Industrial Double Cone Rotary Vacuum Dryer — Low-Temperature Rotary Vacuum Drying for Heat-Sensitive, Oxidizable & Solvent-Containing Materials

The Double Cone Rotary Vacuum Dryer is a batch drying equipment that performs low-temperature drying under vacuum conditions, with jacket heating and tank rotation to tumble the material. Operating in a vacuum environment significantly lowers the drying temperature of the material (the boiling point of water decreases with increasing vacuum), making it especially suitable for drying heat-sensitive, easily oxidizable, flammable/explosive, toxic and organic-solvent-containing materials. It is an important drying equipment in pharmaceutical, fine chemical and food industries.

The double-cone tank consists of two conical cylinders and a middle cylindrical cylinder welded together. The tank is supported at both ends by rotating shafts and driven to rotate slowly around the horizontal axis by a transmission system (motor + reducer + sprocket/gear). Material is loaded into the tank (typically 30% to 50% of tank volume). As the tank rotates, the material is continuously tumbled and mixed inside, updating its contact surface with the tank wall. Heating medium (hot water, steam or thermal oil) is passed through the tank jacket, and heat is conducted through the tank wall to the material, evaporating moisture (or solvent). The tank is maintained under vacuum (by a vacuum pump), and evaporated water vapor (or solvent vapor) is extracted through the vacuum line, condensed and recovered (organic solvents) by a condenser, or discharged to the atmosphere (water vapor). As the tank continues to rotate and vacuum is applied, the material is continuously tumbled and dried, ultimately reaching the required moisture content. After drying is complete, the tank is rotated until the discharge port faces downward, and the discharge valve is opened to discharge the finished product.

• The tank adopts a double-cone structure (cones at both ends + cylinder in the middle), made of high-quality stainless steel (304/316L) plate rolled and welded, with mirror-polished inner wall, no dead corners, facilitating easy discharging and cleaning; the tank jacket can withstand certain pressure for heating medium;
• The rotating shaft adopts a hollow shaft design — one end serves as heating medium inlet/outlet, the other as vacuum extraction port, connected to external pipelines through rotary joints to ensure no pipeline tangling during tank rotation;
• The transmission system uses a variable-frequency speed-regulating motor + reducer + sprocket/gear drive, with stepless speed adjustment (typically 2 to 10 rpm) to suit different material tumbling requirements;
• The vacuum system consists of vacuum pump (water ring pump / Roots pump unit), vacuum lines, condenser and receiving tank, capable of recovering organic solvents; vacuum degree can be automatically controlled and displayed;
• The heating system can use hot water circulation, steam or thermal oil heating, with precise temperature control (typically room temperature to 150°C);
• The tank is equipped with manhole/feed port, discharge port, vacuum gauge, thermometer, rupture disc (safety device) and other interfaces;
• Optional forced stirring device (additional stirring blades inside the tank) for handling caking-prone, high-viscosity materials;
• The equipment base is welded from section steel with a stable structure, equipped with a protective cover for operational safety.

• Vacuum low-temperature drying — material drying temperature is low (boiling point of water is approximately 40°C at -0.09 MPa vacuum), especially suitable for heat-sensitive materials, effectively preventing decomposition and deterioration of active ingredients;
• Vacuum environment isolates oxygen, suitable for drying easily oxidizable materials;
• Enclosed operation, suitable for drying toxic, harmful, flammable and explosive materials with operational safety;
• Solvent recovery — evaporated organic solvents are condensed and recovered by the condenser, being both environmentally friendly and reducing production costs;
• Tank rotation continuously tumbles the material for uniform drying without manual turning;
• Indirect heating (conduction type) — material does not come into direct contact with heating medium, avoiding contamination and ensuring high product purity;
• Simple equipment structure with easy operation and maintenance, long service life.

• Widely used in pharmaceutical (APIs, herbal extracts, antibiotics, vitamins, pharmaceutical excipients, heat-sensitive biological products);
• Chemical (fine chemical products, dyes, pigments, pesticide intermediates, catalysts, plastic additives, materials containing flammable/explosive solvents);
• Food (heat-sensitive food ingredients, nutritional products, health supplement ingredients, seasonings, natural pigments) and other industries for drying heat-sensitive, easily oxidizable, toxic and flammable/explosive organic-solvent-containing materials.