In order to put the shearer water -spraying into the best effictiveness of water-spraying, this paper gives the flow pressure characteristic equation of per group spray nozzle with system analysis, and simulated varying regularity of per group spray nozzle flow pressure when total feeding flow changed.

Probing into similarity law of fully mechanized mining face in dust suppression by spraying;

This paper analyzes the commonly used control measures of coal dust in coal mining,introduces some dust removing technologies such as the coal seam infusion,dust suppression by spraying,dust suppression with dust collector,and foam dust-removing,etc.

Based on engineering examples the paper introduces some matters that need to be considered in the design of water spray fire extinguishing system,such as determination of design flow,selection and arrangement of spray head,arrangement of deluge valve block and laying of water spray pipeline,as well as operation and control of system and selection of water source and pumps,etc.