Tunnel grading fog drop field dust fall ventilation control system

Abstract

A tunnel grading fog drop field dust fall ventilation control system comprises multiple stages of dust fall ventilation devices arranged along a tunnel at intervals, each dust fall ventilation device comprises a jet fan, and an air outlet of each jet fan is provided with a branch water supply pipe; jet fans of the multi-stage dust-falling ventilation device are sequentially connected with air supply cylinders in the tunnel, and branch water supply pipes of the multi-stage dust-falling ventilation device are sequentially connected with a main water supply pipe in the tunnel. The dust fall ventilation control system for the tunnel grading fog drop field is low in dust removal construction cost, easy to operate, capable of guaranteeing quality and high in construction efficiency.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of tunnel dust removal, especially a tunnel hierarchical fog field dust fall ventilation control system. BACKGROUND

[0002] During the blasting stage of the tunnel constructed by the drill and blast method, the rock mass is affected by factors such as friction and collision during drilling and spoil loading and unloading, and a large amount of dust and toxic gases are generated. At the same time, high-speed airflow can destroy the adhesion between the particles, resulting in a high dust concentration in the airflow, which pollutes the internal environment of the tunnel and poses a serious threat to the safety and health of the operating personnel. The traditional tunnel dust fall measure mainly uses the method of ground water spraying by a water spraying vehicle, and according to industry experience, the PM2.5 removal rate is only 40-60%, which is difficult to effectively avoid the great harm of dust to the health of the operating personnel. Obviously, only using conventional dust fall measures cannot meet the actual needs. UTILITY MODEL CONTENT

[0003] The technical problem to be solved by the utility model is to provide a tunnel hierarchical fog field dust fall ventilation control system, which adopts the dust fall ventilation technology of an atomized water curtain, disperses fine droplets by rapid airflow, forms a certain density of fog field in the air, covers each dust raising point in the tunnel space, causes the water mist particles to adhere to the dust particles in the air, forms larger particles, and due to the large mass, the particles are subjected to the action of gravity and settle on the ground. At the same time, the water mist particles and the dust particles are subjected to the action of aerodynamics and undergo turbulent motion, which produces a drag effect on the dust particles and further carries them to the deposition place of the mixed particle groups. The control method has low construction cost, simple operation, more guaranteed quality, and high construction efficiency.

[0004] To solve the above technical problems, the utility model adopts the following technical scheme:

[0005] The tunnel hierarchical fog field dust fall ventilation control system comprises multiple-stage dust fall ventilation devices arranged at intervals along the tunnel, and the dust fall ventilation device comprises a jet fan, and the jet fan outlet is provided with a branch water supply pipe; the jet fans of the multiple-stage dust fall ventilation devices are connected with air supply tubes in the tunnel in sequence, and the branch water supply pipes of the multiple-stage dust fall ventilation devices are connected with main water supply pipes in the tunnel in sequence.

[0006] The branch water supply pipe is spirally fixed to the outer shell of the jet fan outlet in a spiral disc shape, and the distance between the branch water supply pipe and the outer shell of the jet fan is greater than or equal to 50 mm.

[0007] The branch water supply pipe adopts a DN32 polyurethane hose.

[0008] The branch water supply pipe is provided with water scattering holes arranged along the length direction.

[0009] The water dispersing holes of the upper half of the branch water supply pipe are outwardly offset by 60 degrees relative to the axis of the branch water supply pipe, and the water dispersing holes of the lower half are inwardly offset by 60 degrees relative to the axis of the branch water supply pipe.

[0010] The multi-stage dust falling ventilation device is three stages, wherein the first stage dust falling ventilation device is 50-100m away from the working face; the total distance of the effective jet range and the air suction and blowing range of the jet fan is used as the interval between the first stage dust falling ventilation device and the second stage dust falling ventilation device and between the second stage dust falling ventilation device and the third stage dust falling ventilation device.

[0011] The air speed of the air outlet of the jet fan is greater than the water droplet suspension speed, and the air speed is at least 8m / s.

