The Principle Of Spray Dryer for Chinese Traditional Medicine
The principle of Spray Dryer for Chinese Traditional Medicine
The spray dryer for Chinese traditional medicine is to spray, form, and disperse droplets and droplets and disperse them in the hot gas stream to make the water vaporize quickly and achieve the purpose of drying. The hot air flow and material of the spray dryer for Chinese medicine can be contacted by parallel flow, counterflow or mixed flow.
This drying method does not require the mechanical separation of raw materials in advance, and the drying time is very short (usually 5-30 s), so it is suitable for drying heat-sensitive materials, such as Chinese herbal extracts. Spray dryer is also faced with a big problem in Chinese medicine extract, that is, during the drying process, sticky walls and drying products are easy to absorb moisture, so it is difficult to deal with high concentration and high viscosity Chinese medicine extract.
Studies have shown that the softening point of Chinese medicine extract is lower than that of spray drying, which is the main reason for the sticking phenomenon. By adding excipients to improve the softening point of the extract, the sticking phenomenon can be eliminated, but the addition of excipients may affect the purity of the product. In addition, another defect of spray drying is that the recovery rate of products is lower than that of dry technology, so the industry and enterprises should pay attention to this.
The working principle of the spray dryer for Chinese traditional medicine is that air enters the air distributor on the top of the drying tower through filters and heaters and then enters the drying chamber uniformly in a spiral manner. The material liquid is pumped to the centrifugal atomizer at the top of the drying tower from the material liquid tank through the filter. The material liquid is sprayed into very small droplets. The material liquid is in contact with the hot air, and the water evaporates rapidly. The product is dried in a very short time. The finished product is discharged by the bottom of the drying tower and the cyclone separator, and the exhaust gas is discharged by the fan.
There are two kinds of spray dryer for Chinese traditional medicine, one is high temperature spray dryer for Chinese traditional medicine, which is suitable for drying heat-sensitive substances such as biological products, biological pesticides, enzyme preparations, etc. (Shi Moxi, food, Chinese herbal medicine, ceramics, fruit juice, natural products, biochemical and chemical raw materials, etc.), because the materials sprayed out are only high when they are sprayed into mist particles. Temperature, therefore, is only instantaneous heating, which can keep the active ingredients of these materials from being destroyed after drying. The other is a low-temperature spray dryer for Chinese traditional medicine, which is vacuumed in the low-temperature range of 50~80 degrees. It is mainly applied to special materials with high sugar content or organic solvents.