Fluidized-bed normal pressure spray-freezing drying method and device

Abstract

The present invention relates to a fluidized bed atmospheric spray freeze drying method and a device thereof, and is mainly used for dehydration and preservation of liquid food, medicine, biological products and other products with high added-value; the method is formed by combining a low temperature spray freeze granulating technique and a fluidized bed atmospheric freeze drying technique. Liquid material is atomized and frozen by two liquid atomizers which operate in a low temperature; the fine freezing particles are achieved and collected in the fluidized bed layer of the bottom of the device; then the atmospheric freeze drying medium is used to have partial pressure on the low vapour to satisfy the condition of water sublimation; through the fluidization technology, the freezing particles made by spray freezing are dried in the same device to a high quality qualified powdery product which has high void rate and fluidness and can adjust the granularity distribution; the system is a continuous closed operation; the cost of equipment investment and operation expense is lower than that of vacuum freeze drying; the invention has no pollution on environment.

Description

Technical field [0001] The invention relates to the improvement of a normal-pressure air freeze-drying method and device using low-temperature spray freezing pretreatment, belongs to the technical field of process equipment, and is mainly used for dehydration preservation of high value-added products such as liquid food, medicine, and biological products. Background technique [0002] At present, vacuum freeze-drying, which is widely used for dehydration storage of liquid food with high product quality requirements, medicines and biological products, is to provide the heat required for water sublimation under vacuum conditions to perform drying operations. Usually, the dried liquid materials are put into Flasks, trays and other containers are placed in the drying chamber of a vacuum freeze dryer for freezing. Afterwards, in the drying chamber, the heat of sublimation is provided by heat conduction to sublimate and separate the moisture in the material from the frozen material...

AI Technical Summary

Problems solved by technology

Although vacuum freeze-drying can keep the color, flavor, shape, nutritional content and biological activity of the product to the greatest extent, it is an ideal method for preparing and preserving various foods, medicines and biological products, but the disadvantage is that due to the overall freezing of liquid materials, vacuum operation, production The cycle is long, the equipment investment is large, and the operating cost is high, which is about 10 times that of spray drying, so the technology promotion and application are limited, and it is mainly used for high value-added products, mainly on a laboratory scale; and because the vacuum freeze-drying process is controlled by heat conduction , in the second stage of analytical drying process, thermal degradation of quality caused by local over-temperature will occur, and for most pharmaceuticals and biological products, the final product is required to be packaged, stored and used in a powder state, fluidity and microstructure are in the group Unavoidable degradation and damage during the pulverization of block dry products

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