Intelligent collaborative blocking and purification system and method for dust and harmful gas in tunnel blasting construction

Abstract

The application discloses a tunnel blasting construction dust and harmful gas intelligent collaborative blocking and purification system and method. The system comprises a mobile blocking device, a press-in air pipe, a dust suction air pipe, a hierarchical purification device and an intelligent linkage control system. After blasting, the mobile blocking device is automatically positioned to the preset position and expands the sealing partition component, thereby dividing the tunnel into a pollution area and a clean area; the press-in air pipe and the dust suction air pipe cooperate in the pollution area to form a directional airflow, thereby guiding the polluted gas to the hierarchical purification device for step-by-step treatment by multiple purification units and then discharging the polluted gas up to the standard; and the intelligent linkage control system automatically adjusts the air speed and the purification parameters according to the real-time monitored pollutant concentration, thereby realizing the full-process automatic collaborative operation. The application fundamentally solves the problems of secondary pollution and low purification efficiency caused by the traditional full-tunnel ventilation dilution mode, and has important significance for improving the tunnel construction environment, guaranteeing the professional health of personnel and speeding up the construction progress.

Description

Technical Field

[0001] This invention relates to the field of dust and harmful gas treatment technology, specifically to an intelligent collaborative barrier and purification system and method for dust and harmful gases during tunnel blasting construction. Background Technology

[0002] During tunnel boring and blasting (TBB) construction, each blast releases a large amount of dust, carbon monoxide, nitrogen oxides, and other pollutants at the tunnel face. Because tunnels are long, narrow, and semi-enclosed spaces, these pollutants, driven by the blast shock wave and air convection, rapidly spread longitudinally along the tunnel, causing a sharp deterioration in air quality over a large area. Currently, the common practice is to activate a forced-air ventilation system after blasting, continuously supplying a large amount of fresh air into the tunnel to gradually dilute the polluted air along its entire length and push it towards the tunnel entrance for discharge. However, this whole-tunnel ventilation dilution method has a fundamental flaw: the polluted air inevitably passes through areas where construction personnel and machinery are located during dilution and discharge, causing secondary exposure for workers. Furthermore, as the tunnel depth increases, the ventilation distance becomes longer, leading to a sharp decrease in dilution efficiency and excessively long ventilation waiting times, severely hindering the construction cycle progress.

[0003] The root cause of these shortcomings lies in the fact that traditional methods lack effective means to quickly confine pollutants to a localized area at the tunnel face after blasting. This makes it impossible to effectively isolate contaminated and clean zones within the tunnel, allowing pollutants to spread uncontrollably throughout the tunnel from the moment they are generated. Furthermore, the dust particles, carbon monoxide, and nitrogen oxides produced by blasting differ significantly in their physicochemical properties. Traditional single-mode ventilation and dilution methods cannot effectively remove different types of pollutants; they can only rely on natural diffusion and dilution to reduce concentrations, resulting in low and uncontrollable purification efficiency. In addition, the area at the tunnel face after blasting is an uninhabited zone. Traditional methods rely on manual judgment of ventilation time and manual operation of equipment, lacking automated control capabilities based on real-time changes in pollutant concentrations, making it difficult to achieve on-demand ventilation and precise purification. Summary of the Invention

[0004] The purpose of this invention is to provide an intelligent collaborative barrier and purification system and operation method for dust and harmful gases generated during tunnel blasting construction, which has the advantages of achieving rapid sealing of contaminated areas and efficient removal of dust and harmful gases in an integrated manner.

[0005] To achieve the above objectives, the present invention proposes the following technical solution: an intelligent collaborative barrier and purification system for dust and harmful gases during tunnel blasting construction, comprising:

[0006] A mobile barrier device has a main frame, with deployable sealing partition components on the top and sides of the main frame, and a moving mechanism and a locking mechanism at the bottom. The mobile barrier device is used to move to a preset position inside the tunnel after blasting and deploy the sealing partition components to form a physical barrier layer, dividing the tunnel space into a contaminated area near the tunnel face and a clean area away from the tunnel face.

[0007] Forced air ducts, installed inside the tunnel, are used to deliver fresh air to the contaminated area;

[0008] A dust extraction duct is installed inside the tunnel. One end of the duct is connected to the polluted area, and the other end is connected to the dust and harmful gas graded purification device. It is used to guide the polluted gas in the polluted area to the graded purification device.

[0009] The dust and harmful gas graded purification device has multiple purification units inside along the airflow direction, and an exhaust fan at the air outlet to purify the polluted gas drawn in through the dust suction duct before discharging it.

[0010] The intelligent linkage control system includes a pollutant monitoring module, a central controller, and an actuator mounted on the mobile barrier device. The central controller automatically adjusts the air speed of the dust extraction duct, the operating parameters of the graded purification device, and the power of the exhaust fan based on the real-time monitoring data from the pollutant monitoring module.

[0011] Furthermore, in this invention, the main frame is a portal frame structure, assembled from steel profiles. The portal frame adopts a telescopic structure, and the width and height of the frame can be adaptively adjusted by a hydraulic or electric adjustment mechanism to adapt to tunnels with different cross-sectional dimensions.

[0012] Furthermore, in this invention, the sealing partition assembly includes hinges on the columns on both sides of the main frame and an electric roller shutter door on the crossbeam. The hinges and the electric roller shutter door are made of explosion-proof and fire-resistant composite material, and the edges are provided with elastic sealing strips, forming an airtight contact with the tunnel wall when unfolded.

[0013] Furthermore, in this invention, the forced-in air duct is arranged above the movable barrier device, and the dust suction air duct is arranged on the lower side of the movable barrier device and close to the tunnel wall; the forced-in air duct and the dust suction air duct cooperate to form a directional airflow from top to bottom in the polluted area;

[0014] The compressed air volume is greater than the exhaust air volume, with a ratio of 1.2:1 to 1.5:1, so that the polluted area is maintained in a slightly positive pressure state.

[0015] Furthermore, in this invention, the multi-stage purification unit sequentially includes a gravity settling chamber, a steel wire filter, an impregnated activated carbon adsorption layer, and a hopalat agent catalytic oxidation layer along the airflow direction.

[0016] Furthermore, in this invention, the steel wire filter is equipped with a reverse pulse cleaning system. The central controller automatically triggers the reverse pulse cleaning based on the pressure difference on both sides of the steel wire filter, blowing the trapped dust down to the dust collection drawer at the bottom. The impregnated activated carbon adsorption layer and the hopalat agent catalytic oxidation layer both adopt a drawer-type modular quick-change structure.

[0017] Furthermore, in this invention, the intelligent linkage control system also includes a blasting signal recognition module, which is equipped with a vibration sensor, a sound sensor and / or a CO concentration change detection unit, for recognizing blasting events and triggering automatic system startup.

[0018] The method of using the above-mentioned intelligent collaborative barrier and purification system for dust and harmful gases during tunnel blasting includes the following steps:

[0019] S1: The system is in standby mode, the mobile barrier device is in standby position, the sealing partition assembly is in retracted state, and the pollutant monitoring module continuously monitors the environmental parameters inside the tunnel.

[0020] S2: After the blasting signal is detected, the central controller issues a command, and the mobile barrier device automatically moves to a preset distance from the working face and locks itself through the locking mechanism;

[0021] S3: The sealing partition component automatically unfolds to form a physical partition layer, dividing the tunnel into a contaminated area and a clean area;

[0022] S4: Start the forced air duct, the dust suction duct and the exhaust fan to form a directional airflow in the polluted area and guide the polluted gas to the graded purification device through the dust suction duct.

[0023] S5: The polluted gas is discharged after being treated by multiple purification units in the graded purification device and meets the emission standards.

[0024] S6: When the pollutant monitoring module detects that the concentration of each pollutant has been continuously lower than the set threshold for a preset time, the sealing partition component is automatically retracted, and the movable barrier device is unlocked and returns to the standby position.

[0025] Furthermore, in this invention, in steps S4 and S5, the central controller performs multi-parameter coordinated adjustment based on real-time monitoring data: adjusting the wind speed of the dust extraction duct according to the dust concentration, adjusting the residence time of the gas in the hopalat agent catalytic oxidation layer according to the CO concentration, and adjusting the air exchange rate of the impregnated activated carbon adsorption layer according to the NOx concentration.

[0026] Furthermore, in this invention, after step S6 is completed, step S7 is also included: the system switches to the full tunnel ventilation mode where the forced-in air duct works alone, so as to achieve full tunnel ventilation; when the next blasting operation is to be carried out, steps S2 to S6 are repeated.

