U.S. patent application number 12/386385 was filed with the patent office on 2009-11-05 for multiple-stage centrifugal pump of inline design.
Invention is credited to Wil Ouwehand.
Application Number | 20090274555 12/386385 |
Document ID | / |
Family ID | 39735226 |
Filed Date | 2009-11-05 |
United States Patent
Application |
20090274555 |
Kind Code |
A1 |
Ouwehand; Wil |
November 5, 2009 |
Multiple-stage centrifugal pump of inline design
Abstract
The present invention relates to a multiple-stage centrifugal
pump of inline design, comprising a connection housing (1) with
connectors (2, 3) in the form of suction and pressure connectors,
and a pump body (4). The pump body (4) is surrounded at a spacing
by a casing tube (6) with the formation of a flow-guiding annular
space (5). The pump body (4) and the casing tube (6) are fastened
so as to transmit force between the connection housing (1) and a
head piece (7), the head piece (7) is provided with a leadthrough
for a motor-driven pump shaft (8), and the connection piece (1) is
provided with a separating wall (9) which divides the suction and
pressure regions, a flow-diverting guide element (10) being
arranged in the transition region between the annular space (5) and
a connector (3).
Inventors: |
Ouwehand; Wil; (Katwijk,
NL) |
Correspondence
Address: |
DILWORTH & BARRESE, LLP
1000 WOODBURY ROAD, SUITE 405
WOODBURY
NY
11797
US
|
Family ID: |
39735226 |
Appl. No.: |
12/386385 |
Filed: |
April 17, 2009 |
Current U.S.
Class: |
415/203 ;
417/244 |
Current CPC
Class: |
F04D 29/426 20130101;
F04D 1/06 20130101 |
Class at
Publication: |
415/203 ;
417/244 |
International
Class: |
F04D 29/42 20060101
F04D029/42; F04D 1/06 20060101 F04D001/06 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 21, 2008 |
EP |
08 007 716.7 |
Claims
1. Multiple-stage centrifugal pump of inline design, comprising a
connection housing (1) with connectors (2, 3) in the form of
suction and pressure connectors, a pump body (4), the pump body (4)
being surrounded at a spacing by a casing tube (6) with the
formation of a flow-guiding annular space (5), the pump body (4)
and the casing tube (6) being fastened to transmit force between
the connection housing (1) and a head piece (7), the head piece (7)
being provided with a leadthrough for a motor-driven pump shaft
(8), and the connection piece (1) being provided with a separating
wall (9) which divides the suction and pressure regions, wherein a
flow-diverting guide element (10) is arranged in the transition
region between the annular space (5) and a connector (3).
2. Centrifugal pump according to claim 1, wherein the guide element
(10) is arranged between the annular space (5) and the pressure
connector.
3. Centrifugal pump according to claim 1, wherein the guide element
(10) is configured as a constituent part of the separating wall
(9).
4. Centrifugal pump according to claim 1, wherein the guide element
(10) is connected by one or more rib-like elements to the
separating wall (9) and/or to a wall face (11) of the connection
piece (1).
5. Centrifugal pump according to claim 1, wherein the guide element
(10) is arranged as an insert part between the connection piece
(1), pump body (4) and/or casing tube (6) and/or is connected to
it.
6. Centrifugal pump according to claim 1, wherein the guide element
(10) is spatially curved and has a trapezoidal or triangular
contour in a projection onto the throughflow plane.
7. Centrifugal pump according to claim 1, wherein the guide element
(10) is of tab-shaped design.
8. Centrifugal pump claim 7, wherein the guide element (10)
protrudes with its free end as far as up to or into the connector
cross section.
9. Centrifugal pump according to claim 7, wherein the guide element
(10) is fastened by one end in the transition between the
separating wall (9) and the inner wall face of the annular
space.
10. Centrifugal pump according to claim 1, wherein the tab-shaped
guide element (10) has a width in the region of an inner wall face
of the annular space, which width is equal to or less than (=<)
0.75 times (x) the nominal width of the connector (3).
11. Centrifugal pump according to claim 1, wherein the connection
width of the guide element (10) is equal to or less than (=<)
0.5 times (x) the nominal width of the connector (3).
