Tunnel construction safety protection system and operation method

Abstract

The invention discloses a tunnel construction safety protection system and an operation method. Comprising a tunnel construction environment detector mounted on a tunnel construction trolley, and the environment detector is used for detecting harmful gas and dust in tunnel construction; the central control system is positioned in a control room of the tunnel construction trolley; the fan and the spraying system are mounted on the tunnel construction trolley; the environment detector is divided into a harmful gas detection module and a dust detection module which are used for correspondingly detecting harmful gas and dust in tunnel construction, and the central control system can control the fan and the spraying system to operate. The invention relates to a tunnel construction safety protection scheme based on a construction trolley. Harmful gas and dust in a tunnel are detected through an environment detector located at the front end of the trolley; a fan is arranged for blowing away and dust falling; and the fan and the spraying system can be independently started to work cooperatively through the central control system, so that the safety of tunnel construction can be further ensured.

Description

Technical Field

[0001] The present invention relates to the field of tunnel construction safety protection, and in particular to a tunnel construction safety protection system and an operating method. Background Art

[0002] Safety protection is of vital importance in tunnel construction; the following are some key safety protection measures: 1. Geological survey: Before construction, conduct a detailed geological survey of the area where the tunnel is located to understand the geological structure, rock characteristics, groundwater conditions, etc., so as to formulate a reasonable construction plan and predict possible geological disasters. 2. Construction plan formulation: According to the results of geological survey, formulate a scientific and reasonable construction plan, including construction methods, support methods, ventilation and drainage, etc., to ensure the safety and reliability of the construction process. 3. Personnel training: Conduct comprehensive safety training for construction personnel, including training in tunnel construction safety knowledge, operating procedures, emergency rescue, etc., to improve the safety awareness and operating skills of construction personnel.

[0003] Safety protection during construction includes: 1. Support structure - According to the geological conditions and construction progress of the tunnel, timely install appropriate support structures, such as anchors, shotcrete, steel arches, etc., to ensure the stability of the tunnel surrounding rock.

[0004] Carry out regular inspection and maintenance of the support structure and deal with any problems promptly.

[0005] 2. Ventilation system - Establish a complete ventilation system to ensure air circulation in the tunnel, remove harmful gases and dust, and provide a good working environment for construction workers.

[0006] Regularly inspect and maintain ventilation equipment to ensure ventilation effectiveness.

[0007] During the tunnel construction process, necessary safety monitoring equipment is installed, such as displacement monitors, stress monitors, etc., to conduct real-time monitoring of the deformation and stress of the tunnel surrounding rock and supporting structure.

[0008] In addition, during the tunnel construction process, a variety of harmful gases and dust will appear, which pose a serious threat to the health and safety of construction workers and affect the efficiency of tunnel construction. Moreover, tunnel construction will use construction trolleys, and existing construction trolleys lack the ability to detect and handle harmful gases and dust. Summary of the invention

[0009] Therefore, in order to solve the above-mentioned shortcomings, the present invention provides a tunnel construction safety protection system and operation method; the present application is a tunnel construction safety protection solution implemented based on a construction trolley, which detects harmful gases and dust in the tunnel through an environmental detector located at the front end of the trolley; and is equipped with a fan for blowing away and reducing dust; the fan and spray system can also be started separately through the central control system to work together, thereby further ensuring the safety of tunnel construction.

[0010] The present invention is implemented by constructing a tunnel construction safety protection system, characterized in that: the system comprises a tunnel construction environment detector installed on a tunnel construction trolley, the environment detector is used to detect harmful gases and dust in tunnel construction; It also includes a central control system with communication function located in the control room of the tunnel construction trolley; and fans and spray systems mounted on tunnel construction trolleys; The environmental detector is divided into two parts: a harmful gas detection module and a dust detection module, which respectively perform corresponding detections on harmful gases and dust in tunnel construction. The central control system can control the operation of the fan and the spray system.

[0011] Furthermore, it also includes an auxiliary construction module, which is connected to the central control system and is located in the control room of the tunnel construction trolley. It is used to display the relevant operations of the next tunnel construction to the operator of the construction trolley, such as displaying the position, direction and depth of the drilling holes in the tunnel construction, etc.; so that the operator can operate according to the instructions, and the outside world can convey the change of operation instructions to the operator at any time.

