阅读说明：本技术 能够在线检测气体分离膜性能的气相沉积设备及制膜方法 (Vapor deposition equipment capable of detecting performance of gas separation membrane on line and membrane making method ) 是由 王来军 徐庐飞 张平 陈崧哲 于 2019-10-14 设计创作，主要内容包括：能够在线检测气体分离膜性能的气相沉积设备及制膜方法,属于气相沉积和气体分离膜领域。气相沉积设备包括：包括进气系统、真空系统、气相沉积系统和在线检测系统,所述进气系统为双载气进气系统；进气系统与气相沉积系统连接,气相沉积系统与进气系统、真空系统和在线检测系统连接,真空系统与气相沉积系统和在线检测系统连接,在线检测系统与真空系统和气相沉积系统连接；制备气体分离膜时,两种载气携带沉积源进入气相沉积系统,通过气相沉积得到气体分离膜；在线检测气体分离膜性能时,通过气路切换,将双载气转换为气体分离膜的分离对象,在线检测系统检测气体分离膜的分离性能。本发明能够提高工艺数据重复性和可靠性,缩短工艺摸索周期。(Vapor deposition equipment and a film preparation method capable of detecting the performance of a gas separation film on line belong to the field of vapor deposition and gas separation films. The vapor deposition apparatus includes: the device comprises an air inlet system, a vacuum system, a vapor deposition system and an online detection system, wherein the air inlet system is a double-carrier gas inlet system; the gas inlet system is connected with the vapor deposition system, the vapor deposition system is connected with the gas inlet system, the vacuum system and the online detection system, the vacuum system is connected with the vapor deposition system and the online detection system, and the online detection system is connected with the vacuum system and the vapor deposition system; when the gas separation membrane is prepared, two carrier gases carry a deposition source to enter a vapor deposition system, and the gas separation membrane is obtained through vapor deposition; when the performance of the gas separation membrane is detected on line, the double carrier gas is converted into a separation object of the gas separation membrane through gas circuit switching, and the online detection system detects the separation performance of the gas separation membrane. The invention can improve the repeatability and reliability of process data and shorten the process search period.)

1. The vapor deposition equipment capable of detecting the performance of the gas separation membrane on line comprises a gas inlet system, a vacuum system and a vapor deposition system, and is characterized by further comprising an on-line detection system, wherein the gas inlet system is a double-carrier gas inlet system; the gas inlet system is connected with the vapor deposition system, the vapor deposition system is connected with the gas inlet system, the vacuum system and the online detection system, the vacuum system is connected with the vapor deposition system and the online detection system, and the online detection system is connected with the vacuum system and the vapor deposition system; when the gas separation membrane is prepared, two carrier gases carry a deposition source to enter a vapor deposition system, and the gas separation membrane is obtained through vapor deposition; when the performance of the gas separation membrane is detected on line, the double carrier gas is converted into a separation object of the gas separation membrane through gas circuit switching, and the online detection system detects the separation performance of the gas separation membrane.

2. The vapor deposition apparatus of claim 1, wherein the gas inlet system comprises a first carrier gas circuit, a second carrier gas circuit, a deposition source evaporator, a gas mixing chamber, and corresponding piping and valves; the first carrier gas passes through a flowmeter and then enters the gas mixing chamber through a deposition source evaporator, or directly enters the gas mixing chamber through three-way switching; the second carrier gas directly enters the gas mixing chamber after passing through the flowmeter; the gas mixing chamber is connected with the vapor deposition system.

3. The vapor deposition apparatus of claim 2, wherein all lines after the deposition source evaporator and before the vapor deposition system are provided with a thermal insulation means.

4. A vapor deposition apparatus according to claim 2, wherein the first carrier gas is one of nitrogen, hydrogen or argon and the second carrier gas is another of nitrogen, hydrogen or argon.

5. The vapor deposition apparatus of claim 1, wherein the vapor deposition system comprises a sealing flange, a deposition chamber, a ceramic blind pipe and corresponding piping and valves within the deposition chamber; the ceramic blind pipe comprises a deposition section and a glaze sealing treatment section, wherein the deposition section is distributed with air holes and used for gas separation membrane deposition, and the glaze sealing treatment section is airtight.

6. The vapor deposition apparatus of claim 1, wherein the vacuum system comprises a vacuum pump and corresponding piping and valves.

