Suction bend for centrifugal pumps

Claim 2

A suction bend for a centrifugal pump, comprising: wall means forming a conduit having an inlet opening and an outlet opening, said openings being spaced from each other and inclined to each other at an angle of substantially 90*, said conduit being adapted to receive a shaft on the axis of said outlet opening for supporting an impeller adjacent said outlet opening, a central guide fin in said conduit extending in the longitudinal central plane of said conduit from the portion of said wall means which is opposite the outlet opening and within that part of the bend between said wall means confining the space occupied by said shaft, said guide fin being concave on the opposite sides and merging with said wall means on opposite sides, at least one pair or rib means in said conduit serving as boundary layer fences and being arranged symmetrically to each other with respect to said longitudinal central plane of the suction bend and opposite said outlet opening, the contour of each of said rib means being arranged substantially parallel to adjacent lateral parts of said wall means spaced radially to said impeller shaft, the leading edge of each of said rib means being interposed between the lateral part of said wall means and said shaft, said wall means including guide surfaces deflecting the main flow toward said outlet opening so that secondary flows directed substantially oppositely to each other are formed in the boundary layer stream transversely to said main flow approaching said outlet opening, said rib means lying between said oppositely directed secondary flows and deflecting said secondary flows into said main flow to inhibit the formation of vortices in the flow through said outlet opening due to the oppositely flowing secondary flows.

Claim 3

A suction bend according to claim 1, in which said oppositely directed boundary layer streams are of different strength, said rib means being transverse to the stronger one of said streams and being displaced from the plane where the said impact would occur upstream of the said stronger of said streams.

Claim 4

A suction bend according to claim 2, in which said rib means on the side facing the said stronger of said streams is substantially perpendicular to the stream and on the opposite side makes an angle of from about 120* to 150* with the weaker stream, the sides of said rib means converging toward said outlet.

Claim 5

A suction bend according to claim 2, in which said rib means in height is on the order of from about 5 percent to about 10 percent of the distance between the side of the conduit from which the rib means extends and the oppositely disposed side of the conduit, said rib means in height being approximately equal to the localized boundary stream thickness.

Claim 6

A suction bend according to claim 1, in which said rib means is higher in about the middle of the length thereof and decreases in height toward the opposite ends.

Claim 7

A suction bend according to claim 1, in which said conduit is substantially flat on the side having said outlet therein and on the other side which is opposed thereto, a funnel having a smaller end in said outlet and a large end in the conduit in spaced opposed relation to the said other side of the conduit and radially spaced from the closed end of said conduit and the laterally adjacent walls thereof, said guiding fin extending from the adjacent end of said conduit between the said sides thereof downwardly to said larger end of said funnel and into the upper portion of said funnel, said rib means comprising arcuate rib elements upstanding from said other side of the conduit and projecting toward the larger end of said funnel, each rib element extending from said wall member a circumferential distance of about 90* of said funnel.

Claim 8

A suction bend according to claim 6, in which each rib element has the greatest height at The end adjacent said wall member and diminishes in height in a direction away from said wall member.

Claim 9

A suction bend according to claim 6, in which said rib elements at the point of greatest height thereof are disposed radially inside the larger end of said funnel.

Claim 10

A suction bend comprising a conduit having an inlet passage leading from one end to a lateral discharge passage adjacent the other end having its axis at an angle to the axis of said inlet passage, the wall of said conduit adjacent the other end being curved to direct the main flow of fluid in said inlet passage laterally through said outlet passage, the flow of fluid in the boundary layers along the wall of said conduit forming secondary flows directed in opposite directions transverse to the main flow through said discharge passage, said secondary flows including a secondary flow from said curved wall directed inwardly toward said main flow through said discharge passage, and means in said conduit cooperating with the walls of said conduit to direct flow of fluid in said secondary flows through said discharge passage with the elimination of free vortices in the main flow through said discharge passage, comprising deflecting wall structure on the wall of said conduit between said curved wall and the axis of said discharge passage and extending outwardly from said wall in the direction of the axis of said discharge passage to form boundary layer fence means, said wall structure having two oppositely facing surfaces, one surface facing said curved wall and deflecting the secondary flow from said curved wall into said main flow, and the opposite surface facing the axis of said discharge passage and the main flow through said passage, and deflecting the oppositely directed secondary flow into said main flow, each of said surfaces being at an angle to the wall of said conduit on which said wall structure is fixed to deflect said secondary flows along said main flow.

