... ,city waste 3.simple operation ISO 9001 poultry manure drum drying machine The working principlewe produced a rotary kiln system and ... .4) The operation is very simple and reliable.The drum drying machine also named revolving tube dryer , made by our company ... used in building materials, metallurgy, chemical plant, cement plant for drying of limestone slag, coal powder, slag, clay stone. This dryer ...