12. Centrifugal pump according to claim 1, wherein a flow channel
which diverts by at least 75 degrees is formed between a
flow-diverting surface of the guide element (10) and the opposite
wall face of the annular space (5) and/or connector (3).
13. Centrifugal pump claim 12, wherein a part stream of the
annular-space stream flows out of the flow channel approximately
tangentially into the connector cross section or a pipe which is
connected to it.
14. Centrifugal pump according to claim 1, wherein the
flow-diverting surface of the guide element (10) is formed in two
planes which lie perpendicularly with respect to one another and
which are concave/planar or concave/convex and/or
concave/concave.
15. Multiple-stage centrifugal pump of inline design, comprising a
connection housing (1) with connectors (2, 3) in the form of
suction and pressure connectors, a pump body (4), the pump body (4)
being surrounded at a spacing by a casing tube (6) with the
formation of a flow-guiding annular space (5), the pump body (4)
and the casing tube (6) being fastened to transmit force between
the connection housing (1) and a head piece (7), the head piece (7)
being provided with a leadthrough for a motor-driven pump shaft
(8), and the connection piece (1) being provided with a separating
wall (9) which divides the suction and pressure regions, wherein a
flow-guiding annular element (12) having a flow-guiding surface of
convex design bridges the space between an outflow opening (13) of
the pump body (4) and an internal diameter (D.sub.i) at the inlet
cross section (14) of the annular gap.
16. Centrifugal pump according to claim 15, wherein an annular
nozzle is formed between the flow-guiding head-piece face (15) and
the annular element (12).
17. Centrifugal pump according to claim 15, wherein the annular
element (12) is connected by one or more guide elements (16) to the
head piece (7).
18. Centrifugal pump according to claim 1, wherein the head piece
(7) is configured in one piece or multiple pieces.
19. Centrifugal pump according to claim 2, wherein the guide
element (10) is arranged between the annular space (5) and the
pressure connector.
20. Centrifugal pump according to claim 16, wherein the annular
element (12) is connected by one or more guide elements (16) to the
head piece (7).
Description
[0001] The invention relates to a multiple-stage centrifugal pump
of inline design, comprising a connection housing with connectors
in the form of suction and pressure connectors, a pump body, the
pump body being surrounded at a spacing by a casing tube with the
formation of a flow-guiding annular space, the pump body and the
casing tube being fastened so as to transmit force between the
connection housing and a head piece, the head piece being provided
with a leadthrough for a motor-driven pump shaft, and the
connection piece being provided with a separating wall which
divides the suction and pressure regions.
[0002] A centrifugal pump of this type is known from DE 36 29 123
A1. A pump body which is equipped with a plurality of pump stages
lies on its connection piece, rotors which are arranged in the said
pump body being driven via a shaft by a motor which is arranged
above a head piece. A pumping medium flows through the pump body in
the direction of the head piece, in order to be deflected from this
and, after exiting the pump body, radially to the outside into an
annular gap. A perforated supporting ring centres the pump body in
the head piece. A casing tube which surrounds the pump body at a
spacing forms the annular gap. In the annular gap, the pumping
medium flows back to the connection piece, is deflected in it and
exits the connection body through a second connection.
[0003] Connection pieces of this type are configured as a cast
construction or a multiple-part welded construction and have a
separating wall, with the aid of which a division is made into
suction and pressure region. The head pieces are also known as cast
constructions or multiple-part welded constructions. A plurality of
tie rods which are fastened to the connection piece and in the head
piece and between which the pump body and the casing tube are
clamped are usually required to hold the centrifugal pump
together.
[0004] The invention is based on the object of improving the degree
of efficiency of a centrifugal pump of this type. The first
solution of this problem provides for a flow-diverting guide
element to be arranged in the transition region between the annular
space and a connector.
