WO2014170428A1

WO2014170428A1 - Impeller for a centrifugal pump and centrifugal pump

Info

Publication number: WO2014170428A1
Application number: PCT/EP2014/057885
Authority: WO
Inventors: Arnaldo Rodrigues
Original assignee: Sulzer Pumpen Ag
Priority date: 2013-04-17
Filing date: 2014-04-17
Publication date: 2014-10-23
Also published as: BR112015022298A2; RU2015146995A3; US20160025100A1; CA2900445A1; KR20150143431A; RU2015146995A; AU2014255695A1; EP2986855A1; AU2014255695B2; MX2015014511A; CN105209763A; SG11201506237QA

Abstract

The invention relates to an impeller for a centrifugal pump, having at least one vane (11a; 11b), which has a concave bottom side (12a; 12b) at least in a partial region and at least one bending line (13a; 13b) in at least one portion, which extends at least substantially along a primary extension direction of the at least one vane (11a; 11b), wherein the vane (11a; 11b) is opened in a V-shape along the bending line (13a; 13b) in at least one portion in the direction of a surface normal of the bottom side (12a; 12b).

Description

WHEEL FOR A CIRCULAR PUMP AND CIRCULAR PUMP

The invention relates to an impeller for a centrifugal pump according to the preamble of claim 1.

There are already impellers for centrifugal pumps, with at least one wing, which has an upper side, which has at least one bending line in at least one subregion known. The wings are thereby open along the fold line in the direction of a surface normal of a top V-shaped, i. an opening of the wings points in a rotational direction in which the impeller is rotated in an operation for generating a pumping action.

The invention is in particular the object of providing an impeller by means of which a characteristic of a centrifugal pump can be improved. The object is achieved by an inventive impeller according to claim 1. Further developments of the invention will become apparent from the dependent claims.

The invention is based on an impeller for a centrifugal pump, with at least one vane, which has a concavely curved lower side in at least one subregion and at least one crease line in at least one subregion, which extends at least substantially along one

Main extension direction of the bottom runs.

It is proposed that the wing is at least V-shaped along the fold line in at least one partial area in the direction of a surface normal of the underside. By virtue of the fact that the vane of the impeller has a V-shape which is exactly the opposite way round compared with the prior art, a flow behavior, in particular within the pumping wheel, can be improved, whereby in particular a characteristic of a centrifugal pump can be improved. A "wing" is to be understood in particular a component of the impeller, which is a wall of a Pump space forms and having the radially outwardly facing top, which is intended to generate a pumping action in one operation. A "pumping chamber" is to be understood in particular as meaning a volume bounded by the impeller, which connects a radially inner intake region to a radially outer pressure region In principle, however, it is also conceivable that the impeller has a plurality of different pumping chambers located axially one behind the other, each one of them

connect different suction areas to a single pressure area. A "bottom side" should be understood to mean, in particular, a surface formed by the wing whose surface normal has a component which is directed radially inward with respect to an axis of rotation of the impeller Curvature of the wing defined line

be understood. Preferably, in the region of the bend line

Radius of curvature in the axial direction is much greater than a

Radius of curvature in adjacent areas. The radius of curvature in the region of the bend line is preferably a few millimeters at most. Depending on the rounding off in the region of the bending line, however, the radius of curvature can also be in the range of tenths of a millimeter or in the range of hundredths of a millimeter. The references "axial", "radial" and "in

Circumferential direction "is here and hereinafter referred to, unless explicitly stated otherwise, with reference to the axis of rotation of the impeller." V-shaped "open should in particular mean that the underside forms an open V, i. in that the surface has two partial surfaces which are arranged on both sides of the crease line and face each other, the V starting from the crease line

preferably opens radially inward.

Preferably, the at least one wing on the underside an opened angle spanned by the bending line, which in at least one Partial area is less than 180 degrees. As a result, the V-shaped opening can be realized particularly advantageously. In this context, an opening angle is to be understood as meaning, in particular, a clearance angle which the two mutually facing partial surfaces enclose with one another. It is further proposed that the opening angle has an angle bisector in at least one subregion, which lies at least substantially in a plane which is oriented perpendicular to a rotation axis.

