TODAY’S PATENT- PRESERVING SYSTEM

Today’s patent was invented by Kazuo Takemasa on July 18, 2006, bearing patent no. US7076960B2.

The present invention is about a preserving system for cryopreserving biological preservation specimens such as frozen cells, tissue cells, sperms, ova for a long term. It provides a system capable of re-using vaporized nitrogen and capable of always cooling the specimens at a predetermined temperature or lower. This system is comprising a cylinder and the preserving vessel which is supplied with liquid nitrogen from this cylinder that is provided with a Stirling refrigerator and a condensing chamber arranged outside of said preserving vessel.

The gas phase is part of this condensing chamber and it is made to communicate with that of said preserving vessel and also the liquid phase part is made to communicate with that of said preserving vessel. Further, the cooling part of said Stirling refrigerator is arranged in the said condensing chamber, therefore, the nitrogen vaporized in the preserving vessel is cooled by the cooling part of the Stirling refrigerator in the condensing chamber and liquefied again. So this liquid nitrogen when performing maintenance on the Stirling refrigerator, the specimens in the preserving vessel can always be cooled at a predetermined temperature or lower.