[0005] The guide element brings about a directed flow diversion
from the annular channel into a connector. In the connection piece,
this solution improves the overall flow guidance in this complex
diversion and merging zone. This is because, in the connection
piece, the homogenized annular-channel flow is deflected under very
constricted spatial conditions and is merged in the connector cross
section, usually the outlet or pressure connector, to form a
full-surface-area flow cross section. With the aid of the guide
element, a part flow of the annular-space flow, preferably that
part flow which lies closest to the connector, is deflected here in
the direction of an outlet flow in a manner which is favourable in
flow terms. Eddies are therefore avoided and the overall degree of
efficiency of a centrifugal pump of this type is improved
considerably.
[0006] Refinements of the invention provide for the guide element
to be arranged between the annular space and the pressure
connector, for the guide element to be configured as a constituent
part of the separating wall, or for the guide element to be
connected by way of one or more rib-like elements to the separating
wall and/or to a wall face of the connection piece, or for the
guide element to be arranged as an insert part between the
connection piece, pump body and/or casing tube and/or to be
connected to it. The suitable fastening option for the guide
element can therefore be selected as a function of a respectively
used production type of a connection piece.
[0007] Other refinements of the invention provide for the guide
element to be spatially curved and to have a trapezoidal or
triangular contour in a projection onto the throughflow plane, or
for the guide element to be of tab-shaped design, or for the guide
element to protrude with its free end as far as up to or into the
connector cross section, or for the guide element to be fastened by
way of one end in the transition between the separating wall and
the inner wall face of the annular space. These embodiments
effectively facilitate the production and formation of a guide
element of this type.
[0008] According to a further refinement of the invention, the
tab-shaped guide element has a width in the region of an inner wall
face of the annular space, which width is equal to or less than
(=<) 0.75 times (x) the nominal width of the connector. The
connection width of the guide element is preferably equal to or
less than (=<) 0.5 times (x) the nominal width of the connector.
Tests have shown that a very advantageous flow diversion is
possible with this. Furthermore, there is provision for the flow
diversion to form a flow channel which diverts by at least 75
degrees between a flow-diverting surface of the guide element and
an opposite wall face of the annular space and/or connector. A part
stream of the annular-space stream flows out of a flow channel of
this type approximately tangentially into the connector cross
section and/or a pipe which is connected to it. In the simplest
way, negative effects of an annular-space flow which is directed
perpendicularly with respect to the connector on the annular-space
flow which is merged in the connection housing and is deflected and
conducted away are prevented with the aid of the guide element.
[0009] A second solution of the problem provides for a flow-guiding
annular element having a flow-guiding surface of convex design to
bridge the space between an outflow opening of the pump body and an
internal diameter at the inlet cross section of the annular gap.
Eddies which are produced in the prior art by the flow transition
from the pump body into the annular gap are successfully avoided
within the flow with this. Baffles which transmit force and are
provided with throughflow openings cause unnecessary throttling
effects and eddies. In contrast, an undisrupted flow transfer is
made possible by the convex formation of the flow-guiding surface
of the annular element.
[0010] To this end, one refinement provides for an annular nozzle
to be formed between the flow-guiding head-piece face and the
annular element. As a result, additional influencing of the flow is
possible, which flow exits from the last stage of the pump body and
is diverted with low losses into the inlet cross section of the
annular gap. To this end, the flow-guiding surface, which lies
opposite the annular element, in the head piece has a concave
design.
[0011] According to a further refinement, the annular element is
connected by way of one or more guide elements to the head piece.
The guide elements extend in the direction of the pump shaft and
extend in the direction of the flow to be diverted. They therefore
oppose the flow only with a minimum resistance. A further
influencing of the flow and therefore an improvement in the degree
of efficiency are possible as a result of a corresponding shape of
the guide elements, as a function of the swirl directions which are
situated within the flow and as a function of a respective design
concept of the centrifugal pump. The head piece can be configured
in one piece or multiple pieces and can be produced from a very
wide variety of materials. This is dependent on a selected
production process.
[0012] One exemplary embodiment of the invention is shown in the
drawings and will be described in greater detail in the following
text. In the figures:
[0013] FIG. 1 shows a centrifugal pump in part section, and
[0014] FIG. 2 shows a plan view of a connection piece, and
[0015] FIG. 3 shows a section through a head piece.
[0016] FIG. 1 shows a part section of a centrifugal pump of inline
design, the connection housing 1 of which is provided with
connectors 2, 3 in the form of suction and pressure connectors.