Claim 11

A suction bend comprising a conduit having an inlet passage leading from one end to a lateral discharge passage adjacent the other end having its axis at an angle to the axis of said inlet passage, the wall of said conduit adjacent the other end being curved to direct the main flow of fluid in said inlet passage laterally through said outlet passage, the flow of fluid in the boundary layers along the wall of said conduit forming secondary flows directed in opposite directions transverse to the main flow through said discharge passage, said secondary flows including a secondary flow from said curved wall directed inwardly toward said main flow through said discharge passage, and means in said conduit cooperating with the walls of said conduit to direct flow of fluid in said secondary flows through said discharge passage with the elimination of free vortices in the main flow through said discharge passage, comprising deflecting wall structure on the wall of said conduit between said curved wall and the axis of said discharge passage and extending outwardly from said wall in the direction of the axis of said discharge passage to form boundary layer fence means, said wall structure having two oppositely facing surfaces, one surface facing said curved wall and deflecting the secondary flow from said curved wall into said main flow, and the opposite surface facing the axis of said discharge passage and the main flow through said passage, and deflecting the oppositely directed secondary flow into said main flow, each of said surfaces being at an angle to the wall of said conduit on which said wall structure is fixed to deflect said secondary flows along said main flow.

Claim 12

A suction bend as claimed in claim 9, in which said curved wall on opposite sides of the axis of the discharge passage forms secondary streams directed from the sides of said conduit toward the axis of the main flow through said discharge passage, and said wall structure includes two walls fixed to the wall of said conduit on opposite sides of said axis of said main flow, each wall having one surface facing the curved wall on its side with the other surface facing said axis of said main flow.

Claim 13

A suction bend as claimed in claim 17, in which said surface facing the curved wall forms a greater angle with said wall than the surface facing said axis of said main flow.

Claim 14

A suction bend comprising a conduit having an inlet passage leading from one end to a lateral discharge passage adjacent the other end having its axis at an angle to the axis of said inlet passage, the wall of said conduit adjacent the other end being curved to direct the main flow of fluid from said inlet passage through said discharge passage, a longitudinal body extending from adjacent said curved wall of said conduit axially through said discharge passage with its peripheral surface coaxial with said discharge passage to form an annular discharge passage, the flow of fluid in the boundary layers along the wall of said conduit forming oppositely directed secondary flows transverse to said main flow through said discharge passage, said secondary flows including a secondary flow deflected inwardly by said curved wall toward said main flow in said discharge passage, and means in said conduit cooperating with the walls of said conduit to direct flow of fluid in said secondary flows through said discharge passage with the elimination of free vortices in the main flow through said discharge passage, comprising deflecting wall structure on the wall of said conduit upstream of said curved wall between said curved wall and said longitudinal body, and extending outwardly from said wall in the direction of the axis of said discharge passage, to form boundary layer fence means, said wall structure having two oppositely facing surfaces, one surface facing said curved wall and deflecting the secondary flow from said curved wall into said main flow, and the opposite surface facing the said longitudinal body and the main flow through said discharge passage, and deflecting the oppositely directed secondary flow into said main flow, each of said surfaces being at an angle to the wall of said conduit on which said wall structure is fixed to deflect said secondary flows along said main flow.

