JPS63231510A - Fully automatic pressure control system - Google Patents

Abstract

PURPOSE:To maintain a pressure in a pressurized container to a constant value by adjusting a pressurized fluid for control introduced from an external part into a metallic bellows with a programmable controller and setting a pressure in the metallic bellows to a prescribed value. CONSTITUTION:Even when the pressurized fluid for control is not introduced into a metallic bellows 22, since a valve 21 is pressured on a valve seat 23 by the elasticity of the metallic bellows, when the pressure force is Po and a pressurized fluid pressure for control in the metallic belows is set to Ps, the valve 21, is pressured on the valve seat 23 by a pressure of Po + Ps. A fluid in a pressurized container 1, when a pressure P1 exceeds the pressure of the Po + Ps, presses down the valve 21 and flows out and the pressurized container 1 is maintained at the pressure P1. Then, when a reaction in the pressurized container is to be executed by the pressure P1 and the pressurized fluid pressure for control Ps is set to a value equal to P1 - Po in the metallic bellows, the pressurized container is maintained at the pressure P1.

Description

Detailed Description of the Invention A.9 Purpose of the Invention Industrial Application Field The present invention relates to a pressurized vessel incorporating a system for automatically controlling pressure, and is particularly applicable to searching for optimal reaction conditions, developing catalysts, etc. It is convenient if applied to a pressurized container that performs pressure control in multiple stages.

In well-constructed chemical reactions, temperature and pressure have a great influence on the reaction rate, so it is important to search for optimal reaction conditions. In addition, when developing a new catalyst, activity tests are conducted on prototype catalysts at varying temperatures and pressures in a testing device, and those with superior properties are selected. In such test equipment, it is extremely important to maintain the reaction pressure at a predetermined pressure for a certain period of time and to obtain test data in a steady state.

From this point of view, various pressure control methods for reaction test devices have been proposed.

Japanese Patent Publication No. 59-7304 as an automatic pressure regulating small reactor
The method proposed in No. 4 detects the reaction pressure with a pressure sensor, converts this into voltage or current, inputs it into a computer, compares it with the set pressure, and generates an automatic pressure regulating valve with a signal according to the pressure difference. The A section of the pressure is achieved by moving a drive mechanism such as a step motor. However, motor-driven valves that directly open and close the valve have poor responsiveness to small pressure fluctuations, and when used under high pressure conditions, there are restrictions such as the need to be explosion-proof according to high-pressure gas regulations. .

In addition, the diaphragm pressure regulating valve developed by Stecom Corporation in the United States changes the set pressure by turning the control knob and changing the pressure applied to the spring that presses the valve body. However, due to the material of the diaphragm, there are restrictions on the pressure and temperature used, and the temperature is 200℃.
It is difficult to use the control knob at higher temperatures, and if it is automated, a motor is attached to the adjustment knob and the knob is rotated according to the set pressure, but the response to minute fluctuations in pressure is poor, and it is used under high pressure conditions. If this is the case, there are restrictions such as the need to make it explosion-proof.

However, the present invention solves the above-mentioned problems, has good responsiveness to minute pressure fluctuations, can be used even at high temperatures of 500°C, and can be set to different pressure levels sequentially. The aim is to provide a fully automatic pressure control system possible.

A fully automatic pressure control system according to the present invention includes a pressurized container, a pressure regulating valve, and a programmable controller, and a valve body and a metal bellows are installed at the fluid outlet of the pressurized container. The structure controls fluid conduction by pressing the valve element of the integrated valve structure against the valve seat, and pressurized control fluid is introduced from the outside into the metal bellows to press the valve element against the valve seat. A pressure regulating valve that can control the pressure Wfli is connected, and a programmable controller adjusts the control pressurized fluid introduced from the outside into the metal bellows to set the pressure inside the metal bellows to a predetermined value. It is characterized by maintaining the pressure inside the pressurized container at a constant value.

The present invention will be explained in detail below with reference to the accompanying drawings.

FIG. 1 is a diagram showing the configuration of a fully automatic pressure control system of the present invention.

A pressure regulating valve 2 is connected to a fluid outlet 11 of the pressurized container 1 .

The pressure regulating valve 2 has a structure in which the valve body 21, which is a valve structure in which a valve body 21 and a metal bellows 22 are integrated, is pressed against a valve seat 23 to control fluid conduction. 46 allows control pressurized fluid to be introduced to adjust the pressure with which the valve body 21 is pressed against the valve seat 23.

The pressure inside the metal bellows 22 is set to a predetermined value by adjusting the control pressurized fluid introduced into the metal bellows 22 from the outside through a pipe 46 using the programmable controller 3.

