Double cone rotary vacuum dryer is suitable for vacuum drying and mixing of powder and granular materials in medicine, food, chemical industry, etc. It is especially suitable for materials with the following requirements: heat-sensitive materials that can not accept high temperature; easily oxidized and hazardous materials; materials that need to be recovered from solvents and poisonous gases; materials with very low content of residual volatiles; materials that have requirements for crystalline shapes; materials that need to be mixed sufficiently and uniformly. The material is required to be mixed and homogenized.
Double cone rotary vacuum dryer uses vacuum system to pump vacuum while continuously heating the material to be dried, so that the moisture inside the material diffuses to the surface through pressure difference or concentration difference, the water molecules (or other non-condensable gases) get enough kinetic energy on the surface of the material, and diffuse to the low-pressure space of the vacuum chamber after overcoming the mutual attraction of molecules, and then be pumped out by the vacuum pump to complete the separation from the solids. Due to the vacuum drying, the temperature gradient between inside and outside of the material is small, due to the reverse osmosis effect makes the moisture can move alone and collect, effectively overcome the phenomenon of dispersion produced by hot air drying. The heat transfer coefficient U of the jacket of double cone rotary vacuum dryer has nothing to do with the operating pressure, U=116~140W/(m²-K) for non-adhesive materials and U=80~93W/(m²-K) for adhesive materials. The heat transfer area is calculated on the basis of the area of the material contacting the cylinder wall. The cylinder of double-cone rotary vacuum dryer is designed according to the pressure vessel, the inner cylinder is subject to external pressure, and the outer cylinder is subject to internal pressure.
The double cone rotary vacuum dryer is pumped out by vacuum pump through vacuum exhaust pipe. Because the tank is in vacuum state, and the tank rotating makes the material constantly up and down inside and outside, so it speeds up the drying speed of the material, improves the efficiency, and achieves the purpose of uniform drying. Double cone rotary vacuum dryer system mainly consists of double cone rotary vacuum dryer, condenser, dust collector, vacuum pumping system, heating system, cooling system, electric control system and so on. The process of vacuum drying is to put the material to be dried in the sealed cylinder, and keep heating the material to be dried while pumping vacuum with vacuum system, so that the water inside the material diffuses to the surface through the pressure difference or concentration difference, and the water molecules (or other non-condensable gases) get enough kinetic energy on the surface of the material, and diffuse to the low-pressure space of the vacuum chamber after overcoming the mutual attraction of molecules, and then be drawn away by the vacuum pump to complete the separation from the solids. Separation of solids.
Technical requirements of double cone rotary vacuum dryer
(1) Working mode: under vacuum condition, the tank is heated by heat-conducting oil or hot water into the jacket, and the heat is contacted with the wet material through the inner wall of the tank. The water vapor or other gases evaporated from the wet material after absorbing the heat will be pumped away through the vacuum pump via the vacuum exhaust pipe.
(2) The design pressure in the tank is -0.1～0.5MPa, and the jacket is heated by heat-conducting oil, and the design pressure of the jacket is ≤0.3MPa;
(3) Drying chamber volume of 200L, enamel lining, resistance to 130 degrees, the inner temperature and jacket temperature display;
(4) With solvent recovery device, frequency conversion speed control, explosion-proof motor;
(5) Material requirements: inner liner: enamel, jacket and skeleton: Q235A, outer wall: SUS304 stainless steel.