Claim 15

A suction bend comprising a conduit having an inlet passage leading from one end to a lateral discharge passage adjacent the other end having its axis at an angle to the axis of said inlet passage, the wall of said conduit adjacent the other end being curved to direct the main flow of fluid from said inlet passage through said discharge passage, a longitudinal body extending from adjacent said curved wall of said conduit axially through said discharge passage with its peripheral surface coaxial with said discharge passage to form an annular discharge passage, the flow of fluid in the boundary layers along the wall of said conduit forming oppositely directed secondary flows transverse to said main flow through said discharge passage, said secondary flows including a secondary flow deflected inwardly by said curved wall toward said main flow in said discharge passage, and means in said conduit cooperating with the walls of said conduit to direct flow of fluid in said secondary flows through said discharge passage with the elimination of free vortices in the main flow through said discharge passage, comprising deflecting wall structure on the wall of said conduit upstream of said curved wall between said curved wall and said longitudinal body, and extending outwardly from said wall in the direction of the axis of said discharge passage, to form boundary layer fence means, said wall structure having two oppositely facing surfaces, one surface facing said curved wall and deflecting the secondary flow from said curved wall into said main flow, and the opposite surface facing the said longitudinal body and the main flow through said discharge passage, and deflecting the oppositely directed secondary flow into said main flow, each of said surfaces being at an angle to the wall of said conduit on which said wall structure is fixed to deflect said secondary flows along said main flow.

Claim 16

A suction bend as claimed in claim 12, in which the wall structure constituting boundary layer fence means is formed by curved ribs fixed on the wall of said conduit spaced from the curved wall of said conduit and with a curvature corresponding to the curvature of said curved wall, said ribs lying transversely between the oppositely directed secondary flows.

Claim 17

A suction bend as claimed in claim 12, in which the axis of said discharge passage is substantially at 90* to the axis of said inlet passage, and in which said longitudinal body extends axially through said discharge passage to the wall of said inlet passage upstream from said curved wall of said conduit, said curved wall directing the secondary flow in the boundary layer stream toward said longitudinal body, and said wall structure constituting a boundary layer fence means is formed by curved ribs transverse to secondary flow on the wall of said conduit going between said longitudinal body and the curved wall of said conduit.

Claim 18

A suction bend for a centrifugal pump, comprising: wall means forming a conduit having an inlet opening and an outlet opening, said openings being spaced from each other and with their axes inclined to each other at an angle of substantially 90*, a shaft body on the axis of said outlet opening thus forming a substantially annular outlet opening, a central guide fin in said conduit extending in the longitudinal central plane of said conduit from the portion of said wall means which is opposite the outlet opening and within that part of the bend within said wall means confining the space occupied by said shaft body, said guide fin being concave on the opposite sides and merging with said wall means on opposite sides, at least one pair of rib means in said conduit serving as boundary layer fences and arranged symmetrically to each other with respect to said longitudinal central plane of the suction bend and opposite said outlet opening, the contour of each of said rib means being arranged substantially parallel to adjacent lateral parts of said wall means spaced radially of said shaft body, said wall means including guide surfaces deflecting the main flow toward said outlet opening so that secondary flows directed substantially oppositely to each other are formed in the boundary layer stream transversely to said main flow approaching said outlet opening, said rib means lying between said oppositely directed secondary flows and deflecting said secondary flows into said main flow to inhibit the formation of vortices in the flow through said outlet opening due to the oppositely flowing secondary flows.

Claim 19

A suction bend for a centrifugal pump, comprising: wall means forming a conduit having an inlet opening and an outlet opening, said openings being spaced from each other and with their axes inclined to each other at an angle of substantially 90*, a shaft body on the axis of said outlet opening thus forming a substantially annular outlet opening, a central guide fin in said conduit extending in the longitudinal central plane of said conduit from the portion of said wall means which is opposite the outlet opening and within that part of the bend within said wall means confining the space occupied by said shaft body, said guide fin being concave on the opposite sides and merging with said wall means on opposite sides, at least one pair of rib means in said conduit serving as boundary layer fences and arranged symmetrically to each other with respect to said longitudinal central plane of the suction bend and opposite said outlet opening, the contour of each of said rib means being arranged substantially parallel to adjacent lateral parts of said wall means spaced radially of said shaft body, said wall means including guide surfaces deflecting the main flow toward said outlet opening so that secondary flows directed substantially oppositely to each other are formed in the boundary layer stream transversely to said main flow approaching said outlet opening, said rib means lying between said oppositely directed secondary flows and deflecting said secondary flows into said main flow to inhibit the formation of vortices in the flow through said outlet opening due to the oppositely flowing secondary flows.