Double cone rotary vacuum dryer is widely application of raw material medicine production equipment, this is because in the process of vacuum drying, cylinder pressure is always lower than the atmospheric pressure, the less number of gas molecules, low density, low oxygen, so it can dry easily oxidative changes of drug production, can reduce the material contamination opportunity. Also because of the water in the vaporization process, the temperature and vapor pressure is proportional to, so the vacuum drying the moisture content of materials can reach at low temperature vaporization, low temperature drying, double cone rotary vacuum drying machine is especially suitable for heat sensitive materials in the production of drugs are. At the same time, vacuum drying can eliminate atmospheric air drying is easy to produce surface hardening, which is between the material in the vacuum drying and surface pressure, the pressure gradient effect, water quickly moved towards the surface, won't appear surface hardening. In addition, vacuum drying, the material between the internal and external temperature gradient is small, by reverse osmosis that solvent can move independently and collect, effectively overcome the solvent separated phenomenon produced by hot air drying.
Double cone rotary vacuum dryer cylinder pile granular or powder materials, when the material pile inclined surface and the bottom surface of the angle between the increases to a certain angle, the side slip will occur under the phenomenon of material. The angle between the inclined surface and the bottom material slip occurs at this time of the material called slip angle (slip angle and the material composition, moisture content, particle size and viscosity of the). The design and selection of the double cone rotary vacuum drier, should according to the material's slip angle and the choice of cone angle 1.
Also think, the actual loading volume and drying cylinder volume ratio of filling rate. Fill double cone rotary vacuum drying machine rate is usually between 30%~50%, bulk density and the material is related to the.
In the part of double cone rotary vacuum dryer vacuum pumping tube empty sets of rotary shaft device, which adopts double frame shaft seal structure, because the structure of seal is not reliable, extremely easy to cause the leakage in cylinder vacuum effect, sometimes called the "leakage" phenomenon. At the same time, also because the seal is not reliable will balance when dry powder, powder used here balances rotary dynamic water washing method is to wash the ordinary, like this can cause the cross contamination in batch.
In the cleaning part of double cone rotary vacuum dryer cylinder, some by switching the vacuum line into the water, cleaning rotating cylinder and then put the net, so that dynamic cleaning method is not thoroughly cleaned, at least in the dynamic contact surface and the bonding material is not washed.
The second part is the manufacturer did not put the barrel as a pressure vessel to design and manufacturing, it is difficult to achieve switching vacuum pipe into the steam sterilization, sterilization in the no steam. This course involves feeding / discharging structure and sealing structure, its form and the bearing performance is also associated with steam sterilization. In the sterile environment of use of the equipment is essential requirements after cleaning, sterilization, the most effective method and direct method of sterilization is usually in moist and dry heat sterilization, this equipment based on cylinder structure is not detachable, cannot use the dry heat sterilization, can only use damp heat (steam) sterilization.
In this regard, it is trying to facilitate cleaning and sterilization, but also as long as you can around this topic can be launched. The recent domestic manufacturers to make some improvements, in cleaning, by switching the vacuum line into the cleaning water using, rotating cylinder pressure, and then put the net method, although improved, but the effect is not very ideal. In the sterilization, some manufacturers consider confined in cylinder manufacturing and material valve, which can be used to switch the vacuum line and steam into also completed SIP.
From the above, double cone rotary vacuum dryer cylinder cone angle is too large or too small will affect the stirring mixing effect, drying the material surface and the formation of the final effect of drying rate. Similarly, the actual loading volume filling ratio is too high will also affect the stirring mixing effect, effect of drying rate. |