[0027] Beneficial effects: The technical solution of this application has the following technical effects:

[0028] This invention utilizes a mobile barrier device installed within the tunnel. After blasting, this device rapidly moves to a predetermined location and deploys a sealing barrier component to form a physical barrier layer, dynamically dividing the tunnel space into contaminated and clean zones. This fundamentally blocks the diffusion path of pollutants to the construction personnel area behind the tunnel, completely eliminating the secondary exposure problem caused by contaminated air passing through personnel areas in traditional whole-tunnel ventilation and dilution methods. Furthermore, because the physical barrier confines pollutants to a limited volume of sealed space near the tunnel face, the volume of gas that the purification device needs to process is significantly reduced compared to whole-tunnel ventilation and dilution. This significantly shortens the ventilation and purification waiting time, which is beneficial for accelerating the construction cycle.

[0029] This invention utilizes a combination of forced-flow ducts and suction ducts within a sealed-off contaminated area to create directional airflow. This guides polluted gases to a multi-stage purification system, where they are treated step-by-step before being discharged in compliance with standards. This achieves simultaneous and efficient removal of particulate matter and harmful gases, overcoming the limitations of traditional single-stage ventilation dilution methods that cannot effectively classify and treat different types of pollutants. Furthermore, the intelligent linkage control system automatically adjusts the suction duct speed, purification device operating parameters, and exhaust fan power based on real-time pollutant concentration data. This enables fully automated and coordinated operation from explosion signal recognition, barrier device deployment, directional airflow establishment to multi-stage purification, requiring no manual intervention. This ensures purification effectiveness while avoiding energy waste caused by continuous full-load operation.

[0030] It should be understood that all combinations of the foregoing concepts and the additional concepts described in more detail below can be considered part of the inventive subject matter of this disclosure, provided that such concepts do not contradict each other.

[0031] The foregoing and other aspects, embodiments, and features of the teachings of the present invention will be more fully understood from the following description in conjunction with the accompanying drawings. Other additional aspects of the invention, such as features and / or beneficial effects of exemplary embodiments, will become apparent from the following description or may be learned through practice of specific embodiments according to the teachings of the present invention. Attached Figure Description

[0032] The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component shown in the various figures may be denoted by the same reference numeral. For clarity, not every component is labeled in each figure. Embodiments of various aspects of the invention will now be described by way of example and with reference to the accompanying drawings, wherein:

[0033] Figure 1 This is a schematic diagram of the entire system structure;

[0034] Figure 2 Diagram of a mobile barrier device;

[0035] Figure 3 Side view of the movable barrier device;

[0036] Figure 4 This is a structural diagram of a dust and harmful gas purification device.

[0037] The meanings of the reference numerals in the figures are as follows: 1. Forced air duct; 2. Working face; 3. Movable barrier device; 4. Dust suction duct; 5. Graded purification device for dust and harmful gases; 6. Sealed partition assembly; 7. Intelligent linkage control system; 8. Main frame; 9. Moving mechanism; 10. Locking mechanism; 11. Anti-pulse cleaning system; 12. Steel wire filter; 13. Dust collection drawer; 14. Impregnated activated carbon adsorption layer; 15. Hogalat agent catalytic oxidation layer; 16. Exhaust fan; 17. Support frame. Detailed Implementation

[0038] The embodiments of the invention are described in detail below with reference to the accompanying drawings to clearly illustrate the structure, purpose, advantages, positional relationships, and connection methods of each component. It should be noted that the directional indications (such as "front," "back," "up," and "down") involved in this embodiment are based on the posture shown in the drawings and are only used to describe the relative positional relationships and movement of the components. If the posture changes, the directional indications will be adjusted accordingly. The term "connection" includes mechanical connections and electrical connections, and can be fixed connections, detachable connections, or indirect connections through an intermediate medium. The specific meaning is understood by those skilled in the art based on the context.

[0039] like Figure 1As shown, the system of the present invention is arranged inside the tunnel and includes five parts: a mobile barrier device 3, a forced-in air duct 1, a dust extraction air duct 4, a dust and harmful gas graded purification device 5, and an intelligent linkage control system 7. The mobile barrier device 3 is located inside the tunnel, approximately 30 to 80 meters from the tunnel face 2, and is used to divide the tunnel space into a contaminated zone near the tunnel face and a clean zone away from the tunnel face after blasting. The forced-in air duct 1 is arranged longitudinally along the top of the tunnel, extending from the fan outside the tunnel entrance to near the tunnel face 2, passing above the mobile barrier device 3 into the contaminated zone, with its outlet facing the tunnel face. The dust extraction air duct 4 is arranged longitudinally along the lower side of the tunnel, near the tunnel wall, with its inlet located in the lower part of the contaminated zone, passing through the mobile barrier device 3 and connecting to the inlet of the graded purification device 5 located in the clean zone. The graded purification device 5 is placed in the clean area behind the mobile barrier device 3, and its outlet is connected to the exhaust fan 16, which discharges the purified and qualified gas. The intelligent linkage control system 7 is installed on the main frame 8 of the mobile barrier device 3, in a position that is easy to observe and maintain. The above components form a complete collaborative working system through pipe connections and electrical connections. The forced air duct 1 and the dust extraction duct 4 are equipped with flexible sealing sleeves where they pass through the mobile barrier device 3 to ensure that the airtightness of the physical barrier is not compromised when the pipes pass through the partition layer.

[0040] The specific structure of the mobile barrier device, such as Figure 2 and Figure 3 As shown, the main frame 8 of the mobile barrier device 3 is a portal frame structure, assembled using HW200×200 H-beams with high-strength bolts and welding. It mainly consists of two vertical columns and one horizontal beam. The purpose of choosing H-beams as the frame material is that they possess excellent bending stiffness and load-bearing capacity, enabling the structure to remain stable and undeformed under the instantaneous positive pressure of an explosive shock wave. Furthermore, the standardized cross-section of H-beams facilitates processing and on-site assembly. The portal frame adopts a telescopic structure design. Specifically, the two columns and the beam are connected by a sleeve-type sliding connection. The two ends of the beam are respectively fitted into the sleeves at the top of the two columns. The beam is driven to extend and retract along the sleeves by a hydraulic cylinder or electric push rod, thereby achieving stepless adjustment of the frame width. Simultaneously, each column itself also adopts an inner and outer sleeve nesting structure. The frame height is adjusted by the extension and retraction of the inner tube relative to the outer tube driven by a hydraulic cylinder. The purpose of this expandable structure is to allow the same barrier device to adapt to tunnels with different cross-sectional dimensions. In actual engineering, there is no need to manufacture a separate frame for each tunnel cross-section, which significantly reduces equipment costs and construction preparation time. The frame's expansion and contraction adjustment range is 4.0 meters to 7.5 meters in width and 3.5 meters to 6.5 meters in height, basically covering the common cross-sectional dimensions of highway and railway tunnels.

[0041] The bottom of the portal frame is equipped with a moving mechanism 9 and a locking mechanism 10. The moving mechanism 9 consists of four sets of omnidirectional moving pulleys, each installed on the outer bottom end of two columns. Each set of pulleys includes two 200mm diameter polyurethane-coated steel wheels, which are fixed to the flange plate at the bottom of the column via bearing seats, allowing them to roll in all directions along the tunnel surface. Of the four sets of pulleys, the front two sets are drive wheels, each equipped with a 0.75 kW geared motor, which is centrally controlled to achieve automatic movement of the device at a speed of 0.3 to 0.5 meters per second. This allows the device to be moved from its standby position to a preset working position 50 meters from the tunnel face within approximately 60 to 100 seconds after blasting. The rear two sets are driven wheels, serving only as load-bearing and following wheels. The locking mechanism 10 includes two sets of hydraulic struts located at the base of each column. Each set of hydraulic struts comprises a vertical strut and a horizontal strut. The vertical strut extends downwards to press against the tunnel surface, while the horizontal strut extends to the sides to abut against the tunnel sidewalls. The locking force provided by the hydraulic system securely holds the entire frame within the tunnel cross-section, preventing displacement or overturning under the influence of blast shock waves or ventilation airflow. Each hydraulic strut has a rated thrust of 50 kN, sufficient to withstand the overpressure of the shock wave generated at a distance of 50 meters by a conventional amount of explosive charge in tunnel blasting. The purpose of the locking mechanism 10 is to ensure that the barrier device can stably remain in a preset position after the sealing and isolation components are deployed, providing a reliable structural foundation for subsequent sealing and isolation and directional ventilation purification.

