Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
1
IMPELLER WITH AXIALLY CURVING VANE EXTENSIONS
TO PREVENT AIRLOCK
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims benefit to provisional patent application serial no.
62/033,814 (911-017.043-1//M-RLE-X0014), filed 6 August 2014.
BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates to a pump; and more particularly to a
centrifugal
pump having an impeller with vanes for pumping liquid.
2. Description of Related Art
Generally, in a centrifugal pump fluid is accelerated through centrifugal
forces
exerted on it by an impeller. The impeller is a rotating disk driven by a
motor whose
front side has vanes protruding from it that transmit energy to the fluid
being
pumped. The impeller's vanes typically extend close to the inner casing of the
pump
body near the pump's inlet, e.g., as shown in Figure 1.
In particular, Figure 1 shows an example of one known centrifugal pump
generally indicated as P1 having an impeller 2 with radially curved vanes 11.
In the
pump P1, the pumping process will most likely fail when the pump's impeller 2
is not
fully submerged in liquid when it begins rotating. The situation in which this
is likely
to occur is when air becomes trapped in the pump P1. This situation is called
or
known as an airlock situation.
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As shown in Figure 2, airlock can occur when liquid from a previous pumping
cycle remains in a dip 8 (Fig. 2B) in the piping of the discharge piping
system S of
the centrifugal pump P1, but is no longer in the pump chamber 13 of the
housing 7 of
the centrifugal pump P1 itself. For example, compare that shown in Figs. 2A
and 2B,
where the pump P1 in Fig. 2A can push water through the discharge system S
that
includes the piping having one or more dips 8; and the pump P1 in Fig. 2B has
water
trapped in one "dip" 8 between pumping cycles that causes the pump P1 to
airlock,
since air is trapped upstream of the "dip" 8 that prevents water to be pumped
from
entering through the inlet 1 and into the pump chamber or cavity 13 (Figure 1)
of the
pump P1. (In other words, the water outside the pump P1 cannot displace
through
the discharge system S the air trapped in the pump chamber 13.) Because of
this,
the pump's impeller 2 in Fig. 2B is not touching, and cannot touch, any liquid
in the
pump chamber 13, and therefore can't force the trapped air out of the pump P1.
The
impeller 2 will remain spinning in the air indefinitely, and the pump P1 will
fail to
perform its intended purpose.
During normal operation, in the typical centrifugal pump configuration shown
in Figure 1 liquid enters through the inlet 1 and is accelerated by the
impeller 2 to its
periphery due to centrifugal forces caused by the rotation of the impeller 2
from the
action of the motor shaft 6 which is driven by the motor 5. The main flow of
the liquid
.. exits through the outlet 4 to the discharge system shown in Figure 2.
However, in
order for the pumping process to occur, the radially curving vanes 11 must be
physically submerged in some liquid in the pumping chamber or cavity 13 . In
situations such as that shown and described in relation to Fig. 2B, liquid
pumped out
from the pump P1, e.g., during the previous pumping cycles, can become trapped
in
the piping of the discharge system S. As shown in Fig. 2B, the liquid from a
previous
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pumping cycle has become physically trapped in the "dip" 8 in the outlet hose.
This
trapped liquid in the dip 8 prevents air from exiting the outlet 4 of the pump
P1 and
traps air inside of the pump chamber or cavity 13, which is effectively
composed of
the inside of the pump housing or body 7 and that portion of the hose upstream
of
the trapped liquid. This cavity of trapped air prevents the typical
centrifugal pump
impeller 2 from contacting the liquid below the pump P1 and beginning the
pumping
process, e.g., consistent with the situation shown in Figure 5.
In view of the aforementioned, there is a need in the art for a pump having a
better impeller design that overcomes the aforementioned "airlock" problems
with the
known impeller designs.
SUMMARY OF THE INVENTION
The Impeller Equipped with Anti-airlock Axially Curved Vanes
According to some embodiments, the present invention may take the form of
apparatus featuring a new and unique anti-airlock impeller configured to be
mounted
on a motor shaft of a pump, the anti-airlock impeller having radially curved
vanes
configured to rotate inside a pumping chamber of a housing of the pump to pump
liquid from the pumping chamber to an outlet of the pump, the anti-airlock
impeller
also having anti-airlock vanes formed as a set of axially curving vane
extensions
configured to
extend along an axis of the motor shaft,
rotate with one part configured inside the pumping chamber,
protrude through the inlet and rotate with another part configured
outside the inlet for submerging in any liquid to be pumped underneath the
pump,
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draw the liquid through the inlet into the pumping chamber, and
provide the liquid to the radially curved vanes in order to generate
pressure to force any entrapped air out of the pumping chamber of the
housing.
