Liquid helium topping-up apparatus
AssigneeOxford Magnet Technology Limited
InventorDavid A. Grimes
Life of this patent
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Abstract
To ensure that only liquid helium is delivered to a cryostat dureing liquid helium refill, the arrangement automatically diverts hot gas which is produced during cooling of the transfer tube, away from the cryostat. The arrangement comprises a three way valve which is operated by pressure variations as a result of cooling part of an enclosed volume of helium gas to a temperature near the normal boiling point of the liquid at atmospheric pressure. The arrangement provides the advantage in that the transfer of helium to a cryostat now becomes very much a less skilled operation.
Claims11
Apparatus for adding liquid helium to a cryogenic vessel comprising:
- a cryogenic vessel,
- a thermally insulated transfer tube for the transfer of liquid helium from a storage dewar to the cryogenic vessel,
- thermally insulated valve means via which the transfer tube is arranged to communicate with the said vessel, and
- a temperature sensitive valve actuator having a temperature sensor element positioned within the transfer tube at an end region thereof adjacent the cryogenic vessel, to which actuator the valve means is responsive for diverting helium gas away from the said vessel when the gas is above a predetermined temperature as sensed by the temperature sensor element, and
- means for diverting helium gas away from the said vessel.
Dependencies are inferred from the claim text.