Heating medium: The heat exchanger transfers heat to the drying medium (such as air, nitrogen, etc.) to increase its temperature. The hot drying medium comes into full contact with the sludge and transfers heat to the sludge through convection, conduction, and other means, causing the water in the sludge to absorb heat and evaporate into steam, thereby achieving the drying of the sludge.
Recycling waste heat: During the sludge drying process, a large amount of exhaust gas containing heat is generated. The heat exchanger can cool the exhaust gas and recover the heat from it. The recovered heat can be used to preheat fresh air or drying medium entering the dryer, as well as for other process links that require thermal energy, thereby improving the energy utilization efficiency of the entire drying system and reducing energy consumption.
Removing moisture: During the sludge drying process, the heat exchanger can not only heat the drying medium, but also condense the water vapor in the drying medium into liquid water through cooling, thereby achieving dehumidification of the drying medium. Dehumidification of the drying medium is beneficial for improving its ability to absorb moisture from sludge and enhancing the drying effect. For example, in some sludge drying systems that use circulating drying media, by setting up cooling heat exchangers to dehumidify the circulating air, the drying speed of sludge can be increased by 20% -30%.