Level controller for cryogenic liquids - has level sensor for gas above cryogenic liquid contained in movable bellows

摘要

The level controller for cryogenic liquid comprises a closure valve in a pipe for conveying the liquid into the vessel and a level sensor with a transducer which converts the sensor signal to displacement of the valve into a closed position. The sensor comprises a gas which condenses at the temp. of the cryogenic liquid and which is hermetically contained in an inner chamber (31) of an elastic bellows member (27) and within a capillary tube (33) of which one end is connected to the inner chamber while the other end is closed. The capillary tube includes a probe (34) which is disposed at liquid level in the vessel. The transducer consists of the bellows member, and includes a fixed bottom portion (26) connected to a stationary valve portion (10), and a movable bottom portion (28) connected to a movable valve portion (17).