U.S. patent application number 15/257646 was filed with the patent office on 2017-03-09 for volute design for lower manufacturing cost and radial load reduction.
The applicant listed for this patent is Fluid Handling LLC. Invention is credited to Paul J. Ruzica.
Application Number | 20170067481 15/257646 |
Document ID | / |
Family ID | 58188519 |
Filed Date | 2017-03-09 |
United States Patent
Application |
20170067481 |
Kind Code |
A1 |
Ruzica; Paul J. |
March 9, 2017 |
Volute Design For Lower Manufacturing Cost and Radial Load
Reduction
Abstract
A volute for a pump featuring a volute or casing having a pump
inlet for receiving a fluid being pumped, a pump discharge for
providing the fluid, and a volute or casing vane forming double
volutes therein. The volute has an upper cutwater farthest from the
pump discharge defining an upper cutwater throat area and an end of
passage for the upper cutwater, and also has a lower cutwater
closest to the pump discharge defining a lower cutwater throat and
a corresponding end of passage for the lower cutwater. The upper
cutwater throat area is dimensioned to be greater than and not
equal to the lower cutwater throat area so the upper cutwater
throat area and the lower cutwater throat area provide
substantially equal flow velocity at both the upper cutwater and
the lower cutwater in response to an angular sweep of the fluid
being pumped. The end of passage for the upper cutwater is
dimensioned with an upper cutwater passage area that is greater
than and not equal to a corresponding lower cutwater passage area
of the corresponding end of passage for the lower cutwater so that
upper and lower cutwater passage areas at the pump discharge are
balanced as a function of differing rates of flow of the fluid
being pumped therein and so that the fluid being pumped from
associated ends of the upper and lower cutwater passage areas meets
at the pump discharge with a substantially equal velocity.
Inventors: |
Ruzica; Paul J.; (Auburn,
NY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Fluid Handling LLC |
Morton Grove |
IL |
US |
|
|
Family ID: |
58188519 |
Appl. No.: |
15/257646 |
Filed: |
September 6, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62213739 |
Sep 3, 2015 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F04D 29/445 20130101;
F04D 29/428 20130101 |
International
Class: |
F04D 29/44 20060101
F04D029/44; F04D 29/22 20060101 F04D029/22 |
Claims
1. A volute for a pump comprising: a volute wall; a pump inlet for
receiving a fluid being pumped; a pump discharge for providing the
fluid being pumped; and a casing vane configured on the volute wall
forming double volutes in the volute and being configured with an
upper cutwater farthest from the pump discharge defining an upper
cutwater throat area and an end of passage for the upper cutwater,
and also configured with a lower cutwater closest to the pump
discharge defining a lower cutwater throat and a corresponding end
of passage for the lower cutwater; the upper cutwater throat area
being dimensioned to be greater than and not equal to the lower
cutwater throat area so that the upper cutwater throat area and the
lower cutwater throat area provide substantially equal flow
velocity at both the upper cutwater and the lower cutwater in
response to an angular sweep of the fluid being pumped; and the end
of passage for the upper cutwater being dimensioned with an upper
cutwater passage area that is greater than and not equal to a
corresponding lower cutwater passage area of the corresponding end
of passage for the lower cutwater so that upper and lower cutwater
passage areas at the pump discharge are balanced as a function of
differing rates of flow of the fluid being pumped therein and so
that the fluid being pumped from associated ends of the upper and
lower cutwater passage areas meets at the pump discharge with a
substantially equal velocity.
2. A volute according to claim 1, wherein the upper cutwater and
the lower cutwater are radially displaced at an angle .alpha. that
is substantially less than 180.degree..
3. A volute according to claim 1, wherein the upper cutwater and
the lower cutwater are radially displaced at an angle .alpha. that
is in a range of between 100.degree. and 120.degree..
4. A volute according to claim 1, wherein the upper cutwater and
the lower cutwater are radially displaced at an angle .alpha. that
is in a range of between about 108.degree. and about
110.degree..
5. A volute according to claim 1, wherein the volute forms part of
a double volute pump having an impeller with impeller vanes and
being arranged in one of the double volutes in the volute or
casing.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims benefit to provisional patent
application Ser. No. 62/213,739, filed 3 Sep. 2015, which is hereby
incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a volute for a pump; and
more particularly relates to a pump having an improved volute
design.