[0012] Furthermore; the spray system comprises a water tank and a spray gun, a water pump is arranged in the water tank, the water tank and the spray gun are connected through a pipeline, the spray gun is located at the front end of the trolley, and a rotating device is arranged at the lower end of the spray gun, which can drive the spray gun to rotate horizontally.

[0013] Furthermore, a rotating device is provided at the lower end of the fan, which can drive the fan to rotate horizontally.

[0014] Further; the harmful gas detection module comprises a power supply circuit, a gas detection circuit, an electronic switch circuit and an audible and visual alarm circuit; The power supply circuit consists of a power transformer T, rectifier diodes VD1-VD4, filter capacitors Cl, C2, current limiting resistor R1 and voltage stabilizing diode VS1; The gas detection circuit consists of a gas sensor and its peripheral components; The electronic switch circuit is composed of transistors Vl-V3, relay K and related peripheral components; The sound and light alarm circuit is composed of music integrated circuit IC, audio amplifier tubes V4, V5, speaker BL, light emitting diode VL, etc. When the gas sensor is not in contact with harmful gases, the resistance between its A and B poles is very large, Vl-V3 are all cut off, relay K does not attract, and the controller does not work; When the concentration of harmful gases in the tunnel reaches a certain value, the resistance between the two poles of the gas sensor A and B will decrease, making Vl-V3 all conductive, the relay K energized, and its normally open contacts Kl, K2, and K3 all closed, so that the exhaust fan motor M and the sound and light alarm circuit are energized to work, the speaker BL emits a loud alarm signal, and the light-emitting diode VL flashes with the alarm sound; the fan is started to blow away the harmful gases at the front end of the trolley to discharge them; When the volume fraction of harmful gases in the room drops to a certain preset value, the power supply of the fan and the sound and light alarm circuits will be automatically cut off to stop working, thereby achieving the purpose of automatically controlling harmful gases in the tunnel.

[0015] Furthermore, the dust detection module is composed of a series feedback photosensitive circuit composed of an infrared light-emitting tube and a photosensitive diode, a transistor switch circuit, and an IC integrated alarm circuit. When the air in the tunnel is clean and there is no smoke or dust, the light-emitting tube LED emits light at a pre-adjusted starting current, and the resistance of the photosensitive tube decreases due to the light, which increases the current of the series circuit. This current flows through the light-emitting tube to increase its luminous intensity, and then shines on the photosensitive tube to make its resistance smaller. Such a cycle forms a strong positive feedback process, and the current of the series loop rises rapidly to the maximum value. The voltage drop generated on the load resistor R1 causes the transistor VT2 to saturate and conduct through the isolation diode VDI, and the transistor VT3 is cut off, and the alarm does not work. When the smoke in the monitored environment increases rapidly, the light transmittance of the air decreases, which reduces the luminous flux of the light-emitting tube, increases the resistance of the photosensitive tube, and reduces the current of the series loop. Such a cycle quickly leads to a negative feedback process, which reduces the loop current and finally stabilizes at the starting current value. The voltage on the resistor RI is reduced to 1.2V, and the transistor VT2 Cut off, VT3 is saturated and turned on, the alarm sends out an alarm signal, and the fan is started to blow away the dust at the front end of the trolley.