As a result, a symmetrical design of the wing can be achieved, which results in an improved, in particular in the pressure range

Flow behavior can be achieved. A "bisecting line of the opening angle" should be understood to mean, in particular, a line that intersects the bend line and divides the opening angle into two equally large partial angles. "At least substantially" is understood to mean in particular that an angle that the plane is perpendicular to the

Rotary axis and the bisector is less than 5 degrees. Preferably, the angle between the plane is perpendicular to the plane

Rotation axis and the bisector smaller than 3 degrees and

more preferably less than 1 degree.

Further, it is advantageous if the bisector and the bending line span a plane which is oriented perpendicular to a rotation axis.

Thereby, the wing can be formed symmetrically with respect to a plane perpendicular to the axis of rotation, whereby a particularly advantageous flow behavior can be achieved, in particular in the pressure range.

Preferably, the underside of the wing on at least two, each arranged on one side of the bending line faces, which form an acute angle at the bend line with a plane perpendicular to a rotation axis. As a result, the V-shaped design of the underside can be achieved particularly well. An acute angle should be understood to mean an angle of less than 90 degrees, with the angle

is preferably determined in a direction parallel to the axis of rotation.

In addition, it is proposed that the angles between the plane perpendicular to the axis of rotation and the partial surfaces are each less than 80 degrees. This allows a favorable opening angle of the bottom can be achieved. Preferably, the angles are less than 75 degrees. Particularly advantageous are the angles less than 70 degrees.

In a particularly advantageous development, the partial surfaces have an at least substantially planar configuration in the axial direction. A "plane configuration in the axial direction" is to be understood in particular as meaning that the underside of the wing along at least one longitudinal sectional plane in the region of the partial surfaces by a straight line

is writable. Preferably, the opening angle is defined by a relative orientation of the two partial surfaces to each other and in the

Longitudinal plane determinable. A "longitudinal section plane" is to be understood as meaning a section along a plane which has the axis of rotation.

It is further proposed that the impeller has two laterally adjacent to the at least one wing impeller disks, with which the

Include partial surfaces of the underside of the wing in at least a portion of an obtuse angle. As a result, the pressure chambers bounded by the vanes in the radial direction can simply be limited also in the axial direction, with the V-shaped design of the underside extending in the at least one subregion over an entire axial width of the vane in such an embodiment. An "obtuse angle" is to be understood to mean an angle greater than 90 degrees, the angle preferably being determined in a direction parallel to the axis of rotation, the angle between the impeller disks and the subareas can thus be determined in particular in a longitudinal sectional plane. Impeller disc "should in particular a perpendicular to the

Rotation axis arranged disc to be understood, the

Pressure chambers of the impeller limited in the axial direction. In principle, the wings and the chambers can be designed at least partially in one piece or in several parts. Preferably, the at least one wing in at least one

Longitudinal plane on a symmetrical cross-section. This can be a particularly advantageous embodiment, in particular with regard to

Characteristic of the circular pump and / or a structural design can be achieved. A "symmetrical cross-section" should be understood to mean, in particular, a mirror-symmetrical configuration with respect to a plane perpendicular to the axis of rotation.

In addition, it is proposed that the at least one wing has an at least substantially constant thickness in at least one cutting plane. As a result, the impeller can be further improved. By a "constant strength" is meant in particular that the thickness of the wing, i.e. that its dimension is perpendicular to the wing

Bottom, along a cutting line in the cutting plane at least in

Is essentially constant. Furthermore, it is advantageous if the opening angle is at least 60 degrees and / or at most 160 degrees. As a result, the bottom can be advantageously formed. Preferably, the opening angle is at least 80 degrees and / or at most 130 degrees. Particularly advantageously, the opening angle is at least 100 degrees and / or at most 120 degrees. In addition, it is proposed as a further development that the impeller has a middle wall, which is arranged in particular in the region of the bending line. This allows the pumping chambers of the impeller

are fluidically divided into axially successive sub-volume, whereby a particularly advantageous flow behavior can be achieved. A "middle wall" should be understood to mean, in particular, a wall for subdividing pump chambers into two partial volumes connected in parallel in terms of flow

In particular, the middle wall should not be understood as meaning a radially continuous impeller disk which is intended to form a multistage or double-flow impeller. Under a "multi-stage impeller" is to be understood in particular an impeller that several

having fluidically connected in succession intake areas. Under a "double-flow impeller" is in particular an impeller be understood that two ström ungstechnisch parallel intake areas and subsequent to each of the intake areas

Pumping chambers, wherein the suction regions are fluidly connected via the pump chamber with a single, common pressure range.

