Pumping apparatus having a flow guiding element

Abstract

A pumping apparatus includes an impeller, an inlet housing and at least one flow guiding element. The impeller is rotationally supported for the guidance of a pumpable medium about an axis of rotation. The inlet housing spans a suction region upstream of the impeller. The at least one flow guiding element is at least partly arranged within the suction region and the flow guiding element is provided to guide the medium flow in the direction of the impeller.

Claims

1. A pumping apparatus comprising: an impeller rotationally supported about an axis of rotation, being configured to convey a pumpable medium and discharge the pumpable medium in a direction having a major component thereof parallel to the axis of the rotation; an inlet housing spanning a suction region upstream of the impeller and partially spanning a pump region in which the impeller is arranged, and forming a constriction between the pump region and the suction region upstream of the impeller, the pump region extending from the constriction so as to have an increasing diameter at least partially upstream of the impeller, and the constriction having a diameter that is less than both a diameter of the pump region and a diameter of the suction region; and at least one flow guiding element at least partly arranged within the suction region, and further arranged to guide the medium flowing in an axial direction of the impeller, the suction region being provided to guide the medium flowing in the axial direction of the impeller so as to discharge the medium into the pump region, the at least one flow guiding element including at least one ring segment and being at least partially disposed in the constriction, and a spacing defining a distance being present between the inlet housing and the at least one flow guiding element that is less than a radial distance of the flow guiding element from the axis of rotation.

2. A pumping apparatus in accordance with claim 1, wherein the flow guiding element is arranged coaxial with respect to the axis of rotation.

3. A pumping apparatus in accordance with claim 1, wherein the flow guiding element has a radius of curvature smaller than a maximum radius of the impeller.

4. A pumping apparatus in accordance with claim 1, wherein the flow guiding element is a sheet metal component.

5. A pumping apparatus in accordance with claim 4, wherein the flow guiding element has a height directed along the axis of rotation of the impeller, the height being smaller than a radius of curvature of the flow guiding element.

6. A pumping apparatus in accordance with claim 4, wherein the flow guiding element is in the form of a cylinder jacket surface.

7. A pumping apparatus in accordance with claim 4, wherein the inlet housing is a suction nozzle connected upstream of the impeller from a flow point of view, and the at least one flow guiding element being at least partly arranged in the suction nozzle.

8. A pumping apparatus in accordance with claim 7, wherein the inlet housing has at least one constantly tapering part region forming the suction nozzle, the flow guiding element being at least partly arranged in the at least one constantly tapering part region.

9. A pumping apparatus in accordance with claim 4, wherein the at least one flow guiding element and the inlet housing have a constant spacing at least in a cross-sectional plane perpendicular with respect to the axis of rotation of the impeller.

10. A pumping apparatus in accordance with claim 4, wherein at least one fastener connecting the flow guiding element to the inlet housing.

11. A pumping apparatus in accordance with claim 10, wherein the at least one fastener extends in at least one substantially radial direction with respect to the axis of rotation of the impeller.

12. A pump comprising: a pumping apparatus comprising an impeller rotationally supported about an axis of rotation, being configured to convey a pumpable medium and discharge the pumpable in a direction having a major component thereof parallel to the axis of rotation; an inlet housing spanning a suction region upstream of the impeller and partially spanning a pump region in which the impeller is arranged, and forming a constriction between the pump region and the suction region upstream of the impeller, the pump region extending from the constriction so as to have an increasing diameter at least partially upstream of the impeller, and the constriction having a diameter that is less than both a diameter of the pump region and a diameter of the suction region; and at least one flow guiding element at least partly arranged within the suction region, and further arranged to guide the medium flowing in an axial direction of the impeller, the suction region being provided to guide the medium flowing in the axial direction of the impeller so as to discharge the medium into the pump region, the at least one flow guiding element including at least one ring segment and being at least partially disposed in the constriction, and a spacing defining a distance being present between the inlet housing and the at least one flow guiding element that is less than a radial distance of the flow guiding element from the axis of rotation.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Referring now to the attached drawings which form a part of this original disclosure:

(2) FIG. 1 is a cross-section through an inlet housing of a pumping apparatus in accordance with the invention;

(3) FIG. 2 is a flow guiding element of the pumping apparatus in a perspective view;

(4) FIG. 3 is a perspective illustration of the pumping apparatus;

(5) FIG. 4 is a characteristic line of the pump performance of the pumping apparatus;

(6) FIG. 5 is an embodiment of a flow guiding element having fastening elements which are arranged in the shape of a cross; and

(7) FIG. 6 is an embodiment having two concentrically arranged flow guiding elements.

