| 摘要 |
A double-stage method for freezing products for the further freeze drying, according to which the products being frozen are subjected to the effect of a low-temperature inert refrigerating agent, which consists of two equilibrium phases, in particular one of them is liquid and the other vapoury. Said method is conducted in two stages with an additional forming of microfragments of a solid phase as gaseous hydrates safe for cell structures. At the first stage the gaseous hydrates only are formed at a temperature higher than 0 °C. At the second stage the products are frozen up to the temperature which is determined by conditions of the further freeze drying, for example -30-40 °C. Prior to the effect of the low-temperature inert refrigerating agent on the products being frozen air is removed therefrom by means of sucking out up to achieving the value of the pressure above thereof not less than the equilibrium pressure of saturated water vapour at the cryoscopic temperature of the products being frozen. |
