Microgravity cabin fluoride fiber forming exhaust gas treatment and pressure stabilization integrated device and method

Abstract

The application discloses a micro-gravity cabin fluoride optical fiber forming waste gas treatment and pressure stabilization integrated device and method, relates to space manufacturing supporting guarantee equipment and environment control technical field, and the device comprises a sealed manufacturing cabin, a ring-shaped flow guide cover, a local negative pressure generating device, a multi-stage catalytic adsorption unit, a gas pressure sensing unit, a regulating valve, a gas supplement unit and a control module. The sealed manufacturing cabin is internally provided with a melting zone, the ring-shaped flow guide cover is sleeved outside the melting zone and is provided with a negative pressure air suction hole, and the local negative pressure generating device is in communication with the ring-shaped flow guide cover; the multi-stage catalytic adsorption unit is in communication with a gas outlet; and the gas supplement unit is in communication with a gas inlet and internally provided with a high-purity nitrogen source. During treatment, waste gas is collected under negative pressure, and after purification through multi-stage catalytic adsorption, the waste gas is distributed backflow and discharged; the gas supplement rate and the regulating valve opening degree are adjusted according to the gas pressure and flow signals, so that the gas pressure is kept constant. The application realizes in-situ purification of waste gas and accurate and stable control of cabin gas pressure under a micro-gravity sealed environment.

Description

Technical Field

[0001] This invention relates to the field of supporting equipment and environmental control technology for space manufacturing, specifically to an integrated device and method for treating and stabilizing exhaust gas from microgravity chamber fluoride fiber forming. Background Technology

[0002] Fluoride-modified optical fibers (such as ZrF4-BaF2-LaF3-AlF3-NaF, or ZBLAN for short) exhibit extremely low theoretical optical loss in the 0.4–4.5 μm wavelength range, making them a core candidate material for strategic fields such as deep-space laser communication, quantum communication, and high-energy laser transmission. The microgravity environment of space effectively suppresses gravity-induced crystal defects, reducing the transmission loss of ZBLAN fibers from 50–100 dB / km on Earth to below 0.02 dB / km. Since 2017, NASA has conducted multiple in-orbit ZBLAN fiber drawing experiments on the International Space Station.

[0003] However, the on-orbit manufacturing of fluoride optical fibers within the sealed cabin of the space station faces severe safety and environmental challenges. The first challenge lies in the generation of toxic and corrosive gases during the melting process, posing significant safety hazards. During the fiber fusion process, the fluoride components in ZBLAN glass continuously release toxic and corrosive gases such as hydrogen fluoride (HF) and silicon tetrafluoride (SiF4) at high temperatures. While ground-based experiments can utilize open environments like fume hoods for exhaust gas treatment, the space station is a sealed cabin with no outdoor exhaust channels. Any leakage of toxic gases would contaminate the cabin environment, corrode precision instruments and equipment, and threaten the lives of astronauts. The second challenge is that ground-based exhaust purification solutions are completely unsuitable for the space environment. Traditional ground-based exhaust gas treatment uses an open treatment model of collection through exhaust hoods, pipeline transportation, and centralized outdoor discharge. The space station lacks outdoor exhaust channels, and all gases circulate and remain within the cabin. The traditional exhaust depressurization and external purification techniques are completely ineffective in the space environment. The third challenge is that the nitrogen protective atmosphere is prone to imbalance, affecting the quality of the molding process. ZBLAN fiber fusion casting requires a constant nitrogen (N2) protective atmosphere throughout the entire process to avoid issues such as metal ion oxidation, uncontrolled fluoride volatilization, and water / oxygen contamination. Using conventional continuous exhaust purification methods would result in continuous gas loss and pressure drop within the sealed chamber, disrupting the stable nitrogen protection environment and leading to accelerated fluoride volatilization and deviations from the designed glass composition. The fourth challenge lies in the imbalance of fiber glass composition caused by fluoride volatilization. Continuous fluoride volatilization during fiber fusion causes the chemical composition of the fiber matrix glass to deviate from the designed ratio, reducing the stability of the glass network structure and directly affecting the infrared transmittance and optical performance of the finished fiber.

