Automatic fire extinguishing device and method for vent nozzle

Abstract

The invention relates to the technical field of chemical safety, in particular to an automatic fire extinguishing device and method for a vent nozzle, and the automatic fire extinguishing device comprises a detection unit which comprises a flame detector mounted at the vent nozzle of a silane tower and a gas concentration sensor mounted at the front end of the vent nozzle; the execution unit comprises a coarse adjustment valve and a fine adjustment valve which are arranged on the nitrogen supply pipeline; the control unit comprises a control system which is respectively connected with the fine adjustment valve and the coarse adjustment valve; through mutual cooperation of the flame detector, the control system, the adjusting valve, the coarse adjusting valve, the nitrogen supply pipeline, the reflux pump and other equipment, rapid response, accurate control and efficient fire extinguishing of fire at the emptying opening of the silane tower can be achieved, the problems that a traditional fire extinguishing method is lagged in response, extensive in control and incomplete in fire extinguishing are solved, and the fire extinguishing process is safer.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of chemical safety, in particular to an automatic fire extinguishing device and method for a vent. BACKGROUND

[0002] In the process of extinguishing fire at the vent of a conventional silane tower, there are many problems to be solved: due to the particularity of the vent of the silane tower, the fire extinguishing response often has a lag, and it is difficult to take effective measures to intervene at the initial stage of the fire, thereby increasing the risk of further spreading of the fire.

[0003] After the prior art solves the lag of the fire extinguishing response of the vent of the silane tower, it fails to effectively solve the problem of synergistic control between nitrogen dilution and the explosion limit. Nitrogen dilution is a common fire extinguishing and explosion prevention method, and the concentration of nitrogen in the mixed gas needs to be accurately controlled to ensure that the fire extinguishing effect is achieved while avoiding new safety hazards caused by excessively high or low concentration. However, the current technical level cannot accurately control the critical value of nitrogen dilution, and cannot effectively avoid the risk of explosion caused by fluctuations in the concentration of nitrogen during the fire extinguishing process.

[0004] In addition, the high-concentration tail gas contains a large amount of combustible components, and if it cannot be effectively treated and controlled, it will not only pollute the environment, but also may cause secondary explosion accidents, further increasing the difficulty and complexity of fire extinguishing. These problems are intertwined, resulting in a high rekindling rate of the conventional silane tower vent fire extinguishing, which seriously affects the safe operation and production efficiency of the silane tower. SUMMARY

[0005] Some simplifications or omissions may be made in this section as well as in the abstract and the title of the application in order to avoid obscuring the subject matter of the present section, the abstract and the title of the application, and such simplifications or omissions are not to be construed as limiting the scope of the present application.

[0006] To solve the problems of the prior art, one object of the present application is to provide an automatic fire extinguishing device for a vent.

[0007] To achieve the above object, the present application adopts the following technical solution: an automatic fire extinguishing device for a vent, comprising a detection unit comprising a flame detector installed at the vent of a silane tower and a gas concentration sensor installed at the front end of the vent.

[0008] An execution unit comprising a coarse adjustment valve and a fine adjustment valve installed on a nitrogen supply pipeline, and a control unit comprising a control system connected to the fine adjustment valve and the coarse adjustment valve.

[0009] The first branch of the nitrogen supply pipeline is connected to the interior of the silane tower, and the second branch is connected to the venting port.

[0010] As a preferred scheme of the vent automatic fire extinguishing device, the execution unit further comprises a regulating valve, an audible and visual alarm, a reflux pump and a combustion type tail gas treatment device.

[0011] The regulating valve, the audible and visual alarm, the reflux pump and the combustion type tail gas treatment device are connected to the control system.

[0012] As a preferred scheme of the vent automatic fire extinguishing device, the nitrogen supply pipeline is provided with a double-path spray head, the first branch of which extends to the middle part of the interior of the silane tower, and the second branch of which is aligned with the outlet of the venting port.

[0013] As a preferred scheme of the vent automatic fire extinguishing device, the flame detector is installed above the venting port and is electrically connected to the input end of the control system.

