Every year, China's urban sewage treatment plants produce more than 60 million tons of sludge (water content 80%), and the amount of sludge per 10,000 tons of sewage is about 3-8 tons. Due to the long-term problem of "heavy water and light mud", the situation of sludge treatment and disposal is becoming more and more serious. There are a variety of sludge drying technologies, including natural drying, thermal drying, and high drying dehydration. This article mainly talks about sludge drying