[0016] A tunnel construction safety protection operation method, characterized in that it is implemented in the following manner; Personnel use the tunnel construction trolley to carry out corresponding construction operations in the tunnel, and carry out corresponding tunnel construction according to the operation step sequence and construction requirements indicated by the auxiliary construction module located in the control room of the tunnel construction trolley. At the same time, the environmental detector located at the front end of the trolley detects harmful gases and dust in the tunnel construction; The detection operation of harmful gas is as follows: when the concentration of harmful gas in the tunnel reaches a certain value, the resistance between the two poles of gas sensor A and B will become smaller, so that Vl-V3 are all turned on, relay K is energized, and its normally open contacts Kl, K2, and K3 are all closed, so that the exhaust fan motor M and the sound and light alarm circuit are energized to work, and a loud alarm signal is emitted from the speaker BL, and the light-emitting diode VL flashes with the alarm sound; the fan is started to blow away the harmful gas at the front end of the trolley to discharge it; when the volume fraction of harmful gas in the tunnel drops to a certain predetermined value, the working power of the fan and the sound and light alarm circuit will be automatically cut off to stop working, thereby achieving the purpose of automatically controlling harmful gas in the tunnel; The dust detection operation is as follows: when the air in the tunnel is clean and free of smoke and dust, the light-emitting tube LED emits light with a pre-adjusted starting current, and the resistance of the photosensitive tube decreases due to the light, which increases the current in the series circuit. This current flows through the light-emitting tube to increase its luminous intensity, and then shines on the photosensitive tube to make its resistance smaller; such a cycle forms a strong positive feedback process, and the current in the series circuit rises rapidly to the maximum value; the voltage drop generated on the load resistor R1 causes the transistor VT2 to saturate and conduct through the isolation diode VDI, VT3 is cut off, and the alarm does not work; when smoke suddenly appears in the monitored environment, the alarm will be turned off; if the ... Increase, the light transmittance of the air becomes smaller, which reduces the luminous flux of the light-emitting tube, increases the resistance of the photosensitive tube, and reduces the current of the series circuit. Such a cycle quickly leads to a negative feedback process, which reduces the loop current and finally stabilizes at the starting current value. The voltage on the resistor RI drops below 1.2V, the transistor VT2 is cut off, and VT3 is saturated and turned on. The alarm sends out a rapid alarm signal and starts the fan to blow away the dust at the front end of the trolley. When the fan is working, it can rotate horizontally to increase the blowing range. At the same time, the central control system can also be used to control the start of the spray gun to spray water to reduce dust forward. At the same time, the spray gun can rotate horizontally to increase the spraying range.

[0017] The present invention has the following advantages: the present application is a tunnel construction safety protection scheme implemented based on a construction trolley, which detects harmful gases and dust in the tunnel through an environmental detector located at the front end of the trolley; and is equipped with a fan to blow away and reduce dust; the fan and spray system can also be started separately through the central control system to work together, thereby further ensuring the safety of tunnel construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the application arranged on a construction trolley; Figure 2 It is the module block diagram corresponding to this application; Figure 3 It is a schematic diagram of the construction environment detector in this application. DETAILED DESCRIPTION

[0019] The following will be combined with the attached Figure 1-Figure 3 The present invention is described in detail, and the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] The present invention provides a tunnel construction safety protection system. Figure 1-Figure 3 As shown, it can be implemented in the following manner; the system includes a tunnel construction environment detector 2 installed on a tunnel construction trolley 1, and the environment detector 2 is used to detect harmful gases and dust in tunnel construction; It also includes a central control system 3 with communication function located in the control room of the tunnel construction vehicle 1. and a fan 4 and a spray system 5 mounted on the tunnel construction trolley 1; The environmental detector 2 is divided into two parts: a harmful gas detection module and a dust detection module, which respectively perform corresponding detections on harmful gases and dust in tunnel construction. The central control system 3 can control the operation of the fan 4 and the spray system 5.

[0021] In the specific implementation of this application, Figure 2 As shown, an auxiliary construction module 6 is also provided. The auxiliary construction module 6 is connected to the central control system 3 and is located in the control room of the tunnel construction trolley 1. It is used to display the relevant operations of the next tunnel construction to the operator of the construction trolley, such as displaying the position, direction and depth of the drilling holes in the tunnel construction; so that the operator can operate according to the instructions, and the outside world can convey the change of operation instructions to the operator at any time.

[0022] like Figure 1 As shown, the spray system 5 comprises a water tank 5-1 and a spray gun 5-2. A water pump is arranged in the water tank 5-1. The water tank 5-1 and the spray gun 5-2 are connected by a pipeline. The spray gun 5-2 is located at the front end of the trolley. A rotating device is arranged at the lower end of the spray gun 5-2, which can drive the spray gun 5-2 to rotate horizontally.

[0023] like Figure 1 As shown, a rotating device is provided at the lower end of the fan 4, which can drive the fan 4 to rotate horizontally.

