A multi-stage water-washing dust removal activated carbon purification system for highway tunnels

Abstract

The invention discloses a multi-stage water-washing dust removal activated carbon purification system for a highway tunnel, comprising a water-washing chamber, a fan channel, a purification chamber, a water reservoir, etc., and uses a combination of water-washing dust removal and activated carbon adsorption to achieve the removal of main pollutants such as smoke, CO and NO2 in the tunnel. The system is water-washed step by step, and the water mist generated by the atomizing nozzle of the water-washing chamber is first fully contacted with the polluted gas to remove large particles of smoke dust. Then, the polluted gas is forced to collide with water and washed by the filter plate of the grading channel under the action of the fan. Finally, the remaining dust and entrained water vapor in the gas are cleaned by the defoaming device in the fan channel to improve the dust removal efficiency. The harmful gases in the polluted gas are removed by the activated carbon adsorption method, and the simultaneous purification of multiple harmful gases can be achieved. The air baffles at different angles in the purification room can make the equipment in different working modes, so as to increase the speed of the airflow in the purification room and improve the purification efficiency.

Description

Technical Field

[0001] The invention belongs to the technical field of ambient air purification and relates to a multi-stage water-washing dust removal activated carbon purification system for a highway tunnel. Background Art

[0002] The main pollutants in tunnels include particulate matter, CO, and NO2. Particulate matter can reduce visibility in tunnels, while gases such as CO and NO2 can harm the health of people inside. The accumulation of pollutants poses a significant threat to tunnel safety.

[0003] Currently, the main methods for pollutant control are electrostatic precipitators, water-washing precipitators, and activated carbon adsorption. Electrostatic precipitators are widely used abroad for their high dust removal efficiency. However, due to their high operating costs, electrostatic precipitators have not been widely adopted in China, and they cannot purify CO and NO2.

[0004] Water-washing dust removal equipment is a new type of dust removal equipment, mainly used in production environments where dust is easily flying everywhere. The principle of water-washing dust removal is to make water and smoke particles undergo physical reactions such as inertial collision, interception and Brownian diffusion to remove smoke particles from the air. The dust removal rate of water-washing dust removal is determined by the cleanliness of the intake air, which is normally between 60% and 80%. In addition, water-washing dust removal has lower energy consumption than electrostatic dust removal.

[0005] Activated carbon adsorption is the most effective purification method for treating organic waste gas and odors. Activated carbon possesses excellent adsorption properties and is an effective method for removing odors, natural and synthetic dissolved organic matter, and micro-pollutants from water. Most larger organic molecules, aromatic compounds, and halogenated alkynes adsorb firmly on the surface or within the pores of activated carbon, and it is particularly effective at removing humus, synthetic organic matter, and low-molecular-weight organic matter. As a deep purification process, activated carbon adsorption can absorb a variety of harmful gases and is often used in the final stage of wastewater treatment. It can also be used to purify long-term production and domestic water.

[0006] Studies have shown that when there is a lot of dust and particulate matter, activated carbon adsorption can be used together with water washing dust removal and UV plasma to achieve exhaust gas purification and meet emission standards.

[0007] Particulate matter, CO, and NO2 are the main pollutants in domestic highway tunnels. Therefore, developing a device for comprehensive treatment of particulate matter, CO, and NO2 in highway tunnels that effectively filters and removes dust, is highly safe, is more environmentally friendly, and achieves closed-loop control has always been one of the applicant's research topics. Summary of the Invention

[0008] In view of the defects or shortcomings of the prior art, the object of the present invention is to provide a multi-stage water-washing dust removal activated carbon purification system for highway tunnels.

[0009] To achieve the above tasks, the present invention adopts the following technical solutions:

[0010] A multi-stage water-washing dust removal activated carbon purification system for a highway tunnel comprises a water-washing chamber, a purification chamber and a water reservoir, wherein the water-washing chamber and the purification chamber are connected;

[0011] An atomizing nozzle is provided in the water washing chamber, the atomizing nozzle is connected to the first water inlet, an air inlet and a second air quality detector are provided in the water washing chamber, and a drain outlet is provided at the bottom of the water washing chamber;

[0012] The water washing chamber is connected to the fan channel through the filter screen, and the fan channel is connected to the fan through the demister, and there is a second water inlet on the filter screen;

[0013] The fan enters the purification chamber through the air collecting hood. An air baffle is provided inside the air collecting hood of the purification chamber. Four layers of activated carbon adsorption tanks are horizontally provided at the port of the purification chamber. The activated carbon adsorption tanks are placed horizontally on the drawer. Honeycomb activated carbon plates are placed on the activated carbon adsorption tanks. The upper two layers are used to adsorb CO, and the lower two layers are used to adsorb NO2. There is an exhaust port on the other side of the activated carbon adsorption tank, and a first air quality detector is provided above the exhaust port.