[0014] As a preferred scheme of the vent automatic fire extinguishing device, the reflux pump is a variable frequency pump, and the control end of the reflux pump is connected to the analog output end of the control system through a shielded cable.

[0015] Another object of the present application is to provide a vent automatic fire extinguishing method that can accurately control the critical value of nitrogen dilution.

[0016] In order to achieve the above object, the present application adopts the following technical scheme: wherein, comprising,

[0017] S1, a flame detector is used to monitor the vent in real time, and when a flame is detected, a fire signal is generated and sent to the control system.

[0018] S2, the control system sends an opening signal to the coarse adjustment valve according to the signal generated by the flame detector, so that nitrogen enters the silane tower and the vent through the pipeline for dilution and fire extinguishing.

[0019] S3, the fine adjustment valve adjusts the opening degree of the fine adjustment valve through a control algorithm according to the real-time monitoring of the gas concentration sensor to maintain the silane concentration at the vent within a safe range.

[0020] S4, the control system sends a frequency increase signal to the reflux pump to increase the reflux pump flow to improve the silane gas absorption efficiency.

[0021] As a preferred scheme of the vent automatic fire extinguishing method, wherein: S4 further comprises the following steps: S4.1, the control system calculates the current safety margin ΔC before triggering the coarse adjustment valve; S4.2, when ΔC<3%, the control system opens the high-speed fine adjustment valve to spray pulse nitrogen with a pressure of ≥2MPa to the vent for 3s full coverage, and then enters the continuous nitrogen blowing at a pressure of 0.2MPa until ΔC≥8% and the temperature ≤80℃; S4.3, when 3%≤ΔC≤8%, the high-speed fine adjustment valve sprays nitrogen with a linear adjustable pressure of 0.5-2MPa; S4.4, when ΔC>8%, the operation process of S4.2 is maintained, that is, continuous nitrogen blowing at a pressure of 0.2MPa.

[0022] As a preferred scheme of the vent automatic fire extinguishing method, wherein: the nitrogen spraying in S4 comprises: spraying nitrogen into the silane tower, and directly spraying nitrogen to the vent to suppress open fire, and the nitrogen flow rate in the vent pipeline is ≥0.3m / s.

[0023] As a preferred scheme of the vent automatic fire extinguishing method, wherein: further comprising S5, the control system sends a frequency increase signal to the reflux pump to increase the reflux pump flow to improve the silane gas absorption efficiency. The frequency increase signal in S5 increases the reflux pump flow to a preset safety threshold, and the safety threshold is determined by dynamic calculation of the silane tower volume and the silane gas escape rate.

[0024] As a preferred scheme of the vent automatic fire extinguishing method, wherein: steps S3 and S4 are executed synchronously, and the nitrogen spraying pressure in S4 is ≥0.5MPa, when the system detects that ΔC<3%, the control system automatically increases the nitrogen spraying pressure to ≥2MPa to enter the pulse spraying state.

[0025] The present application has the advantages that: through the cooperation between the flame detector, the control system, the adjusting valve, the coarse adjustment valve, the nitrogen supply pipeline, the reflux pump and other devices, the present application can realize rapid response, precise control and efficient fire extinguishing for the silane tower vent fire, solve the problems of response lag, extensive control and incomplete fire extinguishing of the traditional fire extinguishing method, and make the fire extinguishing process safer. BRIEF DESCRIPTION OF DRAWINGS

[0026] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a diagram of the automatic fire extinguishing device for the vent outlet of the present invention.

[0028] Figure 2 This is a flowchart of the automatic fire extinguishing method for the vent outlet of the present invention. Detailed Implementation

[0029] To make the objectives, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0030] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0031] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0032] Example 1

[0033] Reference Figure 1 and Figure 2 This is the first embodiment of the present invention. This embodiment provides an automatic fire extinguishing device for vent outlets, which can achieve a rapid response to fires at the vent outlets of silane towers. It includes a detection unit 100, which includes a flame detector 101 and a gas concentration sensor 102 located outside the vent outlet 103 of the silane tower.

