| 摘要 |
An arrangement for de-icing a recondensing flow loop system (76) includes at least one resistive heating element (106) configured to melt iced particles (122, 124, 126) from the recondensing flow loop system (76). A power delivery circuit (112) delivers power from a power source (110) to the at least one heating element (106) in order to heat and melt ice at positions where ice particles accumulate most often. A cooling system (70) for an MR superconducting magnet (54) comprises a liquid helium bath (72) having the recondenser flow loop system (76). The gaseous helium (78) which boils off from the helium bath (72) escapes from a magnet helium vessel (80) through a supply tube (82) that leads to a recondenser (84). The recondenser cools the gaseous helium and returns liquid helium through a delivery tube (86). In the event of a pressure surge in the vessel (80), a pressure relief valve (90) opens allowing helium gas to flow through an auxiliary cooling loop (92). Once an increase in pressure is detected, the recondenser de-icing system (100) which includes a vacuum pump (108) may be utilised to remove any ice build-up in the cooling loop (76). When a vacuum valve (102) is opened, the auxiliary cooling loop (92) is subjected to vacuum from the pump (108). The heating elements (106a-c) warm the ice formed in the cooling loop (76), with the vacuum pump (108) removing the molecules of melted ice. As the ice clears, the vacuum valve (102) is closed. |