[0004] To address the aforementioned issues, US Patent 10927032B2 proposed an environmental control scheme for a microgravity environment fiber optic manufacturing system, including filters for purifying contaminants. However, this scheme only provides a single filtration function and fails to solve the problems of maintaining air pressure and a stable nitrogen protective atmosphere within the sealed chamber, nor does it design a dedicated multi-stage treatment process for the highly corrosive characteristics of fluoride waste gas. Chinese Patent CN204066517U discloses a simplified microgravity landing chamber physical experiment device, whose technical solution does not involve toxic gas treatment or air pressure control. Summary of the Invention

[0005] In order to overcome the above-mentioned defects of the prior art, the present invention provides an integrated device and method for exhaust gas treatment and pressure stabilization in microgravity chamber fluoride fiber forming process, so as to solve the technical problems that the toxic and corrosive gases generated in the fluoride fiber melting process in the microgravity sealed chamber cannot be purified in situ, the nitrogen protective atmosphere is prone to imbalance, and the exhaust gas treatment and pressure stability cannot be taken into account.

[0006] The technical solution adopted by this invention to solve its technical problem is:

[0007] This invention provides an integrated device for treating and stabilizing exhaust gas from microgravity chamber fluoride fiber forming, comprising a sealed manufacturing chamber with a melting zone inside, and a gas inlet, a gas outlet, and a return gas port on the shell of the sealed manufacturing chamber; an annular guide hood fitted around the melting zone, with negative pressure suction holes on the inner wall of the annular guide hood; a local negative pressure generating device connected to the annular guide hood; a multi-stage catalytic adsorption unit connected to the gas outlet; a pressure sensing unit installed inside the sealed manufacturing chamber; a regulating valve connected between the gas outlet and the return gas port of the multi-stage catalytic adsorption unit; and a gas replenishment unit connected to the gas inlet, with a high-purity nitrogen source inside the gas replenishment unit.

[0008] Based on the above-mentioned device, a control module may also be included, which is connected to the pressure sensing unit, the regulating valve, the gas replenishment unit, the local negative pressure generating device, and the multi-stage catalytic adsorption unit.

[0009] Furthermore, the sealed manufacturing chamber is also equipped with a wire drawing furnace and an optical fiber winding area. The wire drawing furnace, melting zone and optical fiber winding area are enclosed and integrated inside the sealed manufacturing chamber.

[0010] Furthermore, the multi-stage catalytic adsorption unit includes a particulate filter layer, a chemisorption layer, and a catalytic conversion layer arranged sequentially along the gas flow direction. The filter media in the particulate filter layer is ceramic fiber filter media or porous metal filter media; the chemisorption layer is filled with alkaline earth metal oxides or supported alkaline adsorbents; and the catalytic conversion layer is filled with molybdenum-based catalysts or platinum-based catalysts. In a specific configuration, the adsorbent filled in the chemisorption layer is a supported CaO / Al2O3 adsorbent, the catalyst filled in the catalytic conversion layer is a molybdenum-based catalyst, and the operating temperature of the catalytic conversion layer is 300~400℃.

[0011] Furthermore, the annular guide shield is made of ceramic or molybdenum-based material; the local negative pressure generating device is a micro diaphragm pump, the working negative pressure of the micro diaphragm pump is -2~-5kPa; the number of negative pressure suction holes is 32, and the diameter of the negative pressure suction holes is 0.5mm.

[0012] Furthermore, the pressure sensing unit is a miniature absolute pressure sensor with a range of 50~120kPa, an accuracy of ±0.1kPa, and a sampling frequency of not less than 10Hz; the regulating valve is an electric proportional regulating valve with a response time better than 100ms; the high-purity nitrogen source has a nitrogen purity of ≥99.999%, and the gas replenishment unit is connected to the gas inlet through a mass flow controller with a flow rate adjustment range of 0~5L / min.

[0013] The sealed manufacturing chamber is also equipped with an active airflow organization unit, which includes miniature airflow guide fans and deflectors. The miniature airflow guide fans are connected to the control module. Specifically, there are four miniature airflow guide fans and two deflectors, and the speed range of the miniature airflow guide fans is 500~2000 rpm.

[0014] This invention also provides a pressure stabilization method using the aforementioned integrated device for treating and stabilizing exhaust gas from fluoride fiber optic molding in a microgravity chamber. The specific steps are as follows: A fluoride glass preform is placed in the melting zone; the door of the sealed manufacturing chamber is closed; a target gas pressure is set via a control module; a local negative pressure generator is activated to create negative pressure at the negative pressure suction port on the annular guide shroud, collecting the exhaust gas released from the melting zone; the collected exhaust gas is sent to a multi-stage catalytic adsorption unit for multi-stage purification via a gas outlet; the purified gas flows to a regulating valve, which divides the gas into return gas and exhaust gas; the return gas returns to the sealed manufacturing chamber via a return port; during the purification process, a pressure sensing unit monitors the internal pressure of the sealed manufacturing chamber in real time; when the internal pressure is lower than the set target pressure, the control module controls the gas replenishment unit to replenish nitrogen into the chamber via a gas inlet; simultaneously, the control module adjusts the opening of the regulating valve based on the pressure signal and gas flow signal to control the flow ratio of return gas to exhaust gas.