[0012] The utility model provides a tunnel hierarchical mist field dust falling ventilation control system, has the following technical effect:

[0013] 1), adopt tunnel hierarchical mist field dust falling ventilation control method, one is that the DN32 polyurethane hose with the aperture 3mm-7mm, has the water dispersing hole of outward angle, carries out the sustained water supply, two is that one end of the branch water supply pipe is fixed to the air outlet surface shell of SDS series jet fan, utilizes the rapid airflow to scatter the water droplet and forms the mist field, three is that this atomization system is arranged along the tunnel side wall three stages, four is that in the long distance tunnel construction, the air supply cylinder adopts the fresh air supply mode of pressing in and cooperates this atomization system to carry out the dust falling ventilation, this method has the low construction cost, simple operation, and the quality is more guaranteed, and the construction efficiency is high.

[0014] 2), especially in the long distance tunnel excavation construction, the air cylinder adopts the fresh air supply mode of pressing in, the jet fan can accelerate the air circulation in the hole and can also produce the high speed airflow to blow the liquid droplet flowing out of the water dispersing hole of the branch water supply pipe in the air rapidly, and forms the mist field of certain density, these mists can effectively capture the dust particles generated in the process of hole excavation blasting and spoil transportation and promote the settlement.

[0015] 3), the first stage dust falling ventilation is implemented at the place about 50-100m away from the working face, the second stage and the third stage system dust falling ventilation are continuously arranged along the tunnel side wall, the pollution of the dust and harmful gas particulate matters in the tunnel space is gradually weakened through the three stage mist field classification adsorption, this control method realizes the synchronous dust falling and ventilation, the PM2.5 removal rate is above 85%, and the comprehensive operation and maintenance cost is reduced by about 50%.

[0016] 4), search, patent authorization announcement number CN116427989A patent "comprehensive dust fall system and dust fall method for special long tunnel construction operation" depends on the combination of various equipment (such as energy water pressure blasting device, water curtain mist cannon dust fall device, spray water mist maintenance device, electrostatic dust removal purification vehicle, etc.) through physical isolation and local dust removal to reduce dust diffusion, but there are high equipment complexity, high energy consumption and operation and maintenance cost, and lack of fine control. This application takes the spray device as the core, combines the jet fan and the wind cylinder to form a cycle, and is arranged in stages and in echelon to fall dust, which has simple structure and low maintenance cost, and can remove dust particles in a wide range. Through the design of the hierarchical mist field, the PM2.5 removal rate is improved to 80-90%.

[0017] 5), tunnel hierarchical mist field dust fall ventilation control system, through the design of spiral winding branch pipe and asymmetric water distribution hole, the accurate coverage of multi-particle diameter mist is realized, the high-speed airflow of jet fan and the atomization spray of branch water supply pipe are synergized to carry out wind-water linkage, and a dynamic mist field is formed to improve the dust capture efficiency. The hierarchical coverage of the three-stage dust fall device, the multi-stage series synergistic control, the layer-by-layer weakening of dust concentration and the solution of the problem of long tunnel ventilation blind area are realized. BRIEF DESCRIPTION OF DRAWINGS

[0018] The utility model will be further described below in combination with the drawings and examples:

[0019] Figure 1 It is the installation structure schematic diagram in the utility model.

[0020] Figure 2 It is the installation structure schematic diagram (second visual angle) of the utility model.

[0021] Figure 3 It is the schematic diagram of branch water supply pipe in the utility model.

[0022] In the drawing: jet fan 1, main water supply pipe 2, branch water supply pipe 3, water distribution hole 4, air supply cylinder 5, dust fall ventilation device 6, blasting point D. DETAILED DESCRIPTION

