4. Auxiliary ventilation method — Apply the principle of ejector ventilation to quickly remove gun smoke from the face
The principle of ejector ventilation is to use pressurized water or compressed air to spray at high speed through the nozzle to generate a jet. As a result, the jet boundary continues to expand outward (free jet), and the cross-section and flow also increase. At the same time, due to the momentum exchange caused by the mixing of static air, the flow line of the jet boundary is reduced, and the entire jet becomes a turbulent jet after a certain distance.
Applying this principle, in the tunnel excavation and construction, after blasting the face, in order to speed up the smoke and dust and harmful gas generated after blasting the face, A simple water ejector (see Figure 2) made of high-pressure water pipes can be used to spray high-pressure water to the face of the tunnel. On the one hand, according to the principle of the ejector, the air flow speed of the palm surface is accelerated, and the ventilation effect is strengthened. The sprayed water can also take off dust, cool down and dissolve some toxic and harmful gases after being sprayed at the end of the spray.
Figure 2 Simple water ejector
Using this method to cooperate with construction ventilation, it is simple and easy to implement, safe and effective for ventilation and dust removal, smoke exhaust and cooling after blasting of the face.
To be continued……
Post time: May-13-2022