In principle, the impeller may have a single-flow configuration with a single intake region and with a single pressure region which is fluidically connected to the one intake region. Alternatively, it is also conceivable that the impeller is a double-suction design with two axially opposite suction, with one of the two

Suction areas separating impeller disc and with a common, fluidically connected to the two intake areas

Pressure range has. An impeller with doppelflutiger configuration is thereby fed from both sides with fluid, whereas an impeller with einflutiger design is fed only from one side with fluid.

In addition, a centrifugal pump is proposed with an impeller according to the invention.

Further advantages will become apparent from the following description of the figures. In the figures, two embodiments of the invention are shown. The

Figures, the description of the figures and the claims contain numerous features in combination. The skilled person will become the characteristics

expediently consider individually and summarize meaningful further combinations.

1 shows a representation of the prior art,

Fig. 2 is a perspective view of an inventive

Impeller of a centrifugal pump, Fig. 3 is a longitudinal section through the impeller along a

Longitudinal section plane

Fig. 4 is an enlarged view of a portion of Fig. 3 and

Fig. 5 shows an embodiment of an impeller with a middle wall. Figure 1 shows an impeller 1 10 for a centrifugal pump, as is known in the art. The impeller 1 10 is provided for generating a pumping action. To generate the pumping action, the impeller 1 10 comprises a plurality of vanes 1 1 1, which has a concavely curved bottom 1 12 and a convex curved top 126. The wings 1 1 1 each have a bending line 1 13, which extends along a main extension direction of the wings 1 1 1. Along the crease line 1 13, the wings 1 1 1 in the direction of a surface normal of the top 126 V-shaped open, i. an opening of the wings 1 1 1 points in a direction of rotation, in which the impeller 1 10 is rotated in an operation for generating the pumping action. 2 shows a double-flow Kreriselpumpe and Figures 3 and 4 show partially schematically a single-flow centrifugal pump with an impeller 10a according to the invention, which is provided for generating a pumping action. The centrifugal pump comprises a pump housing not shown in detail, in which the impeller 10a is rotatably mounted, and a drive flange 27a, which is rotatably connected to the impeller 10a and which is intended to connect the impeller 10a with a drive machine, not shown. The impeller 10 a, the one

Rotation axis 17a is rotatably mounted, has a radially inner intake region 28a and a radially outer pressure region 29a. To generate the pumping action, the impeller 10a comprises a plurality of vanes 11a. The wings 1 1 a each have a top 26 a, which faces away from the axis of rotation 17 a, and a bottom 12 a, the

Rotary axis 17a facing on. The wings 1 1 a, which are each formed analogously, are distributed uniformly over a circumference of the impeller 10 a. The wings 1 1 a are arranged spirally with respect to the rotation axis 17 a. The tops 26a of the wings 11a are substantially concave curved. The undersides 12 a of the wings 1 1 a are curved substantially convex.

In addition, the impeller 10a comprises two impeller disks 22a, 23a, which adjoin the wings 11a on both sides. The impeller disks 22a, 23a are arranged substantially perpendicular to the rotation axis 17a. Together with the blades 11a, the impeller disks 22a, 23a form a plurality of pumping chambers 30a, which in operation produce a pressure difference between the intake region 28a and the pressure region 29a. The

Pumping chambers 30a are limited in the axial direction by the impeller disks 22a, 23a. Radially inside the pumping chambers 30a are bounded by the top 26a of each one of the wings 1 1 a. Radially outward, the pump chambers 30a are bounded by the underside 12a of the respective subsequent blade 11a. The wings 1 1 a and the impeller disks 22a, 23a are integral in the illustrated embodiment

educated. In principle, however, a multi-part design is conceivable.

