater, and a pressure sensor are provided along the fluid flow path to be controlled, based on the detected pressure signal of the pressure sensor. In addition, it automatically controls the shutoff valve and the control valve, and at the same time, automatically controls the amount of heat generated by the heater based on the signal from the temperature sensor so that the equipment placed downstream is exposed to a low temperature below the condensation temperature. The fluid control apparatus characterized by preventing. 4. The fluid control device according to claim 3, wherein the shutoff valve, the control valve, a temperature sensor disposed downstream of the control valve, a heater, and a pressure sensor are integrated. A fluid control device characterized in that an orifice mechanism is arranged upstream or downstream of the control valve, or upstream and downstream. 6. A fluid control apparatus comprising a purge and a vent channel in a bellows portion of the regulating valve according to claim 1, 2, 3, 4, and 5. The fluid control device according to any one of claims 1, 2, 3, 4, 5, and 6, wherein a filter is disposed downstream of the regulating valve. The pressure sensor according to any one of claims 1, 2, 3, 4, 5, 6, and 7 is additionally provided between the shutoff valve and the regulating valve. A fluid control device. Claim 1, Claim 2, Claim 3, Claim 4, Claim 5, Claim 6, Claim 7, Claim 8 A fluid control device comprising a biasing means and a rubber diaphragm, and is a multi-stage forward operation type. Claim 1, Claim 2, Claim 3, Claim 4, Claim 5, Claim 6, Claim 7, Claim 8 A fluid control device comprising a biasing means, a rubber diaphragm, and a reverse-acting multistage type. In the control valve that controls the fluid by adjusting the gap flow path between the valve seat and the valve body, the flow path control unit formed by the gap flow path between the valve seat and the valve body is a multi-stage type, and the downstream flow path control The control valve is characterized in that the flow passage cross-sectional area of the portion is larger than the flow passage cross-sectional area of the upstream flow passage control section. A control valve for controlling a fluid by adjusting a gap flow path between a valve seat and a valve body, characterized by a structure in which the valve seat and a gasket are integrated. The flow control result of the flow meter provided along the fluid flow path of the fluid control apparatus and the pressure measurement result of the pressure gauge similarly arranged along the fluid flow path of the fluid control apparatus are used as the electrical signal to the fluid control apparatus. A method for controlling a fluid, which is fed back to a controller. Claim 1, Claim 2, Claim 3, Claim 4, Claim 5, Claim 6, Claim 7, Claim 8, Claim 9 or Claim 10 using a metal diaphragm A fluid characterized by comprising a valve and a control valve using a bellows seal, thereby having a structure that minimizes the retention of fluid, and the entire surface of the flow path in contact with the fluid is mirror-polished Control device.

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