Hidden type aerial fog dust falling construction system after sand shale interbed tunnel excavation blasting

Abstract

The utility model discloses a hidden type aerial fog dust falling construction system after sand shale interbed tunnel excavation blasting. Comprising a rack supporting system, a high-pressure spraying dust-settling system and a high-pressure wind path system, the rack supporting system is an excavation trolley, the nozzles are divided into a spraying dust-settling nozzle and a high-pressure air path nozzle, the pipe body is divided into a spraying dust-settling pipe body and a high-pressure air path pipe body, the high-pressure spraying dust-settling system comprises a spraying high-pressure pump and a high-pressure water pipe connector, and one end of the high-pressure water pipe connector is communicated with an inlet of the spraying high-pressure pump; the outlet end of the spraying high-pressure pump is connected with a spraying dust-settling nozzle through a spraying dust-settling pipe body, and the high-pressure air pipe connector is communicated with a high-pressure air path nozzle through a high-pressure air path pipe body. After a tunnel excavation working face adopts the excavation rack hidden type aerial fog dust falling system, water mist flow can surround the section of a lining, settle dust and prevent the dust from flying into the air, meanwhile, rocks are wetted, the generation amount of the dust during falling of the rocks is reduced, the dust throwing length is shortened to 60 m, the smoke exhaust time after blasting is shortened, the construction efficiency is improved, and the construction cost is reduced. And the construction temperature in the hole is reduced.

Description

Technical Field

[0001] The utility model relates to the field of dust reduction construction after tunnel excavation and blasting, in particular to a hidden gas mist dust reduction construction system after sandstone and shale interlayer tunnel excavation and blasting. Background Art

[0002] At present, in tunnel construction, due to the complexity of underground passages and the difficulty of ventilation organization, full-pressure pressure-type air duct ventilation is used for the excavation working face in the tunnel. When the tunnel passes through the sandstone shale formation, there is no water on the face. During construction, there are an average of 4 or more blastings per day. Since the average temperature in the tunnel is above 30°C, the blasting during excavation directly leads to the generation of toxic and harmful gases and a large amount of dust. Since only pressure-type ventilation is used for dust reduction, the dust reduction time is long and the effect is poor. The dust throwing length is more than 130m. During construction, the dust concentration of the excavation working face reaches 1200mg / m 3 As mentioned above, dust is suspended in the air for a long time, which reduces the work efficiency of workers and threatens their life and health. There is a lack of suitable dust reduction construction measures. Utility Model Content

[0003] Therefore, in order to solve the above-mentioned shortcomings, the utility model provides a hidden gas mist dust reduction construction system after sandstone and shale interlayer tunnel excavation blasting.

[0004] The utility model is implemented in this way: a hidden gas mist dust reduction construction system is constructed after excavation and blasting of a sandstone-shale interlayer tunnel; the dust reduction construction system comprises a gantry support system, a high-pressure spray dust reduction system, and a high-pressure air path system; the gantry support system is an excavation trolley, the high-pressure spray dust reduction system and the high-pressure air path system are respectively arranged on the excavation trolley, the nozzle is divided into a spray dust reduction nozzle and a high-pressure air path nozzle, the pipe body is divided into a spray dust reduction pipe body and a high-pressure air path pipe body, the high-pressure spray dust reduction system comprises a spray high-pressure pump and a high-pressure water pipe interface, one end of the high-pressure water pipe interface is connected to the inlet of the spray high-pressure pump, the outlet end of the spray high-pressure pump is connected to the spray dust reduction nozzle via the spray dust reduction pipe body, the high-pressure air duct interface is connected to the high-pressure air path nozzle via the high-pressure air path pipe body, and the high-pressure air duct interface, the high-pressure air path nozzle and the high-pressure air path pipe body constitute a high-pressure air path system.

[0005] Furthermore, the spray high-pressure pump is placed next to the outer pedestrian ladder columns of the two excavation trolleys, so that the spray high-pressure pump and the excavation trolley can move synchronously and are easy to operate. After careful inspection before blasting, the excavation trolley is moved to a position 30-50m away from the face, and the dust reduction system is started. The spray pump station starts high-pressure spray automatic dust reduction. The working time is from 1 minute before blasting to the entire process of slag loading. After the slag is discharged, the dust reduction system is turned off.

[0006] Furthermore, the nozzles are directed toward the excavation working face, 30-50m away from the heading face. The mist flow sprayed by the spray dust suppression device can completely fill the lining section of the tunnel, effectively suppress the dust generated after blasting, and prevent the dust from spreading. At the same time, the sprayed mist flow can also effectively wet the collapsed rock blocks at the bottom of both sides of the tunnel, greatly reducing dust and impact dust.