[0034] The execution unit 200 includes a coarse adjustment valve 203 and a fine adjustment valve 206 installed in the nitrogen supply pipeline, and...

[0035] The control unit 300 includes a control system 301, which is connected to the fine adjustment valve 206 and the coarse adjustment valve 203 respectively.

[0036] The nitrogen supply pipeline has a first branch L connected to the inside of the silane tower and a second branch M connected to the vent 103. The controller output of the control system 301 is also connected to the drive end of the fine adjustment valve 206. The opening of the coarse adjustment valve 203 is controlled by the control system 301 according to the signal from the flame detector 101, and the opening of the fine adjustment valve 206 is adjusted by the control system 301 according to the signal from the gas concentration sensor 102.

[0037] Specifically, the controller algorithm can be: Output = Kp × e(t) + Ki × ∫e(t)dt + Kd × de(t) / dt, where: e(t) is the deviation at the current moment, and Kp, Ki, and Kd are three adjustable parameters that can smoothly reduce the silane gas flow rate instead of abruptly shutting it off, preventing drastic fluctuations in pipeline pressure. Furthermore, the controller automatically calculates and adjusts the opening degree of the shut-off valve fine-tuning valve 206 or the nitrogen supply opening degree to precisely control the nitrogen flow rate, thereby stabilizing the concentration within a safe range.

[0038] When the flame detector 101 detects a flame signal, the control system 301 first controls the coarse adjustment valve 203 to quickly open to a preset opening degree to ensure that the basic extinguishing nitrogen flow rate is not less than 0.3 m / s. At the same time, the gas concentration sensor 102 monitors the silane concentration in real time and transmits the signal to the control system 301. The control system 301 dynamically adjusts the opening degree of the fine adjustment valve 206 according to the deviation of the concentration value from the set safety threshold of 2.5% through the controller algorithm. If the concentration is higher than 2.5%, the opening degree of the fine adjustment valve is increased to increase the nitrogen supply and thus enhance the dilution effect. If the concentration is lower than 2.5%, the opening degree is decreased to save nitrogen consumption. Through the synergistic effect of the coarse adjustment valve 203 and the fine adjustment valve 206, both the rapid response of the initial extinguishing is ensured and the precise and stable control of the concentration during the extinguishing process is achieved, ultimately maintaining the silane concentration at the vent 103 at a safe level below the explosion limit.

[0039] The coarse adjustment valve 203 is located in the nitrogen supply pipeline, and the nitrogen supply pipeline is branched to connect the inside of the silane tower and the vent. The controller output of the control system 301 is also connected to the drive end of the fine adjustment valve 206.

[0040] Furthermore, the execution unit 200 also includes a regulating valve 202, an audible and visual alarm 201, a reflux pump 204, and a combustion-type exhaust gas treatment device 205. The regulating valve is installed on the silane gas input pipeline, the audible and visual alarm 201 is installed at the vent, the reflux pump 204 is installed at the bottom of the silane tower, and the combustion-type exhaust gas treatment device 205 is used to combust the high-concentration exhaust gas.

[0041] Among them, the regulating valve 202, the audible and visual alarm 201, the reflux pump 204, and the combustion exhaust gas treatment device 205 are all connected to the control system 301.

[0042] Specifically, the flame detector 101 is installed at the vent and continuously scans for flame radiation. Once a flame is detected, it immediately outputs a digital ignition signal to the control system 301. The gas concentration sensor 102 is installed at the front end of the vent and sends the real-time silane volume fraction as a process variable to the control system 301 at a period of ≤200 ms.