DETAILED DESCRIPTION OF EMBODIMENTS

(8) The FIGS. 1 to 3 show a pumping apparatus for a pump. FIG. 4 shows a characteristic line 25a in which a feed head pressure H is applied with respect to a feed amount Q of a pump. The pumping apparatus includes an inlet housing 12a and an impeller 10a which is arranged within the inlet housing 12a. The impeller 10a is provided to convey a pumpable medium, such as a liquid. The pump is configured as a vertical pump. The impeller 10a, which is rotatably supported, has an axis of rotation 11a which is preferably vertically oriented during operation, this means that the axis of rotation 11a of the impeller 10a extends in parallel to a gravitational force, against which the pump sucks the medium. A drive is not illustrated in detail which is included in the pump in order to drive the impeller 10a. The pump is provided for very large pump volumes, for example at an order of magnitude of approximately 50,000 m.sup.3/h for a low feed head pressure, for example, between 10 m and 40 m.

(9) The inlet housing 12a spans a suction region 13a which is switched upstream of the impeller 10a. Moreover, the inlet housing 12a partly spans a pump region 26a in which the impeller 10a is arranged. The pump is provided to be immersed into a liquid, up until a liquid level within the inlet housing 12a is above the impeller 10a, whereby the impeller 10a immersed into the liquid can suck the medium and convey this. The inlet housing 12a deflects the medium to be pumped in the direction of the impeller 10a. A flow profile which is set within the suction area 13a, in particular depends on a shape of the inlet housing 12a.

(10) In order to influence the flow profile of the medium flowing within the suction region 13a in the direction of the impeller 10a, the pumping apparatus includes a flow guiding element 14a. The flow guiding element 14a is arranged within the suction region 13a. The flow guiding element 14a is configured in the shape of a ring which is arranged within the inlet housing 12a. For fastening the flow guiding element 14a at the inlet housing 12a, the pumping apparatus has a plurality of fastening elements 21a, 22a, 23a, 24a. The fastening elements 21a, 22a, 23a, 24a divide the flow guiding element 14a into segments which respectively have the shape of a ring segment. In the illustrated embodiment the fastening apparatus includes the four fastening elements 21a, 22a, 23a, 24a. Principally, however, also a different number of fastening elements 21a, 22a, 23a, 24a are plausible.

(11) The flow guiding element 14a is arranged coaxial with respect to the axis of rotation 11a of the impeller 10a. The flow guiding element 14a has a middle point lying at the axis of rotation 11a via which middle point a radius of curvature 17a of the flow guiding element 14a can be defined with respect to the axis of rotation 11a of the impeller 10a. In the illustrated embodiment, in which the flow guiding element 14a is configured in the shape of a ring, the middle point defined by the radius of curvature 17a corresponds to a geometric middle point.

(12) The inlet housing 12a in the region, in which the flow guiding element 14a is arranged, has an internal radius of curvature 27a with respect to the axis of rotation 11a of the impeller 10a which is larger than the radius of curvature 17a of the flow guiding element 14a. The flow guiding element 14a and the inlet housing 12a have a spacing 16a with respect to the axis of rotation 11a which is smaller than the radius of curvature 17a of the flow guiding element 14a. The spacing 16a is in this connection smaller than the radius of curvature over a total head pressure 19a of the flow guiding element 14a.