The present invention may also include one or more of the following features:
The set of axially curving vane extensions may be configured with an axial
vane curvature that is generated through the use of parametric equations in a
Cartesian x, y, z, coordinate system. By way of example, the set of axially
curving
vane extensions may be defined by parametric equations in a Cartesian x, y, z,
coordinate system with t as a sweep parameter, using a set of equations as
follows:
x = D cos(at) * e-ht
y D sin(at)* e- b t , and
z = h ¨ an ,
where:
a, b, c, and n are constants that depend on the particular impeller,
D is the shaft hub diameter, and
h is the extension length.
The radially curving vanes may be configured to provide pumping power for
providing the liquid to be pumped from the pumping chamber to the outlet, and
the
set of axially curving vane extensions may be configured to force the liquid
below the
pump to move axially into the pumping chamber and into the radially curving
vanes
to be pumped.
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Combination of Pump and Anti-airlock Impeller
According to some embodiments, the present invention may take the form of
an apparatus such as a pump featuring a housing in combination with the new
and
unique anti-airlock impeller.
5 The housing may include an inlet configured to receive a liquid to be
pumped,
an outlet configured to provide the liquid being pumped, a pumping chamber
formed
therein between the inlet and the outlet; and a shaft configured to rotate in
relation to
the pumping chamber.
Consistent with that set forth above, the anti-airlock impeller may be
configured on the shaft, and may include radially curved vanes configured to
rotate
inside the pumping chamber to pump the liquid from the pumping chamber to the
outlet. The anti-airlock impeller may also include anti-airlock vanes formed
as a set
of axially curving vane extensions configured to extend along the axis of the
shaft,
rotate with one part inside the pumping chamber, protrude through the inlet
and
rotate with another part outside the inlet for submerging in any liquid to be
pumped
underneath the pump, draw the liquid through the inlet into the pumping
chamber,
and provide the liquid to the radially curved vanes in order to generate
pressure to
force any entrapped air out of the pumping chamber of the housing.
In operation, the set of axially curving vane extensions is configured to
extend
out of the inlet of the housing and cannot be subjected to a trapped air
situation
inside the pumping chamber or cavity of the pump.
The pump may be a centrifugal pump.
According to some embodiments, the present invention may take the form of
an apparatus that includes some combination of the aforementioned features.
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One advantage of the present invention is that it provides a better impeller
design for a pump that overcomes the aforementioned airlock problems with the
known impeller designs. For example, the impeller design according to the
present
invention features the anti-airlock vanes that protrudes out from the bottom
of the
.. pump body or housing, which solves the airlock problem that some pumps
might
otherwise experience using the known impeller designs. Because of this, the
impeller design according to the present invention provides an important
contribution
to the state of the art.
BRIEF DESCRIPTION OF THE DRAWING
The drawing includes Figures 1-8, which are not necessarily drawn to scale,
as follows:
Figure 1 shows a typical centrifugal pump configuration that is known in the
art.
Figure 2 includes Figs. 2A and 2B, where Fig. 2A shows a pump positioning
that is likely to cause airlock that is known in the art; and where Fig. 2A
shows the
pump in Fig. 2A in an airlock situation.
Figure 3 includes Figs. 3A and 3B each showing a typical impeller having only
radially curving vanes interior to a pump housing that is known in the art,
where Fig.
3A shows a top view of the typical impeller; and where Fig. 3B shows a side
view of
the typical impeller.
Figure 4 includes Figs. 4A and 4B each showing an impeller equipped with
anti-airlock vanes, according to some embodiments of the present invention,
where
Fig. 4A shows a top view of the impeller equipped with the anti-airlock vanes,
according to some embodiments of the present invention; and where Fig. 4B
shows
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a side view of the impeller equipped with the anti-airlock vanes, according to
some
embodiments of the present invention.
Figure 5 shows a partial cross-sectional view of a bottom part of a pump
having a pump housing with the typical impeller like that shown in Figure 3
configured therein, which results in the radially curving vanes interior to
the pump
housing "spinning in air" in an airlock situation.
Figure 6 shows a partial cross-sectional view of a bottom part of a pump
having a pump housing with the impeller equipped with the anti-airlock vanes
like
that shown in Figure 4 configured therein, where the axially curving vanes
extensions protrude from a bottom opening in the pump housing, e.g., into
water
underneath the pump.