In one operation, the tops 26a of the wings 11a act as pressure surfaces. The pumping action is essentially due to a course of the tops 26a of the wings 11a. If the impeller 10a rotates about the axis of rotation 17a, the upper sides 26a form pressure surfaces which, in conjunction with a centrifugal force caused by a rotational movement of the impeller 10a, convey a medium to be pumped, in particular liquids, radially outward.

The wings 1 1 a each have a bending line 13 a, which extends substantially along a circumferential direction. The crease line 13a extends along a main direction of extension of the wings 1 1 a and thus along main directions of extension of the bottom 12 a and the top 26 a. Along the crease line 13a, the wings 1 1 a form on the upper side 26a and the lower side 12a each have a kink which, at least in an outer portion of the corresponding wing 11a, is axially centered on the upper side 26a and the bottom 12a extends. The crease line 13a lies on the upper side 26a and on the lower side 12a in a plane 16a which is oriented perpendicular to the axis of rotation 17a.

The crease line 13a, along which the top 26a and the bottom 12 are each kinked, extends in the illustrated embodiment, only in the outer portions of the wings 1 1 a in the circumferential direction. In inner sub-areas, in particular in the intake area 28a, the crease line 13a is guided in the direction of an edge of the wing 1 1 a, whereby the crease line 13a extends obliquely to the circumferential direction. The crease line 13a is guided in particular in the intake region 28a to the edge of the wing 1 1 a, whereby the wings 1 1 a in the illustrated Ausführungsbespiel inside are kink-free and have only outside the kink.

By changing a course of the bending line 13a, the impeller 10a can be adapted to different requirements, which are placed on the centrifugal pump. In particular, an axial position, which have the bending line 13a at different radii, can be represented by the

Deviate embodiment. For example, the crease line 13a can also be brought radially outward to an edge of the wings 11a,

for example, to provide the wings 1 1 a with a kink, which runs along the main extension direction of the wing 1 1 a of the one edge diagonally across the corresponding wing 1 1 a to the other edge.

In principle, middle portions which lie between the outer portion of the wings 11a and an inner portion can also be formed kink-free, while the inner and outer portions have a kink.

The wings 1 1 a are each along their fold line 13 a in the direction of a surface normal of the bottom 12 a V-shaped open. The wings 1 1 a have at the bottom 12a along the respective bending line 13a a

Opening angle 14a, which is smaller than 180 degrees, at least in the sub-areas in which the corresponding wing 1 1 a is kinked. Of the

Opening angle 14a, which defines an opening of the wing 1 1 a, is directed radially inward. In a longitudinal sectional plane, ie a sectional plane in which the axis of rotation 17a lies, the lower side 12a has a V-shaped one Structure (see Figure 4). A dot at the bottom 12a of the

corresponding wing 1 1 a, which lies on the bend line 13a, has to the rotation axis 17a a greater distance than all other points on the bottom 12a of the corresponding wing 1 1 a, in the same

Longitudinal plane lie. At least in outer subregions forms thus the bending line 13a in all longitudinal sectional planes from a radially outer point of the bottom 12a in the corresponding longitudinal section plane.

The opening angle 14a has an angle bisector 15a, which is directed parallel to the circumferential direction. The bisecting line 15a thus extends in a plane 16a, which is oriented perpendicular to the axis of rotation 17a. The crease line 13a extends in the same plane 16a. The bisecting line 15a and the bending line 13a thus span the plane 16a which is perpendicular to the axis of rotation 17a. The bisecting line 15a lies along the entire bending line 13a in the plane 16a, which is oriented parallel to the axis of rotation 17a.

The underside 12a of the wing 1 1 a has on both sides of the bending line 13a

Partial surfaces 18a, 19a, with the plane 16a perpendicular to the

Rotation axis 17a, which is spanned by the bisector 15a and the crease line 13a, include an acute angle 20a, 21 a. The two partial surfaces 18a, 19a are inclined towards each other. The partial surfaces 18a, 19a close with the plane 16a, which is perpendicular to the axis of rotation 17a, each having an angle 20a, 21a of about 60-65 degrees. Of the

Opening angle 14a is thus about 120-130 degrees. In principle, the angles 20a, 21a between the partial surfaces 18a, 19a and the plane 16a perpendicular to the axis of rotation 17a may be between 5 degrees and 70 degrees. In particular, it is also conceivable that the opening angle 14a changes along the bending line 13a, in particular if the bottom 12a is kink-free in a partial area. The opening angle 14a may in such an embodiment of a certain value, for example 120 degrees, along the main direction of extension of the wing 1 1 a gradually pass into a kink-free state.