[0014] The first water inlet and the second water inlet are connected to an external water reservoir through a pipe, and a first water pump and a second water pump are provided on the water reservoir;

[0015] The water discharged from the drain outlet and the filter is connected to the wastewater tank through a pipeline;

[0016] The first air quality detector, the second air quality detector, the air baffle, the first water inlet, the second water inlet, the first water pump and the second water pump are respectively connected to the control unit.

[0017] According to the present invention, the gas collecting hood is connected to the purification chamber at an angle of 45 degrees.

[0018] Furthermore, the demister is composed of a plurality of W-shaped baffles, and a collecting hook is provided at each bend inside the channel formed by the baffles. The collecting hook is used to intercept water mist particles in the air flow, thereby separating large particles of water mist in the air.

[0019] Preferably, the air baffle is controlled by a motor and can form angles of 0 degrees, 45 degrees, and -45 degrees with the horizontal, directing the airflow generated by the fan to the corresponding activated carbon adsorption tank to achieve different working modes.

[0020] Further preferably, the first air quality detector and the second air quality detector are quality detectors that integrate a smoke concentration detector, a CO concentration detector and a NO2 concentration detector.

[0021] Further preferably, the first water pump provides pressure for the atomizing nozzle on the first water inlet, and the second water pump provides pressure for the filter screen on the second water inlet.

[0022] The present invention provides a multi-stage water-washing dust removal activated carbon purification system for highway tunnels. It combines water-washing dust removal with activated carbon adsorption to remove major pollutants in the tunnel, including smoke, CO, and NO₂. The system uses a step-by-step water washing process. First, the water mist generated by the atomizing nozzle in the water-washing chamber fully contacts the polluted gas, removing large particles of smoke dust. The system then passes through filter plates in the graded channels, where a fan forces the polluted gas to collide with water for washing. Finally, a demister in the fan channel removes any remaining dust and entrained water vapor, improving dust removal efficiency. Activated carbon adsorption is used to remove harmful gases from the polluted gas. Adding copper salt activated carbon prepared by different methods can purify different harmful gases, enabling simultaneous purification of multiple harmful gases. A drawer is added to the activated carbon adsorption tank to facilitate replacement of the activated carbon. Air baffles at different angles within the purification chamber enable the system to operate in different modes, increasing the airflow velocity within the purification chamber and improving purification efficiency. The air baffles ensure uniform flow of polluted gas through the activated carbon adsorbent, ensuring full contact between the two and improving purification efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic structural diagram of a multi-stage water-washing dust removal activated carbon purification system for a highway tunnel according to the present invention;

[0024] Figure 2 The three states of the air baffle are shown in Figure 1, where (a) shows the air baffle at 0 degrees to the horizontal, (b) shows the air baffle at 45 degrees to the horizontal, and (c) shows the air baffle at -45 degrees to the horizontal.

[0025] Figure 3 The baffle structure diagram of the demister, wherein (a) is a schematic diagram of the finished baffle, and (b) is a schematic diagram of the expanded baffle;

[0026] Figure 4 This is an application example of the highway tunnel multi-stage water-washing dust removal activated carbon purification system of the present invention being deployed at the tunnel entrance.

[0027] Figure 5 It is the control flow chart of the control unit.

[0028] The marks in the figure represent: 1. Water washing chamber, 2. Fan channel, 3. Purification chamber, 4. Wastewater tank, 5. Air inlet, 6. Atomizing nozzle, 7. First water inlet, 8. Drain, 9. Filter, 10. Second water inlet, 11. Defoamer, 12. Fan, 13. Activated carbon adsorption tank, 14. Drawer, 15. Exhaust port, 16. First air quality detector, 17. Second air quality detector, 18. Control unit, 19. Air collecting hood, 20. Air baffle, 21. Water reservoir, 22. First water pump, 23. Second water pump.