[0043] Upon receiving a fire signal, the control system 301 immediately enters fire extinguishing mode: first, it sends a trigger signal to the audible and visual alarm 201 to trigger an alarm on site. Simultaneously, it sends a closing command to the regulating valve 202 installed on the silane gas input pipeline, reducing the amount of gas entering the silane tower. Then, it sends a fully open signal to the coarse regulating valve 203 installed on the nitrogen supply pipeline, allowing nitrogen to simultaneously enter the silane tower and the vent through a branch pipeline. The controller output of the control system 301 drives the fine regulating valve 206 in real time. Based on the deviation between the silane concentration fed back by the gas concentration sensor 102 and the set safety target, the controller algorithm continuously adjusts the opening of the fine regulating valve 206: when the concentration is high, the opening increases and the nitrogen flow increases; when the concentration is low, the opening decreases and the nitrogen flow decreases, ensuring that the silane concentration in the vent area is always maintained within a safe range. If the concentration is still higher than the set threshold after the above proportional adjustment, the control system 301 sends a start signal to the combustion exhaust gas treatment device 205 to perform combustion treatment on the high-concentration exhaust gas. At the same time, it sends a frequency increase command to the return pump 204 to increase the return flow rate to further reduce the concentration of combustibles at the vent. The entire closed loop completes the entire process of alarm, source reduction, dilution, proportional adjustment, exhaust gas treatment and return enhancement within seconds after the flame appears, realizing rapid fire extinguishing and continuous safety at the vent.

[0044] Furthermore, the nitrogen supply pipeline is equipped with dual nozzles. The first branch L extends to the middle of the silane tower cavity, and the second branch M is aligned with the vent outlet. A flow rate sensor is configured to monitor the nitrogen flow rate in the vent pipeline in real time. The second branch M is further equipped with a pulse accumulator 207 to provide an instantaneous injection pressure of ≥2MPa.

[0045] Specifically, nitrogen gas enters the dual-path nozzle through the main pipeline and splits into two paths. The first branch, L, extends into the middle of the silane tower's inner cavity, forming an inert covering layer with continuous low-pressure nitrogen gas, directly reducing the silane concentration within the tower. The second branch, M, is aligned with the vent outlet and directly connected to the pulse accumulator 207. When the flame detector alarms and the control system 301 issues a fire extinguishing command, the accumulator releases ≥2 MPa high-pressure nitrogen gas within 50 ms, forming an instantaneous pulse jet through the second branch M. This forms a high-speed inert gas curtain at the vent outlet, instantly blocking the flame and entraining surrounding combustible gases. A flow rate sensor monitors the nitrogen gas flow rate in the vent pipeline in real time and returns the signal to the control system 301. The control system 301 adjusts the opening of the accumulator outlet valve based on the measured value, ensuring that the nitrogen gas flow rate in the pipeline remains ≥0.3 m / s, guaranteeing continuous purging and dilution effects. The combined effect of high-pressure injection and continuous purging in the pulse accumulator tank 207 enables the vent area to be extinguished within 1 second without reignition, and reduces nitrogen consumption by more than 30% compared to single continuous purging.

[0046] Furthermore, the flame detector 101 is installed above the vent and is electrically connected to the input terminal of the control system 301.

[0047] Furthermore, the reflux pump 204 is a variable frequency pump, and its control terminal is connected to the analog output terminal of the control system 301 through a shielded cable.

[0048] Specifically, the reflux pump 204 uses a variable frequency motor. Its control terminal is directly connected to the 4~20 mA analog output terminal of the control system 301 via a shielded cable. The control system 301 uses the real-time data from the flame detector and gas concentration sensor to calculate the frequency command corresponding to the required reflux flow rate using a preset algorithm. This command is then sent to the frequency converter without interference via the shielded cable. The frequency converter adjusts the motor speed to the target value within 0.1 s, causing the liquid phase reflux at the bottom of the tower to increase instantaneously, rapidly absorbing gaseous silane and reducing the combustible load at the vent. When the silane concentration is detected to have decreased, the control system 301 automatically reduces the output current, and the frequency converter decelerates synchronously. This maintains a continuous safety margin while avoiding excessive energy consumption, achieving closed-loop precise control of the entire fire extinguishing process with a system response delay of less than 200 ms.

[0049] Example 2

[0050] Reference Figures 1-2 This is the second embodiment of the present invention. Based on the automatic fire extinguishing device for the vent in embodiment 1, this embodiment provides an automatic fire extinguishing method for the vent.

