Xylem

The invention relates to a submersible semi-axial centrifugal pump (1) for installation in a column (2), and comprises an outer pump housing (7) and an inner pump core arrangement (14). The pump core arrangement comprises a drive unit (16), a semi-axial open centrifugal impeller (20) and a plurality of guide vanes (15) extending between and connecting the pump housing (7) and the drive unit (16), wherein the impeller (20) comprises a hub (28) and at least two spirally swept blades (29), wherein the hub (28) is essentially cone-shaped tapering towards the inlet (12) of the pump housing (7). Each blade (29) comprises a leading edge (31), a trailing edge (32) and a lower edge (33). The leading edge (31) of each blade (29) is swept backwards from an inner end (36) located at the hub (28) towards an outer end (37) located at the inner surface (11) of the pump housing (7), wherein a centre axis (A) of the impeller (20) is located at a relative radius R* equal to 0 and the outer end (37) of the leading edge (31) of each blade (29) of the impeller (20) is located at a relative radius R* equal to 1, and wherein a sweep angle (α) of the leading edge (31) is in the range 32 - 45 degrees at a first relative radius R*1 equal to 0,5, and in the range 47 - 60 degrees at a second relative radius R*2 equal to 0,95, and is continuously increasing from the first relative radius R*1 to the second relative radius R*2.

The invention relates to a submersible semi-axial centrifugal pump (1) for installation in a column (2), and comprises an outer pump housing (7) and an inner pump core arrangement (14). The pump core arrangement comprises a drive unit (16), a semi-axial open centrifugal impeller (20) and a plurality of guide vanes (15) extending between and connecting the pump housing (7) and the drive unit (16), wherein the impeller (20) comprises a hub (28) and at least two spirally swept blades (29), wherein the hub (28) is essentially cone-shaped tapering towards the inlet (12) of the pump housing (7). Each blade (29) comprises a leading edge (31), a trailing edge (32) and a lower edge (33). The outer pump housing (7) comprises a diffuser (9), connected to the stationary drive unit (16) via the radially extending guide vanes (15), and an inlet funnel (8), fixedly connected to the diffuser (9), wherein the semi-axial centrifugal pump (1) comprises a pump housing liner (38), located between the outer pump housing (7) and the lower edge (33) of the impeller (20), wherein the pump housing liner (38) is displaceable in the axial direction in relation to the outer pump housing (7) in order to adjust a radial gap (39) between the pump housing liner (38) and the lower edge (33) of the impeller (20).

The present invention relates to a centrifugal pump (1) comprising a drive unit (2) having an electric motor (3) and a drive shaft (4), a hydraulic unit (5) connected to the drive unit (2). The centrifugal pump further comprises an impeller (10) connected to the drive shaft (4) and located in a volute (9). The centrifugal pump (1) further comprises a sealing arrangement (13-14) connected to the housing (8) and configured for sealing between the impeller (10) and the housing (8). The centrifugal pump is characterized in that the seal member (13) is displaceable in the radial direction in relation to the clamping member (14), wherein the seal member (13) comprises a first engagement means (15) and the clamping member (14) comprises a second engagement means (16) configured to cooperate with the first engagement means (15) of the seal member (13), and wherein the sealing arrangement (13-14) has a play in the rotational direction between the first engagement means (15) and the second engagement means (16) whereby the seal member (13) is displaceable in the circumferential direction in relation to the clamping member (14) an angle α that is equal to or less than ± 3 degrees.

The invention relates to a method for monitoring and controlling the operation of a liquid flow generator (1) configured for operation in a tank (18) housing in a liquid comprising solid matter. The flow generator (1) comprises a propeller (3) and a main body (7) having a drive unit (4), wherein a control unit (4) is operatively connected to the flow generator (1) in order to monitor and control the operation of the flow generator (1), the method comprises the steps of: a) driving the propeller (3) in a normal direction of rotation, wherein the liquid flow is directed from an upstream side of the propeller (3) towards a downstream side of the propeller (3), wherein the main body (7) is located at the upstream side of the propeller (3), b) performing a cleaning sequence in response to a main body cleaning signal, wherein the cleaning sequence comprises the steps of: i) stopping the propeller (3) from rotating in the normal direction of rotation, ii) driving the propeller (3) in a reverse direction of rotation, wherein the liquid flow is directed from the downstream side of the propeller (3) towards the upstream side of the propeller (3) and along the main body (7) in order to remove any solid matter accumulated on the main body (7), and iii) stopping the propeller (3) from rotating in the reverse direction of rotation, c) resume driving of the propeller (3) in the normal direction of rotation.

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Zusammenfassung wird geladen …

Zusammenfassung wird geladen …

The invention relates to a hydraulic unit of a pump (1) configured for pumping liquid comprising solid matter, said hydraulic unit comprising a housing (6) and an impeller seat (5), said housing (6) having an axial inlet opening (2) and an outlet opening (3) and said impeller seat (5) having an axial inlet defined by an inlet wall (10), wherein the impeller seat (5) has an inlet radius (R) measured from an axially extending centre axis (A) to the circular intersection (11) between the inlet wall (10) and the upper surface (12) of the impeller seat (5), said impeller seat (5) comprising a guide pin (13) connected to and extending radially inwards from said inlet wall (10), the guide pin (13) having a tip radius (r) measured from the axially extending centre axis (A) to the radially innermost part of the guide pin (13), wherein an imaginary 15%-circle (23) is offset radially inwards from said circular intersection (11) fifteen percent of the difference between said inlet radius (R) and said tip radius (r), said housing (6) comprising a cut water (28), wherein a cut water line (29) is a radius of the impeller seat (5) tangent to the most downstream point of the cut water (28). The hydraulic unit is characterized in that the cut water line (29) is located downstream a radius of the impeller seat (5) that is perpendicular to the outlet opening (3), and in that a guide pin angle (µ) between the cut water line (29) and a radius of the impeller seat (5) intersecting a leading edge of the guide pin (13) at the 15%-circle (23), is equal to or more than 3 degrees and equal to or less than 25 degrees.