[0029] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. DETAILED DESCRIPTION

[0030] See also Figure 1 , this embodiment provides a highway tunnel multi-stage water washing dust removal activated carbon purification system, including a water washing chamber 1, a purification chamber 3 and a water reservoir 21, the water washing chamber 1 and the purification chamber 3 are connected;

[0031] An atomizing nozzle 6 is provided in the water washing chamber 1, and the atomizing nozzle 6 is connected to the first water inlet 7. An air inlet 5 and a second air quality detector 17 are provided in the water washing chamber 1. A drain outlet 8 is provided at the bottom of the water washing chamber 1.

[0032] The washing chamber 1 is connected to the fan channel 2 through the filter screen 9, and the fan channel 2 is connected to the fan 12 through the demister 11. There is a second water inlet 10 on the filter screen 9;

[0033] The fan 12 enters the purification chamber 3 through the air collecting hood 19. An air baffle 20 is provided inside the air collecting hood 19 of the purification chamber 3. Four layers of activated carbon adsorption tanks 13 are horizontally provided at the port of the purification chamber 3. The activated carbon adsorption tanks 13 are horizontally placed on the drawer 14. Honeycomb activated carbon plates are placed on the activated carbon adsorption tanks 13. The upper two layers are used to adsorb CO, and the lower two layers are used to adsorb NO2. An exhaust port 15 is provided on the other side of the activated carbon adsorption tank 13. A first air quality detector 16 is provided above the exhaust port 15.

[0034] The first water inlet 7 and the second water inlet 10 are connected to an external water reservoir through a pipe, and a first water pump 22 and a second water pump 23 are provided on the water reservoir;

[0035] The water discharged from the drain outlet 8 and the filter screen 9 is connected to the wastewater tank 4 through a pipeline;

[0036] The first air quality detector 16 , the second air quality detector 17 , the air baffle 20 , the first water inlet 7 , the second water inlet 10 and the water pump are respectively connected to the control unit 18 .

[0037] In this embodiment, the gas collecting hood 19 is connected to the purification chamber 3 at an angle of 45 degrees.

[0038] The air baffle 20 is controlled by a motor and can form an angle of 0 degrees, 45 degrees, and -45 degrees with the horizontal, directing the airflow generated by the fan 12 to the corresponding activated carbon adsorption tank 13 to achieve different working modes.

[0039] The first water pump 22 on the water reservoir 21 provides pressure for the atomizing nozzle 6 on the first water inlet 7 , and the second water pump 23 provides pressure for the filter screen 9 on the second water inlet 10 .

[0040] The control unit 18 controls the water output of the atomizing nozzle 6 and the filter 9 , as well as the power of the fan 12 and the angle of the air baffle 20 .

[0041] The first air quality detector 16 and the second air quality detector 17 are responsible for detecting the air quality in the highway tunnel, measuring the concentration of smoke, CO, and NO2 in the highway tunnel air, and comparing them with the tunnel pollutant concentration limit to determine the working status of the purification chamber 3 and the fan 12.

[0042] Purification chamber 3 is responsible for purifying the main pollutants such as smoke, CO and NO2 in the highway tunnel.

[0043] The fan 12 is responsible for providing air volume for the clean room 3 .

[0044] The multi-stage water-washing dust removal activated carbon purification system for a highway tunnel of this embodiment has a total volume of 7m×2m×2m. The water-washing chamber 1, the fan channel 2, and the purification chamber 3 are tetrahedrons. A water reservoir 21 and a wastewater tank 4 are placed under the fan channel 2 to save space.

[0045] The working principle of the multi-stage water-washing dust removal activated carbon purification system for highway tunnels in this embodiment is as follows:

[0046] The polluted gas enters the water washing chamber 1 through the air inlet 5, and the water mist generated by the atomizing nozzle contacts the polluted gas to remove large particles of dust; the negative pressure generated by the fan 12 will suck the polluted gas after the water washing and dust removal treatment in the water washing chamber 1 into the fan channel 2, and the polluted gas first contacts the filter 9 to undergo forced impact washing to remove small particles of dust, and then passes through the demister 11 to remove the remaining dust and entrained water mist, thereby realizing multi-stage water washing, filtration and dust removal; after flowing through the fan channel 2, the polluted gas flows into the purification chamber 3, and under the guidance of the gas collecting hood 19 and the air baffle 20, the polluted gas is again fully contacted with the activated carbon adsorbent in the activated carbon adsorption tank 13 to realize the removal of CO and NO2, and finally discharged through the exhaust port 15.

