Here are some factors that affect the performance of double cone rotary vacuum dryer. Let's have a look.
1. The state of the dried material (such as material shape, size, stacking method), moisture content, density, viscosity and other properties of the material itself. In addition, if the initial temperature of the material is increased, the material is pretreated by vacuum filtration, and the moisture content of the material is reduced, the speed of vacuum drying can be increased.
2. Bulk density of material: the bulk density of material refers to the mass of material per unit volume. Because the material is a mixture of the absolute dry material and the moisture content, the absolute dry material is usually in the form of granule or powder, and the gap between the particles of the absolute dry material is also different due to the different moisture content in the material. Therefore, the bulk density of raw wet materials is also very different from that of dry materials, which should be paid special attention to in the preparation of raw materials.
3. Allowable temperature of material: the allowable temperature is the high temperature that the material can bear. Exceeding this temperature will cause the material potency change, decomposition damage or discoloration. Generally, thermosensitive drugs can be used ≤ 60 ℃.
4. Viscosity of the material: the viscosity of the material changes with the moisture content. The viscosity can make the material agglomerate and stick to the wall of the cylinder. After drying, it is easy to adhere to the dust collector and the pipe. In order to solve this problem, the newly developed suspension type double cone rotary vacuum dryer of Jiangsu Zhifang drying equipment Co., Ltd. adopts pneumatic vibrating and crushing device.
5. Slip angle of materials: when stacking granular or powdery materials, when the angle between the materials and the bottom increases to a certain angle, the side materials will slide down. The angle between the material sliding and the bottom is called the sliding angle of the material. The slip angle is related to material composition, moisture content, particle size and viscosity. Therefore, in the design and selection of the double cone rotary vacuum dryer, the angle of the double cone of the cylinder should be selected according to the slip angle of the material.
6. The higher the vacuum degree is, the better the water vaporizes at a lower temperature, but the higher the vacuum degree is, the worse the heat conduction is, and the heating effect on the material is affected. In order to improve the drying speed of materials, the vacuum degree should be considered comprehensively according to the characteristics of materials. In general, the vacuum should not be less than 10 ⁴ PA.