Experimental Investigation on Atomization and Dustfall Characteristics of Combined Nozzles for Shearer External Spray in Fully Mechanized Coal Mining Face

Table 3

Particle size distribution, volume frequency, and dust concentration at different positions of the fully mechanized coal mining face.

Measurement point	Frequency of dust particle size range					Dust concentration (mg/m^3)
	0∼2.5 μm	2.5∼4 μm	4∼10 μm	10∼20 μm	≥20 μm	Total dust concentration	Respirable dust concentration
1#	8.63	19.20	25.78	28.92	17.47	674.2	309.5
2#	12.54	26.09	29.01	21.16	11.20	627.0	263.8
3#	7.30	13.97	27.46	34.12	17.15	826.1	344.7
4#	26.33	31.68	22.13	16.26	3.60	431.3	205.2
5#	29.53	35.09	19.53	12.47	3.38	385.9	171.6