[0047] The dust removal method uses multi-stage water scrubbing, which physically reacts with water and dust particles, dissolving them in the water and releasing them from the air. The first stage of scrubbing is performed by atomizing nozzles 6 within the scrubbing chamber 1. Water, under pressure, forms a mist through the atomizing nozzles 6, which effectively contacts large dust particles. The nozzles of atomizing nozzles 6 are designed to target large dust particles in highway tunnels. Six centrifugal solid-cone nozzles are used, arranged in groups of three, with two groups vertically spaced 10 cm apart. These nozzles are not easily clogged by large dust particles and ensure sufficient contact with them. Water for atomizing nozzles 6 is supplied by a pipe from a reservoir, with water pressure generated by a first water pump 22 located on the reservoir 21. Wastewater is discharged to the wastewater tank 4 through a drain outlet 8.

[0048] The first stage of water scrubbing primarily removes large dust particles from the polluted air in highway tunnels. The remaining small dust particles are removed by the second stage of water scrubbing, using a filter 9 within the fan duct 2. This filter 9 consists of three layers of metal mesh, with 1 cm horizontal spacing between each layer. A second water inlet 10 is located above the metal mesh. Water pressure is generated by a second water pump 23 in a reservoir 21 and supplied to the water supply via a pipeline. Wastewater is discharged to a wastewater tank 4 through a pipeline below the metal mesh.

[0049] like Figure 3 As shown, the demister 11 is used to remove moisture from the air generated during the water washing and dust removal process. The demister 11 is composed of multiple W-shaped baffles. A collecting hook is provided at each bend inside the channel formed by the baffles. The collecting hook is used to intercept water mist particles in the air flow, thereby separating large particles of water mist from the air.

[0050] Activated carbon itself has good adsorption properties and can adsorb a variety of harmful gases. The inventors found through research that the prepared copper-loaded activated carbon exhibits stronger adsorption properties for CO and NO2, which can greatly improve the decontamination efficiency.

[0051] The method for removing CO and NO2 is to use activated carbon. The tunnel polluted gas flows through the activated carbon adsorption tank, and the activated carbon undergoes physical adsorption with CO and NO2 in the air to remove CO and NO2 from the air.

[0052] There are four layers of activated carbon adsorption tanks 13 horizontally arranged at the ports of the purification chamber 3. Each layer of activated carbon adsorption tanks 13 is equipped with a honeycomb-shaped activated carbon plate. The raw materials of the activated carbon plates are two kinds of copper-loaded activated carbons, which have higher adsorption properties than pure activated carbon. The two kinds of copper-loaded activated carbons are prepared by different methods to achieve adsorption of different pollutants. One kind of copper-loaded activated carbon has better adsorption properties for CO, and the other kind of copper-loaded activated carbon has better adsorption properties for NO2.

[0053] Four honeycomb activated carbon plates are evenly placed on the drawer 14 of each layer of activated carbon adsorption tank 13, with the upper two layers of activated carbon plates for adsorbing CO and the lower two layers of activated carbon plates for adsorbing NO2; one side of the activated carbon adsorption tank 13 is connected to the air outlet 15, and a handle is provided on the side of the air outlet 15, so that the activated carbon adsorption tank 13 of each layer can be pulled out to replace the activated carbon plates.

[0054] The mass of pollutants removed per unit time by copper-loaded activated carbon can be obtained from the following formula:

[0055]

[0056] In the formula, i = 2, 3; 2 is CO, 3 is NO2; mi is the mass of the i-th pollutant removed per unit time; ηi is the mass of the i-th pollutant removed per unit area; S is the cross-sectional area of ​​the activated carbon adsorption tank; d is the pore size of the honeycomb activated carbon; ds is the optimal pore size of the honeycomb activated carbon.

[0057] Due to the effect of copper ions, it has better adsorption than ordinary activated carbon, and the maintenance cycle is once a month.

