Sludge paddle drying provides a once-through drying technology that avoids back-mixing. The sludge residence time is long, and the average sludge temperature is 100°C, which can decarbonize and sanitize the sludge. Due to different process types, this machine can accept any type of sludge, so it is very suitable for centralized drying equipment that handles different sludge from different areas. Since no back-mixing is required, any residual moisture content can be selected for the product. This makes the machine ideal for partial drying to 35-40% dry solids, which is required prior to sludge incineration.
All evaporated water is sent to the wet scrubber without adding any sweep air. This means that the volume is limited to the amount of water vapor collected within the dryer dome. The small amount of noncondensables in the exhaust steam should be after-treated to keep the emissions to a minimum. The entire unit is installed on a slight slope, and the sludge flows by gravity to the other end of the unit for discharge.
Dried sludge (with a dry solid content of 90-95%) enters the dry sludge storage at a safe temperature below 40°C through a cold conveyor. Dried sludge products can be used for a variety of purposes, for example as an agricultural composting component or as an alternative fuel for combustion processes.
