Gas phase concentrated return air induced tunnel full section dust collecting device and method

Abstract

The present application belongs to the technical field of tunnel face dust removal, and particularly relates to a kind of gas phase concentrated return air induced tunnel full section dust collection device and method;The device includes dust collection bin, dust collection bin is provided with door hole allowing to pass along the axial direction of tunnel;The side of dust collection bin, the end face facing the tunnel face and the door hole are arranged with dust collection unit;The air outlet of dust collection bin is sequentially connected with gas-liquid mixing mechanism, demisting mechanism and negative pressure mechanism;The negative pressure mechanism cooperates with the dust collection unit, forms a front suction, one is induced by negative pressure after push-pull mode;A kind of gas phase concentrated return air induced tunnel full section dust collection device and method provided by the present application, according to the particle size and spatial distribution characteristics of dust particles formed after blasting, reconstructs the wind flow organization of tunnel section by using face return air and push-pull induction mode, and combines real-time monitoring and adjusting system, realizes full section coverage, directional trapping, centralized processing and phased regulation of dust.

Description

Technical Field

[0001] This invention belongs to the field of tunnel face dust removal technology, specifically relating to a gas-phase centralized return air induced tunnel full-section dust collection device and method. Background Technology

[0002] In railway and highway tunnel construction, the drill-and-blast method is still widely used. Shortly after blasting, the tunnel face area generates a large amount of rock dust, blast fumes, and irritating gases (such as NOx and CO). Engineering practice has shown that post-blast pollution is not uniformly dispersed, but rather exists in concentrated gaseous clumps near the tunnel face, exhibiting a clear tendency to diffuse.

[0003] Based on the particle size and spatial distribution characteristics of dust particles, larger particles (≥5μm) settle rapidly after blasting due to inertia and gravity, mainly concentrated in the near-source area of ​​the tunnel face and the lower part of the cross section; fine particles (1-5μm) and ultrafine particles (<1μm) have strong airflow ability and are prone to forming suspended enrichment areas in the upper and middle parts of the tunnel cross section, the arch and the vicinity of the cross passage, which are the main pollutants affecting the resumption of work time and occupational health.

[0004] Existing technologies have significant drawbacks. Spray dust suppression relies primarily on dispersion and settling, achieving a PM2.5 removal rate of only 30%-50%. Furthermore, it easily causes blurred visibility through vehicle windows and stains on the secondary lining surface, with subsequent repair costs accounting for 5%-8% of the total lining construction cost. Jet fans or forced-flow ventilation are dilution-type ventilation methods that do not control pollution sources. Instead, they easily promote the diffusion of pollutant gases towards the already constructed sections and cross passages. In interconnected tunnel structures, turbulence and backflow cause the pollution diffusion range to expand by 2-3 times. Existing dust removal devices mostly operate under fixed conditions, with energy consumption of 0.8-1.2 kWh / 1000 m³ per unit of air volume. They cannot adaptively adjust according to changes in air quality and construction procedures, resulting in high energy consumption, poor targeting, and a disconnect between operation and construction. Moreover, the waiting time for resumption of work after blasting is generally as long as 30-60 minutes, severely impacting construction efficiency. Summary of the Invention

[0005] This invention aims to solve the problems of insufficient coverage and low dust removal efficiency in current tunnel face dust removal methods.

[0006] This invention provides the following technical solution: a gas-phase centralized return air induced tunnel full-section dust collection device and method, including a dust collection chamber, the suction range of the dust collection units distributed on the dust collection chamber is used to cover the entire tunnel section; the air outlet of the dust collection chamber is connected in series with a gas-liquid mixing mechanism, a demisting mechanism and a negative pressure mechanism; the gas-liquid mixing mechanism is used to spray water into the dust-laden airflow flowing out of the dust collection chamber, so that the dust-laden airflow and water are mixed and the dust particles are degraded, and the airflow and dust particles are separated; the demisting mechanism is used to intercept water droplets in the airflow, and the negative pressure mechanism is used to generate negative pressure and discharge the airflow. The negative pressure mechanism and the dust collection unit cooperate to form a push-pull mode in which one suctions in front and the other is induced by negative pressure in the back.