[0058] The air baffle 20 is provided between the air collecting cover 19 and the activated carbon adsorption tank 13. The air baffle 20 is controlled by an external motor (not shown in the figure) and can form an angle of 0 degrees, 45 degrees, and -45 degrees with the horizontal to guide the airflow generated by the fan 12 to the corresponding activated carbon adsorption tank 13, thereby achieving Figure 2 Different working modes shown:

[0059] Working mode 1: The air baffle 20 forms a 0 degree angle with the horizontal, and the polluted gas flows evenly to the four activated carbon adsorption tanks 13 under the guidance of the air baffle 20, completing the removal of CO and NO2 ( Figure 2 a);

[0060] Working mode 2: The air baffle forms a 45-degree angle with the horizontal. The polluted gas flows evenly to the two activated carbon adsorption tanks 13 above under the guidance of the air baffle 20, completing the removal of CO ( Figure 2 b);

[0061] Working mode 3: The air baffle forms a -45 degree angle with the horizontal. The polluted gas flows evenly to the two activated carbon adsorption tanks 13 below under the guidance of the air baffle 20, completing the removal of NO2 ( Figure 2 c).

[0062] The working mode of the air baffle 20 is set mainly to improve the efficiency of pollutant removal.

[0063] The first air quality detector 16 and the second air quality detector 17 are quality detectors that integrate smoke concentration detectors, CO concentration detectors and NO2 concentration detectors. They are used to transmit the monitored tunnel smoke concentration, CO concentration and NO2 concentration to the control unit 18, and the control unit 18 converts the detected tunnel pollutant concentration ρ ci and tunnel pollutant concentration limit ρ bi Compare and judge whether the pollutants exceed the standard, determine the water output of the atomizing nozzle 6 and the filter 9, as well as the power of the fan 12 and the angle of the air baffle 20, such as Figure 5 The specific process is as follows:

[0064] The fan 12 and the water pump are initially closed, and the initial angle of the air baffle 20 is 0 degrees;

[0065] First, determine whether the smoke concentration exceeds the standard. If ρ c1 -ρ b1 >0, the smoke concentration exceeds the standard, the fan 12 is turned on, and the water pump supplies water to the atomizing nozzle 6 and the filter 9; if ρ c1 -ρ b1 ≤0, then proceed to the next step, and the working status of the fan 12 and the water pump is to be determined;

[0066] Then judge whether the concentrations of CO and NO2 exceed the standard. If ρ c2 -ρ b2 >0 and ρ c3 -ρ b3 >0, the CO and NO2 concentrations exceed the standard, the fan 12 is turned on, and the angle of the air baffle 20 is 0 degrees; if ρ c2 -ρ b2 >0 and ρ c3 -ρ b3 ≤0, only CO exceeds the standard, the fan 12 is turned on, and the angle of the air baffle 20 is 45 degrees; if ρ c2 -ρ b2 ≤0 and ρ c3 -ρ b3 >0, only NO2 exceeds the standard, the fan 12 is turned on, and the angle of the air baffle 20 is -45 degrees; if ρ c2 -ρ b2 ≤0 and ρ c3 -ρ b3 ≤0, then both CO and NO2 are within the standard.

[0067] The relationship between whether each pollutant exceeds the standard and the working status of each device is shown in Table 1 below.

[0068] Table 1: Relationship between whether each pollutant exceeds the standard and the working status of each device

[0069]

[0070]

[0071] The opening time of the fan 20 is determined according to the exceeding of the standard of each pollutant. The specific working time of the fan 20 is determined by the following formula:

[0072] T=max{T1,T2,T3}

[0073]

[0074] Where i = 1, 2, 3, where 1 represents particulate matter (VI), 2 represents CO, and 3 represents NO2; Ti is the operating time of the fan required to remove the i-th pollutant; T is the final operating time of the fan; ρ ci is the measured concentration of the i-th pollutant; ρ bi is the tunnel limit value of pollutant i; v i The wind speed in the working area for removing the i-th pollutant is: v1 is the wind speed at the filter plate, v2 is the wind speed at the CO activated carbon adsorption tank, and v3 is the wind speed at the NO2 activated carbon adsorption tank; S i is the reaction area of ​​the working area for removing the i-th pollutant, specifically S1 is the area of ​​the filter plate, S2 is the cross-sectional area of ​​the CO activated carbon adsorption tank, and S3 is the cross-sectional area of ​​the NO2 activated carbon adsorption tank; m i is the mass of pollutant i removed per unit time.

[0075] There are two water pumps in the water washing and dust removal process, namely the first water pump 22 and the second water pump 23, which provide pressure for the atomizing nozzle 6 and the filter 9 respectively. Due to the differences in pipeline length, height from the water reservoir and atomization degree of the equipment, the pressure required by the atomizing nozzle 6 and the filter 9 is different. The pressure provided by the water pump is determined by the following formula:

[0076]

[0077]

[0078] Where i = 1, 2, where 1 represents the corresponding parameters of the atomizing nozzle and 2 represents the corresponding parameters of the filter; P is the pressure required by the device; u is the atomization coefficient of the device; v is the wind speed generated by the fan; g is the acceleration of gravity; Δp l is the pressure loss per unit length of the pipeline; Δp h The pressure lost per unit height.