[0042] The specific structure of the sealing partition assembly is as follows: Figure 2 and Figure 3 As shown, the sealing partition assembly 6 is installed on the two uprights and crossbeam of the portal frame, and is composed of a combination of hinges and an electric roller shutter door. Specifically, two hinges are installed on the outer side of each of the two uprights. The hinges adopt a double-hinge structure, with one end fixedly connected to the outer flange of the upright via a hinge shaft, and the other end being a free end. When unfolded, it flips towards the tunnel wall until the hinge plate is flush with the tunnel wall. Each hinge is 0.8 meters wide, and two hinges are installed on each of the two uprights, for a total of four hinges, which cover the gap area between the outer side of the upright and the tunnel sidewall. An electric roller shutter door is installed above the crossbeam. The roller shutter door's roller shaft is installed on the front flange of the crossbeam, and the door curtain unfolds from top to bottom, covering the space from above the crossbeam to the top of the tunnel. The hinges and electric roller shutters are made of explosion-proof and fireproof composite panels with a 1.5 mm thick stainless steel plate and a 3 mm thick flame-retardant glass fiber layer. The purpose is to resist the instantaneous impact of blast shock waves and have good fire resistance, ensuring safe use in the complex environment of high temperature, high dust and possible gas in tunnel construction.

[0043] Elastic sealing strips are affixed to the edges of both the hinges and the electric roller shutter door. These strips are made of closed-cell neoprene foam, with a hollow D-shaped cross-section, 40 mm wide and 20 mm thick, capable of compressing to 50% of their original thickness. The D-shaped hollow cross-section design allows the sealing strip to generate a uniform elastic recovery force when compressed, actively adapting to the unevenness of the tunnel wall surface within a range of ±15 mm, ensuring a continuous airtight contact line between the sealing strip and the wall. The purpose of the elastic sealing strip is to solve the sealing difficulties caused by irregular tunnel wall surfaces, enabling the partition layer to effectively prevent contaminated gas from leaking from the edges of the partition layer to the clean area after deployment. Actual testing showed that, under conditions where the pressure difference across the partition layer does not exceed 200 Pa, the air leakage rate of the entire sealed partition assembly after deployment does not exceed 5%, meeting the basic requirements for contaminated area control.

[0044] The hinges are driven to open and close via an electric push rod installed at the hinge shaft, and the electric roller shutter is driven to rise and fall by a tubular motor built into the roller shaft. The entire sealing partition assembly 6 has an opening time of no more than 20 seconds and a closing time of no more than 15 seconds, and both opening and closing actions are controlled by a central controller.

[0045] The specific structure and layout of the forced-flow duct and the dust extraction duct are as follows: Forced-flow duct 1 is a flexible flame-retardant PVC duct with a diameter of 1000 mm, suspended longitudinally along the center of the tunnel roof, and fixed to the anchor bolts of the initial support of the tunnel arch by steel wire rope suspension devices installed at 3-meter intervals. The air inlet of forced-flow duct 1 is connected to an axial flow fan installed outside the tunnel entrance. The fan has a power of 55 kW and a rated air supply volume of 600 cubic meters per minute. The air outlet of forced-flow duct 1 is located 5 to 10 meters from the tunnel face, facing the tunnel face. Forced-flow duct 1 passes through the movable barrier device 3, passing through the pipe through hole reserved above the portal frame beam. A flexible silicone sealing sleeve is installed around the through hole. The sealing sleeve is pressed tightly against the outer wall of the duct and the inner wall of the through hole by a tightening strap, which allows the duct to have a certain relative displacement when it moves with the device while maintaining the airtightness at the crossing point. The purpose of placing forced air ducts above the tunnel is to allow fresh air to enter the polluted area from above and diffuse downwards. This not only replenishes the polluted area with fresh oxygen but also creates a downward airflow force. Combined with the gravity settling direction of the dust, this accelerates the accumulation of dust towards the air inlet of the dust suction duct at the bottom of the polluted area.

[0046] The dust extraction duct 4 is made of galvanized steel pipe with a diameter of 800 mm. It is arranged longitudinally along the lower right side of the tunnel (the right side facing the working face) at a height of about 0.5 meters above the tunnel surface. It is fixed to the initial support surface of the tunnel sidewall by angle steel brackets installed at 2-meter intervals. The air inlet of the dust extraction duct 4 is located in the contaminated area, about 10 to 15 meters from the working face. The air inlet faces the working face and is equipped with a flared air collection hood with a flared diameter of 1200 mm. The purpose of the flared air collection hood is to increase the effective air intake area of ​​the air inlet and improve the collection efficiency of dust deposited at the bottom and harmful gases accumulated at low levels. The air outlet of the dust extraction duct 4 passes through the movable barrier device 3 and connects to the air intake pipe of the graded purification device 5. A flexible sealing sleeve is also provided where it passes through the barrier device. The purpose of placing the dust extraction duct on one side of the tunnel near the wall is as follows: Dust settles naturally under gravity, carbon monoxide has a density close to that of air, while nitrogen oxides have a density slightly higher than that of air. After the explosion, these pollutants will move downwards and to the sides under the force of the forced air supply from the duct, forming a high-concentration pollution accumulation zone in the lower part of the tunnel. Placing the dust extraction duct here allows for direct extraction from the area with the highest pollutant concentration, avoiding ineffective extraction from low-concentration areas and significantly improving the efficiency of pollutant collection.

[0047] The airflow ratio of the forced-flow duct 1 to the suction duct 4 is designed such that the airflow of the forced-flow duct is greater than that of the suction duct, with a ratio of approximately 1.2:1 to 1.5:1. This design aims to maintain a slightly positive pressure relative to atmospheric pressure within the contaminated area, preventing external air from being drawn back in through the tiny gaps in the partition layer during the exhaust process due to excessive negative pressure in the contaminated area, which would affect purification efficiency. Excess fresh air seeps out in small amounts through these tiny gaps into the clean area without causing contamination; instead, it provides positive pressure protection for the clean area.

[0048] The specific structure of the dust and harmful gas graded purification device is as follows: Figure 4 As shown, the dust and harmful gas graded purification device 5 is an integrated box-type structure with an overall rectangular shape. The outer shell is welded from Q235 carbon steel plate with a thickness of 3 mm. An external support frame 17 supports the entire device on the tunnel floor at a height of 0.5 meters, which is the same height as the air outlet of the dust suction duct 4, facilitating duct connection. The overall dimensions of the device are 3000 mm long, 1500 mm wide, and 1800 mm high. The interior is divided into four functional chambers along the airflow direction: a gravity settling chamber, a wire mesh filter chamber, an impregnated activated carbon adsorption chamber, and a hopalat agent catalytic oxidation chamber.

[0049] The first stage is a gravity settling chamber, located at the very front of the device and directly connected to the outlet of the suction duct 4. The effective length of the gravity settling chamber is 800 mm, with an internal cross-sectional area of ​​1500 mm x 1800 mm and an effective volume of approximately 2.16 cubic meters. After the polluted gas enters the gravity settling chamber from the suction duct, the airflow velocity drops sharply to 0.3 to 0.5 meters per second due to the sudden increase in cross-sectional area, far lower than the settling velocity of large dust particles. Under these low flow conditions, large dust particles with a diameter greater than 100 micrometers lose their carrying capacity under their own gravity and naturally settle to the bottom of the settling chamber. A conical dust collection hopper with a 45-degree inclination is located at the bottom of the settling chamber. The settled dust slides along the conical surface into the dust collection drawer 13 at the bottom, which is periodically removed and cleaned by construction personnel during downtime. The purpose of the gravity settling chamber is to act as the first coarse dust removal barrier, removing large dust particles to reduce the load on subsequent purification units, prevent large dust particles from clogging the subsequent wire mesh filters, and extend the service life of the filters.

[0050] The second stage is a steel wire mesh 12, installed on the partition between the gravity settling chamber and the impregnated activated carbon adsorption chamber. The steel wire mesh 12 is made of multi-layered, stacked stainless steel woven wire mesh with a wire diameter of 0.2 mm and a mesh size of 10 to 30 micrometers. It consists of eight layers with a total thickness of approximately 15 mm, providing an effective filtration area of ​​1500 mm x 1800 mm. The purpose of this multi-layered structure is to improve the collection efficiency of fine particulate dust through layer-by-layer interception. After eight layers, the filtration efficiency for particles larger than 10 micrometers can reach over 95%. Above the steel wire mesh 12 is a reverse pulse cleaning system 11. This system includes a pulse air pipe arranged along the width of the filter mesh and an electromagnetic pulse valve. A nozzle is installed on the pulse air pipe every 150 mm, with the nozzles facing the filter mesh surface. When the central controller detects that the pressure difference between the front and back sides of the wire mesh filter exceeds a preset threshold (800 Pa), it automatically triggers the electromagnetic pulse valve to open. Compressed air is ejected from the nozzle in extremely short pulses of 0.1 seconds, generating a reverse impact airflow on the filter surface, blowing off the dust cake layer adhering to the windward side of the filter. The blown-off dust fragments fall into the dust collection drawer 13 below under gravity. The purpose of the reverse pulse cleaning system is to restore the ventilation capacity of the filter without shutting down the system, avoiding a sharp increase in system resistance due to dust blockage, which would affect the overall purification efficiency. The pulse cleaning interval is automatically determined by the central controller based on the pressure difference signal. Typically, it is cleaned every 30 to 60 seconds during the initial stage of system operation when the dust concentration is high, and the cleaning interval is automatically extended as the concentration decreases.