7. The vapor deposition apparatus of claim 1, wherein the online detection system comprises a gas chromatograph, a soap film flow meter, a circulating water cooled trap, and corresponding piping and valves.

8. The vapor deposition apparatus according to claim 1, wherein the gas inlet system comprises a nitrogen gas path, an argon gas path, a deposition source evaporator, a gas mixing chamber, and corresponding pipes and valves; the nitrogen passes through a first stop valve and a mass flow meter, passes through a deposition source evaporator and then enters the gas mixing chamber, or directly enters the gas mixing chamber through three-way switching; the argon gas path directly enters the gas mixing chamber through a second stop valve and a mass flow meter; the gas mixing chamber is connected with a deposition chamber of the deposition system, and all pipelines behind the deposition source evaporator and in front of the deposition system are wrapped by heating sleeves;

the vapor deposition system comprises a sealing flange, a deposition chamber, a ceramic blind pipe in the deposition chamber, and corresponding pipelines and valves; the two ends of the deposition chamber are provided with sealing flanges, and the front end flange is connected with an air inlet system and is provided with a pressure gauge; the ceramic blind pipe comprises a deposition section and a glaze sealing treatment section, wherein air holes are distributed in the deposition section and are used for gas separation membrane deposition, the glaze sealing treatment section is airtight, and the ceramic blind pipe is fixed on a rear end flange; the rear end flange is provided with two outlets, one outlet along the axial direction of the deposition chamber enables the inner cavity of the ceramic blind pipe to be respectively connected with a vacuum system and an online detection system through a third stop valve and a fourth stop valve, and the other outlet along the radial direction of the deposition chamber enables the deposition chamber to be respectively connected with the vacuum system through a baffle valve and the online detection system through a fifth stop valve;

the vacuum system comprises a vacuum pump and a related pipeline; one end of the vacuum pump is communicated with the deposition chamber through the baffle valve and a radial outlet of the rear end flange in sequence, and the other end of the vacuum pump is connected with an axial outlet of the rear end sealing flange through a third stop valve;

the online detection system comprises a gas chromatograph, a soap film flowmeter, a circulating water cooling trap and a related pipeline valve; the radial outlet and the axial outlet of the rear end flange are respectively connected with one way, are respectively converged after passing through a fifth stop valve and a fourth stop valve, and are connected with a gas chromatograph and a soap film flowmeter after passing through a circulating water cooling trap.

9. A vapor deposition apparatus as claimed in claim 8, wherein the deposition chamber is made of 310S stainless steel, the conduit is made of 310S stainless steel or PFA, and the flange and the valve are made of 310S stainless steel or PTFE.

10. A film formation method using the vapor deposition apparatus as claimed in any one of claims 1 to 7, comprising the steps of:

(1) the two carrier gases carry a deposition source to enter a vapor deposition system, and a gas separation membrane is obtained through vapor deposition;

(2) switching the gas circuit after a period of vapor deposition to convert the double carrier gas into a separation object of the gas separation membrane;

(3) the online detection system detects the separation performance of the gas separation membrane;

(4) and (3) judging whether the separation performance of the gas separation membrane meets the requirement, stopping membrane preparation if the separation performance of the gas separation membrane meets the requirement, and switching gas paths to repeat the steps (1) to (3) if the separation performance of the gas separation membrane does not meet the requirement.

11. A film formation method using the vapor deposition apparatus according to claim 8 or 9, characterized by comprising the steps of:

(1) adding a corresponding deposition source into a deposition source evaporator;

(2) fixing the ceramic blind pipe and finishing the sealing installation of the flange;

(3) starting a vacuum pump, opening a baffle valve, closing a third stop valve, a fourth stop valve and a fifth stop valve, vacuumizing the deposition chamber to 1-200 Pa, and exhausting air;

(4) closing the baffle valve, opening the first stop valve, directly passing nitrogen with the flow rate of 0.5-2.0L/min through the gas mixing chamber into the deposition chamber until the pressure rises to the normal pressure, and closing the first stop valve;

(5) raising the temperature of the deposition chamber to 650-950 ℃ through program temperature control, and raising the temperature of a deposition source evaporator to 30-120 ℃;