[0007] The present application provides a hidden aerosol dust reduction construction system after blasting of sandstone-shale interlayer tunnel excavation. After redesign, the dust reduction construction system is based on a gantry support system, and integrates a high-pressure spray dust reduction device, a high-pressure air path system, a spray high-pressure pump, etc. In order to facilitate implementation, it can also include a circuit system and a water filter system. The spray high-pressure pump is placed next to the outer pedestrian ladder column of the two excavation trolleys, so that the spray high-pressure pump and the excavation trolley can move synchronously and are easy to operate. After careful inspection before blasting, move the excavation trolley to a position 30-50m away from the face, start the dust reduction system, start the spray pump station, and automatically reduce dust with high-pressure spray. The working time is from 1 minute before blasting to the entire process of slag loading. After the slag is discharged, turn off the dust reduction system. Among them, the platform support system is an excavation trolley, and a spray dust suppression device is arranged on the excavation trolley. The nozzles of the spray device are facing the excavation working face, 30-50m away from the heading face. The mist flow sprayed by the spray dust suppression device can completely fill the lining section in the tunnel, effectively suppress the dust generated after blasting, and prevent the dust from spreading; at the same time, the sprayed mist flow can also effectively wet the collapsed rock blocks at the bottom of both sides of the tunnel, greatly reducing dust and impact dust.

[0008] The utility model has the following advantages: The utility model provides a hidden gas mist dust reduction construction system after sandstone interlayer tunnel excavation blasting; it has the following characteristics: 1) After the tunnel excavation working face adopts the hidden gas mist dust reduction system of the excavation trolley, the water mist flow can surround the inner lining section, settle the dust and prevent it from flying into the air, and at the same time wet the rock, reduce the amount of dust generated when the rock falls, shorten the dust throwing length to 60m, reduce the smoke exhaust time after blasting, improve construction efficiency, reduce the construction temperature in the tunnel, and create a good working environment for workers. 2) The equipment has the advantages of high efficiency, low consumption, environmental protection, low water consumption, and good atomization effect, which can not only shorten the "smoke" exhaust time, but also greatly improve the construction working environment in the tunnel. After the excavation working face gas mist dust reduction system is put into use, the total dust reduction efficiency and respirable dust reduction efficiency at the driver of the excavation working face are 91.3% and 84.0% respectively, achieving the effect of reducing dust, protecting the environment, and ensuring the occupational health of tunnel workers. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a schematic diagram of the equipment structure;

[0010] Figure 2 Schematic diagram of the equipment's position on the trolley.

[0011] In the figure: the inner contour line of the primary support 1, the upper step 2, the lower step 3, the nozzle 4, the pipe body 5, the high-pressure air duct interface 6, the high-pressure water pipe interface 7, and the excavation trolley 8. DETAILED DESCRIPTION

[0012] The following will be combined with the attached Figure 1-Figure 2 The utility model is described in detail, and the technical solutions in the embodiments of the utility model are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of them. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0013] The utility model provides a hidden gas mist dust reduction construction system after excavation and blasting of a sandstone-shale interlayer tunnel; the dust reduction construction system includes a scaffold support system, a high-pressure spray dust reduction system, and a high-pressure air path system; the scaffold support system is an excavation trolley 8, the high-pressure spray dust reduction system and the high-pressure air path system are respectively arranged on the excavation trolley 8, the nozzle 4 is divided into a spray dust reduction nozzle and a high-pressure air path nozzle, the pipe body 5 is divided into a spray dust reduction pipe body and a high-pressure air path pipe body, the high-pressure spray dust reduction system includes a spray high-pressure pump and a high-pressure water pipe interface 7, one end of the high-pressure water pipe interface 7 is connected to the inlet of the spray high-pressure pump, the outlet end of the spray high-pressure pump is connected to the spray dust reduction nozzle via the spray dust reduction pipe body, the high-pressure air duct interface 6 is connected to the high-pressure air path nozzle via the high-pressure air path pipe body, and the high-pressure air duct interface 6, the high-pressure air path nozzle and the high-pressure air path pipe body constitute a high-pressure air path system.

[0014] The spray high-pressure pump is placed beside the two outer pedestrian ladder columns of the excavation trolley 8, so that the spray high-pressure pump and the excavation trolley can move synchronously and be easy to control. During implementation, the high-pressure water pipe interface 7 and the high-pressure air pipe interface 6 can be used to connect with the external water pipe and air pipe respectively.

