GB1402824A - Thermostats - Google Patents

Abstract

1402824 Thermostats UNITED KINGDOM ATOMIC ENERGY AUTHORITY 25 Feb 1974 [26 Feb 1973] 9450/73 Heading G1D [Also in Divisions F2 and G3] To regulate the temperature of a fluid, e.g. a coolant such as liquid sodium for a nuclear reactor, flowing through a circuit, a thermostat is provided which consists of a duct 1 having fixed and movable walls 5, 8 defining a path for the fluid between them, the walls 5, 8 having complementary cyclically undulating contours, and means for moving the wall 8 parallel to the wall 5 in response to changes in temperature of the fluid to thereby change the area of the fluid-flow path between the contours. If the temperature falls the flow area is reduced and if the temperature rises the flow area is increased. As shown, the means for moving wall 8, in this case mounted between two fixed walls 5, is a closed reservoir R containing the same fluid as that in the flow circuit. A temperature change causes this fluid to expand or contract and thus contracts or expands bellows 18 thereby moving the wall 8, connected thereto by central spine 16 against the bias of a spring 28. A further fluidfilled closed bellows 29 may be provided to act as an overpressure relief valve. In an alternative embodiment Figs. 7-12 (not shown) only one fixed wall is provided, the reservoir R is defined between two bellows (111), (119) and an argon filled pressure relief capsule (123) is provided.