Specific means for setting the pressure inside the metal bellows 22 to a predetermined value include a three-way valve 43 with a driving mechanism that cannot be switched to the external control pressurized fluid source side 41 and the blow side 42, and a closing mechanism with a driving mechanism. The control fluid is introduced from the valve 45 through the pipe 46 into the metal bellows 22 of the pressure regulating valve, and the fluid is introduced into the metal bellows 22 of the pressure regulating valve according to the detected value of the pressure sensor 51 that measures the pressure inside the metal bellows. The programmable controller is programmed to operate the three-way valve 43 with a driving mechanism to set the pressure in the metal bellows to a predetermined value, and then close the closing valve 45 with a driving mechanism.

That is, when the pressure inside the metal bellows is lower than a predetermined value, the three-way valve with drive mechanism 43 is moved to the control pressurized fluid source side 41.
The closing valve 45 with drive mechanism is opened to introduce the pressurized control fluid into the metal bellows 22, and the pressure sensor 51 is opened.
When the detected value reaches a predetermined value, the closing valve with drive mechanism 4
Close 5.

On the contrary, gold! If the pressure inside the bellows is higher than a predetermined value, the three-way valve 43 with a drive mechanism is turned on the blow side 42,
The closing valve 45 with a driving mechanism is opened to blow out the pressurized control fluid in the metal bellows 22, and when the detected value of the pressure sensor 51 reaches a predetermined value, the closing valve 45 with a driving mechanism is closed.

In either case, a needle valve or an orifice 44 is provided between the three-way valve 43 with a drive mechanism and the closing valve 45 with a drive mechanism to throttle the pipeline and reduce the flow rate of the pressurized fluid for control. It becomes easy to correctly set the internal pressure to a predetermined value.

When searching for optimal reaction conditions or developing catalysts, it is common to obtain test results by changing pressure conditions, but this can also be easily done using the fully automatic pressure control system of the present invention.

That is, as one hour passes, the control pressurized fluid inside the metal bellows increases to 1! The programmable controller may be programmed so that pressure values are sequentially set in i number of steps. In this way, it is possible to obtain data in which the pressure conditions are automatically changed according to a predetermined experimental schedule.

Up to now, it has been described that the present invention is mainly used for tests such as catalyst development, but it can also be applied to equipment for production purposes.

The present invention can also be applied to a case where the pressure is maintained at a constant value without performing a reaction in a pressurized container.

Gas or a liquid such as water or oil can be used as the pressurized fluid for control, but when the operating conditions are high temperature, it is preferable to use gas.

As the pressurized fluid source for control, one having a pressure higher than the maximum pressure to be set is used.

In some cases, the pressurized fluid inside the pressurized reactor may be used as the control pressurized fluid source.

FIG. 2 is a diagram showing a specific structural example of the pressure regulating valve 2 used in the present invention, which is roughly divided into a main body 2A, a valve structure 2B, and a main body cover 2C. .

The main body 2A of the pressure regulating valve 2 has a cylindrical recess 24.

An opening for an inlet pipe 26 for guiding fluid from the pressurized reaction chamber is located at the periphery of the bottom surface 25 of the recess, and an outlet pipe 27 is located at the center of the bottom surface.
A valve seat 23 is provided.

The valve structure 2B is an integrated structure in which a valve body 21 and a metal bellows 22 are integrally shaped so as to be able to contact and press a valve seat 23 to control fluid conduction, and a bellows seat 28 for holding these is integrated. has been made into

The valve body 21 and the metal bellows 22 fit into the cylindrical recess 24.
In addition, since it is installed inside without contacting the side wall of the recess 24, it is natural that the outer diameter must be smaller than the inner diameter of the cylindrical recess 24.

In order to integrate the valve structure 2B, the valve body 21, the metal bellows 22, and the bellows seat 28 are sequentially welded, but the welding method is not particularly limited and may be performed by a normal method.

These materials are selected taking into consideration the characteristics of the fluid to be used, but from the viewpoint of welding, it is preferable to select materials of the same type. For example, the material of the valve body, bellows, and bellows seat should all be SUS-based. .

Since the tip of the valve body 21 is in contact with the valve seat 23 and is an important part to maintain airtightness, it is recommended that a tip 21A made of a special material or coated with a special material be screwed into the base of the valve body so that it can be replaced. preferable.

The valve body 21 and the metal bellows 22 configured as described above are housed in the cylindrical recess 24 of the main body 2A without contacting the side wall thereof, so that the valve body 21 contacts the valve seat 23 and the bellows seat 28 is fixed by a main body cover 20 that closes the open end (lower end in the figure) of the main body 2A.

In the illustrated structure, the bellows seat 28 is sandwiched between the main body 2A and the main body cover 20 with a gasket (made of metal such as copper or asbestos for heat resistance), and the main body cover 2C is secured with bolts. The bellows seat 28 is fixed by tightening it to the main body 2A.

If the depth of the cylindrical recess 24 and the height of the metal bellows 22 are set appropriately so that the metal bellows 22 is in a compressed state when fixed, the valve body 21
2 is pressed against the valve seat 23.

