JPH04326106A - Pressure controller - Google Patents

Abstract

PURPOSE:To provide the pressure controller which enables high-temperature baking for improving the purity of gas in use, discharges unnecessary gas in safety, and supplies the gas with stable gas pressure. CONSTITUTION:Plural valves are connected through a piping system to form a gas entrance port 11, a gas exit port 12, a vacuum exhaustion port 13, a discharge gas port 15, and a pressure detector port 14. Then a controller 17 which sets and controls gas supply pressure is connected, a pressure detector 16 is provided to the pressure detector port 14, and a baking heater is arranged in the piping system.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a pressure control device. More specifically, the present invention enables high-temperature baking to improve the purity of the gas used, and also enables gas supply at a stable gas pressure, which allows unused gas to be safely exhausted. This invention relates to a pressure control device.

0002

[Prior Art] Conventionally, pressure control systems include:
For example, a pressure control system using a manual valve, an automatic pressure control system (Auto Pressure Control (A)
TP)), mass flow control system, etc. are known. Auto pressure control system (
For example, as shown in FIG. 5, the ATP is composed of a servo motor drive valve (A), a pressure gauge (B), a controller (C), a discharge valve (D), and a gas supply valve (O). When supplying gas to equipment using gas, connect a gas cylinder, etc. to the gas supply valve (O). The gas pressure during gas supply is based on the pressure detected by the pressure gauge (a).
The controller (c) automatically opens and closes the servo motor drive valve (a) to control the specified pressure. In addition, in this system, unnecessary gas can be released into the atmosphere by a release valve (d).

On the other hand, in the case of a mass flow control system, a flow control valve (
f), pressure gauge (k), flow meter (k), gas supply valve (k)
, a controller (C), and a gas release valve (S). The gas pressure during gas supply is determined by monitoring the pressure of the equipment using the gas and detecting the pressure with a pressure gauge (K) and the flow rate with a flowmeter (K).Based on the detection results, the controller (K) Automatically opens and closes the flow control valve (f) to control the specified pressure. In this system as well, unnecessary gas can be released into the atmosphere using a release valve.

0004

However, in the conventional pressure control systems as illustrated in FIGS. 5 and 6, the servo motor drive valve (A),
Because the sealing material for valves such as the flow control valve (f) is made of rubber material, and the flow meter (k) is made of glass, high-temperature baking is required to reduce gases and moisture released within the system. The disadvantage was that it could not be done. Furthermore, since the structure is not able to withstand reverse pressure, there is also the problem that the inside of the system cannot be kept in a clean state even to a high vacuum.

[0005] For this reason, in conventional systems, gas replacement is performed by a gas extrusion method or the like to improve the purity of the supplied gas. However, in the case of the automatic pressure control system shown in FIG. 5, the gas pressure is controlled to maintain the specified pressure depending on the usage status of the gas usage equipment. It was inevitable that (P) would fluctuate (overshoot) with time (T).

On the other hand, in the case of the mass flow control system illustrated in FIG. 6, since control is also based on the gas flow rate as described above, the pressure (P
) has the disadvantage that it takes a very long time to reach the specified pressure level. In addition, in the case of the conventional system, the amount of gas used for replacement is enormous, and the pressure control response of the valve is slow.

[0007] Therefore, it is possible to improve the purity of the supplied gas by reducing released gas, moisture, etc. in the system, and also to safely exhaust unnecessary gas, and to provide a pressure with excellent gas supply stability. The realization of a control device was desired. especially,
In gas injection devices for supplying raw material gas for nuclear fusion devices, etc., gas purity has a large effect on plasma performance, so a pressure control device that can stably supply high-purity gas is required. Ta.

The present invention has been made in view of the above-mentioned circumstances, and it is an object of the present invention to solve the drawbacks of the conventional pressure control system, reduce the released gas in the system by high-temperature baking, and improve the purity of the gas used. The present invention aims to provide a new pressure control device that can safely exhaust unnecessary gas and provide a stable gas supply to gas-using equipment.

[0009]

[Means for Solving the Problems] The present invention solves the above problems by connecting a plurality of valves through a piping system, and connecting a gas inlet port, a gas outlet port, a vacuum exhaust port, a discharge gas port and A pressure detector port is formed, a controller for setting and controlling the gas supply pressure is connected, a pressure detector is provided in the pressure detector port, and a baking heater is provided in the piping system. Provides a pressure control device.