[0007] Furthermore, the dust collection unit located in the upper part of the tunnel cross-section on the dust collection bin has a dust collection hole diameter of 0.1~1mm, and the dust collection hole adopts a honeycomb hole structure, with a flow resistance pressure loss between 100~200Pa; The dust collection unit located at the lower part of the tunnel cross-section on the dust collection chamber has a dust collection hole diameter of 5~10mm. The dust collection hole adopts a straight hole structure, and the flow resistance pressure loss is between 50-100Pa.

[0008] Furthermore, the gas-liquid mixing mechanism includes an upper mixing chamber, a middle settling chamber, and a lower water tank; The entrance to the mixing chamber is connected to the air outlet of the dust collection chamber. A spray system is installed inside the mixing chamber. The mixing chamber and the settling chamber are connected by a vertical drainage pipe. The bottom opening of the drainage pipe is below the air outlet of the settling chamber. The water tank and the settling chamber are connected by a water pipe. The inlet of the water pipe is located at the bottom of the settling chamber, and the outlet of the water pipe is below the liquid surface of the water tank.

[0009] Furthermore, the demisting mechanism includes a demisting chamber and a baffle plate installed at the air outlet of the settling chamber; the air inlet of the demisting chamber is connected to the air outlet of the settling chamber, the air outlet of the demisting chamber is connected to a negative pressure mechanism, and a demisting filter element is installed in the demisting chamber between its air inlet and air outlet.

[0010] Furthermore, the bottom of the demisting chamber of the demisting mechanism is connected to the water tank of the gas-liquid mixing mechanism, and a liquid seal is formed at the connection.

[0011] Furthermore, the demisting chamber of the demisting mechanism and the settling chamber of the gas-liquid mixing mechanism share a water pipe, with part of the water pipe inlet located in the settling chamber and part of it located in the demisting chamber.

[0012] Furthermore, the dust collection chamber is equipped with a doorway that allows passage along the tunnel axis; dust collection units are arranged on the side of the dust collection chamber, the end face facing the tunnel face, and inside the doorway; the suction range of the dust collection units on the side, end face, and inside the doorway of the dust collection chamber is used to prevent dust in the entire tunnel cross section from spreading to the rear of the dust collection chamber.

[0013] Furthermore, the dust collection bin, dust collection unit, gas-liquid mixing mechanism, demisting mechanism, and negative pressure mechanism are arranged on the traveling mechanism, which has a connecting device that can be connected to the trolley.

[0014] One method involves placing a gas-phase centralized return air induced tunnel full-section dust collection device between the tunnel face and the constructed section, with the device located 5-10m away from the tunnel face. The dust collection unit and negative pressure mechanism are activated, and a controlled negative pressure induction zone with a negative pressure value of -50 to -200Pa is constructed between the tunnel face and the dust collection chamber using the return air from the tunnel face. The dust-laden airflow is introduced into the gas-liquid mixing mechanism through the dust collection chamber, where the gas-liquid mixing mechanism performs dust suppression treatment at a liquid-to-gas ratio of 1-5L / m³. After demisting by the demisting mechanism, the treated airflow is discharged from the negative pressure mechanism.

[0015] Furthermore, air quality monitoring sensors are installed at the tunnel face area, the upper part of the tunnel cross-section where dust is suspended and enriched, and at the air inlet and outlet of the gas-phase centralized return air induced tunnel full-section dust collection device; the air quality monitoring sensors are used to monitor the dust concentration in the tunnel. A pollution concentration of ≥5mg / m³ in the tunnel is considered a high pollution state, a pollution concentration of ≤1mg / m³ is considered a low pollution state, and a pollution concentration of 5mg / m³ < pollution concentration >1mg / m³ is considered a medium pollution state. Under high pollution conditions, all dust collection units on the dust collection chamber are turned on, and the air volume of the dust collection units is 80%~100% of the rated air volume. The fan frequency of the negative pressure mechanism is 50~60Hz; the liquid-gas ratio of the gas-liquid mixing mechanism is maintained between 3~5L / m³. Under medium pollution conditions, all dust collection units on the dust collection chamber are turned on, and the air volume of the dust collection unit is 50%~80% of the rated air volume. The fan frequency of the negative pressure mechanism is 30~50Hz; the liquid-gas ratio of the gas-liquid mixing mechanism is maintained between 2~3L / m³. Under low pollution conditions, only the dust collection unit located in the upper part of the tunnel cross section on the dust collection chamber is turned on. The air volume of the dust collection unit is 30% to 50% of the rated air volume, and the fan frequency of the negative pressure mechanism is 20 to 30 Hz. The liquid-to-gas ratio of the gas-liquid mixing mechanism is maintained between 1 and 2 L / m³.

