Abstract A centrifugal pump having a suction inlet, a discharge outlet and at least one pumping stage with an impeller in direct communication with the suction inlet has an inducer means in the suction inlet operatively associated with the impeller of said pumping system and an annular chamber or passage formed about the suction inlet which is provided with ports or openings in communication with the suction inlet downstream of the inducer means and upstream of the inducer means to permit the automatic bypassing or recirculation of a given portion of the fluid being pumped approximately as a direct function of the differential pressure established across the inducer means by the quantity of fluid being pumped. Angled guide vane means in the portion of the bypass or recirculation chamber or passage which communicates with the upstream side of the inducer means are provided to impart prerotational movement in the recirculated fluid in a direction of rotation the same as that of the inducer means the bypass means and guide vane means acting to maintain a reduced head across the inducer particularly at low or partial flow conditions.
A centrifugal pump including: a suction inlet; a discharge outlet; at least one pumping stage having an impeller in direction communication with the suction inlet; inducer means disposed in suction inlet operatively associated with said impeller; means for rotating said impeller and said inducer means; self regulating by-pass means having inlet means upstream of the inducer means and outlet means downstream of the inducer means for recirculating a given portion of the fluid passing through the suction inlet as a direct function of the differential pressure established across the inducer means by the fluid flowing through said suction inlet; and guide vanes mounted in the bypass means and angled to impart prerotational motion to the recirculated fluid in the same direction of rotation as that of the inducer means to effect a reduction in head across the inducer means particularly at reduced flow conditions.
Claim 2
Dependent Claim
144 words
A centrifugal pump including: a suction inlet; a discharge outlet; at least one pumping stage having an impeller in direction communication with the suction inlet; inducer means disposed in suction inlet operatively associated with said impeller; means for rotating said impeller and said inducer means; self regulating by-pass means having inlet means upstream of the inducer means and outlet means downstream of the inducer means for recirculating a given portion of the fluid passing through the suction inlet as a direct function of the differential pressure established across the inducer means by the fluid flowing through said suction inlet; and guide vanes mounted in the bypass means and angled to impart prerotational motion to the recirculated fluid in the same direction of rotation as that of the inducer means to effect a reduction in head across the inducer means particularly at reduced flow conditions.
Claim 3
Dependent Claim
86 words
In a centrifugal pump as claimed in claim 1 wherein: the self regulating bypass means comprises an annular member connected to said pump about the suction inlet to form a bypass passage; port means in said suction inlet at a point downstream of said inducer means for delivering fluid to said bypass chamber; means forming an outlet for said bypass passage communicating with the suction inlet upstream of said inducer means; and said guide vanes disposed in the means forming said outlet means for said chamber.
Claim 4
Dependent Claim
41 words
In a centrifugal pump as claimed in claim 1 wherein: a casing forms said suction inlet; a member about said casing and connected in spaced relation thereto forms the passage means for recirculating the fluid in the self regulating bypass means.
Claim 5
Dependent Claim
98 words
In a centrifugal pump as claimed in claim 3 wherein port means are provided in the casing forming the suction inlet at a point downstream of said inducer to pass fluid to said passage means to be bypassed; said annular member provided with a radially inward extending flange disposed a spaced distance from the end of the casing; and said guide vanes connected between the end of said casing and said inwardly extending flange to provide a plurality of bypass outlet for passing bypassed fluid from said passage means to the suction inlet upstream of said inducer means.
Claim 6
Dependent Claim
40 words
In a centrifugal pump as claimed in claim 1 wherein: means are provided to vary the angular position of the guide vanes for imparting the desired degree and direction of rotation to said bypass fluid returning to the suction inlet.