[0051] Includes: S1, Real-time monitoring of the vent via flame detector 101, generating an ignition signal and sending it to control system 301 when a flame is detected.

[0052] S2. After receiving a fire signal, the control system 301 triggers the audible and visual alarm 201 to sound an alarm.

[0053] S3. The control system 301 sends a closing or reducing signal to the regulating valve 202 to reduce the flow rate of silane gas entering the silane tower.

[0054] S4. The control system 301 sends an opening signal to the coarse adjustment valve 203, allowing nitrogen to enter the silane tower and vent through the pipeline for dilution and fire extinguishing.

[0055] Before triggering the coarse adjustment valve 203, the control system 301 first obtains the real-time silane volume fraction at the vent using the gas concentration sensor 102, and calculates the current safety margin ΔC based on the preset silane-nitrogen-air ternary system combustion and explosion limit curve. Further, when ΔC < 3%, the control system opens the high-speed fine adjustment valve 206, injecting ≥ 2 MPa pulsed nitrogen into the vent for a 3-second full coverage, then switches to 0.2 MPa continuous nitrogen purging until ΔC ≥ 8% and the temperature ≤ 80℃. Further, when 3% ≤ ΔC ≤ 8%, the high-speed fine adjustment valve 206 injects nitrogen at a linearly adjustable rate of 0.5-2 MPa. Further, when ΔC > 8%, the S4.2 operating procedure is maintained, i.e., 0.2 MPa continuous nitrogen purging. Furthermore, nitrogen injection in S4 includes: injecting nitrogen into the interior of the silane tower, and simultaneously injecting nitrogen directly into the vent (103) to suppress open flame, with the nitrogen flow rate in the vent pipe being ≥0.3m / s.

[0056] Furthermore, in step S5, the control system 301 sends a frequency increase signal to the reflux pump 204 to increase the reflux pump flow rate and improve the silane gas absorption efficiency. In step S5, the frequency increase signal causes the reflux pump 204 flow rate to increase to a preset safety threshold, which is dynamically calculated and determined by the silane tower volume and the silane gas escape rate.

[0057] The control system 301 sends a frequency increase signal to the reflux pump 204, activating it simultaneously with all fire extinguishing measures. This signal increases the flow rate of the reflux pump 204 to a safety margin ΔC determined dynamically by the silane tower volume and the silane gas escape rate. The specific calculation process is as follows: The control system 301 first calculates the theoretical minimum time T_min = V_t / Q_e required for complete silane gas replacement in the tower by using the real-time monitored silane gas escape rate Q_e (m³ / s) and the known silane tower volume V_t (m³). To ensure the absorption efficiency is higher than the escape rate and to leave a safety margin, the target replacement time T_target = 0.6 × T_min is set. Then, the target flow rate required by the reflux pump is calculated as Q_target = V_t / T_target = V_t / (0.6 × V_t / Q_e) ≈ 1.67 × Q_e, the control system 301 uses the calculated Q_target value as a safety threshold to set the frequency increase of the return pump 204. Through this dynamic calculation and control, the flow rate of the return pump 204 can be precisely increased to the optimal level that can both ensure efficient absorption of silane gas to prevent its accumulation and avoid excessive energy consumption. Finally, in conjunction with the nitrogen dilution system, it can achieve safe and efficient fire extinguishing at the vent.

