METHOD OF FREEZING LIQUID BIOLOGICAL AGENT Russian patent published in 2005 - IPC

FIELD: quick freezing of biological agents, blood and plasma for example.

SUBSTANCE: proposed method of freezing biological agent placed in hermetic reservoir includes removal of heat from reservoir to external heat-transfer agent. Method includes three stages. At first stage liquid agent is cooled to phase transition temperature, at second stage agent is solidified over entire volume of each reservoir and at third stage solidified agent is cooled to final temperature which is below preset storage temperature. Freezing process is divided into two stages: at first stage, first and second stages of process are performed in working chamber of first freezing apparatus and higher intensity of removal of heat from agent as compared with second stage is created; to this end, layers of agent are mixed in reservoirs and are set in motion at acceleration regularly changing in magnitude and direction. Then, reservoirs with solidified agent are withdrawn from working chamber of first freezing apparatus for performing second stage and are placed in working chamber of second freezing apparatus where third stage is performed. Magnitude of heat transfer coefficient which is indicative of intensity of heat removal from agent to external heat transfer agent is no less than 50W_-2mc_-1. Reservoirs are made from polymer as a rule.

EFFECT: enhanced efficiency.

3 cl, 4 dwg