(6) opening the first stop valve and the second stop valve, and simultaneously switching the three-way valve to ensure that nitrogen with the flow rate of 0.5-2.0L/min enters the mixing chamber through the deposition source blown by the deposition source evaporator, is fully mixed with argon and then enters the deposition chamber, wherein the ratio of the nitrogen flow rate to the argon flow rate is 0.25-4; opening a third stop valve, and controlling the gas outlet flow rate to ensure that the decomposition products of the mixed gas blowing zone are pumped out by a vacuum pump through a deposition section on the ceramic blind pipe, and simultaneously keeping the normal pressure in the deposition chamber unchanged;

(7) depositing a gas separation membrane on the outer wall of the ceramic blind pipe;

(8) after a period of vapor deposition, closing the third stop valve, and stopping the vacuum pump from exhausting air from the inner cavity of the ceramic blind pipe; simultaneously, switching a three-way valve to stop nitrogen from entering a deposition source evaporator and directly entering a gas mixing chamber to be mixed with argon, so that the pressure in the deposition chamber is increased to 0.1-0.4 MPa;

(9) closing the third stop valve to allow the double carrier gas to diffuse into the inner cavity of the ceramic blind pipe from the deposition chamber through the gas separation membrane;

(10) opening the fourth stop valve, and testing the component M of the double carrier gases in the inner cavity of the ceramic blind pipe by using a gas chromatograph_tTesting the ventilation rate Q by a soap film flowmeter_t；

(11) Closing the fourth stop valve, opening the fifth stop valve, and measuring the composition M of double carrier gases in the deposition chamber by using a gas chromatograph₀(ii) a Comparison M_tAnd M₀If the gas separation membrane has reached the gas separation ratio requirement, stopping deposition; if the gas separation ratio requirement is not met, continuing to deposit according to the following steps until the requirement is met;

(12) and closing the fourth stop valve and the fifth stop valve, opening the third stop valve to communicate with the vacuum pump, switching the three-way valve when the pressure of the deposition chamber is stabilized at normal pressure again, so that nitrogen enters the gas mixing chamber again through the deposition source evaporator, and continuing to perform vapor deposition.

Technical Field

The invention relates to vapor deposition equipment capable of detecting the performance of a gas separation membrane on line and a membrane preparation method, and belongs to the fields of vapor deposition technology and gas separation membranes.

Background

Chemical Vapor Deposition (CVD), which is a technique for forming a uniform coating by decomposing, analyzing, combining, etc. gaseous reaction substances at a certain temperature, pressure, catalyst, etc. to generate solid substances deposited on the surface of a heated solid substrate, is widely used for preparing various thin film materials, including selective gas-permeable films.

In the actual preparation process of the selective breathable film material, the film is subjected to performance test after being deposited once, and the method is suitable for film preparation of known processes. However, in the preparation and research in the laboratory, the relationship between the performance of the film and the preparation process is often unknown, the data of the relevant process can be obtained only through a plurality of series of experiments in the mode of testing after one-time deposition, and the difference between different experiments and the system error generated after various impurities are adsorbed after the film is contacted with air cannot be eliminated. There is a need for an apparatus for on-line detection of film properties during the manufacturing process, which obtains continuous permeability data of the same sample using one process at different deposition times without stopping the apparatus, and thereby determines whether the deposition end point is reached.

Disclosure of Invention

In order to overcome the above-mentioned drawbacks of the prior art, it is an object of the present invention to provide a vapor deposition apparatus capable of on-line detecting the performance of a gas separation membrane. According to the invention, on the basis of conventional deposition source chemical vapor deposition system equipment, a double-carrier gas inlet system, a chemical vapor deposition system for a ceramic blind pipe substrate and an online detection system are improved, so that the data of continuous air permeability of the same sample in different deposition time of one process is obtained under the conditions of no stop, no temperature reduction and no air contact in the preparation process, the repeatability and reliability of process data are improved, and the experimental period of process groping is shortened. In order to achieve the above purpose, the specific technical scheme is as follows.

The vapor deposition equipment capable of detecting the performance of the gas separation membrane on line comprises a gas inlet system, a vacuum system and a vapor deposition system, and is characterized by further comprising an on-line detection system, wherein the gas inlet system is a double-carrier gas inlet system; the gas inlet system is connected with the vapor deposition system, the vapor deposition system is connected with the gas inlet system, the vacuum system and the online detection system, the vacuum system is connected with the vapor deposition system and the online detection system, and the online detection system is connected with the vacuum system and the vapor deposition system; when the gas separation membrane is prepared, two carrier gases carry a deposition source to enter a vapor deposition system, and the gas separation membrane is obtained through vapor deposition; when the performance of the gas separation membrane is detected on line, the double carrier gas is converted into a separation object of the gas separation membrane through gas circuit switching, and the online detection system detects the separation performance of the gas separation membrane.

