the heating cavity is packed on the external wall of the hollow pipe in airtight;
加热腔密闭的包在中空管的外壁上;
the invention discloses a liquid heating device, which comprises a hollow pipe and an electric heating device as well as a heating cavity and a pre-heating pipe.
本发明公开了一种液体加热装置,包括中空管和电加热装置还包括加热腔和预热管;
the spray pipe is a ring hollow pipe body, and the through spray orifices are alternatively distributed around the spray pipe.
所说的喷管为环形中空管体,贯通的喷孔沿喷管的圆周间隔分布。
the valve at the bottom of auger can prevent drilling bits entering hollow pipe during operation. when drilling pipe is taken out and concrete grout is injected, the valve will be opened.