[0023] As Figures 1-2As shown, the tunnel hierarchical fog field dust fall ventilation control system comprises three-stage dust fall ventilation devices 6 (indicated by A, B and C in sequence), each of which comprises a jet fan 1, and the air outlet of the jet fan 1 is provided with a branch water supply pipe 3, which is a spiral disc-shaped DN32 polyurethane hose fixed to the outer shell of the air outlet surface of the jet fan 1. The water holes 4 in the upper half of the branch water supply pipe 3 are outwardly deviated by 60° relative to the axis of the branch water supply pipe 3, and the water holes 4 in the lower half are inwardly deviated by 60° relative to the axis of the branch water supply pipe 3, with a hole diameter of 3mm-7mm. The outwardly deviated water holes spray water obliquely upward in the direction of the air outlet of the jet fan, and the high-speed airflow of the fan is used to diffuse the water mist to the top of the tunnel and the two side walls to form an "umbrella-shaped" coverage, effectively intercepting the dust suspended in the upper part of the tunnel. The inwardly deviated water holes spray water obliquely downward in the direction of the air outlet of the jet fan, combined with the high-speed airflow at the bottom of the fan, to form a "gathered" mist field, and the high-speed airflow is used to secondary atomize the water droplets, reducing the water consumption per unit time, preventing the water droplets from settling prematurely due to gravity, and enhancing the suppression of ground dust (such as dust stirred up by transport vehicles). The water holes with different diameters generate multi-scale mist droplets (coarse mist droplets intercept PM10 and above particles, and fine mist droplets capture PM2.5) under high-pressure water flow. The spiral disc-shaped DN32 polyurethane hose has flexibility and can adapt to the curved surface structure of the air outlet surface of the jet fan. The design of the outward and inward angles reduces the risk of clogging of the water holes.

[0024] The first-stage dust fall ventilation device 6 (A) is about 50-100m away from the working face, and the distance is reserved for blasting flyrock and meets the requirements of the working space of the working face. The total distance of the effective range of the SDS series jet fan 1 and the blowing range of the SDS series jet fan 1 is used as the demarcation line, and the second-stage dust fall ventilation device 6 (B) and the third-stage dust fall ventilation device 6 (C) are arranged at intervals.

[0025]

[0026] In the formula, R is the air suction radius (m), Q is the total air volume generated by the fan (m 3 / s), ρ is the air density (Kg / m 3 ), C V is the wind speed non-uniformity coefficient, which is 0.7-0.9 according to the Tunnel Ventilation Design Specification. Actual application needs to be adjusted appropriately according to the site conditions.

[0027] The branch water supply pipe 3 of the first-stage dust-settling ventilation device 6(A), the second-stage dust-settling ventilation device 6(B) and the third-stage dust-settling ventilation device 6(C) is sequentially connected with the main water supply pipe 2 in the tunnel, and the jet fan 1 of the second-stage dust-settling ventilation device 6(B) and the third-stage dust-settling ventilation device 6(C) is connected with the air supply cylinder 5 in the tunnel. The main water supply pipe 2 and the air cylinder 5 are gradually installed along with the tunnel face advancing; the third-stage dust-settling ventilation system 6 also moves forward synchronously along with the tunnel face advancing, and the distance between the first-stage dust-settling ventilation system 6 and the tunnel face is kept at 50-100 m.

[0028] The jet fan 1 is an SDS series jet fan, and the air outlet wind speed of the SDS series jet fan should be greater than the water droplet suspension speed, and the wind speed is at least 8 m / s. According to the Stokes law, the mist droplet suspension speed is related to the particle size and density thereof. The wind speed of 8 m / s can provide sufficient kinetic energy to enable the mist droplet to overcome the gravity and be suspended in the air, prolong the contact time with the dust particles, avoid the coverage blind area caused by the mist droplet settling too early, and promote the collision, adsorption and coagulation of the mist droplet and the dust in the turbulent field formed by the high-speed airflow in the tunnel. Experimental data show that when the wind speed is increased from 5 m / s to 8 m / s, the PM2.5 removal rate can be increased from 60% to more than 80%.

[0029] The air supply cylinder 5 is used to press fresh air into the hole from the hole opening.

[0030] The blasting operation of the tunnel face will generate strong shock waves and flying stones. If the distance between the air supply cylinder port and the tunnel face is too close (for example, less than 20 m), the air pipe is easy to be damaged or the joint is easy to fall off, causing air leakage or even system paralysis. The distance of 20-50 m can effectively avoid direct damage caused by blasting. The attenuation rate of the blasting shock wave is more than 70% outside 20 m, which significantly reduces the probability of air pipe damage. The air leakage rate of the air pipe per hundred meters is positively correlated with the length. When the distance between the air supply cylinder port and the tunnel face is 50 m, the end air leakage rate can be controlled within 2% (the specification requires that it be less than or equal to 3%), and when the distance exceeds 50 m, the air leakage rate may increase sharply to more than 5%, which causes the energy consumption of the fan to increase by 30%-50%.

