Fog cannon dust falling in city tunnelWith the development of national economy, the problem of urban traffic congestion is becoming more and more serious, especially in some first tier cities. It is urgent to speed up the construction of urban roads. With an engineering example, the dust discharge system of fog cannon in tunnel is introduced.
1 project survey and research background
This project is a tunnel in Hangzhou purple (zijinggang road ~ Zhijiang Road) civil engineering construction section III, located near the city of Hangzhou, Xihu District Bi Longtan, the main projects are 1# tunnel (East West 1400m, 1427m), 2# (1828m tunnel inlet section East, West 1823m), and the two tunnel between 56m road and 1 culverts. At present most of the domestic construction of the tunnel by blasting excavation, trackless transportation, dust, vehicle tunnel blasting operations and shotcrete shotcrete machine when running and running the dust filled the tunnel entrance to the tunnel face to this region, especially the excavating face dust generated in the vicinity of the largest, the largest concentration caused by low visibility, and poor air quality, caused some damage to the workers. At the same time the dust by circulation of placed in the hole of the counter rotating axial flow fan is directly discharged outside without any treatment, but also serious pollution of outside environment. The following is a brief introduction to the combination of fog, dust and dust in urban tunnel.
Overview of 2 fog cannon dustfall
fog cannon dust is a new way of tunnel dust, its advantage lies not only in low cost, simple device structure, simple control, convenient maintenance, and the effect is significant and the stability is not compared to other dust removal, especially without the need to collect and transport the dust gas, eliminating the dust cover, fan and the wind pipe and other equipment, but will not cause two pollution. The key technology is to improve the atomization effect. The more water droplets, the higher the probability of combining dust, the better the effect of dust reduction, but the amount of water is not very large. It is required to achieve the purpose of effective dust removal, and to grasp the amount of water.
Principle of dust falling in 3 fog cannon
The working principle of fog cannon dust is the use of high pressure water pressure of 50-70 kg, after the pipeline is input to a high pressure atomization device, water after atomization device equipment in the air formed floats in the mist, the mist to adsorption in the air, fine dust and particulate matter, at the same time to air humidification.
The use of dust and water through the principle of bond and coalescence increases, make fine dust through interaction between diameter of water droplets, reduce the surface tension of water meter, the dust and water together to form a group, under the action of gravity, the final settlement to the ground. When the particle size of fog is close to the size of dust particles, the effect of dust reduction is best. The sprayer is the water pressure by high pressure pump, high pressure water pressure of similar diameter and dust particles in the water mist by high-pressure atomizing nozzle, spray again through the big power fan will be sent to the area of the water fog mist dust and dust particles adsorption, condensation rapidly increases, and the settlement under its own gravity, so as to reduce the dust, spray machine also has the effect of cooling and humidification.
Make sure that there is enough water in the tank to suit the use of the high pressure jet. Mobile spray vehicles should be placed within 10m of the dust producing area to ensure that water mist can cover dust.