Telescopic slag suction device

A telescopic slag suction device comprises a suction unit, a telescopic slurry pipe, a top slurry pipe and a hoisting steel cable, and a slurry pump and a stirrer of the suction unit are linearly arranged at intervals; a telescopic slurry pipe is fixedly arranged at a slurry pipe connecting plate of the suction unit, and the slurry pipe on the innermost layer is fixedly provided with a transition thread bushing and then is communicated with the transition slurry return pipe; the top slurry pipe is fixedly arranged on the top connecting flange of the telescopic slurry pipe; the hoisting steel rope penetrates through the top slurry pipe and is connected with the slurry pipe lifting lug; according to the telescopic slag suction device, the telescopic slurry pipe is lowered to the bottom of the underground diaphragm wall groove layer by layer through the hoisting steel cable, slurry and disintegrating slag particles in the underground diaphragm wall groove body are sucked away by operating the stirrer of the suct