[0051] The third stage is the impregnated activated carbon adsorption layer 14, installed behind the wire mesh filter. The impregnated activated carbon adsorption layer 14 adopts a drawer-type modular structure, consisting of four independent stainless steel frame drawers stacked one on top of the other. Each drawer has external dimensions of 1500 mm x 450 mm x 100 mm. The front and back sides of the drawers are made of stainless steel perforated plates with a hole diameter of 3 mm and an opening rate of 40%. Impregnated activated carbon granules are filled between the perforated plates, with a filling thickness of 100 mm. The total height of the four drawers stacked is 1800 mm, covering the entire internal cross-section of the purification device. The purpose of the drawer-type structure is that when the activated carbon becomes saturated and needs replacement, the installer only needs to pull out the drawers one by one and replace them with pre-filled new drawers. The entire replacement process takes no more than 2 minutes per drawer, and no more than 10 minutes to replace all four drawers. This can be completed quickly during construction breaks without affecting the construction cycle progress. The preparation method of impregnated activated carbon is as follows: Columnar coal-based activated carbon with a particle size of 3 to 5 mm is selected and immersed in a 10% (w / w) sodium hydroxide aqueous solution. The immersion is carried out at room temperature for 24 hours to allow the activated carbon pores to fully adsorb the sodium hydroxide solution. After removal, it is dried in an oven at 105 degrees Celsius for 12 hours until constant weight. After cooling, it is stored in a drawer for later use. The purpose of the impregnated activated carbon layer is to utilize the high specific surface area of ​​activated carbon to provide gas-solid contact area. Simultaneously, the sodium hydroxide impregnated in the activated carbon pores undergoes an acid-base neutralization reaction with nitrogen oxides, converting gaseous nitrogen oxides into solid sodium nitrate and sodium nitrite, which are deposited in the activated carbon pores, thereby achieving efficient chemical absorption and removal of nitrogen oxides. Each drawer is filled with approximately 8 kg of activated carbon, totaling approximately 32 kg for all four drawers. Based on a typical tunnel blasting operation that generates approximately 500 mg / m³ of nitrogen oxides per blast and a sealed-off area volume of 5000 m³, a single filling can handle the nitrogen oxides generated from approximately 15 to 20 blasts, meaning it needs to be replaced approximately every 2 to 3 working days.

[0052] The fourth stage is the hogalat agent catalytic oxidation layer 15, installed behind the impregnated activated carbon adsorption layer and before the exhaust fan 16. The hogalat agent catalytic oxidation layer 15 also adopts a drawer-type modular structure, consisting of two independent stainless steel frame drawers stacked one on top of the other. Each drawer measures 1500 mm x 900 mm x 150 mm and is filled with hogalat agent particles to a thickness of 150 mm. The hogalat agent is prepared by uniformly mixing analytical grade manganese dioxide powder and copper oxide powder at a mass ratio of 1:1, adding an appropriate amount of deionized water to form a paste, pressing it into spherical particles with a diameter of 3 to 5 mm in a mold, then calcining them in a muffle furnace at 400 degrees Celsius for 4 hours, cooling to room temperature, and then storing them in the drawers for later use. The purpose of the hogalat agent catalytic oxidation layer is to utilize the composite metal oxide catalyst formed by manganese dioxide and copper oxide to catalytically oxidize carbon monoxide to non-toxic carbon dioxide under normal temperature and pressure conditions. The activity of this catalytic reaction originates from the synergistic catalytic effect between manganese dioxide and copper oxide. The multivalent state change characteristics of manganese and copper ions allow lattice oxygen on the catalyst surface to participate in the oxidation reaction of carbon monoxide. The oxygen vacancies generated after the reaction are replenished and regenerated by oxygen molecules in the gas phase, forming a complete catalytic cycle. The catalytic conversion rate of carbon monoxide by the hogallat agent can reach over 95% under dry conditions. Considering that the high humidity inside the tunnel may affect the catalyst activity, a 50 mm thick silica gel drying layer is placed in front of the hogallat agent layer and behind the impregnated activated carbon layer to absorb moisture in the gas flow, reduce the humidity of the gas entering the hogallat agent layer, and protect the catalyst's activity and lifespan. Each drawer is filled with approximately 15 kg of hogallat agent, totaling approximately 30 kg for both drawers. Based on a catalyst lifespan of approximately 200 hours, it needs to be replaced approximately every 15 to 20 working days.

[0053] The exhaust fan 16 is installed on the duct at the air outlet of the purification device. It is an explosion-proof centrifugal fan with a rated power of 30 kW, a rated air volume of 500 cubic meters per minute, and a maximum total pressure of 3000 Pa. The power of the exhaust fan is steplessly adjusted by the central controller via a frequency converter, with an adjustment range of 30% to 100% of the rated power, corresponding to an air volume range of 150 to 500 cubic meters per minute. The purpose of the exhaust fan is to provide suction power for the entire purification system, overcome the resistance loss of the dust suction duct and each level of purification unit, and continuously draw polluted gas from the contaminated area into the purification device for treatment. The exhaust fan outlet is connected to a 600 mm diameter galvanized steel pipe, extending along the lower part of the tunnel to the outside of the tunnel entrance for discharge. The purified and compliant gas is discharged into the atmosphere and does not flow back into the tunnel, avoiding the accumulation effect of even trace amounts of residual pollutants.

[0054] The specific structure of the intelligent linkage control system is as follows: the intelligent linkage control system 7 is installed on the front side of the portal frame beam of the mobile barrier device 3, and consists of four parts: pollutant monitoring module, central controller, actuator and explosion signal recognition module.

[0055] The pollutant monitoring module includes three types of sensors: a laser scattering dust sensor with a range of 0 to 10,000 mg / m³, an accuracy of ±5%, and a response time of less than 1 second; an electrochemical CO sensor with a range of 0 to 2,000 ppm, an accuracy of ±3%, and a response time of less than 5 seconds; and an electrochemical NOx sensor with a range of 0 to 500 ppm, an accuracy of ±3%, and a response time of less than 10 seconds. These three types of sensors are installed at the top, middle, and bottom of the portal frame facing the contaminated area, respectively, and transmit real-time monitoring data to the central controller once per second via an RS485 communication interface. The same three types of sensors are also symmetrically installed on the portal frame facing the clean area to monitor the air quality in the clean area, verify the isolation effect, and determine if there is a pollutant leak. The purpose of the monitoring module is to provide the central controller with real-time, accurate, and continuous pollutant concentration data as a basis for intelligent adjustment decisions.

[0056] The central controller uses a Siemens S7-1200 series programmable logic controller, equipped with a 7-inch touchscreen display for parameter setting and status display, and has a built-in pre-programmed multi-level purification control algorithm. After receiving data from all sensors, the central controller automatically adjusts according to the following control logic: when the dust concentration is higher than 5000 mg / m³, the exhaust fan operates at 100% rated power, and the suction duct wind speed reaches its maximum value; when the dust concentration drops to 1000-5000 mg / m³, the exhaust fan power linearly decreases to 60%-100%; when the dust concentration drops below 1000 mg / m³, the exhaust fan power is maintained at 30%-60%. For carbon monoxide concentration adjustment, when the CO concentration is higher than 500 ppm, the exhaust fan power is appropriately reduced to prolong the residence time of the gas in the hopalat agent layer and improve the catalytic conversion rate; when the CO concentration drops below 200 ppm, the exhaust fan returns to normal power. Regarding the regulation of nitrogen oxide concentration, when the NOx concentration is higher than 100 ppm, the central controller maintains a high suction airflow to ensure sufficient air exchange rates for the activated carbon layer; when the NOx concentration drops below 25 ppm, it automatically reduces the airflow to save energy. When the regulation requirements for dust concentration and CO concentration conflict—that is, high dust concentration requires high airflow while high CO concentration requires low airflow—the system prioritizes the safe control of CO concentration, because the acute harm of CO poisoning far outweighs the harm of dust exposure. Based on this, the system compensates for the reduced dust removal speed caused by lower airflow by extending the operating time. The purpose of the central controller is to replace manual judgment and operation, achieving precise on-demand purification based on real-time concentration data, ensuring both purification effectiveness and maximum energy savings.

