SU1659039A1 - Device for freezing biomaterials - Google Patents

Abstract

This invention relates to a cryogenic technique. The purpose of the invention is to increase the efficiency of operation by improving the safety of biological material due to the gradual freezing of the latter. The device consists of a Dewar vessel 1 with liquid nitrogen, which enters through the pipeline 4 in the form of a collector with an opening2. The PS at the exit to the heat-insulated container 5, having pre-cooling and final freezing sections, is filled with a liquid with different solidification temperature. Containers 15 with biological material are inserted into the holes of the pre-cooling section. The device works as follows. Liquid nitrogen from the Dure vessel enters the sections through the manifold and, after passing through a layer of liquid over the collector, cools it. Liquid nitrogen, when converted to gas, exits through the gas flow controllers. The process of cooling liquids continues until they solidify, after which liquids turned into ice shut off the flow of nitrogen. The selection of solidification temperatures of liquids and their cooling rates maintains the freezing mode of biomaterials. 1 hp f-ly, 3 ill. ON SL O O W che

Description

fig.Z

This invention relates to a cryogenic technique.

The purpose of the invention is to increase the efficiency of operation by improving the safety of biological material due to the gradual freezing of the latter.

FIG. 1 shows the proposed device with containers in the form of polyethylene tubes arranged horizontally; figure 2 - section aa in figure 1; on fig.Z - device with containers in the form of vertically arranged ampoules.

The device consists of a liquid nitrogen Dewar vessel 1 sealed and pressurized with a cylinder 2 with compressed gas and a pressure reducer 3, a pipeline 4 for supplying liquid nitrogen to a thermally insulated container 5 consisting of sections 6–8, gas flow regulators 9–11 connected to the upper parts of the sections by pipes 12. The pipe 4 is connected to the lower parts of the sections and is made to evenly distribute the liquid refrigerant in the form of manifolds 13. In sections 6 and 7 of the pre-cooling there are holes 14 The section 6 is filled with a liquid with a solidification temperature equal to the onset temperature of the biomaterial, section 7 with a liquid with a solidification temperature below the crystallization end temperature but above the biomaterial cooling end temperature and section 8 of the final freezing liquid with a temperature solidification, equal to the temperature of the end of the cooling of the biomaterial.

The device works as follows.

First place the biomaterial in. containers 5 and open the reducer 3, adjusted to a predetermined pressure necessary to displace liquid nitrogen from the Dewar vessel, while liquid nitrogen through line 4 through the collector 13 comes from section 6-8 of the container 5. Liquid nitrogen passing through the layer located by the collectors the liquid cools it and, turning into a gas, goes through the regulators 9-11 to the atmosphere. The gas flow rate through the regulators is experimentally adjusted in such a way that each section is cooled at a predetermined rate (during the cooling process, the regulators keep it constant).

The process of cooling liquids continues to temperatures equal to the temperatures of their solidification, after which the liquids, turning into ice, shut off the flow of nitrogen, preventing them from further

cooling, while ensuring the accuracy of maintaining the desired temperature, since as hardened liquids melt, their temperature remains constant until complete thawing, after which

the supply of liquid nitrogen is resumed and the process is automatically repeated. The selection of solidification temperatures of liquids and their cooling rates is maintained. Freezing of biomaterials is maintained.

Claims (2)

Claim 1. Device for freezing biological materials, containing a heat-insulated container with containers of biological material placed in it, a Dewar vessel with liquid nitrogen, a gas flow regulator, and a pipeline for supplying liquid nitrogen to the container e with the fact that, in order to increase the efficiency of operation by improving the safety of biological material due to the stepwise freezing of the latter, the capacity is divided into sections pre-cooling, filled with a liquid, the solidification temperature of which is lower than the crystallization end temperature of the biological material, but higher than the cooling end temperature, inside which the containers with the material are located, and the final freezing section filled with a liquid with a solidification temperature equal to the final cooling temperature of the material, in contact with the pre-cooling sections, the lower part of each section being connected by pipeline to the Dewar vessel, and pn - with gas flow control. 0 2. Device pop. 1, characterized in that the pipeline connecting the Dewar vessel to the sections is designed as a manifold with openings at the outlet. 7 Aa