[0016] Compared with the prior art, the advantages of the present invention are: This invention provides a gas-phase centralized return air induced full-section dust collection device and method for tunnels. Targeting the particle size and spatial distribution characteristics of dust particles formed after blasting, it reconstructs the airflow organization of the tunnel cross-section using face return air and push-pull induction methods. Combined with a real-time monitoring and adjustment system, it achieves full-section dust coverage, directional collection, centralized treatment, and phased control. This invention is applicable to single-track / double-track railway and highway tunnels with a cross-section width of 6-15m and a height of 5-10m, as well as tunnel structures where the left and right tracks are interconnected with the pilot tunnel.

[0017] After blasting, the tunnel face area typically experiences a return airflow trend from the tunnel face towards the constructed section due to pressure changes, temperature differences, and ventilation conditions. This invention uses this return airflow as the basic airflow condition, constructing a controlled negative pressure induction zone with a negative pressure value of -50 to -200 Pa between the tunnel face and the dust collection chamber through a push-pull induction method. This constrains and enhances the return airflow direction and flow rate, causing the polluted gaseous agglomerates formed after blasting to be pushed and guided along a predetermined path into the treatment chain. Based on this, a real-time monitoring and adjustment system dynamically adjusts the dust collection area and airflow according to changes in air quality at the tunnel cross-section, ensuring that the device's operating status matches the pollution level and construction procedures.

[0018] The dust collection unit on the dust collection bin is designed with a structure matching dust particle size, tunnel space characteristics, and dust collection unit structure to improve the targeting and stability of dust removal. The collection efficiency of particles of different sizes is more than 30% better than that of existing technologies.

[0019] The gas-liquid mixing mechanism adopts a gas-liquid mixing spray structure, which forms a dense water curtain through the spray head, allowing the dust-laden airflow to fully collide with the water. The degradation of suspended dust particles is achieved by utilizing the collision, agglomeration and sedimentation effects of gas and liquid.

[0020] The defogging mechanism adopts a composite structure of baffle plate and defogging filter element, with a water droplet interception efficiency of ≥99%. It can effectively intercept water droplets with a particle size of ≥10μm, prevent water mist from entering the tunnel construction space, and avoid vehicle glass fogging and secondary lining surface contamination.

[0021] Using post-blast contaminated gaseous masses as the control target, a controlled negative pressure induction zone effectively suppresses the spread of pollution to the constructed section and cross passage, reducing the pollution diffusion range by more than 85%. Based on the return air and push-pull induced reconstructed cross-sectional airflow organization, combined with a full-section zoned dust collection design, full-section coverage dust collection is achieved under non-uniform pollution source conditions, with a fine particulate matter (PM2.5) removal rate of ≥95% and a total dust removal rate of ≥98%. Through a real-time monitoring and adjustment system, automatic adjustment of dust collection area and air volume is achieved, with energy consumption per unit processing air volume of only 0.3-0.5 kWh / 1000m³. Compared with existing technologies, dust collection devices reduce dust levels by 30%-50%; after the slag removal operation is completed, the dust collection device automatically enters the low-treatment stage, achieving construction process-friendly operation, reducing equipment operating load by more than 50%, and extending equipment service life; it significantly shortens the waiting time for resumption of work after blasting, from 20-60 minutes in existing technologies to 5-8 minutes, greatly improving construction efficiency, while improving the occupational health environment of tunnel construction, so that the dust concentration in the tunnel working environment is stably controlled below 0.3mg / m³, which meets the requirements of "Occupational Exposure Limits for Hazardous Factors in the Workplace" (GBZ2.1-2019). Attached Figure Description

