Product Details

Small capacity food freeze dryer sale price

Dry Matter Content of Feed Material

The initial installation cost and the operating cost of a freeze-drying installation are relatively high compared with other traditional drying methods. Thus in freeze-drying it is particularly important that the solid concentration and drying conditions should be determined through extensive test work before an industrial installation is finally selected.

Freezing

In order not to spoil the appearance of the product and the structure of the cells during the evacuation period, the product is first frozen. The freezing temperature depends on the type of product, dry matter content, and freezing speed.

The best way to determine the freezing temperature is to find the maximum sublimation temperature (see under drying pressure)

Drying pressure

The necessary drying pressure may vary from one product to another. If the pressure is not low enough, the product will immediately start to boil. Whit certain products no boiling is noticed, but after product has been dried it will show signs of discoloration and shrinkage. The necessary drying pressure, I.e., the drying pressure under which the product dose not boil, will at the same time determine the necessary freezing temperature (vapor table).

However, it will be necessary to use a somewhat lower freezing temperature to compensate for a temperature increase of the product before the trays are brought under vacuum in cabinet.

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