Arrows show the flow direction within the connection housing 1. The
connectors 2, 3 define the principal throughflow direction of the
centrifugal pump and a pump body 4 is arranged perpendicularly with
respect thereto, which pump body 4 is surrounded at a spacing by a
casing tube 6 with formation of a flow-guiding annular space 5. A
head piece 7 which is fastened above the pump body 4 serves to
receive a drive motor. A pump shaft 8 is guided through the head
piece 7, with the aid of which pump shaft 8 the individual rotors
are driven within the pump body 4 of multiple-stage configuration.
A separating wall 9 is situated within the connection piece 1, with
the aid of which separating wall 9 the connection piece 1 is
divided into a suction region and a pressure region.
[0017] A guide element 10 is integrated into the connection piece
1, which is configured here as a cast part, and is configured as a
constituent part of the separating wall 9. In the case of a
multiple-part configuration of the connection piece, for example in
a segmented design with use of formed components, the guide element
can also be integrated into another component or can be connected
to it as a separate component.
[0018] A fluid flow which is conveyed by the pump part 4 is
diverted in the head piece 7 and flows back to the connection piece
1 through the annular gap 5 which is formed by the casing tube 6.
Since the flow direction in the annular gap stands perpendicularly
on the inflow and outflow direction of the pump, a flow diversion
takes place in the connection piece 1 along the separating wall 9
in the direction of the connector 3. Here, the flow is diverted by
the guide element 10 in a manner which is favourable for flow and
with low losses out of the annular-space region 5.1 which adjoins
the connector 3, and is guided to the outlet cross section of the
connector 3. The guide element 10 therefore prevents flows which
cross totally or partially in the annular-space region 5.1.
Instead, the annular-gap region 5.1 is shielded from the flow in
the connection housing 1, as a result of which a substantial
improvement in the degree of efficiency within the centrifugal pump
is brought about. connection housing 1, as a result of which a
substantial improvement in the degree of efficiency within the
centrifugal pump is brought about.
[0019] FIG. 2 shows a plan view of the connection piece 1 in half
section. The upper half of FIG. 2 exposes the view of the
connection plane for the pump part 4. In the upper illustration of
FIG. 2, the guide element 10 can be seen in the region of the
connector 3, with the aid of which guide element 10 a flow
diversion is effected out of the perpendicular downward direction
into the horizontal direction from the annular space 5 to the
connector 3 with the aid of the guide element 10. In this half
section, the guide element 10 is drawn in plan view in the upper
half in the annular-gap region 5.1 as a visible edge and is
continued into the connector 3 as a dashed line. It can be seen
from the projection onto the throughflow direction which is marked
by the arrows that the guide element 10 is of tab-shaped design in
this exemplary embodiment. In one embodiment of the connection
housing in multiple-part form, for example as a sheet-metal part
construction, the guide element 10 can be fastened with the aid of
rib-like elements to the separating wall 9 and/or to a
flow-diverting wall face 11 (cf. FIG. 1) of the connection piece 3.
The lower half of FIG. 2 corresponds to a section through the
centre line of the connectors 2, 3. The separating wall 9 is
connected to the connector 2 in a fluid-tight manner and brings
about the diversion of a fluid which is flowing into the connection
piece 1 into the pump part 4 which stands perpendicularly on the
centre line.
[0020] FIG. 3 is a detail from FIG. 1 and shows, in section, the
final pump stage of the pump part 4 and the annular gap 5 which is
formed by the casing tube 6. The end of the pump body 4 is covered
by a flow-guiding annular element 12 which bridges between an
outflow opening 13 of the pump body 4 and an internal diameter in
the region of the inlet cross section 14 of the annular gap. Arrows
show the throughflow direction within the head piece 7. Together
with the annular element 12, a flow-guiding head-piece face 15
forms a type of annular nozzle for the flow to be diverted. A flow
diversion with very low losses is therefore achieved. The annular
element 12 is connected to the head piece 7 by way of one or more
guide elements 16. Additional influencing of the flow to be
diverted can be achieved with the aid of the guide elements 16
which are configured as a type of ribs or as flow fins.
* * * * *