The problems in leakage protection and executive circuit of synthetical protection set in coal electric drill have been analyzed and calculated.
通过分析和计算说明老式煤电钻综合保护装置在漏电保护和执行电路中存在的问题。
2
The causes of using traditional wet drilling difficultly are analysed. And the wet drilling method of the coal electric drill of external spray hydroelectric interlock is related.
分析了传统湿式打眼难以推广应用的原因，叙述了外喷雾水电联锁煤电钻湿式打眼法。
3
The hydrocarbon source rocks of coal measures developed in this basin were studied on the basis of drill cores, which involved in many fields such as geology, organic geochemistry and petrology.