Wet materials are sent to push-floor silo by belt conveyor, screw conveyor and sludge pump. Then, wet materials will enter feeding end through feeding pipe of feeder set under silo. MED drum dryer is a horizontal rotary drum dryer slightly inclined with horizontal line. Materials enter to dryer through higher end and heat carrier enters dryer through lower end. Heat carrier will contact with materials counter-currently. There are also some situations where materials enter dryer with heat medium. Along with the rotation, materials move to lower end under the function of gravity. During the moving forward process, wet materials are directly or indirectly heated by heat medium. In this way, wet materials are dried and dry products will be discharged out by belt conveyor or screw conveyor. There is lifting plates set inside drum. The function of lifting plates is lifting and scattering materials so that to enlarge the contact surface between materials and air flow, improve drying efficiency and drive materials move forward. Heat medium is generally divided into hot air and flue gas. After passing by rotary drum dryer, materials brought by heat carrier shall be caught by cyclone. If dust content in exhaust gas needs to be further reduced, exhaust gas shall pass by bag filter or wet type dust removing machine before discharging to air.