[0022] Figure 1 A three-dimensional view of a full-section dust collection device for a gas-phase concentrated return air induced tunnel. Figure 2 Left view of the full-section dust collection device for the gas-phase concentrated return air induced tunnel; Figure 3 This is a diagram showing the internal structure of a full-section dust collection device for a gas-phase centralized return air induced tunnel. Figure 4 This is a diagram of the internal structure of the gas-liquid mixing mechanism and the demister mechanism (first angle). Figure 5 This is a diagram of the internal structure of the gas-liquid mixing mechanism and the demisting mechanism (second angle). Figure 6 Perspective view of the gas-liquid mixing mechanism and the demisting mechanism; Figure 7 This is a schematic diagram showing the flow of the medium within the gas-liquid mixing mechanism and the demisting mechanism.

[0023] In the diagram: 1-Dust collection bin; 1.1-Door opening; 2-Dust collection unit; 3-Gas-liquid mixing mechanism; 3.1-Mixing chamber; 3.2-Settling chamber; 3.3-Water tank; 3.4-Spraying system; 3.5-Drainage pipe; 3.6-Water pipe; 4-Demisting mechanism; 4.1-Demisting chamber; 4.2-Baffle plate; 4.3-Demisting filter element; 5-Negative pressure mechanism; 6-Traveling mechanism; A-Airflow direction; B-Dust particle direction; C-Water droplet direction; D-Liquid surface. Detailed Implementation

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Example 1 like Figure 1 , Figure 2The diagram illustrates a gas-phase centralized return air induced tunnel full-section dust collection device, comprising a dust collection chamber 1, with dust collection units 2 distributed on the dust collection chamber 1 whose suction range covers the entire tunnel cross-section. In a first embodiment, the outer contour of the dust collection chamber 1 is adapted to the contour of the tunnel cross-section, and the dust collection chamber 1 itself forms a "retaining wall" located between the tunnel face and the constructed section. The dust collection units 2 are distributed on the end face of the dust collection chamber 1 facing the tunnel face. In a second embodiment, the outer contour of the dust collection chamber 1 is adapted to the contour of the tunnel cross-section, and the dust collection chamber 1 itself forms a "retaining wall" located between the tunnel face and the constructed section. The dust collection chamber 1 is designed as a "retaining wall," but it also has a pre-reserved doorway 1.1 along the tunnel axis that allows passage of construction equipment. The doorway 1.1 does not impede the passage of construction equipment. Dust collection units 2 are arranged on the sides, the end face facing the tunnel face, and inside the doorway 1.1. The suction range of the dust collection units 2 on the sides, end faces, and inside the doorway 1.1 of the dust collection chamber 1 is used to prevent dust from spreading from the entire tunnel cross-section to the rear of the dust collection chamber 1. The dust collection units 2 on the dust collection chamber 1 form a dust collection area covering the tunnel cross-section without any dead angles. In the third embodiment, the dust collection chamber 1 is an internally connected support structure, and the dust collection units 2 are distributed on the dust collection chamber 1. Regardless of the specific structural modification, the purpose is to achieve the suction of dust from the entire tunnel cross-section by the dust collection units 2.

[0026] The air outlet of the dust collection chamber 1 is connected in series with the gas-liquid mixing mechanism 3, the demisting mechanism 4, and the negative pressure mechanism 5. The gas-liquid mixing mechanism 3 is used to spray water into the dust-laden airflow flowing out of the dust collection chamber 1, so that the dust-laden airflow and water are mixed and the dust particles are degraded, and the airflow and dust particles are separated. The demisting mechanism 4 is used to intercept water droplets in the airflow. The negative pressure mechanism 5 is used to generate negative pressure and discharge the airflow. The negative pressure mechanism 5 cooperates with the dust collection unit 2 to form a push-pull mode in which one is suctioned in front and the other is induced by negative pressure in the back.

