Heat pump + mesh belt + insulation board are combined in one integrate module, thus structural airtight performance is improved, on-site installation is facilitated. Condenser and evaporator as well as refrigerant pipelines all are not made of copper, but advanced stainless steel. The heat pump support adopts SUS316L, improving product corrosion resistance. Two modules share one blower and the blower is belt-driven type, which makes repair simple; The blower in not designed under the sludge conveying belt, which makes cleaning and maintenance easier. The service access door are upgraded to quick-opening type, and improved with unique airtight structure design.