[0004] 2. Brief Description of Related Art
[0005] FIG. 1 shows a normal or conventional dual volute V.sub.pa
having a volute wall V.sub.wall with a pump inlet represented by
the label i and a pump outlet or discharge represented by the label
o. The conventional dual volute V.sub.pa includes a casing vane
CV.sub.pa formed therein, which has a lower cutwater c1 and an
upper cutwater c2 that are arranged on an axis A.sub.c1, c2 on
opposite sides of the volute wall V.sub.wall and about 180.degree.
apart in a radial separation, e.g., consistent with that shown in
FIG. 1. In FIG. 1, the radial degrees of 0.degree., 90.degree.,
180.degree., 270.degree. are indicated to provide the reader with
an angular radial frame of reference. FIG. 1 also includes a
circular dashed line Iv that represents the impeller's outer
peripheral vane surface. FIG. 1 also shows the circled reference
label 1 as a lower cutwater throat area, the circled reference
label 2 as an upper cutwater throat area, the circled reference
label 3 as an end of passage for lower cutwater C1, and the circled
reference label 4 as an end of passage for upper cutwater c2. In
FIG. 1, for the conventional double volute V.sub.pa the areas
labeled 1 and 2 are equal, and these lower and upper cutwaters c1
and c2 are effectively arranged diametrically opposed.
[0006] In the prior art, and consistent with that shown in FIG. 1,
the normal double volute V.sub.pa utilizes a typical 180 degree
opposed casing cutwaters c1 and c2 of equal section area labeled 1
and 2 respectively. In other words, FIG. 1 shows that for the
conventional double volute V the sectional areas labeled 1 and 2
formed between the cutwaters c1 and c2 of the casing vane CV.sub.pa
and the volute wall V.sub.wall are substantially equal, and the
associated cutwaters c1 and c2 are substantially diametrically
opposed. These substantially equal sectional areas labeled 1 and 2
respectively are understood to be the minimum area as measured from
the furthest radial edge of the cutwaters C1 and c2 to the next
portion of the vertical wall V.sub.wall of the volute V.sub.pa.
This sectional area is known as the casing throat area.
[0007] One disadvantage of the known volute design V.sub.pa, e.g.,
like that shown in FIG. 1, is that the development of the opposed
casing tongues results in a long passage length for cutwater
farthest away from the pump discharge o, otherwise know as the
upper cutwater C2. This long length adds complexity to the casing
and increases the difficulty to properly clean the casting. This
results in additional costs, and if not properly cast and cleaned
will result in loss of pump performance.
[0008] In view of this, there is a need for a better double volute
design.
SUMMARY OF THE INVENTION
[0009] The present invention provides a new volute design that
reduces the radial load on the impeller by establishing an improved
pressure balance through the operating flow range of a rotodynamic
pump.
[0010] By way of example, and according to some embodiment, the
present invention may be characterized by the total throat section
area required by the volute not being distributed equally as in the
conventional known double volute (see FIG. 1). The velocities being
controlled by these equal sectional areas are also equal as half
the pump flow passes through each passage. The area of the throat
section of the upper cutwater is increased as a function of the
angular sweep as measured along the volute centerline from the
cutwater closest to the discharge. As a result of the angular
sweep, the rate of flow in this passage is greater than that of a
conventional volute (e.g., see FIG. 1). Conversely, the throat area
of the cutwater closest to the pump discharge, i.e., the lower
cutwater, is reduced as a function of the angular sweep from the
upper to the lower cutwater, the rate flow in this passage is
reduced. In the present invention, these unequal sectional areas
continue to provide roughly equal velocities at both upper and
lower cutwaters.
[0011] The area of the two passages at the pump discharge is also
balanced as a function of the differing rates of flow within these
two passages.
[0012] It is also established so that the velocity at the end of
these two passages, e.g., where they meet in the pump discharge, is
substantially equal. In effect, the solution according to the
present invention reduces the length of the passage of the upper
cutwater furthest away from the pump discharge and increases the
size of its associated passage.
