What are the characteristics of double cone rotary vacuum dryer

- Feb 06, 2020-

The double cone rotary vacuum drying unit is a double cone rotary tank. In the vacuum state of the tank, steam or hot water is introduced into the jacket for heating. The heat contacts with the wet material through the inner wall of the tank. The water vapor evaporated after the wet material absorbs heat is extracted through the vacuum exhaust pipe through the vacuum pump. Because the tank is in a vacuum state, and the rotation of the tank makes the material constantly up and down inside and outside, so it speeds up the drying speed of the material, improves the drying efficiency, and achieves the purpose of even drying. The system of double cone rotary vacuum drying unit mainly consists of double cone rotary vacuum drying unit, condenser, dust remover, vacuum extraction system, heating system, cooling system, electric control system, etc.

The double cone rotary vacuum drying unit is a drying equipment which integrates mixing and vacuum drying. The process of vacuum drying is to place the dried material in a sealed cylinder, vacuum the dried material with a vacuum system and heat it continuously, so that the water in the material diffuses to the surface through the pressure difference or concentration difference, and the water molecules (or other non condensable gases) obtain enough kinetic energy on the surface of the material, and then diffuse to the low-pressure air of the vacuum chamber after overcoming the mutual attraction between the molecules It is separated from the solid by vacuum pump. Therefore, the double cone rotary vacuum drying unit has the following characteristics:

(1) In the process of vacuum drying, the pressure in the cylinder is always lower than the atmospheric pressure, the number of gas molecules is small, the density is low, and the oxygen content is low, so it can dry easily oxidized drugs and reduce the chance of material contamination.

(2) Because the temperature of the moisture in the vaporization process is directly proportional to the steam pressure, the moisture in the material can vaporize at low temperature during the vacuum drying, and reach low temperature drying, which is especially suitable for the production of drugs with heat sensitive materials.

(3) Vacuum drying can eliminate the surface hardening phenomenon which is easy to occur in atmospheric hot air drying. This is because the pressure difference between the inner and the surface of vacuum drying materials is large. Under the effect of pressure gradient, the water will move to the surface quickly, without surface hardening.

(4) Due to the small temperature gradient between the inside and outside of the material during the vacuum drying, the moisture can be moved and collected by itself due to the reverse osmosis, which effectively overcomes the loss caused by the hot air drying.