[0057] The blasting signal identification module is equipped with vibration and sound sensors. The vibration sensor is a piezoelectric accelerometer with a sensitivity of 100 mV / g, installed at the bottom of the portal frame column to detect ground vibration waves generated by blasting. The sound sensor is an industrial-grade sound pressure sensor with a sensitivity of 50 mV / Pa, installed on the portal frame beam. When the vibration sensor detects an acceleration amplitude exceeding 2g or the sound sensor detects a sound pressure level exceeding 140 dB, the blasting signal identification module determines that a blasting event has occurred and immediately sends a start command to the central controller. Simultaneously, the central controller also uses data from the CO sensor as an auxiliary basis for judgment. If the CO concentration suddenly rises by more than 100 ppm from the background concentration within 5 seconds, the system will automatically start even if the vibration and sound sensors are not triggered due to distance. The purpose of multi-sensor fusion judgment is to improve the reliability of blasting identification and avoid false triggering or missed triggering by a single sensor.

[0058] The actuators include a geared motor that drives the moving pulleys, a hydraulic pump station that drives the hydraulic struts, an electric push rod that drives the hinges, a tubular motor that drives the roller shutter door, a frequency converter that controls the exhaust fan, and a solenoid valve that controls the pulse cleaning. All actuators are controlled uniformly through the digital and analog output ports of the central controller.

[0059] The overall working principle of this system can be summarized as five coordinated stages: "sensing, containment, guidance, purification, and removal." When a blasting event occurs, the blasting signal recognition module first senses the blasting signal and notifies the central controller. The central controller then instructs the mobile barrier device to automatically move to a preset position, lock via hydraulic struts, and unfold its hinges to form a physical barrier with the roller shutter door, completing the rapid containment of the contaminated area. After containment is completed, fresh air is supplied to the contaminated area from above through the forced-flow duct, creating a downward airflow within the contaminated area. Dust and harmful gases gather downwards under the combined action of gravity and airflow, and are efficiently collected and extracted by the suction duct located below to the graded purification device. Inside the tiered purification system, polluted gas undergoes a four-stage treatment process: gravity settling to remove large dust particles, wire mesh to intercept fine particulate matter, activated carbon impregnation for chemical adsorption of nitrogen oxides, and hopalat agent for catalytic oxidation of carbon monoxide. After these four stages, the gas is discharged outside the tunnel in compliance with emission standards. Throughout the operation, the central controller continuously and dynamically adjusts the exhaust fan power and the operating status of each purification unit based on concentration data from sensors. When all monitored indicators remain below the safety threshold for a preset time, the system automatically retracts the isolation components, unlocks, and returns to the standby position, switching the tunnel to full-tunnel conventional ventilation mode. These five interconnected and automatically linked stages form a complete closed-loop operation process, requiring no manual intervention. This ensures that pollutants are contained and purified in the shortest possible time after each blast, protecting the occupational health of construction workers and ensuring the efficient progress of the construction cycle.

[0060] The specific operating steps of the intelligent collaborative blocking and purification method for dust and harmful gases in tunnel blasting construction of the present invention will be clearly and completely described below with reference to the system structure and accompanying drawings described in Embodiment 1.

[0061] Step S1: System Initialization and Standby Monitoring

[0062] Before tunnel blasting, the mobile barrier device 3 is moved to a standby position approximately 100 meters from the tunnel face 2. The four sets of movable pulleys are unlocked and can roll, the hydraulic struts are retracted, the hinges are closed and fitted against the side of the column, and the electric roller shutter is rolled up and stored in the roller above the crossbeam. The entire sealed partition assembly 6 is in a compact, retracted state, not occupying tunnel passage space. The system power is connected, the central controller powers on and initializes, self-checks the connection and operating status of all sensors and actuators, and enters standby mode after displaying normal status for each channel on the touch screen. In standby mode, the pollutant monitoring module continuously collects dust, CO, and NOx concentration data in the tunnel once per second, and records the current background concentration value as a reference line for subsequent blasting signal identification. The vibration and sound sensors of the blasting signal identification module are simultaneously in continuous monitoring mode.

[0063] The purpose of step S1 is to ensure that the system is fully ready before the blast occurs, that all sensors and actuators have been verified to be usable, that the background concentration benchmark value has been collected, and that it can respond and start immediately once the blast signal arrives, without any cold start delay.

[0064] II. Step S2: Automatic positioning of the blasting signal identification and blocking device

[0065] After the construction workers complete the loading and detonation of the explosives, the strong ground vibrations generated by the blast propagate through the surrounding rock at a speed of 3,000 to 5,000 meters per second, reaching the standby position 100 meters from the working face in less than 0.1 seconds. If the vibration sensor detects that the acceleration amplitude exceeds the set threshold of 2g, or the sound sensor detects that the sound pressure level exceeds 140 decibels, the blasting signal recognition module immediately sends a trigger signal to the central controller indicating that "blasting has occurred." Upon receiving the trigger signal, the central controller immediately exits standby mode and enters working mode, issuing the following instructions sequentially according to the pre-programmed control flow: First, it starts the drive motors of the four sets of moving pulleys, controlling the mobile barrier device 3 to automatically move along the tunnel longitudinal direction towards the tunnel face at a speed of 0.5 meters per second; Second, during the movement, the central controller continuously measures the distance traveled by the device through encoder counting or laser rangefinder sensors. When the device has traveled approximately 50 meters from the standby position and reached the preset working position approximately 50 meters from the tunnel face, it automatically stops the drive motors; Third, it starts the hydraulic pump station to drive the four sets of hydraulic struts to extend, with the vertical struts pressing against the tunnel ground and the horizontal struts abutting against the tunnel side walls, firmly locking the device in the working position. The total time from the triggering of the blasting signal to the completion of the device positioning and locking is approximately 100 to 120 seconds.

[0066] The purpose of step S2 is to utilize the physical property that the propagation speed of shock waves is much faster than the diffusion speed of gases, to position the blocking device in place before the high concentration of polluting gases generated by the blast spreads to an area more than 50 meters from the tunnel face. Based on empirical data on gas diffusion in tunnel blasting, although the blast shock wave propagates extremely quickly within the tunnel, the diffusion speed of the dust and harmful gases it carries after the shock wave attenuates is typically on the order of 3 to 10 meters per second. It takes approximately 5 to 15 seconds for the gas to diffuse from the tunnel face to a location 50 meters away. The total travel and positioning time of this system is approximately 100 seconds. During this time, the polluting gases have already begun to diffuse. Therefore, there is a certain time difference between steps S2 and S3, which needs to be compensated for by the rapid deployment and sealing in step S3. In actual engineering, the distance between the standby position and the working position can be adjusted according to the tunnel cross-section size and the amount of blasting charge. When conditions permit, the standby position can be set closer to the working position to shorten the travel time.

[0067] 3. Step S3: Deployment of the sealing partition assembly and sealing of the contaminated area

[0068] Once the movable barrier device 3 reaches its working position and locks in place, the central controller immediately issues an deployment command: First, the electric push rods of the four hinges are activated, and the four hinges simultaneously unfold and flip towards the tunnel side walls within 5 seconds until they are flush with the walls. The elastic sealing strips on the edges of the hinges are pressed tightly against the walls under the continuous pushing force of the push rods. Then, the tubular motor of the electric roller shutter door is activated, and the roller shutter curtain unfolds upward from the roller axis (or downward if there is insufficient space above the crossbeam). Within 15 seconds, it is fully unfolded, covering the space between the crossbeam and the tunnel arch. The elastic sealing strips on the upper edge and both sides of the roller shutter curtain are pressed tightly against the tunnel arch surface and side walls. The total deployment time of the entire sealing barrier assembly does not exceed 20 seconds. After deployment, the door frame, the four hinges, and the electric roller shutter door together form a nearly completely sealed physical barrier layer within the tunnel cross section, dividing the tunnel space into a contaminated area approximately 50 meters long on the side closer to the working face and a clean area on the side farther from the working face.

[0069] The purpose of step S3 is to complete the physical containment of the contaminated area in the shortest possible time, cutting off the path for pollutants to continue spreading to the clean area. After deployment, the central controller immediately reads the data from the sensors on the clean area side to verify whether the concentration of dust and harmful gases in the clean area is maintained at the background level. If the concentration in the clean area rises abnormally, it indicates a significant leak in the barrier layer, and the system will issue an alarm to check the sealing condition. The total time from the blast to the complete deployment and containment of the barrier layer is approximately 120 to 140 seconds. During this time, some polluted gases have already spread to more than 50 meters away. However, due to the cutoff effect of the barrier layer, most of the high-concentration pollutants that continue to be generated and remain near the working face are effectively contained within the contaminated area, significantly reducing the total amount of pollutants spreading to the clean area.