[0027] After blasting, the tunnel face area typically experiences a return airflow trend from the tunnel face towards the constructed section due to pressure changes, temperature differences, and ventilation conditions. This invention uses this return airflow as the basic airflow condition, constructing a controlled negative pressure induction zone with a negative pressure value of -50 to -200 Pa in front of the dust collection chamber 1 using a push-pull induction method. This constrains and strengthens the return airflow direction and flow rate, causing the polluted gaseous agglomerates formed after blasting to be pushed and guided along a preset path into the processing chain.

[0028] The dust collection chamber 1, dust collection unit 2, gas-liquid mixing mechanism 3, demisting mechanism 4, and negative pressure mechanism 5 are arranged on the traveling mechanism 6, which has a connecting device for connecting to the trolley. The traveling mechanism 6 is electrically driven, with a moving speed of 0.5~1m / min. After being connected to the secondary lining trolley, the traveling mechanism 6 can move forward synchronously with the trolley along the tunnel axis. The bottom of the traveling mechanism 6 is equipped with an anti-slip braking mechanism to ensure stable parking inside the tunnel. The traveling mechanism 6 is located on both sides of the portal 1.1 of the dust collection chamber 1, without occupying the construction passage area, ensuring normal passage for vehicles and equipment.

[0029] The dust collection units 2 on the dust collection chamber 1 are arranged in zones according to the particle size and spatial distribution characteristics of dust particles in the tunnel cross section. Different dust collection units 2 are equipped with dust collection hole structures with different pore sizes, pore shapes or flow resistance characteristics to adapt to the movement and collection characteristics of dust particles of different sizes under the action of airflow.

[0030] For the suspended enrichment area in the upper part of the tunnel cross section, which is mainly composed of fine particles with a particle size of <5μm; the dust collection unit 2 located in the upper part of the tunnel cross section on the dust collection bin 1 has a dust collection hole diameter of 0.1~1mm, the dust collection hole adopts a honeycomb hole structure, and the flow resistance pressure loss is between 100~200Pa. For the area in the lower part of the tunnel cross section that is dominated by larger particles with a diameter of ≥5μm, the dust collection unit 2 located in the lower part of the tunnel cross section on the dust collection bin 1 has a dust collection hole diameter of 5~10mm, the dust collection hole adopts a straight hole structure, and the flow resistance pressure loss is between 50-100Pa.

[0031] like Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 As shown: the gas-liquid mixing mechanism 3 includes an upper mixing chamber 3.1, a middle settling chamber 3.2, and a lower water tank 3.3; The inlet of mixing chamber 3.1 is connected to the outlet of dust collection bin 1. A spray system 3.4 is installed inside mixing chamber 3.1. The spray heads of spray system 3.4 form a dense water curtain, allowing the dust-laden airflow to fully collide with the water. This utilizes gas-liquid collision, agglomeration, and settling to degrade suspended dust particles. Mixing chamber 3.1 and settling chamber 3.2 are connected by a vertical guide pipe 3.5. The bottom opening of guide pipe 3.5 is located below the outlet of settling chamber 3.2. Guide pipe 3.5 forcibly guides the wetted dust particles below the outlet of settling chamber 3.2, hindering the movement of the wetted dust particles. The air escapes from the air outlet of the settling chamber 3.2, while the airflow flows out from the air outlet of the settling chamber 3.2. The water tank 3.3 is connected to the settling chamber 3.2 by a water pipe 3.6. The inlet of the water pipe 3.6 is located at the bottom of the settling chamber 3.2, and the outlet of the water pipe 3.6 is located below the liquid surface of the water tank 3.3. The wetted dust particles fall to the bottom of the settling chamber 3.2 and then enter the water pipe 3.6. The outlet of the water pipe 3.6 is located on the bottom side. The outlet of the water pipe 3.6 is located below the liquid surface of the water tank 3.3 to form a liquid seal, preventing the open water tank 3.3 from depressurizing. The water in the water tank 3.3 is replaced regularly to clean the dust.