The partial surfaces 18a, 19a have a planar configuration in the axial direction. The partial surfaces 18a, 19a are curved only in the circumferential direction. In a section along the longitudinal sectional planes, the partial surfaces 18a, 19a have a planar course (cf., FIG. 3). In a section in the plane 16a perpendicular to the axis of rotation 17a, the partial surfaces 18a, 19a are curved. With the impeller disks 22a, 23a, which laterally adjoin the wing 11a, the partial surfaces 18a, 19a on the underside 12a of the wing 11a each include an obtuse angle 20a, 21a. The angles 24a, 25a, which the partial surfaces 18a, 19a at the bottom 12a respectively with the

Include impeller disks 22a, 23a, each about 120-130 degrees. With the top 26 a of the wing 1 1 a close the impeller disks 22 a, 23 a each an angle 31 a, 32 a of about 60 degrees. The angle 24a, 25a on the bottom 12a and the angle 31a, 32a on the top 26a are each formed complementary to each other.

The wings 1 1 a have, at least in the outer portions of a substantially constant thickness, i. in a corresponding longitudinal section plane, the radial strength of the wings 1 1 a is substantially constant. The upper surface 26a thereby has a shape corresponding to the V-shaped configuration of the lower surface 12a. On the underside 12a, the outwardly facing surface of the wing 11a has the V-shaped configuration, which is open radially inward. At the

Top 26a forms a material of the wing 1 1 of the same shape, wherein the material has the V-shaped, inwardly open configuration.

The wing 1 1 a has in the longitudinal section plane a symmetrical

Cross-section on. The plane 16a perpendicular to the axis of rotation 17a, which is spanned by the bisecting line 15a and the bending line 13a, forms a plane of symmetry. With respect to the plane 16a of the wing 1 1 a is formed mirror-symmetrically in the outer portion. In the inner portion, in particular in the intake region 28a, the wing 1 1 a is formed asymmetrically. FIG. 5 shows a further exemplary embodiment of the invention of a double-flow centrifugal pump. The following descriptions are essentially limited to the differences between the exemplary embodiments, wherein reference can be made to the description of the exemplary embodiment of FIGS. 2 to 4 with regard to components, features and functions that remain the same. To distinguish the embodiments, the letter a in the reference numerals of the embodiment in Figures 2 to 4 by the letter b in the reference numerals of

Embodiment of Figure 5 replaced. With regard to identically named components, in particular with regard to components having the same reference numerals, reference may in principle also be made to the drawings and / or the description of the exemplary embodiment of FIGS. 2 to 4.

Figure 5 shows a section of an impeller 10b for a double-flow centrifugal pump having a plurality of wings 1 1 b, wherein in the present sectional view, only one wing is visible. The wings 1 1 b each have a concave curved bottom 12 b and a convex curved top 26 b. In addition, the flights 1 1 b on a crease line 13b, which runs along a main extension direction of the wing 1 1 b. The underside 12b has a surface normal, which is oriented at each point of the bending line 13b perpendicular to a surface of the wing 1 1 b. Along the crease line 13b, the wing 1 1 b in the direction of the surface normal of the bottom 12 b is open V-shaped. In addition, the impeller 10b comprises two impeller disks 22b, 23b which connect on both sides to the vanes 11b and, together with the vanes 11b, span pumping chambers 30b for conveying a fluid to be pumped.

In contrast to the preceding exemplary embodiment, the impeller 10b comprises a middle wall 33b which subdivides the pumping chambers 30b into two partial volumes 34b, 35b arranged axially one behind the other. The middle wall 33b is arranged in the region of the bending line 13b. The

Middle wall 33b extends in a section substantially parallel to the impeller disks 22b, 23b. By means of the middle wall 33b can can be advantageously achieved that the respectively sucked by the suction portions 28b liquid in the intake does not meet directly for an improved pumping action. By the means wall 33b is the

Pumping chamber 30b fluidically divided into two axially successively arranged partial volume 34b, 35b.