[0058] Specifically: Flame detector 101 continuously scans the vent and immediately outputs a high-level ignition signal to control system 301 upon detecting a flame. Within the same clock cycle of receiving the signal, control system 301 drives audible and visual alarm 201 to issue an audible and visual alarm, and simultaneously outputs a 4-20 mA current to the regulating valve 202 to rapidly reduce the silane gas feed flow rate. Subsequently, control system 301 reads the silane volume fraction uploaded in real-time by gas concentration sensor 102, and calculates the safety margin ΔC using the internally solidified silane-nitrogen-air ternary system combustion and explosion limit curve. If ΔC < 3%, it immediately triggers the high-speed fine-tuning valve 206 to open and performs a 3-second full-coverage injection of ≥2 MPa pulsed nitrogen gas. After the injection, it automatically reduces to 0.2 MPa for continuous purging. During this period, control system 301 uses a nitrogen gas flow rate of ≥0.3 m / s as feedback to perform closed-loop controller calculations to continuously correct the opening of fine-tuning valve 206 until ΔC ≥ 8% and the temperature ≤ 80 ℃. If ΔC is between 3% and 8%, the control system 301 linearly adjusts the fine-tuning valve 206 to inject within the 0.5-2 MPa range. If ΔC > 8%, continuous purging at 0.2 MPa is maintained. Simultaneously, the control system 301 sends an up-frequency signal to the return pump 204 through the analog output terminal, causing the return flow rate to increase instantaneously, thereby quickly absorbing gaseous silane and reducing the load on the vent. The entire process completes the fire extinguishing within 2 seconds and ensures no reignition, with nitrogen consumption reduced by approximately 30% compared to traditional continuous purging.

[0059] Furthermore, nitrogen injection in S4 includes: injecting nitrogen into the interior of the silane tower, and simultaneously injecting nitrogen directly into the vent to suppress open flames, with the nitrogen flow rate in the vent pipe being ≥0.3m / s.

[0060] Specifically, when control system 301 executes S4, nitrogen gas is simultaneously diverted to two branches through the same main pipe. One branch directly sends nitrogen gas into the inner cavity of the silane tower, forming a continuous inert gas curtain within the cavity, rapidly diluting the silane concentration in the tower and reducing the overall explosion risk. The other branch directly sprays nitrogen gas at high speed towards the vent outlet, creating an impact force opposite to the flame direction, instantly shearing and engulfing the flame core, causing its temperature to drop sharply and the concentration of combustible molecules below the lower flammability limit. A flow rate sensor installed in the vent pipe sends the measured value back to control system 301 in real time. Control system 301 uses a closed-loop controller to adjust fine-tuning valve 206 with a set value of ≥0.3 m / s, ensuring that the nitrogen gas in the pipe always maintains a purging speed of ≥0.3 m / s, thereby continuously carrying away residual silane. The synergistic effect of the two nitrogen gas streams extinguishes the open flame within 1 second, maintaining an inert environment in both the tower and the pipe outlet area, completely blocking the conditions for reignition.

[0061] Furthermore, S4 also includes: real-time monitoring of silane concentration via a concentration sensor; when the concentration is >0.34%, the control system 301 automatically switches to the combustion exhaust gas treatment device 205 and maintains nitrogen-assisted injection.

[0062] Specifically, the concentration sensor continuously uploads the silane volume fraction at the vent to the control system 301 in real time. Once the value exceeds 0.34%, the control system 301 immediately switches the process to the combustion-type exhaust gas treatment device 205 while maintaining nitrogen-assisted injection. The control system 301 first sends a start command to the combustion-type exhaust gas treatment device 205 to ignite and heat it to the set combustion temperature. Then, all the silane-containing exhaust gas is introduced into the device for high-temperature oxidation and decomposition. At the same time, the fine-tuning valve 206 maintains continuous nitrogen purging at 0.2 MPa, which prevents backfire and ensures that the flow velocity in the pipe is ≥0.3 m / s. The exhaust gas is discharged after complete reaction in the combustion chamber. The system is under closed-loop control throughout, achieving automatic switching within ≤2 seconds, zero leakage, and zero reignition.

[0063] Furthermore, in S5, the frequency signal is increased to increase the flow rate of the reflux pump 204 to a preset safety threshold. The safety threshold is determined dynamically by the silane tower volume and the silane gas escape rate.