[0032] The bottom surface of the settling chamber 3.2 is an inclined surface that slopes towards the inlet of the water pipe 3.6. Dust particles deposited on the bottom surface of the settling chamber 3.2 automatically gather towards the inlet of the water pipe 3.6.

[0033] The demisting mechanism 4 includes a demisting chamber 4.1 and a baffle plate 4.2 installed at the air outlet of the settling chamber 3.2; the air inlet of the demisting chamber 4.1 is connected to the air outlet of the settling chamber 3.2, the air outlet of the demisting chamber 4.1 is connected to the negative pressure mechanism 5, and a demisting filter element 4.3 is provided in the demisting chamber 4.1 between its air inlet and air outlet. When the airflow containing mist flows through the baffle plate 4.2 at a certain speed, due to the inertial impact of the airflow, the mist collides with the baffle plate 4.2 and the resulting droplets become so large that their own gravity exceeds the resultant force of the airflow's upward force and the liquid's surface tension. The droplets are then separated from the surface of the baffle plate 4.2; this is the first stage of demisting. The airflow continues to rise and passes through the demisting filter element 4.3; this is the second stage of demisting. After demisting by the composite structure of baffle plate 4.2 and demisting filter element 4.3, the airflow is discharged, ensuring that the water droplet size in the discharged airflow is <10μm. The water droplet interception efficiency in the demisting mechanism 4 is ≥99%, used to demist the treated water-containing airflow to prevent water mist from entering the tunnel construction space.

[0034] The bottom of the demisting chamber 4.1 of the demisting mechanism 4 is connected to the water tank 3.3 of the gas-liquid mixing mechanism 3, and a liquid seal is formed at the connection. The demisting mechanism 4 is adjacent to the gas-liquid mixing mechanism 3. The demisting chamber 4.1 of the demisting mechanism 4 and the settling chamber 3.2 of the gas-liquid mixing mechanism 3 share a water pipe 3.6. Part of the inlet of the water pipe 3.6 is located in the settling chamber 3.2, and part of it is located in the demisting chamber 4.1. The water separated in the demisting chamber 4.1 also enters the water tank 3.3 through the water pipe 3.6.

[0035] The negative pressure mechanism 5 uses a centrifugal fan with a fan pressure range of 200~500Pa. It is used to stabilize and maintain the airflow direction and flow rate inside the device, so that the airflow passes continuously along a single treatment path.

[0036] Example 2 One method involves arranging a gas-phase centralized return air induced tunnel full-section dust collection device, as described in Example 1, between the tunnel face and the constructed section, with the device located 5-10m from the tunnel face. The dust collection unit 2 and the negative pressure mechanism 5 are activated, and a controlled negative pressure induction zone with a negative pressure value of -50 to -200Pa is constructed between the tunnel face and the dust collection chamber 1 using the return air from the tunnel face. The dust-laden airflow is introduced into the gas-liquid mixing mechanism 3 through the dust collection chamber 1, where it undergoes dust suppression at a liquid-to-gas ratio of 1-5 L / m³. After demisting by the demisting mechanism 4, the treated airflow is discharged from the negative pressure mechanism 5.

[0037] Air quality monitoring sensors are installed at the inlet and outlet of the dust collection device for the entire tunnel face, the upper part of the tunnel cross-section where dust is concentrated, and the air quality monitoring sensors are used to monitor the dust concentration in the tunnel. The control unit electrically connected to each air quality monitoring sensor is a PLC controller. The PLC controller regulates the working status of each mechanism by controlling the actuators (frequency converters controlling the motors or solenoid valves regulating the flow) in the dust collection unit 2, the gas-liquid mixing mechanism 3, the demisting mechanism 4, and the negative pressure mechanism 5.