[0070] IV. Step S4: Ventilation system startup and directional airflow establishment

[0071] Within 5 seconds of the partition layer being deployed, the central controller activates the forced-flow fan outside the tunnel entrance and the exhaust fan 16 at the air outlet of the purification device. After the forced-flow fan starts, fresh air is delivered into the contaminated area from above the tunnel via the forced-flow duct 1. The exhaust outlet blows fresh air towards the working face at a speed of 8 to 12 meters per second from a distance of 5 to 10 meters from the working face. Upon reaching the working face, the fresh air is reflected back, diffuses in all directions, and flows downwards. After the exhaust fan 16 starts, negative pressure is generated within the suction duct 4, creating an intake air velocity of 6 to 10 meters per second at the suction duct inlet. This continuously draws contaminated gas from the lower part of the contaminated area into the suction duct and delivers it to the graded purification device 5. The downward thrust of the fresh air delivered from above, combined with the suction force of the suction duct below, establishes an organized, directional airflow field within the contaminated area, from top to bottom and from the working face to the suction duct inlet.

[0072] The purpose of step S4 is to establish a directional airflow within the sealed-off contaminated area that facilitates pollutant collection. From a fluid dynamics perspective, after the blast, the dust and harmful gases in the contaminated area are initially distributed in a highly concentrated and disordered manner. Without external guidance, the natural settling and diffusion of these pollutants would take a long time to reduce their concentration. By combining upward airflow and downward suction, an airflow channel is artificially created within the contaminated area, flowing downwards and from the far end to the near end (towards the suction port). This allows the originally disordered pollutants to be carried by the airflow and directed to converge at the inlet of the suction duct, significantly improving the collection speed and efficiency. Simultaneously, since dust naturally tends to settle downwards under gravity, the downward thrust of the upward airflow aligns with the direction of dust settling due to gravity. The combined effect of these two forces results in an effective settling velocity significantly higher than the natural settling velocity under gravity alone, accelerating the dust's accumulation process towards the downward suction port. During this stage, the central controller adjusts the exhaust fan power based on real-time data from the dust concentration sensor: when the dust concentration is extremely high in the initial stage, it operates at maximum power to extract the high-concentration dust as quickly as possible; as the concentration gradually decreases, the power is automatically reduced to avoid excessive exhaust leading to excessive pressure difference on both sides of the partition layer and causing leakage.

[0073] V. Step S5: Graded purification treatment and emission compliance

[0074] The polluted gas extracted through the dust extraction duct 4 enters the graded purification device 5 and undergoes four stages of purification treatment in sequence according to the airflow direction.

[0075] First-stage gravity settling: After the polluted gas enters the gravity settling chamber, the flow velocity decreases to 0.3 to 0.5 meters per second. Large dust particles with a diameter greater than 100 micrometers are separated from the airflow and settle into the dust collection hopper at the bottom under the action of gravity. After the first-stage treatment, the removal rate of large dust particles is about 70% to 80%, and the dust remaining in the gas is mainly fine particulate matter with a diameter less than 100 micrometers.

[0076] Second-stage steel wire filtration: As gas passes through the 8-layer stacked stainless steel wire mesh 12, fine dust particles are intercepted by the mesh and captured by inertial impaction. The filtration efficiency for particles larger than 10 micrometers reaches over 95%. After this second-stage treatment, the total suspended particulate matter concentration in the gas is reduced from several thousand milligrams per cubic meter to below 20 milligrams per cubic meter. During operation, the central controller automatically triggers the reverse pulse cleaning system 11 based on the pressure difference across the filter to maintain the filter's ventilation capacity.

[0077] The third stage is chemical adsorption using impregnated activated carbon: When the gas after dust removal passes through the impregnated activated carbon adsorption layer 14, gaseous nitrogen oxides react chemically with sodium hydroxide in the pores of the activated carbon. The reaction mechanism is as follows: First, nitric oxide reacts with oxygen in the gas to form nitrogen dioxide on the surface of the activated carbon; then, nitrogen dioxide reacts with sodium hydroxide to form sodium nitrate and sodium nitrite; simultaneously, nitric oxide and nitrogen dioxide can combine in an equimolar ratio to form dinitrogen trioxide, which then reacts with sodium hydroxide to form sodium nitrite. All of the above reactions are carried out at room temperature and pressure without external heating or pressurization. The reaction products are solid sodium nitrate and sodium nitrite, which are deposited in the pores of the activated carbon and removed when the activated carbon is replaced. Under the conditions of a gas flow rate of 1 to 2 meters per second and an activated carbon layer thickness of 100 mm, the single-pass removal rate of nitrogen oxides is approximately 80% to 90%. After the third stage of treatment, the NOx concentration in the gas is reduced from tens to hundreds of ppm initially to below 15 ppm, meeting the requirements of the national occupational exposure limits for hazardous factors in the workplace.

[0078] The fourth stage of hopalat agent catalytic oxidation: When the gas passes through the hopalat agent catalytic oxidation layer 15, carbon monoxide undergoes a catalytic oxidation reaction on the surface of the manganese dioxide and copper oxide composite catalyst to produce carbon dioxide. The reaction mechanism follows the Mars-van Krevelen mechanism: carbon monoxide molecules first adsorb onto the active sites of metal cations on the catalyst surface, react with active oxygen in the catalyst lattice to produce carbon dioxide, which desorbs into the gas phase; the oxygen vacancies generated on the catalyst surface during the reaction are subsequently replenished and regenerated by oxygen molecules in the gas phase, allowing the catalyst to return to its initial state and continue participating in the next catalytic cycle. The entire catalytic process proceeds spontaneously at room temperature without external energy input. Under conditions of a gas flow rate of 0.5 to 1 meter per second and a catalyst layer thickness of 150 mm, the single-pass catalytic conversion rate of carbon monoxide is approximately over 95%. After the fourth stage treatment, the CO concentration in the gas decreases from the initial hundreds to thousands of ppm to below 24 ppm, meeting the national workplace occupational exposure limit safety standards.

[0079] The purified gas is discharged into the atmosphere through the exhaust pipe connected to the tunnel entrance via the exhaust fan 16.

[0080] The synergistic effect between the purification units at each stage in step S5 is reflected in the following aspects: The first-stage gravity settling removes large dust particles, preventing them from clogging the second-stage wire mesh filter and extending the filter's continuous working time and service life; the second-stage wire mesh filter thoroughly removes particulate matter, preventing dust from covering the surface of the third-stage activated carbon and clogging its pores, ensuring that the activated carbon's adsorption contact area for nitrogen oxides is not blocked by the dust layer; while the third-stage activated carbon adsorbs and removes nitrogen oxides, due to the adsorption characteristics of activated carbon itself, it can also partially adsorb residual water vapor in the gas, reducing the humidity of the gas entering the fourth stage, which is beneficial to protecting the catalytic activity of the hogallat agent. Although the four purification units each target different types of pollutants, the treatment effect of the preceding stage directly affects the working conditions and purification efficiency of the following stage. This progressive relationship of "the preceding stage protecting the following stage" means that the purification units at each stage are not simply functional superpositions, but form an organically synergistic overall purification chain.

[0081] VI. Step S6: Concentration Monitoring and Automatic System Deactivation

[0082] During steps S4 and S5, the central controller continuously collects data from the pollutant monitoring module every second. The system's set safety thresholds are: dust concentration below 4 mg / m³, CO concentration below 24 ppm, and NOx concentration below 5 ppm. When all three monitoring indicators on one side of the polluted area are simultaneously and continuously below their respective safety thresholds for more than 10 minutes, the central controller determines that the air quality in the polluted area has returned to a safe level and automatically enters the removal procedure. The removal procedure performs the following operations in sequence: turn off the exhaust fan 16 to stop the exhaust from the dust extraction duct 4; start the tubular motor of the electric roller shutter door to roll the roller shutter door up to the top of the crossbeam, start the electric push rod of the hinge to close the four hinges and attach them to the side of the column, and completely close the sealing partition assembly 6; start the hydraulic pump station to retract the four sets of hydraulic support rods and release the device from locking; start the drive motor of the moving pulley to move the movable barrier device 3 back to the standby position along the tunnel longitudinally at a speed of 0.5 meters per second; after reaching the standby position, stop the drive motor, and the system re-enters standby mode, waiting for the next blasting signal.

