GB630483A - Rotary pumps for liquefied gases - Google Patents

Abstract

630,483. Centrifugal pumps; stuffing-box substitutes. LINDE AIR PRODUCTS CO. Dec. 15, 1947, No. 33056. Convention date, Jan. 9. [Classes 110(i) and 122(v)] The shaft bearings, which are of the ball or roller type, are free of lubricants and are exposed to the liquefied gas being pumped. The bearings may be of stainless steel. In a two-stage pump, Fig. 1, impellers 14, 15 are carried by a sleeve 17, being separated by a spacer ring 22 and clamped by a nut 24 against a shoulder 23. A nut 31 threaded on the pump shaft 18 holds the inner race of a ball-bearing 19 against the shoulder 23 and holds the sleeve 17 against a shoulder 30. An interstage seal ring 53 is carried by a partition 16. The sealing means may comprise labyrinth grooves 51 on either or both the seal ring 53 and the impeller 15. Alternatively, labyrinth grooves may be provided on either or both the spacer ring 22 and the adjacent surface of the seal ring 53. When grooves are provided on one member only, they may be helical or spiral. Additional sealing is provided by close clearances between the impeller 15 and the partition 16 and between a partition 41 and the shaft 18. In a singlestage pump, Fig 5, the impeller 103 is clamped between spacer rings 106 and 107 against a shoulder 108 by a nut 109. The nut also secures the inner race of a ballbearing 114 and a slinger disc 113. The slinger disc flings solid particles outwards to prevent them from reaching the bearing 114, and is preferably tapered at the periphery. Sealing grooves 130 may be provided on either or both the surfaces of the ring 106 and a partition 128.