The large diameter replaceable flush pipe assembly design and engineering application

In the process of large-diameter rescue drilling using the air reverse circulation drilling process, the through hole in the main shaft of the top drive head of the vehicle-mounted drilling rig and the punching pipe assembly are often blocked. In order to solve the common technology in the construction process The problem is that this article analyzes and locates the cause of the blockage on the basis of a brief introduction to the air reverse circulation drilling process, and then proposes the design of a large diameter replaceable flushing pipe assembly. In the design process, the key breakthrough was made in the four groups of packing and the rotating seal of the flushing tube in the lower packing box of the flushing tube assembly, and a replaceable and vulnerable module was designed at the gooseneck tube, which greatly reduced the use cost. Engineering application results show that the application of the large-diameter replaceable flushing pipe assembly and slag discharge pipeline designed in this paper makes the slag discharge smooth during the air reverse circulation drilling process of the cluster type DTH hammer, the drilling efficiency is improved, and the labor intensity of workers is greatly reduced.