HX-C25EL/C45EL Semi-retractable soot blower is a derivative of the ordinary HX-C25 and HX-C45 long telescopic soot blower. Except that the soot blower barrel is lengthened and the soot blower barrel support plate is added accordingly, the structure, control method and action principle of all other parts are exactly the same as the ordinary long telescopic soot blower. Ordinary long telescopic soot blower only has a nozzle at the end (nozzle head). When not blowing soot, the soot blowing gun barrel is completely outside the furnace. A part of the soot blowing barrel of the Semi-retractable soot blower is always placed in the furnace, and a number of nozzles (1 or 2 in each group) are installed at the end and waist of the barrel. During the expansion and contraction process of the soot blower, the nozzles at different parts blow different areas respectively, and the soot blowing area is often twice or more than the stroke.