rotary vacuum dryer

The double cone rotary vacuum dryer is a drying equipment integrating mixing and vacuum drying. The process of vacuum drying is to put the material to be dried in a sealed cylinder, and use the vacuum system to draw a vacuum while heating the material to be dried continuously, so that the water inside the material diffuses to the surface through the pressure difference or the concentration difference, and the water molecules (or other Non-condensable gas) obtains sufficient kinetic energy on the surface of the material, diffuses into the low-pressure space of the vacuum chamber after overcoming the mutual attraction between molecules, and is pumped away by the vacuum pump to complete the separation from the solid.

 SZG double-cone vacuum dryer is a new generation of drying device developed by our factory in combination with the technology of similar domestic products. The double-cone vacuum adopts two elastic connection methods of belt and chain, so the equipment runs smoothly. The specially designed process fully reflects the good concentricity of the two shafts. The heat medium and vacuum system adopt reliable mechanical seals or American technology rotary joints. On this basis, we developed SZG-A which can not only stepless speed regulation, but also constant temperature control.

As a professional drying equipment manufacturer, our products are available from high-temperature heat transfer oil as the heat medium, medium-temperature steam and low-temperature hot water.

The double cone rotary vacuum dryer has the following characteristics:

(1) During the vacuum drying process, 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. Therefore, it can dry easily oxidized drugs and reduce the chance of material contamination.

(2) Because the temperature of moisture is proportional to the vapor pressure during the vaporization process, the moisture in the material can be vaporized at low temperature during vacuum drying to achieve low-temperature drying, which is especially suitable for the production of heat-sensitive materials.

(3) Vacuum drying can eliminate the surface hardening phenomenon that is easily caused by normal pressure hot air drying. This is because the pressure difference between the inside and the surface of the vacuum drying material is large. Under the pressure gradient, the water will quickly move to the surface, and the surface will not appear. hardening.

(4) Due to the small temperature gradient between the inside and outside of the material during vacuum drying, the moisture can move and collect independently due to reverse osmosis, which effectively overcomes the loss of hot air drying.

The top angle of the double cone rotary vacuum dryer is 90°～60° (depending on the angle of rest of the material), and the filling rate of the material is 30%～50%. The equipment speed is generally determined by N≤42.3D½r/min (D is the maximum turning diameter). The heat transfer coefficient U of the jacket has nothing to do with the operating pressure. For non-bonding materials, U=116～140W/(m²·K), and for cohesive materials U=80～93W/(m²·K). The heat transfer area is calculated based on the area of the material contacting the cylinder wall. The cylinder of the dryer is designed according to the pressure vessel, the inner cylinder is subjected to external pressure, and the outer cylinder is subjected to internal pressure [1].