The study of sewage sludge thermo-drying efficiency

摘要

With the population exploding and improvement of urbanization, the sewage sludge production increases rapidly with the increasing of sewage. However, high water content has been a big problem for sewage sludge treatment and disposal. Thermo-heating is one of the mature methods to reduce the water content in sewage sludge, but the promotion of thermo drying is very restricted by its high cost because of abundant consumption of energy and its expensive equipments. In order to save energy and reduce investment for equipments, we studied the low-temperature thermo-drying efficiency by varying the temperature from 100°C to 200 °C, and changing the shape of the sewage sludge sample, We tried three shapes (cake, cylindrical and spherical) and three temperature (at 150°C,175°C and 200°C). It is found that cake sludge has the highest drying efficiency and spherical sludge is the lowest in each condition. At 200 °C the drying efficiency could get the highest point.