[0015] The nozzles 4 are respectively directed toward the excavation working face, 30-50m away from the heading face, and the mist flow sprayed by the spray dust suppression device can completely fill the lining section in the tunnel.

[0016] This application has the following features:

[0017] 1) After the tunnel excavation working face adopts the hidden aerosol dust reduction system of the excavation trolley, the water mist flow can surround the inner lining section, settle the dust and prevent it from flying into the air, and at the same time moisten the rock, reducing the amount of dust generated when the rock blocks fall. The dust throwing length is shortened to 60m, reducing the smoke exhaust time after blasting, improving construction efficiency, reducing the construction temperature in the tunnel, and creating a good working environment for the workers.

[0018] 2) The equipment has the advantages of high efficiency, low consumption, environmental protection, low water consumption and good atomization effect. It can not only shorten the "smoke" exhaust time, but also greatly improve the construction working environment in the tunnel. After the excavation working face aerosol dust reduction system was put into use, the total dust reduction efficiency and respirable dust reduction efficiency at the driver's side of the excavation working face were 91.3% and 84.0% respectively, achieving the effect of reducing dust, protecting the environment and ensuring the occupational health of tunnel workers.

[0019] Scope of application: Suitable for highway tunnel excavation and blasting construction that enters the main tunnel from an inclined shaft with an underground fan room and passes through interlayers of sand and shale.

[0020] Implementation principle: The aerosol dust reduction process can be regarded as a bonding process between liquid mist particles and solid dust particles. Its main mechanisms include inertial collision interception, diffusion, gravity effect, electrostatic effect and eddy current condensation. The nozzle spray characteristics mainly include droplet size, distribution density, movement speed, effective range, fog structure, charge, and the time the droplets exist in the fog. When spray dust reduction is applied during tunnel construction, the most important factors affecting the spray characteristics are nozzle diameter and spray pressure.

[0021] Through multiple aerosol dust reduction tests, combined with the on-site geological conditions, theoretical analysis and test data of the sandstone and shale interlayers of the test working face, a reasonable spray layout and scientific spray parameters were selected to ensure that polluted air in each construction area in the tunnel does not flow, the air quality is qualified, and the gas discharged to the outside of the tunnel meets the emission standards, achieving an ideal dust reduction effect.

[0022] Construction process and operation points

[0023] Construction process: excavation and blasting → dust data collection → initial setting of spray parameters → installation test → determination of nozzle and spray pressure → effect testing.

[0024] Operation points

[0025] Working surface dust particle size distribution sampling test

[0026] The dust from the driver's side during the slag loading at the left line large pile excavation face of the inclined shaft work area of ​​Jiashatian Tunnel was collected on site by using the filter membrane dust measurement method, and the dust particle size was measured using the MD-1 dust particle size analyzer. The results are shown in Table 5.2.1-1. The dust particle size of the excavation working face is less than 10μm, accounting for 13.7% of the total dust, the average dust diameter is 35.2μm, the dust particle size is less than 50μm, accounting for 73.7% of the total dust, and the proportion of respirable dust is 19.0%.

[0027] Table 1.1 Test results of dust particle size distribution in excavation working surface

[0028]

[0029] Dust suppression system design and implementation:

[0030] 1) Design of the spray device for the excavation trolley

[0031] According to the actual situation of the test working face, the following arrangement is made on the excavation trolley according to the idea that the high-pressure spray mist flow completely covers the lining section of the excavation working face: Figure 1 The spray dust suppression device shown. The two nozzles of the spray device are facing the excavation working face, 30-50m away from the face. The spray dust suppression device can completely fill the tunnel lining section, effectively suppress the dust generated after blasting, and prevent the dust from spreading; at the same time, the sprayed mist can also effectively wet the collapsed rocks at the bottom of both sides of the tunnel, greatly reducing dust and impact dust. Figure 1 Schematic diagram of the equipment structure.

[0032] 2) System composition and use

[0033] Schematic diagram of the installation layout of the excavation trolley spray dust suppression system Figure 2 As shown, it is mainly composed of a gantry support system, a high-pressure spray dust suppression device, a high-pressure air circuit system, a spray high-pressure pump, a circuit system, and a water filter system. The spray high-pressure pump is placed next to the pedestrian ladder column on the outside of the two excavation trolleys, so that the spray high-pressure pump and the excavation trolley can move synchronously and be easy to operate. After careful inspection before blasting, move the excavation trolley to a position 30-50m away from the face, start the dust suppression system, start the spray pump station, and automatically suppress dust with high-pressure spray. The working time is from 1 minute before blasting to the entire process of slag loading. After the slag is discharged, turn off the dust suppression system. Figure 2 Schematic diagram of the equipment's position on the trolley.