Figure 7 shows a side view of a pump having a pump housing with the typical
impeller like that shown in Figures 3 and 5 that is completely enclosed inside
the
pump body or housing.
Figure 8 shows a side view of a pump having a pump housing with the
impeller equipped with the anti-airlock vanes like that shown in Figures 4 and
6 that
protrude out from the bottom of the pump body or housing.
DETAILED DESCRIPTION OF BEST MODE OF THE INVENTION
Figures 4, 6 and 8
As shown in Figures 4, 6 and 8, the present invention may include, or take the
form of, an anti-airlock impeller generally indicated as 20 (Figure 4) for
configuring in
a pump generally indicated as P2 (Figures 6 and 8), having a housing 7
(Figures 6
and 8).
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The housing 7 may include an inlet 1 configured to receive a liquid to be
pumped, an outlet 4 configured to provide the liquid being pumped, a pumping
chamber 13 formed therein between the inlet 1 and the outlet 4; and a motor
shaft 6
configured to rotate in relation to the pumping chamber 13, e.g., all as shown
in
Figure 6.
The anti-airlock impeller 20 may be configured on the motor shaft 6, and may
include radially curved vanes generally indicated as 22 configured to rotate
inside
the pumping chamber 13 to pump the liquid from the pumping chamber 13 to the
outlet 4 (Figure 8). In Figure 4, the impeller 20 is shown with a base portion
21, and
the radially curved vanes 22a, 22b, 22c, 22d, 22e.
The anti-airlock impeller 20 may also include anti-airlock vanes generally
indicated as 24 formed as a set of axially curving vane extensions 24a, 24b,
24c,
24d, 24e configured to extend along the axis A (Figure 6) of the motor shaft
6, rotate
with one part generally indicated as 24' (aka 24 w/ a single prime) inside the
pumping chamber 13, protrude through the inlet 1 and rotate with another part
24"
(aka 24 w/ a double prime) outside the inlet 1 for submerging in any liquid to
be
pumped that is underneath the pump P2, draw the liquid through the inlet 1
into the
pumping chamber 13, and provide the liquid to the radially curved vanes 22a,
22b,
22c, 22d, 22e in order to generate pressure to force any entrapped air out of
the
pumping chamber 13 of the housing 7.
By way of example, the radially curved vanes 22a, 22b, 22c, 22d, 22e may be
configured to curve radially from the periphery or outer rim of the anti-
airlock impeller
20, spiral inwardly towards the center of the anti-airlock impeller 20 and the
axis A of
the motor shaft 5, and meet the axially curving vane extensions 24a, 24b, 24c,
24d,
24e, e.g., as shown in Figure 4A. In comparison, and by way of example, the
axially
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curving vane extensions 24a, 24b, 24c, 24d, 24e may be configured to curve
axially
and spiral about or in relation to the axis A of the motor shaft 5, and extend
outwardly from the inlet 1 of the housing 7, e.g., as shown in Figure 4A.
In Figure 4, the anti-airlock impeller 20 is shown with five (5) radially
curved
vanes and five (5) axially curving vane extensions, although the scope of the
invention is not intended to be limited to the number of radially curved vanes
and/or
axially curving vane extensions. For example, embodiments are envisioned in
which, and the scope of the invention is intended to include, the anti-airlock
impeller
20 having more or less than five radially curved vanes and/or axially curving
vane
extensions, e.g., including either four radially curved vanes and/or four
axially
curving vane extensions, or six radially curved vanes and/or six axially
curving vane
extensions, etc. By way of further example, embodiments are envisioned in
which,
and the scope of the invention is intended to include, the anti-airlock
impeller 20 may
include a different number of radially curved vanes than axially curving vane
extensions, e.g., including either four radially curved vanes and/or five
axially curving
vane extensions, or five radially curved vanes and/or four axially curving
vane
extensions, etc.
In operation, according to some embodiments of the present invention the
pump P2 may include the anti-airlock impeller 20 having the extension or part
24"
protruding out through the inlet 1 of the pump P2 so as to be in contact with
liquid
underneath the pump P2 regardless of air that may be entrapped within the pump
P2. This extension or part 24" may be configured with the axially curving
vanes 24a,
24b, 24c, 24d, 24e which draw or force the liquid to move axially (e.g., in
relation to
the axis A) into the pump chamber 13, e.g., as shown in Figure 6. Once the
liquid is
inside the pump chamber 13, the radially curving vanes 22a, 22b, 22c, 22d, 22e
can
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generate enough pressure to force the trapped air out of the pumping system
and
the pump P2 can operate normally.