Furthermore, the air inlet system comprises a first carrier gas path, a second carrier gas path, a deposition source evaporator, a gas mixing chamber, a corresponding pipeline and a corresponding valve; the first carrier gas passes through a flowmeter and then enters the gas mixing chamber through a deposition source evaporator, or directly enters the gas mixing chamber through three-way switching; the second carrier gas directly enters the gas mixing chamber after passing through the flowmeter; the gas mixing chamber is connected with the vapor deposition system.

Further, all pipelines behind the deposition source evaporator and in front of the gas phase deposition system are provided with heat preservation devices.

Further, the first carrier gas is one of nitrogen, hydrogen, or argon, and the second carrier gas is the other of nitrogen, hydrogen, or argon.

Further, the vapor deposition system comprises a sealing flange, a deposition chamber, a ceramic blind pipe in the deposition chamber, and corresponding pipelines and valves; the ceramic blind pipe comprises a deposition section and a glaze sealing treatment section, wherein the deposition section is distributed with air holes and used for gas separation membrane deposition, and the glaze sealing treatment section is airtight.

Further, the vacuum system comprises a vacuum pump and corresponding pipelines and valves.

Furthermore, the online detection system comprises a gas chromatograph, a soap film flowmeter, a circulating water cold trap and corresponding pipelines and valves.

The invention also aims to provide a film making method adopting the vapor deposition equipment, which can detect the performance of the gas separation film on line, and can obtain the data of continuous air permeability of the same sample under different deposition times by using one process under the conditions of no stop, no temperature reduction and no air contact in the preparation process, thereby improving the repeatability and reliability of process data and shortening the experimental period of process groping. In order to achieve the above purpose, the specific technical scheme comprises the following steps.

(1) The two carrier gases carry a deposition source to enter a vapor deposition system, and a gas separation membrane is obtained through vapor deposition;

(2) switching the gas circuit after a period of vapor deposition to convert the double carrier gas into a separation object of the gas separation membrane;

(3) the online detection system detects the separation performance of the gas separation membrane;

(4) and (3) judging whether the separation performance of the gas separation membrane meets the requirement, stopping membrane preparation if the separation performance of the gas separation membrane meets the requirement, and switching gas paths to repeat the steps (1) to (3) if the separation performance of the gas separation membrane does not meet the requirement.

In some embodiments, a vapor deposition apparatus capable of on-line detection of gas separation membrane performance includes a gas inlet system, a vacuum system, a vapor deposition system, and an on-line detection system. The gas inlet system comprises a nitrogen gas path, an argon gas path, a deposition source evaporator, a gas mixing chamber, corresponding pipelines and valves; the nitrogen passes through a first stop valve and a mass flow meter, passes through a deposition source evaporator and then enters the gas mixing chamber, or directly enters the gas mixing chamber through three-way switching; the argon gas path directly enters the gas mixing chamber through a second stop valve and a mass flow meter; the gas mixing chamber is connected with a deposition chamber of the deposition system, and all pipelines behind the deposition source evaporator and in front of the deposition system are wrapped by heating sleeves. The vapor deposition system comprises a sealing flange, a deposition chamber, a ceramic blind pipe in the deposition chamber, and corresponding pipelines and valves; the two ends of the deposition chamber are provided with sealing flanges, and the front end flange is connected with an air inlet system and is provided with a pressure gauge; the ceramic blind pipe comprises a deposition section and a glaze sealing treatment section, wherein air holes are distributed in the deposition section and are used for gas separation membrane deposition, the glaze sealing treatment section is airtight, and the ceramic blind pipe is fixed on a rear end flange; the rear end flange is provided with two outlets, one outlet along the axial direction of the deposition chamber enables the inner cavity of the ceramic blind pipe to be respectively connected with a vacuum system and an on-line detection system through a third stop valve and a fourth stop valve, and the other outlet along the radial direction of the deposition chamber enables the deposition chamber to be respectively connected with the vacuum system through a baffle valve and the on-line detection system through a fifth stop valve. The vacuum system comprises a vacuum pump and a related pipeline; one end of the vacuum pump is communicated with the deposition chamber through the baffle valve and the radial outlet of the rear end flange in sequence, and the other end of the vacuum pump is connected with the axial outlet of the rear end sealing flange through a third stop valve. The online detection system comprises a gas chromatograph, a soap film flowmeter, a circulating water cooling trap and a related pipeline valve; the radial outlet and the axial outlet of the rear end flange are respectively connected with one way, are respectively converged after passing through a fifth stop valve and a fourth stop valve, and are connected with a gas chromatograph and a soap film flowmeter after passing through a circulating water cooling trap.