[0024] like Figure 3 As shown, the harmful gas detection module comprises a power supply circuit, a gas detection circuit, an electronic switch circuit and an audible and visual alarm circuit; The power supply circuit consists of a power transformer T, rectifier diodes VD1-VD4, filter capacitors Cl, C2, current limiting resistor R1 and voltage stabilizing diode VS1; The gas detection circuit consists of a gas sensor and its peripheral components; The electronic switch circuit is composed of transistors Vl-V3, relay K and related peripheral components; The sound and light alarm circuit is composed of music integrated circuit IC, audio amplifier tubes V4, V5, speaker BL, light emitting diode VL, etc. When the gas sensor is not in contact with harmful gases, the resistance between its A and B poles is very large, Vl-V3 are all cut off, relay K does not attract, and the controller does not work; When the concentration of harmful gases in the tunnel reaches a certain value, the resistance between the two poles of the gas sensor A and B will decrease, making Vl-V3 all conductive, the relay K energized, and its normally open contacts Kl, K2, and K3 all closed, so that the exhaust fan motor M and the sound and light alarm circuit are energized to work, the speaker BL emits a loud alarm signal, and the light-emitting diode VL flashes with the alarm sound; the fan 4 is started to blow away the harmful gases at the front end of the trolley to discharge them; When the volume fraction of harmful gases in the room drops to a certain predetermined value, the working power supply of the fan 4 and the sound and light alarm circuit will be automatically cut off to stop working, thereby achieving the purpose of automatically controlling harmful gases in the tunnel.

[0025] like Figure 3 As shown in the figure, the dust detection module is composed of a series feedback photosensitive circuit composed of an infrared light-emitting tube and a photosensitive diode, a transistor switch circuit, and an IC integrated alarm circuit. When the air in the tunnel is clean and there is no smoke or dust, the light-emitting tube LED emits light at a pre-adjusted starting current, and the resistance of the photosensitive tube decreases due to light exposure, which increases the current of the series circuit. This current flows through the light-emitting tube to increase its luminous intensity, and then shines on the photosensitive tube to make its resistance smaller. Such a cycle forms a strong positive feedback process, and the current of the series circuit rises rapidly to the maximum value. The voltage drop generated on the load resistor R1 causes the transistor VT2 to saturate and conduct through the isolation diode VDI, and the transistor VT3 is turned off, and the alarm does not work. When the smoke in the monitored environment increases rapidly, the light transmittance of the air decreases, which reduces the luminous flux of the light-emitting tube, increases the resistance of the photosensitive tube, and reduces the current of the series circuit. Such a cycle quickly leads to a negative feedback process, which reduces the circuit current and finally stabilizes at the starting current value. The voltage on the resistor RI decreases below 1.2V, and the transistor VT2 Cut off, VT3 is saturated and turned on, the alarm sends out an alarm signal, and at the same time, the fan 4 is started to blow away the dust at the front end of the trolley.

[0026] The following is an explanation of the operation method of the tunnel construction safety protection system of the present application in conjunction with the accompanying drawings, which can be implemented in the following manner: Personnel perform corresponding construction operations in the tunnel through the tunnel construction trolley 1, and perform corresponding tunnel construction according to the operation step sequence and construction requirements indicated by the auxiliary construction module 6 located in the control room of the tunnel construction trolley 1. At the same time, the environmental detector 2 located at the front end of the trolley detects harmful gases and dust in the tunnel construction; The detection operation of harmful gases is as follows: when the concentration of harmful gases (carbon monoxide, etc.) in the tunnel reaches a certain value, the resistance between the two poles of the gas sensor A and B will decrease, making Vl-V3 all conductive, the relay K energized, and its normally open contacts Kl, K2, and K3 all closed, so that the exhaust fan motor M and the sound and light alarm circuit are powered on, and a loud alarm signal is emitted from the speaker BL, and the light-emitting diode VL flashes with the alarm sound; the fan 4 is started to blow away the harmful gases at the front end of the trolley to discharge them; when the volume fraction of the harmful gases in the tunnel drops to a predetermined value, the working power of the fan 4 and the sound and light alarm circuit will be automatically cut off to stop working, thereby achieving the purpose of automatically controlling the harmful gases in the tunnel; at the same time, the tunnel's exhaust system can also be started through the central control system to forcibly extract the harmful gases; The dust detection operation is as follows: when the air in the tunnel is clean and free of smoke and dust, the light-emitting tube LED emits light with a pre-adjusted starting current, and the resistance of the photosensitive tube decreases due to the light, which increases the current in the series circuit. This current flows through the light-emitting tube to increase its luminous intensity, and then shines on the photosensitive tube to make its resistance smaller; such a cycle forms a strong positive feedback process, and the current in the series circuit rises rapidly to the maximum value; the voltage drop generated on the load resistor R1 causes the transistor VT2 to saturate and conduct through the isolation diode VDI, VT3 is cut off, and the alarm does not work; when the smoke in the monitored environment increases sharply and the air The transmittance of light becomes smaller, which reduces the luminous flux of the light-emitting tube, increases the resistance of the photosensitive tube, and reduces the current of the series circuit. Such a cycle quickly leads to a negative feedback process, which reduces the loop current and finally stabilizes at the starting current value. The voltage on the resistor RI drops below 1.2V, the transistor VT2 is cut off, VT3 is saturated and turned on, the alarm sends out a rapid alarm signal, and at the same time starts the fan 4 to blow away the dust at the front end of the trolley. When working, the fan 4 can rotate horizontally to increase the blowing range; at the same time, the central control system 3 can also control the start of the spray gun 5-2 to spray water to reduce dust forward, and the spray gun 5-2 can rotate horizontally to increase the spraying range.

