| 摘要 |
A liquid cryogen withdrawal device includes a plug (14) for insertion into the neck of a cryogen-containing dewar (10) in gas-tight relationship. A withdrawal tube (17) passes through the plug to conduct liquid from the bottom of the dewar through a sintered bronze filter to a container to be filled with cryogen. Cryogen is stored in the dewar with a loose fitting cap thereon, with no withdrawal device in the dewar. When liquid is desired to be retrieved from the dewar, the withdrawal device is inserted into the dewar; the withdrawal device has a passive heat source (18) disposed at the bottom thereof to cause sufficient boiling of the liquid to create enough pressure to force a suitable amount of liquid from the dewar. The plug may have a handle and a gas pressure relief valve disposed thereon. |
