This article introduces the practice of releasing gas by using the wind coal drill in the big road of shaft,which shows that the technology is reasonably,the economic efficiency is remarkable,the security has guarantee,is a practical feasible effective way and has broad application prospect.

The method of drilling by the wind coal drill,the coal body produces the crack and releases gas under the conditions of the dynamic pressure function of mining field,then draining gas with drainage facility to govern the local high gas region at working surface are introduced.

By the test analysis methods of simulating field production,we study on the working instability of integrated protector for coal electronic drill.

Discussion on the reason of influencing coalfield drilling efficiency and its countermeasure

New-style quick interruption versatile protector of electric coal drill;

In this paper, the structure and operation mode of an electric coal drill, temporarily named MSZ-12C with hydrau-electric control is introduced.

According to the enlarging embrasure and making use of ZM12T and ZM12D coal electric drill,develops a type of ZMJ-1 equipment of determining anti_cutting intension of coal and rock used in coal_mine underground,and educes dependence formula of anti_cutting intension of coal and rock and the height of measuring curve.

The problems in leakage protection and executive circuit of synthetical protection set in coal electric drill have been analyzed and calculated.

Carrier frequency short circuit protection of integrated protector for coal electric drill was analysed by doing experiment,proves protect action of carrier friquency is regular when the length of cable is shorter than 200m.