Further, the deposition chamber is made of 310S stainless steel material, the pipeline is made of 310S stainless steel material or PFA material, and the flange and the valve are made of 310S stainless steel material or polytetrafluoroethylene material.

The film preparation method adopting the vapor deposition equipment is characterized by comprising the following steps:

(1) adding a corresponding deposition source into a deposition source evaporator;

(2) fixing the ceramic blind pipe and finishing the sealing installation of the flange;

(3) starting a vacuum pump, opening a baffle valve, closing a third stop valve, a fourth stop valve and a fifth stop valve, vacuumizing the deposition chamber to 1-200 Pa, and exhausting air;

(4) closing the baffle valve, opening the first stop valve, directly passing nitrogen with the flow rate of 0.5-2.0L/min through the gas mixing chamber into the deposition chamber until the pressure rises to the normal pressure, and closing the first stop valve;

(5) raising the temperature of the deposition chamber to 650-950 ℃ through program temperature control, and raising the temperature of a deposition source evaporator to 30-120 ℃;

(6) opening the first stop valve and the second stop valve, and simultaneously switching the three-way valve to ensure that nitrogen with the flow rate of 0.5-2.0L/min enters the mixing chamber through the deposition source blown by the deposition source evaporator, is fully mixed with argon and then enters the deposition chamber, wherein the ratio of the nitrogen flow rate to the argon flow rate is 0.25-4; opening a third stop valve, and controlling the gas outlet flow rate to ensure that the decomposition products of the mixed gas blowing zone are pumped out by a vacuum pump through a deposition section on the ceramic blind pipe, and simultaneously keeping the normal pressure in the deposition chamber unchanged;

(7) depositing a gas separation membrane on the outer wall of the ceramic blind pipe;

(8) after a period of vapor deposition, closing the third stop valve, and stopping the vacuum pump from exhausting from the inner cavity of the blind pipe; simultaneously, switching a three-way valve to stop nitrogen from entering a deposition source evaporator and directly entering a gas mixing chamber to be mixed with argon, so that the pressure in the deposition chamber is increased to 0.1-0.4 MPa;

(9) closing the third stop valve to allow the double carrier gas to diffuse into the inner cavity of the ceramic blind pipe from the deposition chamber through the gas separation membrane;

(10) opening the fourth stop valve, and testing the component M of the double carrier gases in the inner cavity of the ceramic blind pipe by using a gas chromatograph_tTesting the ventilation rate Q by a soap film flowmeter_t；

(11) Closing the fourth stop valve, opening the fifth stop valve, and measuring the composition M of double carrier gases in the deposition chamber by using a gas chromatograph₀(ii) a Comparison M_tAnd M₀If the gas separation membrane has reached the gas separation ratio requirement, stopping deposition; if the gas separation ratio requirement is not met, continuing to deposit according to the following steps until the requirement is met;

(12) and closing the fourth stop valve and the fifth stop valve, opening the third stop valve to communicate with the vacuum pump, switching the three-way valve when the pressure of the deposition chamber is stabilized at normal pressure again, so that nitrogen enters the gas mixing chamber again through the deposition source evaporator, and continuing to perform vapor deposition.

The invention can detect the performance of the prepared gas separation membrane on line under the conditions of no stop, no temperature reduction and no air contact in the process of preparing the gas separation membrane by vapor deposition, and obtain the air permeability data of the same sample using one process at different deposition times, thereby improving the repeatability and reliability of process data and shortening the experimental period of process groping.

Drawings

FIG. 1 is a schematic view of the composition of a vapor deposition apparatus according to the present invention.

Fig. 2 is a structural view of an intake system.

FIG. 3 is a block diagram of a deposition system, vacuum system, and in-line inspection system.

FIG. 4 is a back end flange configuration and gas path flow diagram.

Fig. 5 is a flow chart of a film forming method using the vapor deposition apparatus provided by the invention.

