顶驱车载钻机空气潜孔锤钻进用低压防喷装置的研制

在空气潜孔锤钻进时，孔口安装防喷装置可将高速返出的粉尘或泥浆导离孔口，防止喷向工作台而污染孔口工作环境。综合考虑ZMK5530TZJ60型车载钻机孔口工作台结构特点、配套的斜坡钻杆外形特征、钻进工艺特点以及装卸操作环境等因素，设计了一款适用于顶驱车载钻机的空气潜孔锤钻进用低压防喷装置。该低压防喷装置具有结构简单、安装方便；通过胶芯与钻具之间的过盈实现孔口密封，密封胶芯补偿量大，可密封外径变化较大的斜坡钻杆；可在加接钻杆时更换密封胶芯；设置了2个导流口，上返流体在此压降变化小，有利于排渣的通畅等优点。现场试验表明，该低压防喷装置能够有效密封粉尘泄漏、明显改善孔口施工环境，达到了设计的目的。

Development of Low Pressure Blowout Preventer for Air DTH Hammer Drilling Used on Top Drive Truck Driller

In order to prevent working environment pollution, a blowout preventer is necessary to carry high-speed upward downhole dust or slurry away from the hole top during DTH hammer drilling. Comprehensively considering the main factors of the structure characteristics of hole top workbench for truck driller, the shape features of matched drill pipe with taper at the joint, the drilling process characteristics and the mount-dismount operating conditions, a low pressure blowout preventer for air DTH hammer drilling used on top drive truck driller was designed with the advantages of simple structure and convenient installation. The borehole entrance sealing was conducted by interference fit between rubber sealing plug and drilling pipes, the sufficient compensation quantity of rubber sealing plug is effective for sealing of those pipes with large outside diameter difference; the rubber sealing plug can be easily replaced while adding drilling pipes; 2 diversion ports were set up to reduce returned fluid pressure drop. It is showed by the field application that the blowout preventer can effectively prevent the dust or slurry leakage and obviously improve the construction environment.