RHG rolling drained expander is the patent product (patent No.002293803) developed by our company. The capacity of single machine is up to 1000t/d and is suitable for oil plant which adopting pre-pressing extraction and direct extraction. The capacity can vary from 50-2000t/d. It’s mainly used in softening and drying of raw material, increasing the plasticity of raw material, decreasing the water content of raw material, making flake thin and not broken. Then, the effect of cooking, pressing, and extraction can be strengthened. Adopting cage heating and gear driving, the heating of material is more even and complete, and power and steam consumption is decreased. New designing is adopted to adjust the softening method and time of meal in the expander at any time, according to different variety and properties of material.