Hollow Oar Blade Sludge Dryer

Technical process
1 Feeding. Using helical conveyor feeding dehydrated sludge which solid content rate is 15%-30%, some times will carry out pre-mixing for tiny dried sludge after sieved and wet sludge according to characteristic of sludge.
2 Heat resource producing. The machine could use steam or oil to be as resource of heat exchange. Temperature of general thermal fluid is 180℃-200℃. Heat medium is introduced to hollow drier shell and rotating shaft, rotating oar.
3 Sludge drying. Surface of heated metal is content with sludge, to evaporate the moisture in sludge. Along with axial length of drier, water steam will experience constant evaporation rate phase and low evaporation rate phase. There are plasticizing, plastic breaking, massing and granulating four steps in sludge. The temperature of discharging sludge is 100℃-110℃. Solid content rate is above 90%.
4 Cooling and sieving. There are two methods in cooling: direct cooling and indirect cooling, then sieving sludge after cooling, or use molding machine to make the shape of sludge.
5 Condensation and recovery. Hot steam in drier will be sent to the condenser, recover the solvent. Non condensable gas will be sent into boiler to become heat resource. Condensated water will be sent to sewage plant.