[0079] The water flow required by the atomizing nozzle 6 and the filter 9 is determined by the following formula:

[0080]

[0081]

[0082] Where Q1 is the flow rate required by the atomizing nozzle, Q2 is the flow rate required by the filter, and Q is the flow rate required by the overall equipment; μ is the flow coefficient of the fluid, usually 0.82; A is the cross-sectional area of ​​the pipe; and P is the required pressure.

[0083] When the working time of the fan 12 reaches T, the second air quality detector 17 starts to work, detects the smoke concentration, CO concentration and NO2 concentration in the purified air, and transmits the detection data to the control unit 18. The control unit 18 compares the three detected ambient air quality data with the tunnel pollutant limit and provides feedback on the purification result. If the concentration of any one or more pollutants exceeds the standard, the control unit 18 displays that the purification of the corresponding pollutants is incomplete. The staff can inspect and maintain the highway tunnel multi-stage water-washing dust removal activated carbon purification system of this embodiment according to the information displayed by the control unit.

[0084] In this embodiment, the fan 12 can be an axial flow fan, providing an air volume of 26120m 3 / h, wind pressure 380Pa, power 4kW. Water pump power is 120W.

[0085] Tests have shown that the highway tunnel multi-stage water-washing dust removal activated carbon purification system of this embodiment has a purification efficiency of about 90% for smoke and dust particles, and a purification rate of 60% to 80% for CO and NO2.

[0086] Research shows that the highest concentration of environmental pollutants occurs 50 meters from the entrance of a highway tunnel. To improve purification efficiency, the highway tunnel multi-stage water-washing dust removal activated carbon purification system of this embodiment is recommended to be deployed in areas with high tunnel pollutant concentrations, generally near the tunnel entrance, or in a transverse passageway outside or near the tunnel entrance. The system's power supply can be provided by a substation within the tunnel.

[0087] Application examples:

[0088] like Figure 4 As shown, the tunnel is 1792 meters long and 1654 meters long, with two tunnels and two lanes in one direction. Each lane has 10 jet fans, each producing 30 kW of power per day, arranged in groups of two near the tunnel entrance. According to the "JTG / T D70 / 2-01-2014 Highway Tunnel Lighting Design Specifications," tunnel pollutant concentrations are specified as shown in Table 2. The amendment to the "Ambient Air Quality Standard" (GB3095-2012) stipulates pollutant limits for scenic areas. Vehicle emission standards for 5A-level scenic highway tunnels should be higher than those for general highway tunnels. Classification is based on ambient air functional zones: Class I areas include nature reserves, scenic spots, and other areas requiring special protection. Class I concentration limits apply to these areas, as shown in Table 3.

[0089] Table 2: Tunnel pollutant concentration limits

[0090] Types of tunnel pollutants Soot particles CO <![CDATA[NO2]]> Tunnel pollutant limits <![CDATA[0.007m -1 ]]> 100ppm 1ppm

[0091] Table 3: Concentration limits for basic items of ambient air pollutants

[0092]

[0093] Combining Tables 2 and 3, we determined that the smoke particulate matter concentration limit for this 5A-level scenic area highway tunnel is 0.075 ppm, the CO concentration limit is 10 ppm, and the NO2 concentration limit is 0.2 ppm. The tunnel's existing ventilation system was designed in accordance with the "JTG / T D70 / 2-01-2014 Highway Tunnel Lighting Design Specifications." Its tunnel pollutant limits are lower than the air quality requirements for 5A-level scenic areas. Traditional ventilation decontamination methods are no longer suitable, and pollutant purification is required.