0010

[Operation] In the pressure control device of the present invention, when raw material gas is supplied from the gas inlet port, the pressure detector installed at the pressure detector port detects the supply pressure, and the pressure is adjusted to an arbitrary set value (specified pressure) by the controller. Based on the comparison with the detected pressure, the valve operates at high speed to prevent sudden pressure changes. Thereby, gas at a stable gas pressure controlled to a specified pressure can be supplied to the gas outlet port. The unused gas can be diluted with air and discharged to the atmosphere through the discharge gas port to the exhaust area of the vacuum pump. After becoming the exhaust area of the vacuum pump,
It is possible to evacuate to a high vacuum using a vacuum pump as an evacuation system connected to the evacuation port.

[0011] Furthermore, in the pressure control device of the present invention,
If released gas, moisture, etc. in the system affect the purity of the supplied gas, a voltage can be applied to a baking heater provided in the piping system to perform vacuum evacuation while performing high-temperature baking.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS The pressure control device of the present invention will be explained in more detail below by showing embodiments with reference to the drawings. 1 and 2 are a plan view and a sectional view, respectively, showing an embodiment of the pressure control device of the present invention.

In this example, a supply valve (1), a pressure increase valve (2), a bypass valve (3), a pressure reduction valve (5), and an exhaust valve (4) are used.
), pressure boosting orifice valve (6) and pressure reducing orifice valve (
7) are each connected to the pedestal (8) with a piping system via a packing such as a metal packing. These supply valves (1), boost valves (2), bypass valves (3), pressure reduction valves (5), and exhaust valves (4) may be suitably metal-sealed pneumatic valves using compressed air, high-speed solenoid valves, etc. It can be used for. When using a high-speed solenoid valve, it is possible to downsize the device and achieve high-speed control operation. In addition, the supply valve (1), boosting valve (2), bypass valve (3), pressure reducing valve (5), and exhaust valve (4) each set and control the gas supply pressure as shown in FIG. It is also connected to a controller (17) for

On the other hand, metal seal orifice valves or the like can be appropriately adopted as the pressure increasing orifice valve (6) and the pressure reducing orifice valve (7), and the opening degree is adjusted so as not to cause sudden pressure changes in the supplied gas. We make it easy to do this. This makes it possible to quickly respond to differences in gas velocity caused by the type of gas.

As shown in FIG. 3, the gas inlet port (1
A gas cylinder for supplying raw material gas can be connected to 1), and gas can be supplied to the equipment used which is connected to the gas outlet port (12). Pressure detector port (14
) is equipped with a pressure detector (16), which detects the gas pressure during gas supply. The detected results are
It is sent to the controller (17) shown in FIG. In this controller (17), the specified pressure (set value) of the gas supply pressure is compared with the actual measured value. Further, a vacuum pump as an exhaust system can be connected to the vacuum exhaust port (13), and the inside of the system can be evacuated to a high vacuum. The gas that is no longer needed in the gas-using equipment is diluted with air through the discharge gas port (15) and then safely discharged to the exhaust area of the vacuum pump. After this, further evacuation is performed by, for example, a vacuum evacuation pump connected to the evacuation port (13).

Further, in this device, a baking heater for baking the inside of the system at a high temperature is connected from the upstream side of the supply valve (1) to each of the valves (2) to (7) and each port (11).
) to (15) are also attached to non-inductive windings. A heat insulating material (18) is provided on this baking heater to prevent heat from radiating therefrom. For example, the operation of the pressure control device having the above configuration during gas supply will be described next. Connect the raw gas cylinder to the gas inlet port (
In step 11), a desired specified pressure P0 is input to the controller (17) while the vacuum pump is connected to the vacuum exhaust port (13) and the gas usage equipment is connected to the gas outlet port (12). Then, the pressure reducing valve (5), bypass valve (3), and exhaust valve (4) remain closed, but first the supply valve (1) opens, and then the pressure boost valve (2) opens. Become. In this way, the outlet pressure is increased to the designated pressure P0 via the boost orifice valve (6).