[0027] The present application is a tunnel construction safety protection solution implemented based on a construction trolley. The harmful gases and dust in the tunnel construction are detected by an environmental detector located at the front end of the trolley. A fan is equipped for blowing and dust reduction. At the same time, the spray system can be started through the central control system to cooperate with dust reduction, thereby further ensuring the safety of tunnel construction.

[0028] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A tunnel construction safety protection system, characterized in that; The system comprises a tunnel construction environment detector (2) installed on a tunnel construction trolley (1), wherein the environment detector (2) is used to detect harmful gases and dust in tunnel construction; It also includes a central control system (3) with communication function located in the control room of the tunnel construction trolley (1), and a fan (4) and a spray system (5) mounted on a tunnel construction trolley (1); The environmental detector (2) is divided into two parts: a harmful gas detection module and a dust detection module, which respectively perform corresponding detections on harmful gases and dust in tunnel construction. The central control system (3) can control the operation of the fan (4) and the spray system (5).

2. A tunnel construction safety protection system according to claim 1, characterized in that: The system further comprises an auxiliary construction module (6), which is connected to the central control system (3) for communication and is located in the control room of the tunnel construction trolley (1) and is used to display to the operator of the construction trolley relevant operations of the next tunnel construction, such as displaying the position, direction and depth of the drilling holes in the tunnel construction, so that the operator can operate according to the instructions, and the outside world can convey the change of operation instructions to the operator at any time.

3. A tunnel construction safety protection system according to claim 1, characterized in that: The spray system (5) comprises a water tank (5-1) and a spray gun (5-2); a water pump is arranged in the water tank (5-1); the water tank (5-1) and the spray gun (5-2) are connected via a pipeline; the spray gun (5-2) is located at the front end of the trolley; a rotating device is arranged at the lower end of the spray gun (5-2) to drive the spray gun (5-2) to rotate horizontally.

4. A tunnel construction safety protection system according to claim 1, characterized in that: A rotating device is provided at the lower end of the fan 4, capable of driving the fan (4) to rotate horizontally.

5. A tunnel construction safety protection system according to claim 1, characterized in that: The harmful gas detection module consists of a power supply circuit, a gas detection circuit, an electronic switch circuit and an audible and visual alarm circuit; The power supply circuit consists of a power transformer T, rectifier diodes VD1-VD4, filter capacitors Cl, C2, current limiting resistor R1 and voltage stabilizing diode VS1; The gas detection circuit consists of a gas sensor and its peripheral components; The electronic switch circuit is composed of transistors Vl-V3, relay K and related peripheral components; The sound and light alarm circuit is composed of music integrated circuit IC, audio amplifier tubes V4, V5, speaker BL, light emitting diode VL, etc. When the gas sensor is not in contact with harmful gases, the resistance between its A and B poles is very large, Vl-V3 are all cut off, relay K does not attract, and the controller does not work; When the concentration of harmful gases in the tunnel reaches a certain value, the resistance between the two poles of the gas sensor A and B will decrease, making Vl-V3 all conductive, the relay K energized, and its normally open contacts Kl, K2, and K3 all closed, so that the exhaust fan motor M and the sound and light alarm circuit are energized to work, the speaker BL emits a loud alarm signal, and the light-emitting diode VL flashes with the alarm sound; the fan 4 is started to blow away the harmful gases at the front end of the trolley to discharge them; When the volume fraction of harmful gases in the tunnel drops to a certain predetermined value, the working power supply of the fan 4 and the sound and light alarm circuit will be automatically cut off to stop working, thereby achieving the purpose of automatically controlling harmful gases in the tunnel.