[0015] In step S5 of the above method, the control module calculates the replenishment gas rate Qreplenish(t) and the regulating valve opening Vvalve(t) according to the control law, with the following formulas: ΔP(t) = P(t) - P0; Qreplenish(t) = Kp·ΔP(t) + Ki·∫ΔP(t)dt + Kd·dΔP(t) / dt + Kc·C(t); Vvalve(t) = V0 - Kq·Q(t) + Kp2·ΔP(t). Where P0 is the set target gas pressure, ΔP(t) is the real-time gas pressure deviation, Q(t) is the gas flow signal, C(t) is the toxic gas concentration signal, and Kp, Ki, Kd, ​​Kc, Kq, and Kp2 are the coefficients of each control parameter.

[0016] Furthermore, in step S3, the supported CaO / Al2O3 adsorbent in the chemical adsorption layer captures hydrogen fluoride through the chemical reaction CaO+2HF→CaF2+H2O, and the concentration of toxic gas in the outlet gas after treatment by the multi-stage catalytic adsorption unit is controlled below 1 ppm.

[0017] In addition, during the collection, purification and recirculation process, a micro airflow guide fan is activated simultaneously. The micro airflow guide fan and the guide plate work together to guide the exhaust gas in the sealed manufacturing chamber into the negative pressure suction port along a preset path.

[0018] The beneficial effects of this invention are as follows:

[0019] First, it breaks away from the traditional approach of terrestrial exhaust purification, abandoning the outdoor emission mode and achieving in-situ collection, in-situ purification, and intra-cabin circulation of exhaust gas within a microgravity-sealed cabin, perfectly adapting to the special operating conditions of the space station without an external exhaust channel. Second, it integrates the two major functions of toxic exhaust gas purification and nitrogen protective atmosphere pressure stabilization into a single system, achieving simultaneous and coordinated purification and pressure stabilization operations. Third, it establishes a dynamic adaptive compensation mechanism for protective gas, enabling real-time dynamic nitrogen replenishment to compensate for gas loss during the exhaust gas purification process, maintaining constant nitrogen atmosphere parameters within the cabin throughout the entire process. Fourth, it forms a multi-parameter linked closed-loop control system for gas concentration throughout the entire process, achieving multi-parameter linked regulation of toxic gas concentration, cabin pressure, and gas flow rate, ensuring long-term stability of the operating environment. Fifth, it constructs an active gas flow field organization technology adapted to the microgravity environment, actively constructing an artificially controllable airflow field to forcibly guide exhaust gas into the purification module, solving the problems of exhaust gas dispersion and low purification efficiency under microgravity. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the device of the present invention.

[0021] Figure 2 This is a schematic diagram of the structure of the annular flow guide of the present invention.

[0022] In the diagram: 1-Sealed manufacturing chamber; 2-Wire drawing furnace; 3-Melting zone; 4-Fiber optic winding zone; 5-Annular guide hood; 6-Negative pressure suction port; 7-Local negative pressure generating device; 8-Particle filter layer; 9-Chemical adsorption layer; 10-Catalytic conversion layer; 11-Gas pressure sensing unit; 12-Regulating valve; 13-Gas replenishment unit; 14-High-purity nitrogen source; 15-Control module; 16-Miniature airflow guiding fan; 17-Guide plate; 18-Gas inlet; 19-Gas outlet; 20-Return port. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] This embodiment provides a waste gas treatment and environmental protection device suitable for the on-orbit manufacturing process of ZBLAN ultrapure fluoride optical fibers on a space station platform. For example... Figure 1 As shown, in this device, the sealed manufacturing chamber 1 serves as the carrier for the entire sealed operation. The sealed manufacturing chamber 1 is made of fluoride-resistant 316L stainless steel, with a wall thickness of 3mm and an internal volume of approximately 0.5m³. 3 The drawing furnace 2, melting zone 3, and optical fiber winding zone 4 are all completely enclosed inside the sealed manufacturing chamber 1. A gas inlet 18, a gas outlet 19, and a return gas port 20 are provided on the body of the sealed manufacturing chamber 1, and several sensor interfaces are reserved.