Reference numerals: 1-an air inlet system, 2-a vapor deposition system, 3-a vacuum system, 4-an online detection system, 5 a-a nitrogen gas path, 5 b-an argon gas path, 6 a-a first stop valve, 6 b-a second stop valve, 6 c-a third stop valve, 6 d-a fourth stop valve, 6 e-a fifth stop valve, 7-a mass flowmeter, 8-a three-way valve, 9-a deposition source evaporator, 10-a one-way valve, 11-a gas mixing chamber, 12 a-a front end sealing flange, 12 b-a rear end sealing flange, 13-a deposition chamber, 14-a ceramic blind pipe, 14 a-a glaze sealing treatment section, 14 b-a deposition section, 15-a baffle valve, 16-a circulating water cold trap, 17-a gas chromatograph, 18-a soap film flowmeter, 19 vacuum pump.

Detailed Description

The invention is further described below with reference to the accompanying drawings.

The invention provides vapor deposition equipment and a film making method capable of detecting the performance of a gas separation film on line. On the basis of the conventional deposition source chemical vapor deposition system equipment, a double-carrier gas inlet system, a chemical vapor deposition system aiming at a ceramic blind pipe substrate and an online detection system are improved, so that the online detection of the film performance in the film making process is realized.

As can be seen from FIG. 1, the system comprises an air inlet system 1, a vapor deposition system 2, a vacuum system 3 and an online detection system 4, wherein the air inlet system 1 is connected with the vapor deposition system 2, the vapor deposition system 2 is connected with the air inlet system 1, the vacuum system 3 and the online detection system 4, the vacuum system 3 is connected with the vapor deposition system 2 and the online detection system 4, and the online detection system 4 is connected with the vacuum system 3 and the vapor deposition system 2.

When the gas separation membrane is prepared, two carrier gases carry deposition sources to enter a vapor deposition system 2, and the gas separation membrane is obtained through vapor deposition; when the performance of the gas separation membrane is detected on line, the double carrier gas is converted into a separation object of the gas separation membrane through gas path switching, and the on-line detection system 4 detects the separation performance of the gas separation membrane.

As can be seen from fig. 2, the gas inlet system 1 is a dual carrier gas inlet system matched with online detection, and includes a nitrogen gas path 5a, an argon gas path 5b, a deposition source evaporator 9, a gas mixing chamber 11, and corresponding pipelines and valves. The nitrogen is used as the purge gas of the deposition source, can enter the gas mixing chamber 11 through the deposition source evaporator 9 after passing through the mass flow meter 7, or can directly enter the gas mixing chamber 11 through the switching of the tee joint 8. The argon gas path 5b is directly connected to the gas mixing chamber 11 through the mass flow meter 7. The two inlets of the nitrogen gas into the gas mixing chamber 11 and the inlet of the argon gas into the gas mixing chamber 11 are provided with one-way valves 10. The gas mixing chamber 11 is connected with a deposition chamber 13 of the deposition system. All the pipelines behind the deposition source evaporator 9 and in front of the vapor deposition system 2 are wrapped by heating jackets.

As can be seen from fig. 2 and 3, the vapor deposition system 2 includes a sealing flange, a deposition chamber 13, a ceramic blind pipe 14 and related valves. The two ends of the deposition chamber 13 are provided with sealing flanges. The front end sealing flange 12a is connected to the intake system 1 and is provided with a pressure gauge. A ceramic blind pipe 14 is fixed to the rear end sealing flange 12 b. The rear end sealing flange 12b has two outlets, one outlet along the axial direction of the deposition chamber 13 enables the inner cavity of the ceramic blind pipe 14 to be respectively connected with the vacuum system 3 through a third stop valve 6c and the online detection system 4 through a fourth stop valve 6d, and the other outlet along the radial direction of the deposition chamber 13 enables the deposition chamber 13 to be respectively connected with the vacuum system 3 through a baffle valve 15 and the online detection system 4 through a fifth stop valve 6 e.

As can be seen from fig. 3, the vacuum system 3 includes a vacuum pump 19 and associated piping. One end of the vacuum pump 19 is communicated with the deposition chamber 13 through the baffle valve 15 and the radial outlet of the rear end sealing flange 12b in sequence, and the other end is connected with the axial outlet of the rear end sealing flange 12b through a third stop valve 6 c.

