Sewage grinder is a high torque, low rotating speed and double shaft grinder under water. It is designed to pulverizing all kinds of solid waste ( clothing, plastic, trash, wood, aluminum can, glass bottle and other debris) to 8-12mm in the modern waste water and sludge to protect pumps, prevents binding and clogging problems. Accommodates high speed water flow while pulverizing various solid waste into particles that let the water flow harmlessly through pumps, pipes and so on.