[0025] An annular flow guide shroud 5 is disposed around the periphery of the molten zone 3. The annular flow guide shroud 5 is made of a high-temperature resistant molybdenum-based material, such as... Figure 2 As shown, 32 negative pressure suction holes 6 are evenly distributed circumferentially on the inner wall of the annular guide shroud 5, with a hole diameter of 0.5 mm. The local negative pressure generating device 7 employs a micro diaphragm pump and is connected to the annular guide shroud 5 via a pipe. The working negative pressure range is set to -2 to -5 kPa. This structure enables the formation of a directional negative pressure field around the molten zone 3, allowing for precise collection of fluoride gas at the moment of volatilization.

[0026] In the multi-stage catalytic adsorption unit, located downstream of the gas outlet 19 of the sealed manufacturing chamber 1, it comprises a particulate filter layer 8, a chemisorption layer 9, and a catalytic conversion layer 10 connected sequentially along the airflow direction. The particulate filter layer 8 uses ceramic fiber filter material with a filtration accuracy of 5 μm, used to intercept micron-sized particles entrained in the exhaust gas. The chemisorption layer 9 is filled with a supported CaO / Al2O3 adsorbent at a loading of 500 g, used to capture acidic gases such as hydrogen fluoride in the exhaust gas. The catalytic conversion layer 10 uses a molybdenum-based catalyst, with an operating temperature set at 300~400℃, used to catalytically decompose residual fluoride gases into non-toxic or low-toxic substances.

[0027] In the construction of the constant pressure closed-loop control module, the pressure sensing unit 11 is installed inside the sealed manufacturing chamber 1. The pressure sensing unit 11 is a miniature absolute pressure sensor with a range of 50~120kPa, an accuracy of ±0.1kPa, and a sampling frequency of 10Hz. The regulating valve 12 is an electric proportional regulating valve with a response time better than 100ms. The regulating valve 12 is connected between the outlet of the multi-stage catalytic adsorption unit and the return gas port 20 of the sealed manufacturing chamber 1, and is used to adjust the ratio of the return flow rate to the emission rate of the purified gas according to the received control signal. The gas replenishment unit 13 is connected to the gas inlet 18 of the sealed manufacturing chamber 1, and the gas replenishment unit 13 has a built-in high-purity nitrogen source 14. The nitrogen purity of the high-purity nitrogen source 14 is above 99.999%. The gas replenishment unit 13 is connected to the gas inlet 18 through a mass flow controller. The flow rate adjustment range of the mass flow controller is 0~5L / min, and it is used to replenish nitrogen when the gas pressure inside the chamber is lower than a set threshold.

[0028] The control module 15 is connected to the pressure sensing unit 11, the regulating valve 12, the gas replenishment unit 13, the local negative pressure generating device 7, and the multi-stage catalytic adsorption unit, forming a closed-loop control circuit. The control module 15 has a built-in multi-parameter linkage control algorithm, which uses the cabin pressure signal P(t), the toxic gas concentration signal C(t), and the gas flow signal Q(t) as core input parameters. The output gas replenishment rate and the regulating valve opening are calculated through the following control laws: ΔP(t)=P(t)-P0; Q_replenish(t)=Kp·ΔP(t)+Ki·∫ΔP(t)dt+Kd·dΔP(t) / dt+Kc·C(t); V_valve(t)=V0-Kq·Q(t)+Kp2·ΔP(t). Where P0 is the target air pressure, Q_complement(t) is the air compensation rate, V_valve(t) is the valve opening, and Kp, Ki, Kd, ​​Kc, Kq, and Kp2 are the proportional, integral, derivative, and compensation coefficients of each control parameter, respectively.

[0029] To adapt to the special working conditions of microgravity environment where there is no natural convection and gas cannot diffuse autonomously, the sealed manufacturing chamber 1 is also equipped with an active airflow organization unit. The active airflow organization unit includes four miniature airflow guide fans 16 and two guide plates 17. The miniature airflow guide fans 16 are connected to the control module 15 and operate under the command of the control module 15, with a speed range of 500~2000 rpm. The miniature airflow guide fans 16 and the guide plates 17 work together to create an artificially controllable airflow field inside the chamber, forcibly guiding the exhaust gas inside the chamber to flow directionally into the negative pressure suction port 6 of the annular guide shroud 5 along a preset path, avoiding local accumulation of exhaust gas inside the chamber.