As can be seen from FIG. 3, the on-line detection system 4 is used for detecting the composition M of the dual carrier gas entering the inner cavity of the ceramic tube through the newly deposited film_tThe device comprises a gas chromatograph 17, a soap film flowmeter 18, a circulating water cooling trap 16 and relevant pipeline valves. The radial outlet and the axial outlet of the rear end sealing flange 12b are respectively connected into one path, and the paths are converged after passing through a fifth stop valve 6e and a fourth stop valve 6d respectively, and are connected with an external gas chromatograph 17 and a soap film flowmeter 18 after passing through a circulating water cooling trap 16.

FIG. 5 is a flow chart of an operation method for realizing film preparation and on-line detection, based on FIG. 5, for preparing SiO₂-TiO₂The composite membrane is illustrated as an example, and the operation is as follows:

1) a mixed deposition source of tetraethyl orthosilicate and butyl titanate, where Si: and Ti is 5: 1.

2) and fixing the ceramic blind pipe 14 and finishing flange seal installation.

3) And starting the vacuum pump 19, opening the baffle valve 15, closing the third stop valve 6c, the fourth stop valve 6d and the fifth stop valve 6e, vacuumizing the deposition chamber 13 to 1-200 Pa, and exhausting air.

4) The flapper valve 15 is closed and the first shut-off valve 6a is opened, with a flow rate N of 1.5L/min₂Directly through the gas mixing chamber 11 into the deposition chamber 13 until the pressure rises to the normal pressure, and the first stop valve 6a is closed.

5) The temperature of the deposition chamber 13 was raised to 900 ℃ and the deposition source evaporator 9 was raised to 90 ℃ by temperature programming.

6) The first stop valve 6a and the second stop valve 6b are opened, and the three-way valve 8 is switched simultaneously so that the flow rate N is 0.5-2.0L/min₂The deposition source is blown by the deposition source evaporator 9 and enters the gas mixing chamber 11, and then the gas is fully mixed with Ar with corresponding flow rate and enters the deposition chamber 13. The initial composition M of the nitrogen and argon is controlled and recorded by adjusting the temperature of the mass flow meter 7 and the deposition source evaporator 9₀(M₀Is N₂The ratio of the flow rate to the Ar flow rate, M is adjusted by a flow meter₀1). The third stop valve 6c is opened and the flow rate of the outlet gas is controlled so that the decomposition products of the mixed gas blown by the gas are led to pass through the ceramic blind pipe 14The deposition section 14b is evacuated by the vacuum pump 19 (as shown in fig. 4) while keeping the atmospheric pressure in the deposition chamber 13 constant.

7) Depositing dense SiO on the outer wall of the ceramic blind pipe 14₂-TiO₂A composite membrane.

8) After a period of time of chemical vapor deposition, the third stop valve 6c is closed, and the vacuum pump 19 stops pumping air from the inner cavity of the ceramic blind pipe 14. By simultaneously switching the three-way valve 8 to N₂Stopping entering the deposition source evaporator 9 and directly entering the gas mixing chamber 11 to be mixed with Ar, so that the pressure in the deposition chamber 13 is increased to 0.2 MPa.

9) The third shut-off valve 6c is closed to allow the dual carrier gas to diffuse from the deposition chamber 13 through the membrane into the inner cavity of the ceramic blind tube 14.

10) The fourth stop valve 6d is opened, and the gas chromatograph 18 is used for analyzing the composition M of the double carrier gases in the inner cavity of the ceramic blind pipe 14_tTesting the air permeability rate Q by a soap film flowmeter 19_t。

11) The fourth cut-off valve 6d is closed, the fifth cut-off valve 6e is opened, and the composition M of the double carrier gases in the deposition chamber 13 is measured by the gas chromatograph 18₀. Comparison M_tAnd M₀If the membrane reaches the requirement of the gas separation ratio, namely, a gas separation membrane meeting the requirement is prepared, the deposition is stopped; if the separation ratio is not reached, the deposition is continued according to the following steps until the requirements are met.

12) The fourth stop valve 6d and the fifth stop valve 6e are closed, the third stop valve 6c is opened to communicate with the vacuum pump 19, and the three-way valve 8 is switched to ensure that the pressure of the deposition chamber 13 is stabilized at the normal pressure again to ensure that N is generated₂And the film enters the gas mixing chamber 11 again through the deposition source evaporator 9, and the chemical vapor deposition of the film is continued.