[0094] according to Figure 5 The control process is purified, and the results are as follows:

[0095] When the tunnel standard passenger car design peak hour traffic volume is 2112pcu / h, the corresponding proportion coefficients of each vehicle type are small truck 6%, medium truck 7%, large truck 5.9%, small passenger car 12%, large bus 48.9%, trailer 12.9%, and container 7.3%. The required air volume for the traditional mechanical ventilation method is calculated to be 359m 3 / s, after using the highway tunnel multi-stage water washing dust removal activated carbon purification system of this embodiment, the required air volume is 273m 3 / s, reducing the required air volume by 24%. The fan operating time is T = 23 minutes, the total water demand is Q = 20L / min, and based on the assumption that the jet fan in the tunnel operates for 2 hours per day and the electricity cost is 0.5 yuan / kWh, the economic analysis of mechanical ventilation and the highway tunnel multi-stage water-washing dust removal activated carbon purification system (referred to as purification equipment in Table 4) using the above embodiment is shown in Table 4 below.

[0096] Table 4: Economic Analysis

[0097]

[0098] The use of the highway tunnel multi-stage water-washing dust removal activated carbon purification system of this embodiment can save 200,000 yuan in electricity costs each year during the tunnel operation period, saving about 20% of the operating electricity costs.

Claims

1. A highway tunnel multi-stage water-washing dust removal activated carbon purification system, comprising a water-washing chamber (1), a purification chamber (3) and a water reservoir (21), characterized in that: The washing chamber (1) and the purification chamber (3) are connected; An atomizing nozzle (6) is provided in the water washing chamber (1), the atomizing nozzle (6) is connected to a first water inlet (7), an air inlet (5) and a second air quality detector (17) are provided in the water washing chamber (1), and a drain outlet (8) is provided at the bottom of the water washing chamber (1); The washing chamber (1) is connected to the fan channel (2) through a filter screen (9), the fan channel (2) is connected to the fan (12) through a demister (11), and a second water inlet (10) is provided on the filter screen (9); The fan (12) enters the purification chamber (3) through the air collecting hood (19), an air baffle (20) is arranged inside the air collecting hood (19) of the purification chamber (3), and four layers of activated carbon adsorption tanks (13) are arranged horizontally at the port of the purification chamber (3), the activated carbon adsorption tanks (13) are placed horizontally on the drawer (14), the upper two layers are used for adsorbing CO, and the lower two layers are used for adsorbing NO2; a honeycomb activated carbon plate is placed on the activated carbon adsorption tank (13), and the raw materials of the honeycomb activated carbon plate are two kinds of copper-loaded activated carbon, one copper-loaded activated carbon is used for adsorbing CO, and the other copper-loaded activated carbon is used for adsorbing NO2; an exhaust port (15) is arranged on the other side of the activated carbon adsorption tank (13), and a first air quality detector (16) is arranged above the exhaust port (15); The first water inlet (7) and the second water inlet (10) are connected to a water reservoir (21) through a pipeline, and a first water pump (22) and a second water pump (23) are provided on the water reservoir (21); The water discharged from the drain outlet (8) and the filter screen (9) is connected to the wastewater tank (4) through a pipeline; The first air quality detector (16), the second air quality detector (17), the air baffle (20), the first water inlet (7), the second water inlet (10), the first water pump (22) and the second water pump (23) are respectively connected to the control unit (18); The demister (11) is composed of a plurality of W-shaped baffles, and a collecting hook is provided at each turning point inside the channel formed by the baffles, and the collecting hook is used to intercept water mist particles in the air flow, so as to separate large particles of water mist in the air; The first air quality detector (16) and the second air quality detector (17) are quality detectors integrating a smoke concentration detector, a CO concentration detector and a NO2 concentration detector; and are used to transmit the monitored tunnel smoke concentration, CO concentration and NO2 concentration to a control unit (18); The control unit (18) is used to compare the detected pollutant concentration of each tunnel with the tunnel pollutant concentration limit value to determine whether the pollutant exceeds the limit, thereby determining the water output of the atomizing nozzle (6) and the second water inlet (10) above the filter (9), the power of the fan (12), and the angle of the air baffle (20); The air baffle (20) is controlled by a motor and can form an angle of 0, 45 or -45 degrees with the horizontal, directing the airflow generated by the fan (12) to the corresponding activated carbon adsorption tank (13), thereby realizing different working modes.

2. The highway tunnel multi-stage water-washing dust removal activated carbon purification system according to claim 1 is characterized in that: The gas collecting hood (19) is connected to the purification chamber (3) at an angle of 45 degrees.

3. The highway tunnel multi-stage water-washing dust removal activated carbon purification system according to claim 2 is characterized in that: The first water pump (22) provides pressure for the atomizing nozzle (6) on the first water inlet (7), and the second water pump (23) provides pressure for the filter screen (9) on the second water inlet (10).

Images