Review on Sludge Drying Process and Dryer in Solar Energy

The objective of this work is to give the fundamental information that should be known about solar sludge drying. The solar sludge drying process and characteristics are presented. Based on some researchers’ theoretical analysis and experimental results, the main influence factors of sludge drying process are air temperature and humidity, drying air flow rate, intensity of solar radiation, sludge thickness and drying ways. Some innovative developed solar sludge drying systems are exposed in this review, such as the use of waste flue gas heat/sun capable system. Finally author put forward a new way of solar heat pipe-greenhouse drying system.