The machine is suitable for medium-sized radial flow secondary settling tank sludge and slag. The machine is the central buttress double (single) peripheral transmission, the transmission torque, energy saving. With central water and mud, surrounding drainage, to ensure uniform flow using the level difference between self-priming mud. With overload protection device, you can control and computer networking. In operation, sewage diversion tube by diffusion from the central buttress at a mixture of coarse particles after sedimentation the sludge in the bottom layer, the proportion of light floating in the liquid, driven by the work of the bridge in the vicinity of the drive mechanism along the center seat slowly rotating, driven wiper arm scraper to scrape the sludge layer by layer from the periphery to the center tank vent the mud outside the pool, scum blade along the guide tube to float on the surface of the pond scum thrown the inner periphery of slag bucket, is discharged out of the pool.