[0034] Initial spray parameters

[0035] Through theoretical and experimental research, the minimum particle size relationship of dust captured by spray droplets is obtained:

[0036]

[0037] Where: d pmin is the dust particle size (m), μ is the air dynamic viscosity (P a / 0 ), take 1.8×10 -5 P a / 0 , D is the droplet diameter (m), S ik is the inertial collision coefficient; ρ p is the dust density (kg / m 3 ), v0 is the flow field velocity (m / s).

[0038] In order to find the spray parameters suitable for the sand-sheet interlayer tunnel, the aerosol spray pressure was selected as 1MPa, 2MPa, 3MPa, 4MPa, and 5MPa, the nozzle diameter was selected as 1.0mm, 1.5mm, and 2.0mm, the spray angle was 30°, 60°, and 90°, and the spray parameter settings are shown in Table 1-2.

[0039] Table 1-2 Spray parameter table

[0040]

[0041] Nozzle and spray pressure selection

[0042] The closer the particle size of fog particles and dust is, the higher the dust reduction efficiency of the spray will be. If the particle size of fog particles is large, when dust and fog particles meet, the dust particles will bypass the edge of the fog particles under the action of swirl and will not be captured; when the particle size of fog particles is too small, the fog particles are easy to vaporize, thus affecting the dust reduction efficiency.

[0043] Since the dust particle size generated during the tunneling of the face is relatively small, it can be seen from the field test results that with the increase of spray pressure, the total dust reduction rate and the respirable dust reduction rate both increase linearly. In order to obtain ideal spray mist particles, a nozzle with a nozzle diameter of 1.5mm is selected. Taking into account economic and safety factors and the efficiency of mist particle gasification and dust reduction, the spray pressure is determined to be 5MPa. The diameter of the mist particles generated by the high-pressure atomization nozzle is calculated to be 40μm, which is relatively close to the dust particle size of the tunneling working face and can better meet the purpose of efficient spray dust reduction.

[0044] Benefit analysis: The construction of the inclined shaft end portal project of Shangjiashatian Tunnel of this project will start in February 2021 and is scheduled to be completed in June 2023. It will officially enter the main tunnel in August 2021, and the construction period of the main tunnel is 22 months.

[0045] Construction progress: Traditional pressure-type ventilation and dust reduction resulted in poor air conditions in the tunnel, low worker efficiency, high turnover rate, and construction stagnation caused by worker replacement, with slow monthly progress. After adopting aerosol dust reduction, workers' work enthusiasm increased, process connection was reasonable, and the construction period was reduced by about 2 months. Four face operations were arranged on the construction site, with an average of four face cannons fired per day, and the dust reduction and smoke exhaust time for each face was shortened by about 30 minutes.

[0046] Economic benefits: If the traditional forced-in ventilation dust suppression is used, the fan will run at high power for 50 minutes after blasting. After adopting aerosol dust suppression, the high-speed operation time of the fan is reduced by 30 minutes per shift and 120 minutes per day. The cost comparison is shown in Table 1-3 through the statistics of the dedicated fan electric meter installed on site.

[0047] Table 1-3 Cost Comparison

[0048]

[0049] This method saves a total of 6,055,200 yuan in costs.

[0050] Social benefits: As a key control project of the Yangtze River Expressway, the application of aerosol dust reduction method ensures the construction progress and safety of the inclined shaft end of Jiashatian Tunnel and saves project costs.

[0051] Application Examples

[0052] Project Overview: The starting and ending mileage pile numbers of the left and right tunnels of Jiashatian Tunnel are ZK217+130.784~ZK225+960, YK217+107~YK226+009, and the lengths are 8863m and 8902m respectively. According to the ventilation professional requirement that "the clearance cross-sectional area required for the independent space of each ventilation section should be guaranteed when the left and right line supply / exhaust shafts are built together", Jiashatian Tunnel is equipped with two parallel inclined shafts. The two inclined shafts are arranged in parallel, and the net distance between the two tunnels is about 40.2m. The length of the 1# inclined shaft is 170m, the horizontal curve is a straight line, and the longitudinal slope is 9.742%; the length of the 2# inclined shaft is 170m, the horizontal curve is a straight line, and the longitudinal slope is 9.264%.

