| 摘要 |
A pump for pumping pulp, comprising a main housing (1); a shaft (4) rotatable therein; a rotor (15) on the shaft (4) for fluidization of the pulp; an impeller (12) on the shaft (4) for pumping the pulp; a vacuum pump (23) having a vacuum pump housing (24), a vaccum impeller (26) on the shaft (4) and an end wall (10) of the vacuum pump housing (24), said end wall and an inner partition (9) between them defining a vacuum chamber (25) in which the vacuum impeller (26) and a liquid ring rotate; a gas passage system for withdrawing gas separated out of the pulp, said gas passage system comprising besides the vacuum chamber (25) gas passageways (20, 21, 22, 36) in the impeller (12), partition (9) and end wall (10); and a make-up air passageway (39) for supplying air from outside when the vacuum exceeds a predetermined value. According to the invention the make-up air passageway (39) is arranged in said end wall (10) of the vacuum pump (23), extends through the end wall (10) directly to said vacuum chamber (25) and opens into this radially inside the liquid ring and circumferentially at a distance from the conduit (36) of the gas passageway through which gas is evacuated from the vacuum chamber (25) to outside the pump. |
