Dust Concentration Changing Regularities and Dust Reduction Technology by Spray Negative Pressure in Fully Mechanized Mining Face

Table 9

The spray dust removal efficiency with the pressure of 8 MPa and fan rotate speed of 300 r/min.

Nozzle number	Dust removal rate (%)
	Total dust	Respirable dust
Nozzle 1	42.71	35.87
Nozzle 2	39.21	32.39
Nozzle 3	50.37	46.61
Nozzle 4	47.32	41.71
Nozzle 5	56.30	51.21
Nozzle 6	63.56	59.78
Nozzle 7	60.72	56.17
Nozzle 8	65.82	61.70