[0030] When using the device provided in this embodiment for waste gas treatment and pressure stabilization control, the specific operation is as follows: First, the ZBLAN fluoride glass preform is loaded into the drawing furnace 2 inside the sealed manufacturing chamber 1, and the chamber door is closed to complete the seal. Then, the control module 15 is started, the target gas pressure P0 is set to 101.3 kPa, and the local negative pressure generating device 7 is started, so that the negative pressure suction holes 6 around the annular guide shroud 5 begin to work. Subsequently, the drawing furnace 2 is started to heat the preform to a molten state, and the fluoride melt begins to release toxic gases such as HF and SiF4 in the melting zone 3.

[0031] Driven by the local negative pressure generating device 7, the annular guide hood 5 precisely collects the gas at the moment of evaporation and transports the waste gas through pipelines to the multi-stage catalytic adsorption unit. The waste gas first passes through the particulate filter layer 8 to remove micron-sized particles, and then enters the chemical adsorption layer 9. In the chemical adsorption layer 9, the supported CaO / Al2O3 adsorbent captures HF through the chemical reaction CaO + 2HF → CaF2 + H2O. The gas after chemical adsorption treatment then enters the catalytic conversion layer 10, where residual fluoride gas is catalytically decomposed into non-toxic or low-toxic substances at 300~400℃. The purified gas flows to the regulating valve 12, which divides the purified gas into return gas and exhaust gas. The return gas returns to the sealed manufacturing chamber 1 through the return port 20, achieving gas recycling, while the other part is discharged from the system.

[0032] During the exhaust gas purification process, the pressure sensing unit 11 collects the chamber pressure data in real time at a sampling frequency of 10Hz and transmits it to the control module 15. When the chamber pressure P(t) is lower than the set value P0 of 101.3 kPa, the control module 15 automatically calculates the replenishment rate and drives the replenishment unit 13 to replenish nitrogen from the high-purity nitrogen source 14 into the chamber until the pressure returns to the set value. At the same time, the control module 15 dynamically adjusts the opening of the regulating valve 12 according to the gas flow signal Q(t), adjusting the ratio of the return flow rate of the purified gas to the emission rate. Ultimately, the chamber pressure is always controlled within the range of 101.3 ± 0.5 kPa. Simultaneously, the active airflow organization unit operates, and the micro airflow guide fan 16 and the guide plate 17 cooperate to guide the exhaust gas in the chamber along a preset path into the negative pressure suction port 6 of the annular guide shroud 5.

[0033] The concentration of toxic gases in the outlet gas after treatment by the multi-stage catalytic adsorption unit in this embodiment is found to be below 1 ppm, fully meeting the air quality safety standards for the space station cabin. The entire exhaust gas purification and pressure stabilization process is fully automated and closed-loop controlled by control module 15, requiring no manual intervention from astronauts. This embodiment achieves sealed operation of all processes using a sealed manufacturing cabin, precise collection of exhaust gas at the source using an annular guide hood and local negative pressure, deep purification of fluoride exhaust gas using multi-stage catalytic adsorption, constant pressure closed-loop control using pressure sensing, regulating valves, and gas replenishment units, and intelligent linkage of multiple parameters using control modules. This forms an integrated technical system of source sealing, directional collection, multi-stage purification, constant pressure compensation, and intelligent management, effectively meeting the needs of unmanned, continuous, and highly safe space manufacturing scenarios on the space station.

[0034] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A microgravity chamber fluoride fiber forming waste gas treatment and voltage stabilization integrated device, characterized in that, include: A sealed manufacturing chamber (1) is provided with a melting zone (3) inside the sealed manufacturing chamber (1). A gas inlet (18), a gas outlet (19) and a return gas port (20) are provided on the shell of the sealed manufacturing chamber (1). An annular flow guide (5) is sleeved around the molten zone (3), and a negative pressure suction hole (6) is provided on the inner wall of the annular flow guide (5). A local negative pressure generating device (7) is connected to the annular flow guide (5); A multi-stage catalytic adsorption unit is connected to the gas outlet (19); A pressure sensing unit (11) is installed inside the sealed manufacturing chamber (1); A regulating valve (12) is connected between the outlet of the multi-stage catalytic adsorption unit and the return port (20); The gas replenishment unit (13) is connected to the gas inlet (18), and the gas replenishment unit (13) is equipped with a high-purity nitrogen source (14).