[0013] Both these features improve the casting quality, reducing
the potential of foundry defects while still providing a pressure
balance and reducing the resultant radial load over the operating
range of the pump.
[0014] Additionally, losses through the casing are reduced as a
result of the reduction of fluid friction from the shorter passage
and the ability to better match velocities of the two passages at
the pump discharge. In effect, the present invention reduces the
cost and improves the quality of the cast volute.
[0015] Moreover, in the case of a split case pump, where the volute
is formed in two halves, the upper half is greatly simplified as it
has no cutwater and the portion of the passage contained in it,
thus reducing the cost of the core, simplifying the cleaning and
the tooling required to manufacture the casing half, and reducing
the cost to produce the casting.
Specific Embodiments
[0016] According to some embodiment of the present invention may
include, or take the form of, a volute for a pump, e.g., such as a
double volute pump, having the following features: [0017] a volute
wall; [0018] a pump inlet for receiving a fluid being pumped;
[0019] a pump discharge for providing the fluid being pumped; and
[0020] a casing vane configured on the volute wall.
[0021] The casing vane may be configured to form double volutes in
the volute, configured with an upper cutwater farthest from the
pump discharge defining an upper cutwater throat area and an end of
passage for the upper cutwater, and also configured with a lower
cutwater closest to the pump discharge defining a lower cutwater
throat and a corresponding end of passage for the lower
cutwater.
[0022] The upper cutwater throat area may be dimensioned to be
greater than and not equal to the lower cutwater throat area so
that the upper cutwater throat area and the lower cutwater throat
area provide substantially equal flow velocity at both the upper
cutwater and the lower cutwater in response to an angular sweep of
the fluid being pumped.
[0023] The end of passage for the upper cutwater may be dimensioned
with an upper cutwater passage area that is greater than and not
equal to a corresponding lower cutwater passage area of the
corresponding end of passage for the lower cutwater so that upper
and lower cutwater passage areas at the pump discharge are balanced
as a function of differing rates of flow of the fluid being pumped
therein and so that the fluid being pumped from associated ends of
the upper and lower cutwater passage areas meets at the pump
discharge with a substantially equal velocity.
[0024] According to some embodiments, the upper cutwater and the
lower cutwater may be radially displaced at an angle .alpha. that
is in a range of between about 108.degree. and about
110.degree..
[0025] Embodiments are also envisioned in which the upper cutwater
and the lower cutwater may be radially displaced at an angle
.alpha. that is substantially less than 180.degree., e.g.,
consistent with that set forth herein.
[0026] Embodiments are also envisioned in which the upper cutwater
and the lower cutwater may be radially displaced at an angle
.alpha. that is in a range of between 90.degree. and 120.degree.,
e.g., also consistent with that set forth herein.
[0027] The volute may be configured as part of a double volute
pump, e.g., that may include an impeller having impeller vanes and
being arranged in one of the double volutes in the casing.
[0028] In effect, for the present invention, the total sum of both
the upper and lower casing throats are similar to that of the
conventional double volute in FIG. 1, but are distributed as the
included angle of the radial sweep.
[0029] Similar velocities are maintained at the throat section but
are not necessarily equal. The net radial loads acting on the
impeller are reduced by the maintenance of the velocities and the
pressure balance with in the volute. The exit areas are also
distributed in the fraction of the flow rate and are controlled to
provide an equal velocity at the end of the passages in the pump
discharge.
BRIEF DESCRIPTION OF THE DRAWING
[0030] The drawing, which is not necessarily drawn to scale,
includes the following Figures:
[0031] FIG. 1 shows a volute for a pump that is known in the
art.
[0032] FIG. 2 shows a new and improved volute for a pump, according
to some embodiments of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 2: The Basic Invention
[0033] FIG. 2 shows the present invention, e.g. in the form of a
volute V.sub.I for configuring in relation to a pump (not shown),
such as a double volute pump. The volute V.sub.I may include one or
more of the following features: [0034] a volute wall V.sub.wall;
[0035] a pump inlet i (in) for receiving a fluid being pumped;
[0036] a pump discharge o (out) for providing the fluid being
pumped; and [0037] a casing vane CV.sub.I.
