The biggest feature of the spray dryer is that the surface area for evaporation and drying is very large. For example, a liquid of 1 cm3 is atomized into droplets of 100 μm, and the surface area thereof is increased by more than 19,000 times, thereby causing a sharp increase in the drying rate. Freeze drying requires a longer sublimation drying time, but can maintain the original quality of the dried product without causing material denaturation. Therefore, in combination with the above two drying methods, the advantages of the two drying techniques can be exerted, and the material quality requirements can be maintained while shortening the drying time.
In recent years, the fruit and vegetable processing industry has made great achievements, and the fruit and vegetable processing industry has occupied an important position in the trade of agricultural products.
At present, a new type of spray freeze-drying device small spray dryer has been researched and developed. The low-temperature and low-humidity air is continuously prepared by freezing and dehumidifying dehydration, and the specially designed atomization device is combined to realize continuous ice making and drying of the liquid.
Quick-frozen fruit and vegetable fields: In recent years, fruit and vegetable quick-freezing technology has made many significant developments. Firstly, the form of the fruit and vegetable of the quick-drying combined dryer spray dryer is turned from the whole large package to the small package after the processing and fresh-cut processing; the secondary freezing method has begun to widely use the air-type blowing hot air dryer wind-type freezing device, The pipe rack freezing device, the continuously-dissipating freezing device, the fluidized freezing device, etc., make the freezing temperature more uniform, the production efficiency is higher in winter, and the third freezing device as a cold source also has new breakthroughs, such as The liquid nitrogen, liquid carbon dioxide and the like are directly sprayed and frozen, so that the frozen temperature dryer accessories are significantly reduced, the freezing speed is greatly improved, and the quality of the quick-frozen vegetables is comprehensively improved. In terms of quick-freezing equipment, domestic equipment such as spiral quick-freezer, drift-net drying and quick-drying machine have been developed to meet some of the needs of the domestic quick-freezing industry.
In the field of fruit and vegetable logistics fluidized bed dryer: research and application of main fruits and vegetables, such as apples, pears, citrus, grapes, tomatoes, green peppers, garlic, Chinese cabbage, etc. Storage and preservation technology is basically mature, MAP technology , CA technology, etc. have been widely used in the storage and transportation of major fruits and vegetables in even countries.
Spray dryer significantly improves the processing of fruit and vegetable juices: high-efficiency juicer tumble dryer, high-temperature short-time sterilization technology, aseptic packaging technology, enzyme liquefaction and clarification technology, membrane technology, etc. have been widely used in production. Fruit and vegetable processing equipment can not be caged and dried, such as apple juice concentrate and tomato sauce processing equipment is basically the introduction of the most advanced equipment from abroad.
The spray dryer has good uniformity, fluidity and solubility, and the product has high purity and good quality. The production process is simplified and the operation control is convenient. For liquids with a moisture content of 40-60% (up to 90% of special materials), it can be dried into a powder product at one time. After drying, no pulverization and screening are required, which reduces the production process and improves the purity of the product. The particle size, bulk density and moisture of the product can be adjusted within a certain range by changing the operating conditions, and the control and management are very convenient.