[0064] Specifically, after flame confirmation, the control system 301 immediately invokes its internal algorithm, substituting the silane tower volume and the silane gas escape rate measured in real time by the gas concentration sensor 102 into the formula Q_safe = k × V × C_escape / 1 - C_target, where k is the absorption efficiency coefficient, V is the tower volume, C_escape is the current escape rate, and C_target is the upper limit of the safe concentration. This formula is used to calculate the required reflux pump flow rate threshold online. The control system 301 then outputs a 4-20 mA frequency-up signal to the reflux pump 204, and the frequency converter drives the pump to increase its speed to the calculated value within 0.2 seconds, instantly matching the liquid phase reflux rate with the gas phase load. This enhances gas-liquid mass transfer within the tower, causing the silane concentration to rapidly drop back to the safe range and remain stable. The entire process is free of overshoot and secondary fluctuations.

[0065] Furthermore, steps S3 and S4 are executed synchronously, and the nitrogen injection pressure of S4 is ≥0.5MPa. When the system detects ΔC<3%, the control system 301 automatically increases the nitrogen injection pressure to ≥2MPa and enters the pulse injection state.

[0066] Specifically, upon receiving a fire signal, the control system 301 issues two parallel commands: one immediately closes the regulating valve 202 to reduce the silane intake flow, and the other simultaneously opens the coarse regulating valve 203 and begins purging with nitrogen at a stable pressure of ≥0.5 MPa. Simultaneously, the control system 301 continuously reads the ΔC calculated by the gas concentration sensor 102. When ΔC drops below 3%, the control system 301 instantly opens the fine regulating valve 206 to its full extent within 50 ms, causing the nitrogen injection pressure to jump to ≥2 MPa and maintain a pulse injection for 3 s, forming a high-speed inert gas curtain. This instantly pushes the silane concentration in the vent area away from the flammable zone and cools the flame. After the pulse ends, the pressure automatically drops back to a continuous purging state of ≥0.5 MPa. After the open flame is instantly extinguished, if silane gas still leaks from the vent or pipeline, its concentration may accumulate again and reach the combustion and explosion range, posing a risk of reignition. Therefore, nitrogen needs to be continuously introduced to form a stable inert environment until ΔC rises to above 8% and the temperature is ≤80℃. The entire process requires no human intervention, the extinguishing time is shortened to less than 1 second, and there is no reignition.

[0067] In summary, this invention, by setting up a flame detector 101, a gas concentration sensor 102, and a control system 301 for real-time linkage, and synchronously controlling the frequency conversion output of the regulating valve 202, coarse adjustment valve 203, fine adjustment valve 206, and reflux pump 204, enables nitrogen to form a closed-loop synergistic effect of staged injection, pulse pressurization, and continuous purging at the vent and inside the tower. This can instantly suppress open flames, accurately maintain ΔC ≥ 8%, ensure nitrogen flow velocity ≥ 0.3 m / s and temperature ≤ 80 ℃, thereby solving the problems of delayed fire extinguishing response, coarse control, high risk of reignition, and difficulty in coordinating the control of nitrogen dilution and combustion / explosion limits in traditional silane towers.

[0068] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. An automatic fire extinguishing device for an air vent, characterized in that: include, The detection unit (100) includes a flame detector (101) located outside the vent (103) of the silane tower and a gas concentration sensor (102). An execution unit (200) includes a coarse adjustment valve (203) and a fine adjustment valve (206) installed on a nitrogen supply pipeline; and, The control unit (300) includes a control system (301) which is connected to the fine adjustment valve (206) and the coarse adjustment valve (203) respectively; The first branch (L) of the nitrogen supply pipeline is connected to the inside of the silane tower, and the second branch (M) is connected to the vent (103). The controller output of the control system (301) is also connected to the drive end of the fine adjustment valve (206). The opening degree of the coarse adjustment valve (203) is controlled by the control system (301) according to the signal of the flame detector (101), and the opening degree of the fine adjustment valve (206) is adjusted by the control system (301) according to the signal of the gas concentration sensor (102).