After this, if the outlet pressure exceeds the specified pressure P0, the pressure boosting valve (2) closes and the pressure reducing valve (5
) opens and the pressure is reduced to the specified pressure P0 via the pressure reducing orifice valve (7). The pressure at this time can be monitored with a pressure detector (16). Further, the opening and closing of a series of valves are all controlled by a controller (17). The gas supply pressure is maintained stably and continuously by opening and closing the pressure increasing valve (2) and pressure reducing valve (5) within the range of ±ΔP (specified pressure change) input to the controller (17) with respect to the specified pressure P0. controlled by. This range of ±ΔP (specified pressure change) can be arbitrarily set in the controller (17).

When the gas supply is no longer needed in the gas-using equipment, an exhaust command is input to the controller (17) to close, for example, the supply valve (1) and booster valve (2), and bypass Open the valve (3) and the pressure reducing valve (5) to safely release the system while diluting it with air until the pressure in the system reaches the exhaust area of the vacuum pump. The pressure at this time can also be detected by the pressure detector (16). The gas pressure is
When the evacuation pressure of the vacuum evacuation pump is reached, the pressure reducing valve (5
) closes and the exhaust valve (4) opens, making it possible to evacuate the system to a high vacuum.

On the other hand, if released gas, residual gas, moisture, etc. in the system affect the purity of the supplied gas, the baking command and baking temperature are input to the controller (17) while the system is in the exhaust state. Then, voltage is applied to the baking heater, raising the temperature in the system to the specified temperature. The released gas, residual gas, moisture, etc. in the burned out system are safely exhausted in a gaseous state by a vacuum pump connected to the vacuum exhaust port (13).

The above-described operation sequence of supply, exhaust, and baking can be performed automatically or manually by programming the controller (17). FIG. 4 is a correlation diagram showing the relationship between gas supply pressure and time when raw material gas is supplied at an arbitrary set pressure P0 using the pressure control device of the present invention. As is clear from FIG. 4, if the pressure control device of the present invention is used, the gas supply pressure will quickly rise to the specified pressure P0, and the
Gas can be supplied stably and continuously within the range of .

[0021] In addition, when we measured the gas purity when using a 99.99999% hydrogen cylinder in a gas injection device that supplies raw material gas to a nuclear fusion device, we found that it was about 99.9% before baking and about 99.9% after baking. 99.999%
It was experimentally confirmed that the purity was as high as above (outside the measurement range of a dew meter). Of course, the invention is not limited to the above examples. It goes without saying that various aspects are possible with respect to details such as the type of gas, the detection range and accuracy of the pressure detector, etc.

[0022]

As described above in detail, according to the present invention, any gas supply pressure can be stably and continuously supplied to the equipment in use at a desired set value easily and accurately. Additionally, unnecessary gas can be safely discharged, and the system can be evacuated to a high vacuum. Furthermore, released gas, residual gas, moisture, etc. in the system can be discharged from the system by high-temperature baking, making it possible to stably supply high-purity gas to the equipment used.

[Brief explanation of drawings]

FIG. 1 is a plan view showing one embodiment of a pressure control device of the present invention.

FIG. 2 is a sectional view of the pressure control device illustrated in FIG. 1;

FIG. 3 is a block diagram systematically showing the pressure control device illustrated in FIGS. 1 and 2. FIG.

FIG. 4 is a correlation diagram showing the relationship between supply pressure and time regarding gas supply using the pressure control device of the present invention.

FIG. 5 is a block diagram systematically showing a conventional autopressure control system.

FIG. 6 is a block diagram systematically showing a conventional mass flow control system.

7 is a correlation diagram showing the relationship between the supply pressure and time of the automatic pressure control system shown in FIG. 5. FIG.

8 is a correlation diagram showing the relationship between the supply pressure and time of the mass flow control system shown in FIG. 6. FIG.

[Explanation of symbols]

1 Supply valve 2 Boost valve 3 Bypass valve 4 Exhaust valve 5 Pressure reducing valve 6 Boost orifice valve 7 Pressure reducing orifice valve 8　　　　　　　　　　　　 11 Gas inlet port 12 Gas outlet port 13 Vacuum exhaust port 14 Pressure detector port 15 Release gas port 16 Pressure detector 17 Controller 18 Heat insulation material

Claims (1)

[Claims] [Claim 1] A plurality of valves are connected through a piping system, and include a gas inlet port, a gas outlet port, a vacuum exhaust port,
In addition to forming a discharge gas port and a pressure detector port, a controller for setting and controlling the gas supply pressure is connected, a pressure detector is provided at the pressure detector port, and a baking heater is installed in the piping system. A pressure control device featuring: