Cryogenic vessel boil-off monitoring system

摘要

A cryogenic vessel boil-off monitoring system comprises a chamber 5 connectable to a cryogenic vessel 1, and electrically operated valves 2 and 3 positioned within conduits 2A and 3A linking the exhaust outlet of the cryogenic vessel 1 to an inlet of the chamber 5 and an outlet of the chamber 5 to atmosphere 7. A pressure transducer 6 is provided within the chamber 5, and a programmed controller 4 serves to control the opening and closing of the valves 2 and 3 in dependence on a preset programme and an electrical output signal from the pressure transducer 6 indicative of the pressure within the chamber 5. The controller 4 also provides an electrical output signal indicative of the flow rate of the exhaust gas from the cryogenic vessel 1 that may be used for monitoring the system performance and for providing an alarm in the event that system parameters are exceeded. Such a monitoring system is not only more accurate and more easily controllable than known monitoring arrangements, but is also less costly to produce and has the advantage that it produces an output signal indicative of the flow rate of the exhaust gas