2. The integrated device for treating and stabilizing exhaust gas from microgravity chamber fluoride fiber forming as described in claim 1, characterized in that, It also includes a control module (15), which is connected to the pressure sensing unit (11), the regulating valve (12), the gas replenishment unit (13), the local negative pressure generating device (7) and the multi-stage catalytic adsorption unit respectively.

3. The integrated device for treating and stabilizing exhaust gas from microgravity chamber fluoride fiber forming as described in claim 1, characterized in that, The sealed manufacturing chamber (1) is also equipped with a wire drawing furnace (2) and an optical fiber winding area (4). The wire drawing furnace (2), the melting zone (3) and the optical fiber winding area (4) are enclosed and integrated inside the sealed manufacturing chamber (1).

4. The integrated device for treating and stabilizing exhaust gas from microgravity chamber fluoride fiber forming as described in claim 1, characterized in that, The multi-stage catalytic adsorption unit includes a particle filter layer (8), a chemisorption layer (9), and a catalytic conversion layer (10) arranged sequentially along the gas flow direction.

5. The integrated device for treating and stabilizing exhaust gas from microgravity chamber fluoride fiber forming as described in claim 4, characterized in that, The filter material in the particulate filter layer (8) is a ceramic fiber filter material or a porous metal filter material; the chemical adsorption layer (9) is filled with alkaline earth metal oxides or supported alkaline adsorbents; the catalytic conversion layer (10) is filled with molybdenum-based catalysts or platinum-based catalysts.

6. The integrated device for treating and stabilizing exhaust gas from microgravity chamber fluoride fiber forming as described in claim 1, characterized in that, The sealed manufacturing chamber (1) is also equipped with an active airflow organization unit, which includes a miniature airflow guide fan (16) and a baffle plate (17). The miniature airflow guide fan (16) is connected to the central controller (15).

7. A method for stabilizing exhaust gas using the integrated device for treating and stabilizing exhaust gas from a microgravity chamber fluoride fiber forming process as described in any one of claims 1 to 10, characterized in that, Includes the following steps: S1: Place the fluoride glass preform into the melting zone (3), close the door of the sealed manufacturing chamber (1), and set the target gas pressure through the control module (15); S2: Start the local negative pressure generating device (7) to generate negative pressure in the negative pressure suction hole (6) on the annular guide shroud (5) and collect the waste gas released from the melting zone (3); S3: The collected waste gas is sent to the multi-stage catalytic adsorption unit through the gas outlet (19) for multi-stage purification; S4: The purified gas flows to the regulating valve (12), which divides the gas into return gas and exhaust gas. The return gas returns to the sealed manufacturing chamber (1) through the return port (20). S5: During the purification process, the pressure sensing unit (11) detects the pressure inside the sealed manufacturing chamber (1) in real time. When the pressure inside the chamber is lower than the set target pressure, the control module (15) controls the gas replenishment unit (13) to replenish nitrogen into the chamber through the gas inlet (18). At the same time, the control module (15) adjusts the opening of the regulating valve (12) according to the pressure signal and the gas flow signal to control the flow ratio of the return gas and the exhaust gas.

8. The voltage stabilization method according to claim 11, characterized in that, In step S5, the control module (15) calculates the replenishment rate Qreplenish(t) and the regulating valve opening Vvalve(t) according to the following control law: ΔP(t) = P(t) - P0; Q complement (t) = Kp·ΔP(t) + Ki·∫ΔP(t)dt + Kd·dΔP(t) / dt + Kc·C(t); V valve (t) = V0 - Kq·Q(t) + Kp2·ΔP(t); Where P0 is the set target air pressure, ΔP(t) is the real-time air pressure deviation, Q(t) is the gas flow signal, C(t) is the toxic gas concentration signal, and Kp, Ki, Kd, ​​Kc, Kq, and Kp2 are the coefficients of each control parameter.

9. The voltage stabilization method according to claim 11, characterized in that, In step S3, the supported CaO / Al2O3 adsorbent in the chemical adsorption layer (9) captures hydrogen fluoride through the chemical reaction CaO+2HF→CaF2+H2O. The concentration of toxic gas in the outlet gas after treatment by the multi-stage catalytic adsorption unit is controlled below 1 ppm.

10. The voltage stabilization method according to claim 11, characterized in that, During the operation of steps S2 to S4, the micro airflow guide fan (16) is started synchronously. The micro airflow guide fan (16) and the guide plate (17) cooperate to guide the exhaust gas in the sealed manufacturing chamber (1) into the negative pressure suction hole (6) along a preset path.

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