The set of axially curving vane extensions 24a, 24b, 24c, 24d, 24e may be
configured to protrude out from below the pump P2 out through the pump inlet
1,
5 .. e.g., consistent with that shown in Figures 6 and 8. The axially curving
vane
extensions 24a, 24b, 24c, 24d, 24e protrude out of the pump inlet 1 for
submerging
into any water that may be below the pump P2, e.g., as shown in Figure 6.
These
axially curving vane extensions 24a, 24b, 24c, 24d, 24e force the water below
the
pump P2 to move axially into the pumping chamber 13 and into the radially
curving
10 .. vanes 22a, 22b, 22c, 22d, 22e. This anti-airlock impeller 20 effectively
submerges
them and allows them to generate enough pressure to force any entrapped air
out of
the pumping system. Figures 7 and 8 show respectively an exterior view of a
pump
P1 equipped with a typical impeller that is completely enclosed inside the
pump body
and not shown and the anti-airlock impeller 20 having the extension or part
24" that
protrudes out from the bottom of the pump P2, according to some embodiments of
the present invention respectively.
The Length of Extending Part 24"
The scope of the invention is not intended to be limited to any particular
length
.. or amount that the extension or part 24" of the anti-airlock impeller 20
extends or
protrudes out from the bottom of the pump P2. For example, depending on the
particular application, the extension or part 24" of the anti-airlock impeller
20 may be
configured to extend or protrude more or less out from the bottom of the pump
P2.
In particular, in some applications, embodiments are envisioned in which, and
the
scope of the invention is intended to include, the extension or part 24" of
the anti-
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airlock impeller 20 configured to extend or protrude about one inch out from
the
bottom of the pump P2; in other applications, embodiments are envisioned in
which,
and the scope of the invention is intended to include, the extension or part
24" of the
anti-airlock impeller 20 configured to extend or protrude more than one inch
(e.g.,
two inches) out from the bottom of the pump P2; and in still other
applications,
embodiments are envisioned in which, and the scope of the invention is
intended to
include, the part 24" of the anti-airlock vane extension impeller 20
configured to
extend or protrude less than one inch out from the bottom of the pump P2.
The Axial Vane Curvature
The set of axially curving vane extensions may be configured with an axial
vane curvature that is generated through the use of parametric equations in a
Cartesian x, y, z, coordinate system. By way of example, the axial vane
curvature
can be generated through the use of the below parametric equations in a
Cartesian
x, y, z, coordinate system with t as the sweep parameter:
x = D * cos(at) * ,
y = D sin(at)* e¨bc, and
z = h ¨
Where:
a, b, c, and n are constants that depend on the particular impeller,
D is the shaft hub diameter, and
h is the extension length.
However, the scope of the invention is not intended to be limited to the
aforementioned axial vane curvature, or any particular axial vane curvature
that is
now known, or any particular predetermined parametric equations in the
Cartesian x,
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y, z coordinate system. For example, embodiments are envisioned, and the scope
of the invention is intended to include, using other axial vane curvatures
that are now
known or later developed in the future, as well as other predetermined
parametric
equations in the Cartesian x, y, z coordinate system, within the spirit of the
underlying invention.
Other Components of the Pump P2
As a person skilled in the art would appreciate, the pump P2 includes other
components showing in the drawing that do not form per se part of the
underlying
invention, and thus are described in detail. For example, the other components
may
include the shaft seal 3, the motor 5, the motor shaft 6 and/or a fastener 6a
for
coupling the anti-airlock impeller 20 to the motor shaft 6 of the motor 5,
e.g., as
shown in Figure 6. These other components are known in the art, and the scope
of
the invention is not intended to be limited to any particular type or kind
thereof that is
either now known or later developed in the future.
Possible Applications:
Possible applications include: any centrifugal pump which may be used in a
situation in which it can airlock.
The Scope of the Invention
While the invention has been described with reference to an exemplary
embodiment, it will be understood by those skilled in the art that various
changes
may be made and equivalents may be substituted for elements thereof without
departing from the scope of the invention. In addition, modifications may be
made to
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adapt a particular situation or material to the teachings of the invention
without
departing from the essential scope thereof. Therefore, it is intended that the
invention not be limited to the particular embodiment(s) disclosed herein as
the best
mode contemplated for carrying out this invention.