[0038] The casing vane CV.sub.I may be configured on the volute
wall V.sub.wall forming double volutes in the volute V.sub.I and
being configured with an upper cutwater C.sub.2 farthest from the
pump discharge o defining an upper cutwater throat area labeled 2'
(in a circle) and an end of passage 4' (in a circle) for the upper
cutwater C.sub.2, and also configured with a lower cutwater C.sub.1
closest to the pump discharge o defining a lower cutwater throat
labeled 1' (in a circle) and a corresponding end of passage 3' (in
a circle) for the lower cutwater C.sub.1.
[0039] The upper cutwater throat area label 2' (in a circle) may be
dimensioned to be greater than and not equal to the lower cutwater
throat area labeled 1' (in a circle) so that the upper cutwater
throat area labeled 2' (in a circle) and the lower cutwater throat
area labeled 1' (in a circle) provide substantially equal flow
velocity at both the upper cutwater C.sub.2 and the lower cutwater
C.sub.1 in response to an angular sweep of the fluid being
pumped.
[0040] The end 4' of passage for the upper cutwater C.sub.2 may be
dimensioned with an upper cutwater passage area that is greater
than and not equal to a corresponding lower cutwater passage area
of the corresponding end of passage labeled 3' (in a circle) for
the lower cutwater C.sub.1 so that upper and lower cutwater passage
areas at the pump discharge are balanced as a function of differing
rates of flow of the fluid being pumped therein and so that the
fluid being pumped from associated ends of the upper and lower
cutwater passage areas labeled 3', 4' (in respective circle) meets
at the pump discharge o with a substantially equal velocity.
[0041] In FIG. 2, the upper cutwater C.sub.2 and the lower cutwater
C.sub.1 are shown to be radially displaced at an angle .alpha. that
is in a range of between about 108.degree. and about
110.degree..
The Angle .alpha.
[0042] Moreover, embodiments are envisioned, and the scope of the
invention is intended to include, using the upper cutwater C.sub.2
and the lower cutwater C.sub.1 radially displaced at an angle
.alpha. that is at least substantially less than 180.degree., so
that the fluid being pumped from associated ends of the upper and
lower cutwater passage areas labeled 3', 4' (in respective circle)
meets at the pump discharge o with a substantially equal velocity.
Moreover, embodiments are envisioned, and the scope of the
invention is intended to include, using the upper cutwater C.sub.2
and the lower cutwater C.sub.1 radially displaced at an angle
.alpha. that is in a range of between 100.degree. and 120.degree.,
so that the fluid being pumped from associated ends of the upper
and lower cutwater passage areas labeled 3', 4' (in respective
circle) meets at the pump discharge o with a substantially equal
velocity. In other words, the scope of the invention is intended to
include, embodiments having non-diametrically opposed radially
displaced upper cutwater C.sub.2 and the lower cutwater C.sub.1,
for example, that are not radially displaced at any specific angle
.alpha. that is in the range of between about 108.degree. and about
110.degree., but where the fluid being pumped from associated ends
of the upper and lower cutwater passage areas labeled 3', 4' (in
respective circle) meets at the pump discharge o with a
substantially equal velocity.
Applications
[0043] By way of example, possible applications of the present
invention may include the following:
[0044] Pumps,
[0045] Fans,
[0046] Blowers, and
[0047] Compressors.
The Scope of the Invention
[0048] Further still, the embodiments shown and described in detail
herein are provided by way of example only; and the scope of the
invention is not intended to be limited to the particular
configurations, dimensionalities, and/or design details of these
parts or elements included herein. In other words, one skilled in
the art would appreciate that design changes to these embodiments
may be made and such that the resulting embodiments would be
different than the embodiments disclosed herein, but would still be
within the overall spirit of the present invention.
[0049] It should be understood that, unless stated otherwise
herein, any of the features, characteristics, alternatives or
modifications described regarding a particular embodiment herein
may also be applied, used, or incorporated with any other
embodiment described herein. Also, the drawings herein are not
drawn to scale.
[0050] Although the invention has been described and illustrated
with respect to exemplary embodiments thereof, the foregoing and
various other additions and omissions may be made therein and
thereto without departing from the spirit and scope of the present
invention.
* * * * *