Study and application on foam-water mist integrated dust control technology in fully mechanized excavation face

The dust produced by the roadheader during the tunneling process will change with time. Water mist can achieve high dust removal efficiency when the dust production is relatively small, and foam technology can realize high efficiency in the treatment of large dust production. It is necessary to choose water mist and foam dust removal technology freely according to the dust yield. Therefore, this paper puts forward the research of foam and water mist integrated dust removal technology. According to the characteristics of dust production in excavating operation, a new type of flat fan foam nozzle is put forward. Through the internal channel of gradual change, the foam jet is transformed from a cylindrical fluid to a flat one and diffuses at a certain angle. And the outlet area of the nozzle is determined to be 120 mm2, with the nozzle’s uniform angle of 6° and the compression angle of 25° as the final angle of the nozzle through simulation and field experiments. Combined with the characteristics of water mist, the function of water atomization is added to foam technology. On the basis of foam nozzle, 10 symmetrical water inlet channels with a diameter of 1.5 mm are uniformly arranged on the side wall, and the original foam inlet is changed into air inlet. Through multi-stage atomization of air and water, water mist with fine atomization size and uniform distribution can be produced. Relevant atomization operation conditions are tested through experiments. The test results show that the new technology could greatly reduce the cost, achieve the goal of efficient dust removal, and guarantee the working environment and the health of the workers.