[0053] The length from the open-cut entrance of the inclined shaft to the end of the intersection of air supply and exhaust is 192m, the straight-line distance from the end of the intersection to the center line of the fan room is 33.5m, the center line of the fan room to the left line design line is 55m, the distance between the left and right lines of the main line is 30m, the horizontal center line distance is 24m, and the longitudinal slope is large. From the open-cut entrance to the right line, it takes 5 90-degree bends to enter the right line of the main line, and exhausting the air in the tunnel is extremely difficult.

[0054] Construction situation: After the inclined shaft work area of ​​Jiashatian Tunnel entered the main tunnel for construction, there were many intersections in the tunnel, the temperature in the tunnel was high, and it suffered from problems such as poor tunnel ventilation and long dust reduction process. For this project, after field tests on the efficiency of water atomization and energy conversion of secondary atomizing nozzles with different geometric structures and dynamic performance parameters under different working conditions, a hidden spray device with a nozzle diameter of 1.5mm and a spray pressure of 5MPa was selected to better meet the purpose of efficient spray dust reduction.

[0055] Results evaluation: The measurement points were arranged at the driver's side during the slag loading operation at the excavation working face, and the full-time dust measurement personnel conducted follow-up measurements on the effect of the spray dust reduction system before and after use. Through the use of the spray dust reduction system: the average concentration of total dust and respirable dust at the driver's side of the slag loading truck increased from 1163.4 mg / m 3 and 344.4 mg / m 3 Reduced to 100.1 mg / m 3 and 55.1 mg / m 3, and the dust reduction efficiency is 91.3% and 84.0% respectively. This method has the advantages of high efficiency, low consumption, environmental protection, low water consumption and good atomization effect. It can not only shorten the "smoke" exhaust time, but also greatly improve the construction working environment in the tunnel, which is worthy of reference for similar projects.

[0056] Although the dust concentration on the excavation working surface has been greatly reduced after taking aerosol dust reduction measures, the dust concentration in the raised part of the arch at the intersection of the air duct and the fan room is still relatively high due to the complex cross-section of the underground fan room passage. Local spray dust reduction measures should be taken at the same time to achieve comprehensive dust prevention.

[0057] During the construction of the main tunnel at the inclined shaft end of the Jiashatian Tunnel of the ZCB1-9 / 10 project of the Jinning section of the Yanjiang Expressway of Sichuan Highway and Bridge Construction Group Co., Ltd., a hidden aerosol dust reduction test was used after blasting. Under the optimal working pressure conditions, an ideal dust reduction effect was achieved. It is safe, economical and efficient, and can provide a reference for the dust prevention and control design of other tunnels.

[0058] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be 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 present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A hidden gas mist dust reduction construction system after sandstone-shale interlayer tunnel excavation blasting, characterized in that; The dust reduction construction system includes a stand support system, a high-pressure spray dust reduction system, and a high-pressure air duct system; The platform support system is an excavation trolley (8), the high-pressure spray dust suppression system and the high-pressure air path system are respectively arranged on the excavation trolley (8), the nozzle (4) is divided into a spray dust suppression nozzle and a high-pressure air path nozzle, the pipe body (5) is divided into a spray dust suppression pipe body and a high-pressure air path pipe body, the high-pressure spray dust suppression system comprises a spray high-pressure pump and a high-pressure water pipe interface (7), one end of the high-pressure water pipe interface (7) is connected to the inlet of the spray high-pressure pump, the outlet end of the spray high-pressure pump is connected to the spray dust suppression nozzle via the spray dust suppression pipe body, the high-pressure air duct interface (6) is connected to the high-pressure air path nozzle via the high-pressure air path pipe body, and the high-pressure air duct interface (6), the high-pressure air path nozzle and the high-pressure air path pipe body form a high-pressure air path system.

2. According to claim 1, the hidden gas mist dust reduction construction system after sandstone-shale interlayer tunnel excavation blasting is characterized in that; The spray high-pressure pump is placed beside the two outer pedestrian ladder columns of the excavation trolley (8), so that the spray high-pressure pump and the excavation trolley can move synchronously and be easily controlled.

3. According to claim 1, the hidden gas mist dust reduction construction system after sandstone-shale interlayer tunnel excavation blasting is characterized in that; The nozzles (4) are respectively directed toward the excavation working faces, 30-50 m away from the heading face, and the mist flow sprayed by the spray dust suppression device can completely fill the tunnel lining section.

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