(13) In the illustrated embodiment the internal radius of curvature 27a of the inlet housing 12a is larger by approximately a factor of 1.05 to 1.2 times the radius of curvature 17a of the flow guiding element 14a, this means that the spacing 16a between the flow guiding element 14 and the inlet housing 12a amounts to less than 20% of the radius of curvature 17a of the flow guiding element 14a. The spacing 16a between the flow guiding element 14a and the inlet housing 12a is thus substantially smaller than the radius of curvature 17a which the flow guiding element 14a has. The radius of curvature 17a of the flow guiding element 14a, for example, amounts to approximately 119 mm. The internal radius of curvature 27a of the inlet housing 12a amounts to approximately 135 mm.

(14) The radius of curvature 17a of the flow guiding element 14a is moreover smaller than an outer radius 28a which the impeller 10a has (cf. FIG. 3). The outer radius 28a of the impeller 10a, this means the largest radius 28a definable at the impeller 10a at the inlet is approximately larger by a factor of 1.2 than the radius of curvature 17a of the flow guiding element 14a. In the illustrated embodiment the impeller 10a has a radius 28a of approximately 145 mm. An axial spacing between the impeller 10a and the flow guiding element 14a in the axial direction, this means along the axis of rotation 11a, is substantially smaller than the maximum radius 28a of the impeller 10a. A factor between the axial spacing and the maximum radius 28a of the impeller 10a amounts to approximately 0.04. Generally, however, also other dimensions of the impeller 10a, the inlet housing 12a and the flow guiding element 14a are plausible.

(15) The flow guiding element 14a is configured as a single piece sheet metal component (cf. FIG. 2). The flow guiding element 14a has a head pressure 19a directed along the axis of rotation 11a of the impeller 10a which head pressure is substantially larger than a thickness which the flow guiding element 14a has in a direction radial with respect to the axis of rotation 11a of the impeller 10a. The thickness can, for example, lie in a range of a few millimeters or less, in contrast to which the head pressure 19a can amount to several centimeters. The thickness of the flow guiding element 14a is substantially constant over the overall circumference of the flow guiding element 14a. The flow guiding element 14a is configured in the shape of a cylinder jacket surface, whose head pressure 19a is smaller than its radius of curvature 17a.

(16) The inlet housing 12a has a round internal cross-section in a cross-sectional plane perpendicular with respect to the axis of rotation 11a. Moreover, the inlet housing 12a is at least partly configured curved in the suction region 13a also along the axis of rotation 11a of the impeller 10a. A further internal radius of curvature can be defined for the inlet housing 12a, at least in the region in which the flow guiding element 14a is arranged, which further internal radius of curvature has a reference with respect to an axis perpendicular to the axis of rotation 11a. The inlet housing 12a in this connection preferably, but not necessarily, has a constantly tapering part region, and a constantly expanding part region. It is naturally understood that also a pure axial pump having a cylindrical inlet housing, this means with constant diameter is possible.

(17) The inlet housing 12a forms a suction nozzle by its two curvatures which are switched upstream of the impeller 10a from a flow point of view. The flow guiding element 14a is arranged in the suction nozzle. The flow guiding element 14a is arranged partly in the constantly tapering part region and partly in the expanding part region along the axis of rotation 11a of the impeller 10a. The flow guiding element 14a extends from the tapering part region of the suction region 13a into the expanding part region.

(18) The inlet housing 12a forms a constriction 20a whose internal diameter is smaller than a maximum diameter of the impeller 10a. At the constriction 20a the internal diameter of the inlet housing 12a is minimum. The flow guiding element 14a is installed in the constriction 20a. The spacing 16a between the inlet housing 12a and the flow guiding element 14a varies along the axis of rotation 11a of the impeller 10a. It becomes minimal in the region of the constriction 20a.

(19) Since the flow guiding element 14a is configured ring-like and the inlet housing 12a has a round internal cross-section, the spacing 16a between the flow guiding element 14a and the inlet housing 12a is of equal size in each cross-sectional plane over the entire circumference of the flow guiding element 14a. With respect to a feed direction, along which the conveyed medium flows, the spacing 16a between the flow guiding element 14a and the inlet housing 12a upstream and downstream of the constriction 20a is larger than in the constriction 20a.