[0038] A pollution concentration of ≥5mg / m³ in the tunnel is considered a high pollution state, a pollution concentration of ≤1mg / m³ is considered a low pollution state, and a pollution concentration of 5mg / m³ < pollution concentration >1mg / m³ is considered a medium pollution state. Under high pollution conditions, such as after blasting, all dust collection units on the dust collection chamber are turned on, and the air volume of the dust collection units is 80% to 100% of the rated air volume. The fan frequency of the negative pressure mechanism is 50 to 60 Hz. The liquid-to-gas ratio of the gas-liquid mixing mechanism is maintained between 3 and 5 L / m³. Under medium pollution conditions, all dust collection units on the dust collection chamber are turned on, and the air volume of the dust collection unit is 50%~80% of the rated air volume. The fan frequency of the negative pressure mechanism is 30~50Hz; the liquid-gas ratio of the gas-liquid mixing mechanism is maintained between 2~3L / m³. Under low pollution conditions, only the dust collection unit located in the upper part of the tunnel cross section on the dust collection chamber is turned on. The air volume of the dust collection unit is 30% to 50% of the rated air volume, and the fan frequency of the negative pressure mechanism is 20 to 30 Hz. The liquid-gas ratio of the gas-liquid mixing mechanism is maintained between 1 and 2 L / m³. Based on the intensity of pollutant gas phase generation and diffusion trend, adjust the operating parameters of each mechanism to match the airflow induction intensity with the pollution load, and reduce energy consumption and equipment operating load.

[0039] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those 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 invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A gas-phase centralized return air induced tunnel full-section dust collection device, characterized in that: The dust collection chamber (1) is included, and the dust collection unit (2) distributed on the dust collection chamber (1) has a suction range that covers the entire tunnel cross section. The air outlet of the dust collection chamber (1) is connected in series with a gas-liquid mixing mechanism (3), a demisting mechanism (4), and a negative pressure mechanism (5). The gas-liquid mixing mechanism (3) is used to spray water into the dust-laden airflow flowing out of the dust collection chamber (1), so that the dust-laden airflow and water are mixed and the dust particles are degraded, and the airflow and dust particles are separated. The demisting mechanism (4) is used to intercept water droplets in the airflow. The negative pressure mechanism (5) is used to generate negative pressure and discharge the airflow. The negative pressure mechanism (5) cooperates with the dust collection unit (2) to form a push-pull mode with one suction in front and the other induced by negative pressure in the back.

2. The gas-phase centralized return air induced tunnel full-section dust collection device according to claim 1, characterized in that: The dust collection unit (2) located in the upper part of the tunnel section on the dust collection bin (1) has a dust collection hole diameter of 0.1~1mm, and the dust collection hole adopts a honeycomb hole structure with a flow resistance pressure loss between 100~200Pa. The dust collection unit (2) located at the lower part of the tunnel section on the dust collection bin (1) has a dust collection hole diameter of 5~10mm. The dust collection hole adopts a straight hole structure, and the flow resistance pressure loss is between 50-100Pa.

3. The gas-phase centralized return air induced tunnel full-section dust collection device according to claim 1 or 2, characterized in that: The gas-liquid mixing mechanism (3) includes an upper mixing chamber (3.1), a middle settling chamber (3.2), and a lower water tank (3.3). The inlet of the mixing chamber (3.1) is connected to the air outlet of the dust collection chamber (1). A spray system (3.4) is arranged in the mixing chamber (3.1). The mixing chamber (3.1) and the settling chamber (3.2) are connected by a vertical drain pipe (3.5). The bottom opening of the drain pipe (3.5) is located below the air outlet of the settling chamber (3.2). The water tank (3.3) is connected to the settling chamber (3.2) by a water pipe (3.6). The inlet of the water pipe (3.6) is located at the bottom of the settling chamber (3.2), and the outlet of the water pipe (3.6) is located below the liquid surface of the water tank (3.3).

4. The gas-phase centralized return air induced tunnel full-section dust collection device according to claim 3, characterized in that: The demisting mechanism (4) includes a demisting chamber (4.1) and a baffle plate (4.2) installed at the air outlet of the settling chamber (3.2); the air inlet of the demisting chamber (4.1) is connected to the air outlet of the settling chamber (3.2), the air outlet of the demisting chamber (4.1) is connected to a negative pressure mechanism (5), and a demisting filter element (4.3) is provided in the demisting chamber (4.1) between its air inlet and air outlet.