In addition, a spring may be installed inside the bellows 22 so that the valve body 21 is stably positioned within the main body 2. In this case, the valve body 21 has a spring that is the sum of the elasticity of the metal bellows 22 and the elasticity of the spring. value is pressed against the valve seat 23.

Pressurized fluid for control is introduced into the metal bellows 22 through a passage 29 provided in the main body cover 20 and the bellows seat 28.

The pressure inside the working pressurized container l is measured by a pressure sensor 5 installed at its outlet.
The detected value P1 is slightly different from the control pressurized fluid pressure Ps set in the bellows 22 made of gold 11.

That is, even when no pressurized control fluid is introduced into the metal bellows 22, the valve body 21 is pressed against the valve seat 23 by the elasticity of the metal bellows.

If the pressing force (the sum of the pressing force by the metal bellows and the pressing force by the spring when a spring is installed inside the metal bellows) is PO, then the control fluid pressure inside the metal bellows should be set to Ps. For example, the valve body 21 is PO
It is pressed against the valve seat 23 with a pressure of +PS. Pressurized container
When the pressure Pr exceeds po+Ps, the fluid inside presses down the valve body 21 and flows out, and the pressurized container l reaches the pressure P.
maintained at l.

Therefore, when it is desired to carry out the reaction in a pressurized container at pressure P1, the control fluid pressure Ps in the metal bellows is set to P1.
-Pa, the pressure in the pressurized vessel l is set to a value equal to P1.
will be maintained.

Furthermore, a pressure sensor 52 is provided to detect the pressure inside the pressurized container 1, and the difference between the detected value and the detected value of the pressure sensor 51 that measures the pressure inside the metal bellows 22 exceeds a predetermined tolerance range. As a countermeasure in this case, the set pressure inside the metal bellows can be reset and the detected value of the pressure sensor that detects the pressure inside the pressurized reactor can be compared with the detected value of the pressure sensor that measures the pressure inside the metal bellows. The programmable controller may be programmed so that the difference is within a predetermined tolerance.

Note that the pressure regulating valve 2 may be placed in a constant temperature bath so that it is not affected by temperature.

Effects of the invention l) Pressure setting is easy and stable pressure conditions can be maintained.

2) Easily follows small fluid flow rate and pressure fluctuations in a pressurized vessel to stabilize reaction conditions, for example in the case of catalyst testing.

3) It can be programmed to sequentially set pressure values in multiple stages over time, and data can be obtained by automatically changing pressure conditions according to a predetermined experimental schedule.

4) Since materials such as rubber and synthetic resin are used for the pressure regulating valve, it can be used even at high temperatures of 500°C.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of a fully automatic pressure control system of the present invention, and FIG. 2 is a diagram showing an example of the structure of a pressure regulating valve used in the present invention.

Claims (1)

[Claims] 1. A valve structure consisting of a pressurized container, a pressure regulating valve, and a programmable controller, in which a valve body and a metal bellows are integrated at a fluid outlet of the pressurized container, and the valve structure is pressed against a valve seat. A pressure regulating valve is connected to the metal bellows, which has a structure that controls fluid conduction by introducing pressurized control fluid from the outside into the metal bellows to adjust the pressure that presses the valve body against the valve seat. The pressure inside the pressurized container is maintained at a constant value by adjusting the pressure inside the metal bellows to a predetermined value by controlling the pressurized control fluid introduced into the container from the outside using a programmable controller. Fully automatic pressure control system. 2 The pressurized control fluid is piped to introduce the control fluid into the metal bellows of the pressure regulating valve via a three-way valve with a drive mechanism and a closing valve with a drive mechanism that can be switched to the source side and blow side. After the pressure inside the metal bellows is set to a predetermined value by operating a three-way valve with a drive mechanism according to the detected value of a pressure sensor that measures the pressure inside the metal bellows, the closing valve with a drive mechanism is closed. A fully automatic pressure control system according to claim 1, wherein the programmable controller is programmed. 3. The fully automatic pressure control system according to claim 2, wherein a needle valve is provided between the three-way valve with a drive mechanism and the closing valve with a drive mechanism. 4. The fully automatic pressure control system according to claim 2, wherein an orifice is provided between the three-way valve with a drive mechanism and the closing valve with a drive mechanism. 5. Claims 1, 2, and 3, wherein the programmable controller is programmed so that the control pressurized fluid in the metal bellows is sequentially set to a plurality of pressure values as time passes. Or the fully automatic pressure control system according to item 4. 6. Provide a pressure sensor to detect the pressure inside the pressurized container,
If the difference between the detected value and the detected value of the pressure sensor that measures the pressure inside the metal bellows exceeds a predetermined tolerance range, the set pressure inside the metal bellows is reset and the pressure inside the pressurized container is adjusted. Claims in which the programmable controller is programmed so that the difference between the detected value of the pressure sensor that detects pressure and the detected value of the pressure sensor that measures the pressure inside the metal bellows is within a predetermined tolerance range. The fully automatic pressure control system according to item 1, 2, 3, 4, or 5.