6. A tunnel construction safety protection system according to claim 1, characterized in that: The dust detection module consists of a series feedback photosensitive circuit composed of an infrared light-emitting tube and a photosensitive diode, a transistor switch circuit, and an IC integrated alarm circuit. When the air in the tunnel is clean and there is no smoke or dust, the light-emitting tube LED emits light at a pre-adjusted starting current. The resistance of the photosensitive tube decreases due to light exposure, which increases the current of the series circuit. This current flows through the light-emitting tube to increase its luminous intensity, and then shines on the photosensitive tube to make its resistance smaller. This cycle forms a strong positive feedback process, and the current of the series circuit rises rapidly to the maximum value. The voltage drop generated on the load resistor R1 causes the transistor VT2 to saturate and conduct through the isolation diode VDI, and the transistor VT3 is turned off, and the alarm does not work. When the smoke in the monitored environment increases rapidly, the light transmittance of the air decreases, which reduces the luminous flux of the light-emitting tube, increases the resistance of the photosensitive tube, and reduces the current of the series circuit. This cycle quickly leads to a negative feedback process, which reduces the circuit current and finally stabilizes at the starting current value. The voltage on the resistor RI decreases below 1.2V, and the transistor VT2 Cut off, VT3 is saturated and turned on, the alarm sends out an alarm signal, and at the same time, the fan 4 is started to blow away the dust at the front end of the trolley.

7. A tunnel construction safety protection operation method, characterized in that: Implement as follows; Personnel use the tunnel construction trolley (1) to perform corresponding construction operations in the tunnel, and perform corresponding tunnel construction according to the operation step sequence and construction requirements indicated by the auxiliary construction module (6) located in the control room of the tunnel construction trolley (1). At the same time, the environmental detector (2) located at the front end of the trolley detects harmful gases and dust during the tunnel construction. The harmful gas detection operation is as follows: when the concentration of harmful gas in the tunnel reaches a certain value, the resistance between the two electrodes of the gas sensor A and B will decrease, so that Vl-V3 are all turned on, the relay K is energized, and its normally open contacts Kl, K2, and K3 are all closed, so that the exhaust fan motor M and the sound and light alarm circuit are energized to work, and a loud alarm signal is emitted from the speaker BL, and the light emitting diode VL flashes with the alarm sound; the fan (4) is started to blow away the harmful gas at the front end of the trolley to discharge it; when the volume fraction of the harmful gas in the tunnel drops to a certain predetermined value, the working power of the fan (4) and the sound and light alarm circuit will be automatically cut off to stop working, thereby achieving the purpose of automatically controlling the harmful gas in the tunnel; The dust detection operation is as follows: when the air in the tunnel is clean and free of smoke and dust, the light-emitting tube LED emits light with a pre-adjusted starting current, and the resistance of the photosensitive tube decreases due to the light, which increases the current in the series circuit. This current flows through the light-emitting tube to increase its luminous intensity, and then shines on the photosensitive tube to make its resistance smaller; such a cycle forms a strong positive feedback process, and the current in the series circuit rises rapidly to the maximum value; the voltage drop generated on the load resistor R1 causes the transistor VT2 to saturate and conduct through the isolation diode VDI, VT3 is cut off, and the alarm does not work; when the smoke in the monitored environment increases sharply, the light transmittance of the air becomes The smaller the voltage, the smaller the luminous flux of the light-emitting tube, the larger the resistance of the photosensitive tube, and the smaller the current of the series circuit. This cycle quickly leads to a negative feedback process, which reduces the circuit current and finally stabilizes at the starting current value. The voltage on the resistor RI drops below 1.2V, the transistor VT2 is cut off, VT3 is saturated and turned on, and the alarm sends a rapid alarm signal. At the same time, the fan (4) is started to blow away the dust at the front end of the trolley. When the fan (4) is working, it can rotate horizontally to increase the blowing range. At the same time, the central control system (3) can control the start of the spray gun (5-2) to spray water to the front to reduce dust. At the same time, the spray gun (5-2) can be rotated horizontally to increase the spraying range.

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