(20) For fastening the flow guiding element 14a at the inlet housing 12a the pumping apparatus includes the four fastening elements 21a, 22a, 23a, 24a. The fastening elements 21a, 22a, 23a, 24a are likewise configured as sheet metal components. They have a radial direction of extent with respect to the axis of rotation 11a of the impeller 10a. They are arranged cross shaped with respect to the axis of rotation 11a of the impeller 10a. The fastening elements 21a, 22a, 23a, 24a and the flow guiding element 14a are configured as separate multi parts, however, are fixedly connected to one another. In the illustrated embodiment they are connected to one another in a material flow manner by means of a welded connection or a brazed connection. Principally, however, also a different type of connection between the fastening elements 21a, 22a, 23a, 24a and the flow guiding element 14a are plausible, such as, in particular also a shape matched and/or force matched connection, by means of clamps or screws. For a connection to the inlet housing 12a, the fastening elements 21a, 22a, 23a, 24a can respectively have bores, by means of which the fastening elements 21a, 22a, 23a, 24a can be screwed or riveted to the inlet housing 12a. Generally, however, also a different type of connection between the fastening elements 21a, 22a, 23a, 24a and the inlet housing 12a is plausible, such as, for example by welding.

(21) In the FIGS. 5 and 6 two further embodiments of the invention are shown. The subsequent description is limited substantially to the differences between the embodiments, wherein one can refer to the description of the other embodiments with respect to equal components, features and functions, in particular to that of FIGS. 1 to 4. For differentiating the embodiments, the letter a is used in the reference numerals of the embodiment shown in the FIGS. 1 to 4 and is respectively replaced by the letters b and c with respect to the reference numerals of the embodiments of FIGS. 5 and 6. With respect to the same reference to the components, in particular with respect to components having the same reference numerals, one can generally refer also to the drawing and/or the description of the other embodiments, in particular to that of FIGS. 1 to 4.

(22) The FIG. 5 shows a flow guiding element 14b having fastening elements 21b, 22b, 23b, 24b for a pumping apparatus in accordance with the invention which differentiates, in particular with respect to the fastening elements 21b, 22b, 23b, 24b from the embodiment illustrated in FIG. 1. The flow guiding element 14b corresponds to the previously mentioned embodiment. In contrast to the previous embodiment the fastening elements 21b, 22b, 23b, 24b are centrally joined and arranged radially with respect to an axis of rotation 11b of an impeller not illustrated in detail. The fastening elements 21b, 22b, 23b, 24b thereby form a cross which acts as a suction protection for the impeller.

(23) The FIG. 6 shows a pumping apparatus having two flow guiding elements 14c, 15c, as well as having fastening elements 21c, 22c, 23c, 24c. The fastening elements 21c, 22c, 23c, 24c are configured in analogy to the previous embodiment. The fastening elements 21c, 22c, 23c, 24c which are radially arranged with respect to an axis of rotation 11c of an impeller are centrally joined in the form of a cross which acts as a suction protection for the impeller 10c.

(24) The two flow guiding elements 14c, 15c are arranged coaxial with respect to one another. The outer flow guiding element 14c corresponds to the embodiment of the FIGS. 1 to 3. The second flow guiding element 15c differentiates, in particular with respect to its radius of curvature from a radius of curvature 17c of the first flow guiding element 14c. In analogy to the first flow guiding element 14c, also the second flow guiding element 15c is configured in the shape of a ring. The radius of curvature 18c of the second flow guiding element 15c is significantly smaller than the radius of curvature 17c of the first flow guiding element 14c. A factor between the larger radius of curvature 17c and the smaller radius of curvature 18c can in this connection lie between 0.2 and 0.8. In the illustrated embodiment it amounts to approximately 0.7.

(25) Generally also a design with more than two flow guiding elements is plausible. Preferably the flow guiding elements are arranged coaxially in the form of rings. In this connection, in particular an arrangement of all flow guiding elements in a plane is advantageous.