| 摘要 |
1,259,935. Rotary shaft seals. BORGWARNER CORP. 4 March, 1970 [5 May, 1969], No. 10524/70. Heading F2B. A sodium vapour trap for sealing the rotary shaft 19 in a liquid sodium (or potassiumsodium) pump comprises a rotary member 38 sealed to the shaft and having baffles 44 which co-operate with baffles 54 on a stationary member 37 to provide a tortuous passageway communicating the space 52 within the pump housing with the space outside the housing, the members being arranged to maintain the temperature of the trap above the melting point of the sodium so that the vapour is condensed to the liquid state to flow freely back to the space 52 down the baffles which slope downwardly. The metal vapour rising through the space 52 condenses on the sloping surfaces of the baffles and returns as liquid slightly above the melting point back through the space 52 to the pump chamber. The sodium vapour is carried in an inert atmosphere of argon gas to prevent oxidation and a small clearance between a cap 46 and the stationary member 37 allows the escape of this gas. An end-face seal having stationary and rotary co-operating rings 30, 31 is provided above the sodium vapour trap to prevent the escape of gas along the shaft to atmosphere. A chamber 32 surrounding the end-face seal is filled with oil at a pressure above that of the gas in the space 33 below the seal, an oil flirige 62 being provided to direct any oil leakage to a chamber (65), Fig. 1 (not shown). |