[0031] The spiral disc layout is consistent with the rotation direction of the airflow at the air outlet of the jet fan, which can reduce the direct collision of the airflow and the pipeline and reduce the local resistance; when the high-speed airflow (≥8 m / s) passes through the spiral disc gap, a local acceleration zone may be generated due to the Venturi effect, which enhances the mixing efficiency of the mist droplet and the airflow, and the peripheral constraint structure can improve the airflow utilization rate. The distance between the spiral disc and the fan shell should be greater than or equal to 50 mm to avoid excessive compression of the airflow passage.

[0032] In long-distance tunnel construction, the third-stage dust-settling ventilation system 6 can obviously reduce dust and speed up the air circulation in the hole.

[0033] a, water supply

[0034] The three-way element of the main water supply pipe 2 of the tunnel DN200 is connected with one end of the branch water supply pipe 3 to continuously supply water.

[0035] b. atomization

[0036] The other end of the DN32 branch water supply pipe 3 is evenly fixed to the outflow surface shell of the SDS jet fan, and the water outlet is blocked. The jet fan 1 is started to output high-speed airflow to blow away the water droplets continuously sprayed from the soft hose water hole, forming an atomized water curtain.

[0037] c. arrangement

[0038] The first-stage dust-settling ventilation device 6(A) is arranged in the tunnel at a distance of 50-100 m from the working face 50, and the second-stage and third-stage dust-settling ventilation devices 6(B) and 6(C) are arranged in stages and sections with the total distance of the effective jet range of the SDS series jet fan and the air suction and blowing range of the SDS series jet fan as the demarcation.

Claims

1. A tunnel graded droplet field dust fall ventilation control system characterized by: The application relates to a multi-stage dust-settling ventilation device (6) arranged at intervals along a tunnel, wherein the dust-settling ventilation device (6) comprises a jet fan (1), and a branch water supply pipe (3) is arranged at the air outlet of the jet fan (1); the jet fan (1) of the multi-stage dust-settling ventilation device (6) is sequentially connected with a wind supply cylinder (5) in the tunnel, and the branch water supply pipe (3) of the multi-stage dust-settling ventilation device (6) is sequentially connected with a main water supply pipe (2) in the tunnel.

2. The tunnel graded droplet field dust fall ventilation control system of claim 1, wherein: The branch water supply pipe (3) is spirally fixed to the air outlet surface shell of the jet fan (1) and has a spacing of greater than or equal to 50 mm from the shell of the jet fan (1).

3. The tunnel graded mist field dust fall ventilation control system of claim 2, wherein: The branch water supply pipe (3) is a DN32 polyurethane hose.

4. The tunnel graded mist field dust fall ventilation control system of claim 3, wherein: The branch water supply pipe (3) is provided with water scattering holes (4) along the length direction.

5. The tunnel graded droplet field dust fall ventilation control system of claim 4, wherein: The water scattering holes (4) in the upper half of the branch water supply pipe (3) are outwardly inclined by 60 degrees relative to the axis of the branch water supply pipe (3), and the water scattering holes (4) in the lower half are inwardly inclined by 60 degrees relative to the axis of the branch water supply pipe (3).

6. The tunnel graded droplet field dust fall ventilation control system of claim 5, wherein: The multi-stage dust-settling ventilation device (6) is a three-stage device, wherein the first-stage dust-settling ventilation device is 50-100 m away from the tunnel face; the total distance of the effective jet range and the air suction and blowing range of the jet fan (1) is used as the interval for the distribution of the first-stage dust-settling ventilation device, the second-stage dust-settling ventilation device and the third-stage dust-settling ventilation device.

7. The tunnel graded droplet field dust fall ventilation control system of claim 6, wherein: The air speed at the air outlet of the jet fan (1) is greater than the water droplet suspension speed, and the air speed is at least 8 m / s.

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