[0083] The purpose of step S6 is to automatically determine whether the purification task is complete based on objective monitoring data, avoiding the uncertainty and conservatism of traditional manual estimation of ventilation time. Traditionally, a fixed ventilation waiting time (e.g., 30 to 60 minutes) is set based on experience, and personnel are only allowed to enter after a sufficient period, regardless of whether the actual concentration has dropped to a safe level. This method is neither safe (entry may be allowed before the concentration reaches the standard due to inaccurate experience) nor economical (conservative estimation may lead to continued waiting even after the concentration has reached the standard, wasting time). This system, through real-time concentration monitoring and automatic determination, ensures that the lockdown is only lifted after the concentration has indeed reached the standard, and can lift the lockdown and release construction space as soon as the standard is reached, achieving an optimal balance between safety and construction efficiency.

[0084] VII. Step S7: Switching and Circulating the Ventilation Mode of the Entire Tunnel

[0085] After the mobile barrier device 3 returns to the standby position, the physical barrier layer has been completely removed, and the tunnel space is restored to a through state. The fan in the forced ventilation duct 1 continues to operate, switching to the traditional forced ventilation mode, continuously supplying fresh air towards the tunnel face to provide uniform ventilation throughout the entire tunnel length, providing a standard working environment for subsequent muck removal, support, and other construction procedures. When the construction personnel complete the next cycle of drilling, charging, and preparation for detonation, the system automatically starts from the standby monitoring state in step S1 and repeats the entire process from steps S2 to S7, achieving intelligent and coordinated barrier purification of dust and harmful gases during the blasting construction cycle.

[0086] The purpose of step S7 is to achieve seamless integration between this system and traditional tunnel ventilation methods. This system does not replace traditional forced ventilation, but rather rapidly completes centralized treatment of pollutants in the high-concentration pollution stage after blasting using a "sealing and directional purification" mode. After treatment, it automatically switches off to give way to the traditional ventilation mode to continue serving subsequent construction procedures. The automatic switching between the two modes ensures uninterrupted and conflict-free ventilation throughout the entire construction cycle.

[0087] To verify the actual purification effect of this system, a field comparative test was conducted in a highway tunnel under construction. The tunnel is a two-lane tunnel with an excavated cross-sectional area of ​​approximately 100 square meters. The blasting face is about 600 meters from the tunnel entrance. Smooth blasting was used, and the charge for a single blast was approximately 120 kilograms of emulsion explosive.

[0088] Comparative Experiment 1: Dust Removal Effect with and without Physical Partitions

[0089] Under the same blasting conditions, the dust concentration at a distance of 100 meters from the tunnel face (the area where construction workers typically work) was tested over time under two conditions: with and without a barrier device. Without a barrier device, using only traditional forced ventilation, the dust concentration at this location reached approximately 3500 mg / m³ one minute after the blast, decreased to approximately 800 mg / m³ after 10 minutes, approximately 120 mg / m³ after 30 minutes, and approximately 15 mg / m³ after 60 minutes. The time required to reach the safe standard of 4 mg / m³ was approximately 80 minutes. With a barrier device, the system completed containment and activation within approximately 2 minutes after the blast. Because the physical barrier prevented pollutants from spreading to a distance of 100 meters, the dust concentration at this location remained below the background concentration level of 2 to 4 mg / m³ after the blast, without any increase in concentration. Within the contaminated area (30 meters from the working face), the dust concentration dropped from a peak of approximately 8,000 milligrams per cubic meter after the blast to below 4 milligrams per cubic meter about 20 minutes after the system was started, after which the system automatically removed the isolation barrier.

[0090] The above comparison results show that after adopting this system, the dust concentration in the work area of ​​construction personnel is always maintained below the safety standard, completely eliminating secondary exposure. This is an effect that traditional ventilation methods cannot achieve no matter how long they operate. At the same time, the total waiting time from blasting to the restoration of the air quality of the entire tunnel to a safe level is reduced from about 80 minutes in the traditional method to about 22 minutes (including 2 minutes of sealing start time and 20 minutes of purification time), which is about 72 percent shorter and has significant implications for accelerating the construction cycle.

[0091] Comparative Experiment 2: Testing the Purification Effect of Each Stage of the Stage-Based Purification Device

[0092] Under normal operating conditions, samples were taken and analyzed at the inlet and outlet of each purification unit in the graded purification device to test the purification efficiency of each stage. The test was conducted 5 minutes after the explosion, when the concentration of pollutant gas was at a high level. The test results are as follows:

[0093] Before entering the purification device (at the dust extraction duct outlet): dust concentration is approximately 6500 mg / m³, CO concentration is approximately 850 ppm, and NOx concentration is approximately 180 ppm.

[0094] After passing through the gravity settling chamber: the dust concentration drops to about 1600 mg / m³, with a removal rate of about 75%; the CO and NOx concentrations remain basically unchanged.

[0095] After passing through the steel wire filter: the dust concentration drops to about 12 mg / m³, with a removal rate of over 99% (compared to imported products); the CO and NOx concentrations remain basically unchanged.

[0096] After being impregnated with an activated carbon layer: the dust concentration is approximately 10 mg / m³, the CO concentration remains basically unchanged at approximately 830 ppm, the NOx concentration drops to approximately 22 ppm, and the NOx removal rate is approximately 88%.

[0097] After passing through the hogalat agent layer: the dust concentration is about 8 mg / m³, the CO concentration is reduced to about 18 ppm, the CO removal rate is about 98%, and the NOx concentration remains basically unchanged at about 20 ppm.

[0098] Final emission gas indicators: dust concentration approximately 8 mg / m³, CO concentration approximately 18 ppm, and NOx concentration approximately 20 ppm. Both CO and NOx concentrations are below the occupational exposure limits for workplaces stipulated by national standards (30 ppm for short-term CO exposure and 25 ppm for NOx), meeting emission standards. Although the dust concentration of 8 mg / m³ is slightly higher than the total dust time-weighted average allowable concentration of 4 mg / m³, this value represents the instantaneous emission during the high-concentration phase 5 minutes after the blast. The concentration continuously decreased as the purification process progressed, and by 15 minutes after the blast, the emitted dust concentration had dropped to below 2 mg / m³.

[0099] The aforementioned graded test data demonstrates that: First, each of the four purification units possesses highly efficient removal capabilities for its target pollutants. Gravity settling and wire filtration work together to achieve efficient dust removal, impregnated activated carbon achieves effective chemical absorption of nitrogen oxides, and hogallat agent achieves efficient catalytic oxidation of carbon monoxide. Second, the pre- and post-stage protection relationships between each stage achieve the expected synergistic effect. After the first two stages of dust removal, the gas entering the activated carbon layer is essentially free of particulate matter, ensuring that the activated carbon adsorption area is not obscured by dust, resulting in a high NOx removal rate of 88%. Third, when faced with extremely high concentrations of multi-component mixed pollutants after an explosion, the overall system can simultaneously and effectively remove three different types of pollutants—dust, CO, and NOx—and achieve emission standards, verifying the feasibility and effectiveness of the "graded synergistic purification" technical approach.

[0100] Comparative Experiment 3: Energy Consumption Comparison Between Intelligent Adjustment and Fixed Parameter Operation

[0101] In five consecutive purification cycles, the system's cumulative energy consumption was compared between two modes: an automatic adjustment mode using an intelligent linkage control system and a fixed maximum power operation mode. In the fixed maximum power mode, the exhaust fan operated at full power (30 kW) until manually shut down after the air quality was deemed acceptable. In the intelligent adjustment mode, the exhaust fan power was automatically adjusted by the central controller based on concentration data. The results showed that in the five purification cycles, the exhaust fan in the fixed maximum power mode ran for approximately 350 minutes, consuming approximately 175 kWh; while the exhaust fan in the intelligent adjustment mode ran for approximately 110 minutes, consuming approximately 68 kWh, representing a reduction of approximately 61%. This is because the intelligent adjustment mode automatically reduced the exhaust fan power in the later stages of purification when the concentration had significantly decreased, while the fixed mode consistently operated at full load, resulting in substantial wasted energy.

[0102] Based on the above three sets of comparative experiments, the technical effects and underlying mechanisms of this invention can be summarized as follows:

[0103] First, it completely eliminates secondary pollution. The underlying mechanism of this effect lies in the physical barrier, which spatially cuts off the diffusion path of pollutants. In the traditional full-tunnel ventilation dilution mode, pollutants diffuse along the entire longitudinal length of the tunnel through two mechanisms: molecular diffusion driven by concentration gradient and airflow carrying. Regardless of the ventilation volume, as long as the pollutants are inside the tunnel, there will inevitably be a concentration gradient-driven diffusion backward. However, the physical barrier creates a "cliff" of concentration gradient in the tunnel. There are no free flow channels for gas on both sides of the barrier layer, and the diffusion process driven by concentration gradient is forcibly interrupted. Therefore, the concentration in the rear area can be maintained at the background level without being affected.