The impeller 10b has a radially inner intake region 28b, which is fluidically connected to the axially successive partial volume 34b, 35b. In addition, the impeller 10b on a radially outer pressure region 29b, which is also fluidly connected to the axially one behind the other partial volume 34b, 35b. Each of the sub-volumes 34b, 35b thus connects the inner suction region 28b with the outer pressure region 29b.

The middle wall 33b, which subdivides the pumping chambers 30b into the partial volumes 34b, 35b arranged axially one behind the other, is designed in the form of an increase at the so-called stroke of the centrifugal pump. The suction portion 28b is disposed within the middle wall 33b. The pressure area 29b is arranged outside the middle wall 33b. The middle wall 33b is arranged radially inwardly relative to the wings 11b.

The impeller 10b is disposed on a drive shaft 27b for driving the impeller 10b.

Claims

claims

1 . Impeller for a centrifugal pump, with at least one wing (1 1 a; 1 1 b), the at least one subarea concavely curved bottom (12a, 12b) and in at least one subregion at least one

Kink line (13a, 13b) which extends at least substantially along a main extension direction of the at least one wing (11a, 11b),

characterized in that

the wing (1 1 a; 1 1 b) along the fold line (13a, 13b) in at least a partial area in the direction of a surface normal of the bottom (12a, 12b) is V-shaped.

Impeller according to claim 1,

characterized in that

the at least one wing (1 1 a; 1 1 b) on the underside (12a, 12b) has an opening angle (14a) spanned by the crease line (13a; 13b), which is smaller than 180 degrees in at least one partial area.

Impeller according to claim 2,

characterized in that

the opening angle (14a) in at least a partial area a

Angle bisector (15a) which lies at least substantially in a plane (16a) which is oriented perpendicular to a rotation axis (17a).

Impeller according to claim 3,

characterized in that

the bisecting line (15a) and the bending line (13a; 13b) span the plane (16a) oriented perpendicular to the axis of rotation (17a). Impeller according to one of the preceding claims,

characterized in that

the underside (12a, 12b) of the wing (11a, 11b) has at least two partial surfaces (18a, 19a) arranged on opposite sides of the folding line (13a, 13b), which engage in the bend line (13a, 13b) a plane (16a) perpendicular to a rotational axis (17a) each include an acute angle (20a, 21 a).

Impeller according to claim 5,

characterized in that

the angles (20a, 21a) between the plane (16a) perpendicular to the axis of rotation (17a) and the partial surfaces (18a, 19a) are each less than 80 degrees.

Impeller according to claim 5 or 6,

characterized in that

the partial surfaces (18a, 19a) in the axial direction at least in

Have substantially planar design.

Impeller at least according to claim 5,

marked by

two impeller disks (22a, 23a, 22b, 23b) adjoining the at least one vane (1 1 a; 1 1 b), with which the partial surfaces (18a, 19a) of the lower side (12a, 12b) of the vane (1 1 a ; 1 1 b) include an obtuse angle (24a, 25a) in at least one subregion.

Impeller according to one of the preceding claims,

characterized in that

the at least one wing (1 1 a; 1 1 b) in at least one

Longitudinal sectional plane has a symmetrical cross-section.

Impeller according to one of the preceding claims,

characterized in that

the at least one wing (1 1 a; 1 1 b) has an at least substantially constant thickness in at least one cutting plane.

1 1. Impeller according to one of the preceding claims,

characterized in that

the opening angle (14a) is at least 60 degrees and / or at most 160 degrees. 12. Impeller according to one of the preceding claims,

marked by

a middle wall (33b), which is arranged in particular in the region of the bending line (13b).

13. Impeller according to one of the preceding claims,

marked by

a single-flow design.

14. Impeller according to one of claims 1 to 12,

marked by

a double-flow design. 15. Centrifugal pump with an impeller (10 a, 10 b) after one of

previous claims.