2. The automatic fire extinguishing device for the vent as described in claim 1, characterized in that: The execution unit (200) also includes a regulating valve (202), an audible and visual alarm (201), a reflux pump (204), and a combustion-type tail gas treatment device (205). The regulating valve is installed on the silane gas input pipeline, the audible and visual alarm (201) is installed at the vent, the reflux pump (204) is installed at the bottom of the silane tower, and the combustion-type tail gas treatment device (205) is used to combust the high-concentration tail gas. The regulating valve (202), the audible and visual alarm (201), the reflux pump (204), and the combustion exhaust gas treatment device (205) are all connected to the control system (301).

3. The automatic fire extinguishing device for the vent as described in claim 2, characterized in that: The first branch (L) of the nitrogen supply pipeline extends to the middle of the silane tower cavity, and the second branch (M) is aligned with the outlet of the vent (103). A flow rate sensor is installed on the second branch (M) to monitor the nitrogen flow rate in the vent pipeline in real time. A pulse energy storage tank (207) is also installed on the second branch (M) to provide an instantaneous injection pressure of ≥2MPa.

4. The automatic fire extinguishing device for vent outlets as described in claim 3, characterized in that: The flame detector (101) is installed above the vent (103) and is electrically connected to the input terminal of the control system (301).

5. The automatic fire extinguishing device for vents as described in claim 3 or 4, characterized in that: The reflux pump (204) is a variable frequency pump, and its control terminal is connected to the analog output terminal of the control system (301) through a shielded cable.

6. An automatic fire extinguishing method for vent outlets, characterized in that: include, S1. The vent (103) is monitored in real time by the flame detector (101). When a flame is detected, an ignition signal is generated and sent to the control system (301). S2. The control system (301) sends an opening signal to the coarse adjustment valve (203) based on the signal generated by the flame detector (101), so that nitrogen gas enters the silane tower and vent (103) through the pipeline for dilution and fire extinguishing; S3. The fine adjustment valve (206) adjusts the opening of the fine adjustment valve (206) according to the silane volume fraction monitored in real time by the gas concentration sensor (102) through the control algorithm to maintain the silane concentration at the vent (103) within a safe range. S4. The control system (301) sends an increased frequency signal to the reflux pump (204) to increase the flow rate of the reflux pump in order to improve the silane gas absorption efficiency.

7. The automatic fire extinguishing method for vent outlets as described in claim 6, characterized in that: S4 further includes the following steps: S4.1, before triggering the coarse adjustment valve (203), the control system (301) calculates the current safety margin ΔC; S4.2, when ΔC < 3%, the control system (301) opens the high-speed fine adjustment valve (206) to spray ≥ 2MPa pulsed nitrogen gas onto the vent (103) for 3 seconds to achieve full coverage, and then switches to 0.2MPa continuous nitrogen purging until ΔC ≥ 8% and the temperature ≤ 80℃; S4.3, when 3% ≤ ΔC ≤ 8%, the high-speed fine adjustment valve (206) sprays nitrogen gas at 0.5-2MPa linearly adjustable level; S4.4, when ΔC > 8%, the operation process of S4.2 is maintained, that is, 0.2MPa continuous nitrogen purging.

8. The automatic fire extinguishing method for vent outlets as described in claim 6 or 7, characterized in that: Nitrogen injection in S4 includes: injecting nitrogen into the interior of the silane tower, and simultaneously injecting nitrogen directly into the vent (103) to suppress open flame, with the nitrogen flow rate in the vent pipe being ≥0.3m / s.

9. The automatic fire extinguishing method for vent outlets as described in claim 8, characterized in that: It also includes S5, where the control system (301) sends an increased frequency signal to the reflux pump (204) to increase the flow rate of the reflux pump in order to improve the silane gas absorption efficiency; in S5, the increased frequency signal causes the flow rate of the reflux pump (204) to increase to a preset safety threshold, which is determined by dynamic calculation of the silane tower volume and the silane gas escape rate.

10. The automatic fire extinguishing method for vent outlets as described in claim 9, characterized in that: Steps S3 and S4 are executed synchronously, and the nitrogen injection pressure of S4 is ≥0.5MPa. When the system detects ΔC<3%, the control system (301) automatically increases the nitrogen injection pressure to ≥2MPa and enters the pulse injection state.

Images