[0104] Second, it significantly reduces purification waiting time. The underlying mechanism of this effect lies in the substantial reduction in processing volume. Assuming a tunnel cross-section of 100 square meters, the total tunnel volume from the face to the entrance (600 meters) in the traditional model is 60,000 cubic meters. However, the volume of the contaminated area after sealing off by this system is 50 meters multiplied by 100 square meters, equaling 5,000 cubic meters, only one-twelfth of the total tunnel volume. Under the same ventilation conditions, the number of air changes and the time required to reduce the pollutant concentration in a 5,000 cubic meter space from a high value to a safe threshold are far less than the time required to dilute a 60,000 cubic meter space to the same concentration. This is not a linear one-twelfth relationship, because the concentration reduction rate within the sealed space also benefits from the efficient collection brought about by directional airflow guidance, making the actual reduction even more significant.

[0105] Third, the simultaneous and efficient removal of multiple pollutants. The underlying mechanism of this effect lies in the staged purification process, which employs the removal mechanism best suited to the physicochemical properties of different pollutants: large dust particles, with their high density and inertia, are suitable for gravity settling; fine dust particles are suitable for mechanical filtration; NOx, being an acidic gas, is suitable for alkaline chemical absorption; CO, chemically stable and not easily adsorbed or dissolved at room temperature, can be catalytically oxidized on the surface of transition metal oxide catalysts. By combining these four purification technologies, each with its own strengths, in a rational sequence of "dust removal before gas removal, acidic gas removal before stable gas removal," each pollutant is efficiently removed when passing through its corresponding purification stage without interfering with the normal operation of other purification stages.

[0106] Fourth, it significantly saves energy. The underlying mechanism of this effect lies in the application of the negative feedback control principle. After the blast, the concentration of pollutants decays exponentially over time. In the early stage of purification when the concentration is high, a large air volume is needed for rapid extraction. However, in the later stage when the concentration has decreased significantly, continuing to extract with a large air volume yields very little marginal purification benefit. The intelligent adjustment system automatically reduces the fan power in the later stage by monitoring the concentration changes in real time, so that the fan power curve decreases synchronously with the concentration decay curve. This avoids the ineffective energy consumption of operating at fixed power in the low concentration stage and achieves a precise match between energy consumption and purification needs.

[0107] The overall working principle of this method is a fully automated closed-loop operation process centered on "time-sequential linkage" and "parameter coupling". Time-sequential linkage is reflected in the strict sequential relationship between steps S1 to S7: the completion of each step is a prerequisite for the next step, and the execution of each step is triggered by the completion signal or sensor data of the previous step, forming a complete time-sequence chain of "standby monitoring → explosion trigger → movement and positioning → deployment of containment → ventilation start → graded purification → concentration reaching standard → removal and reset → mode switching". Parameter coupling is reflected in the operation of steps S4 and S5, where the three parameters of dust concentration, CO concentration, and NOx concentration are interconnected through the control algorithm of the central controller, jointly determining the working power of the exhaust fan and the actual working status of each purification unit, achieving synergistic optimization purification of multiple pollutants rather than independent treatment of a single pollutant. This operation mode, which combines time-series linkage and parameter coupling, enables the system to adaptively respond to the actual pollution situation throughout the entire blasting construction cycle. This ensures the reliability of the purification effect while optimizing operating efficiency and energy consumption. No manual intervention is required throughout the process, fundamentally changing the extensive management method of ventilation and sewage discharge in traditional tunnel blasting construction that relies on experience judgment and manual operation.

[0108] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention shall be determined by the claims.

Claims

1. A smart collaborative barrier and purification system for dust and harmful gases during tunnel blasting, characterized in that, include: The mobile barrier device (3) has a main frame (8), the top and sides of which are provided with deployable sealing partition components (6), and the bottom is provided with a moving mechanism (9) and a locking mechanism (10); the mobile barrier device is used to move to a preset position in the tunnel after blasting and deploy the sealing partition components to form a physical partition layer, dividing the tunnel space into a contaminated area close to the working face (2) and a clean area away from the working face; A forced-air duct (1) is arranged inside the tunnel to deliver fresh air to the contaminated area; The dust extraction duct (4) is arranged inside the tunnel. One end of it is connected to the polluted area, and the other end is connected to the dust and harmful gas graded purification device (5). It is used to guide the polluted gas in the polluted area to the graded purification device. The dust and harmful gas graded purification device (5) has multiple purification units inside along the airflow direction, and an exhaust fan (16) is provided at the air outlet to purify the polluted gas drawn in through the dust suction pipe step by step before discharging it. The intelligent linkage control system (7) includes a pollutant monitoring module, a central controller and an actuator installed on the mobile barrier device. The central controller automatically adjusts the wind speed of the dust extraction duct, the operating parameters of the graded purification device and the power of the exhaust fan according to the real-time monitoring data of the pollutant monitoring module.

2. The system according to claim 1, characterized in that: The main frame (8) is a portal frame structure, assembled from steel profiles. The portal frame adopts a telescopic structure, and the width and height of the frame can be adaptively adjusted by a hydraulic or electric adjustment mechanism to adapt to tunnels with different cross-sectional dimensions.

3. The system according to claim 1 or 2, characterized in that: The sealing partition assembly includes hinges on the columns on both sides of the main frame (8) and an electric roller shutter door on the crossbeam. The hinges and the electric roller shutter door are made of explosion-proof and fire-resistant composite materials and have elastic sealing strips on the edges. When unfolded, they form an airtight contact with the tunnel wall.

4. The system according to claim 1, characterized in that: The forced air duct (1) is arranged above the mobile barrier device, and the dust suction duct (4) is arranged on the lower side of the mobile barrier device and close to the tunnel wall; the forced air duct and the dust suction duct cooperate to form a directional airflow from top to bottom in the polluted area; The compressed air volume is greater than the exhaust air volume, with a ratio of 1.2:1 to 1.5:1, so that the polluted area is maintained in a slightly positive pressure state.

5. The system according to claim 1, characterized in that: The multi-stage purification unit includes, in sequence along the airflow direction, a gravity settling chamber, a steel wire filter (12), an impregnated activated carbon adsorption layer (14), and a hopalat agent catalytic oxidation layer (15).

6. The system according to claim 5, characterized in that: The steel wire filter (12) is equipped with an anti-pulse cleaning system (11). The central controller automatically triggers the anti-pulse cleaning according to the pressure difference on both sides of the steel wire filter, and blows the trapped dust into the dust collection drawer (13) at the bottom. The impregnated activated carbon adsorption layer (14) and the hopalat agent catalytic oxidation layer (15) both adopt a drawer-type modular quick-change structure.

7. The system according to claim 1, characterized in that: The intelligent linkage control system also includes a blasting signal recognition module, which is equipped with a vibration sensor, a sound sensor and / or a CO concentration change detection unit to identify blasting events and trigger the system to start automatically.

8. A method using the intelligent collaborative barrier and purification system for dust and harmful gases during tunnel blasting construction as described in any one of claims 1 to 7, characterized in that, Includes the following steps: S1: The system is in standby mode, the mobile barrier device is in standby position, the sealing partition assembly is in retracted state, and the pollutant monitoring module continuously monitors the environmental parameters inside the tunnel. S2: After the blasting signal is detected, the central controller issues an instruction and the mobile barrier device automatically moves to a preset distance from the working face and locks itself through the locking mechanism (10); S3: The sealing partition component automatically unfolds to form a physical partition layer, dividing the tunnel into a contaminated area and a clean area; S4: Start the forced air duct, the dust suction duct and the exhaust fan to form a directional airflow in the polluted area and guide the polluted gas to the graded purification device through the dust suction duct. S5: The polluted gas is discharged after being treated by multiple purification units in the graded purification device and meets the emission standards. S6: When the pollutant monitoring module detects that the concentration of each pollutant has been continuously lower than the set threshold for a preset time, the sealing partition component is automatically retracted, and the movable barrier device is unlocked and returns to the standby position.

9. The method according to claim 8, characterized in that: In steps S4 and S5, the central controller performs multi-parameter coordinated adjustment based on real-time monitoring data: adjusting the wind speed of the dust suction duct according to the dust concentration, adjusting the residence time of the gas in the hopalat agent catalytic oxidation layer according to the CO concentration, and adjusting the air exchange rate of the impregnated activated carbon adsorption layer according to the NOx concentration.

10. The method according to claim 8, characterized in that: After step S6 is completed, step S7 is also included: the system switches to the full tunnel ventilation mode where the forced air duct works alone, so as to achieve full tunnel ventilation; when the next blasting operation is to be carried out, steps S2 to S6 are repeated.

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