5. The gas-phase centralized return air induced tunnel full-section dust collection device according to claim 4, characterized in that: The bottom of the demisting chamber (4.1) of the demisting mechanism (4) is connected to the water tank (3.3) of the gas-liquid mixing mechanism (3), and a liquid seal is formed at the connection.

6. The gas-phase centralized return air induced tunnel full-section dust collection device according to claim 5, characterized in that: The demisting chamber (4.1) of the demisting mechanism (4) and the settling chamber (3.2) of the gas-liquid mixing mechanism (3) share a water pipe (3.6). Part of the inlet of the water pipe (3.6) is located in the settling chamber (3.2) and part of the inlet is located in the demisting chamber (4.1).

7. The gas-phase centralized return air induced tunnel full-section dust collection device according to claim 1, characterized in that: The dust collection chamber (1) is provided with a doorway (1.1) that allows passage along the tunnel axis; dust collection units (2) are arranged on the side of the dust collection chamber (1), the end face facing the tunnel face, and inside the doorway (1.1); the suction range of the dust collection units (2) on the side of the dust collection chamber (1), the end face, and inside the doorway (1.1) is used to prevent dust in the entire tunnel section from spreading to the rear of the dust collection chamber (1).

8. The gas-phase centralized return air induced tunnel full-section dust collection device according to claim 1, characterized in that: The dust collection chamber (1), dust collection unit (2), gas-liquid mixing mechanism (3), demisting mechanism (4) and negative pressure mechanism (5) are arranged on the walking mechanism (6), which has a connecting device that can be connected to the trolley.

9. A method, characterized in that: The gas-phase centralized return air induced tunnel full-section dust collection device described in claim 3 is arranged between the tunnel face and the constructed section, with the gas-phase centralized return air induced tunnel full-section dust collection device 5~10m away from the tunnel face; the dust collection unit (2) and the negative pressure mechanism (5) are started, and a controlled negative pressure induction zone with a negative pressure value of -50~-200Pa is constructed between the tunnel face and the dust collection chamber (1) using the return air from the tunnel face. The dust-laden airflow is introduced into the gas-liquid mixing mechanism (3) through the dust collection chamber (1), and the gas-liquid mixing mechanism (3) performs dust reduction treatment with a liquid-gas ratio of 1~5L / m³; after demisting by the demisting mechanism (4), the treated airflow is discharged from the negative pressure mechanism (5).

10. A method according to claim 9, characterized in that: Air quality monitoring sensors are installed at the tunnel face area, the upper part of the tunnel cross-section where dust is concentrated, and at the air inlet and outlet of the gas-phase centralized return air induced tunnel full-section dust collection device; the air quality monitoring sensors are used to monitor the dust concentration in the tunnel. A pollution concentration of ≥5mg / m³ in the tunnel is considered a high pollution state, a pollution concentration of ≤1mg / m³ is considered a low pollution state, and a pollution concentration of 5mg / m³ < pollution concentration >1mg / m³ is considered a medium pollution state. Under high pollution conditions, all dust collection units (2) on the dust collection chamber (1) are turned on, the air volume of the dust collection unit (2) is 80%~100% of the rated air volume, the fan frequency of the negative pressure mechanism (5) is 50~60Hz, and the liquid-gas ratio of the gas-liquid mixing mechanism (3) is maintained between 3~5L / m³. Under medium pollution conditions, all dust collection units (2) on the dust collection chamber (1) are turned on, the air volume of the dust collection unit (2) is 50%~80% of the rated air volume, the fan frequency of the negative pressure mechanism (5) is 30~50Hz, and the liquid-gas ratio of the gas-liquid mixing mechanism (3) is maintained between 2~3L / m³. Under low pollution conditions, only the dust collection unit (2) located in the upper part of the tunnel section on the dust collection chamber (1) is turned on. The air volume of the dust collection unit (2) is 30%~50% of the rated air volume, and the fan frequency of the negative pressure mechanism (5) is 20~30Hz. The liquid-gas ratio of the gas-liquid mixing mechanism (3) is maintained between 1~2L / m³.

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