WO2016022781A2

WO2016022781A2 - Impeller with axially curving vane extensions to prevent airlock

Info

Publication number: WO2016022781A2
Application number: PCT/US2015/043982
Authority: WO
Inventors: Jeffrey D. Lopes
Original assignee: Flow Control Llc.
Priority date: 2014-08-06
Filing date: 2015-08-06
Publication date: 2016-02-11
Also published as: EP3177834A4; EP3177834A2; CN106715915B; CN106715915A; CA2957279C; CA2957279A1; AU2015300990A1; AU2019203725B2; WO2016022781A3; US20160186758A1; MX2017001588A; SA517380848B1; AU2019203725A1

Abstract

A pump has a housing that includes an inlet to receive a liquid to be pumped, an outlet to provide the liquid being pumped, a pumping chamber between the inlet/outlet; and a motor shaft to rotate in the pumping chamber. The impeller is arranged on the motor shaft, includes radially curved vanes to rotate inside the pumping chamber to pump the liquid from the pumping chamber to the outlet; and includes anti-airlock vanes formed as a set of axially curving vane extensions that 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 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 to generate pressure to force entrapped air from the pumping chamber.

Description

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 (91 1 -017.043-1 //M-RLE-X0014), filed 6 August 2014, which is

incorporated by reference in their entirety.

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 1 1 . 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. 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 1 1 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 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, 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 ^~bt

y = D * sin( £) * e^→c _ancj

z = h - ct " 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. 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.

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. 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 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). 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 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 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 , 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 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- 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 - * cos (at) * e^~bt

y = D * sin(at) * e^~'^jt _ancj

z = h - ctⁿ

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, 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 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.

Claims

WHAT IS CLAIMED IS:

1 . Apparatus comprising:

an anti-airlock impeller configured to be mounted on a motor shaft, 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,

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.

2. Apparatus according to claim 1 , wherein the set of axially curving vane extensions are 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:

A' = D * cosf at) * e ^~bt

y = D * sm(cEf) * _and

z = h— ctⁿ 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.

3. Apparatus according to claim 1 , wherein the radially curving vanes are 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 is configured to force the liquid below the pump to move axially into the pumping chamber and into the radially curving vanes to be pumped.

4. Apparatus according to claim 1 , wherein the apparatus comprises the housing having the inlet configured to receive the liquid to be pumped, the outlet configured to provide the liquid being pumped, the pumping chamber formed therein between the inlet and the outlet; and the motor shaft configured to rotate in relation to the pumping chamber.

5. Apparatus according to claim 1 , wherein the apparatus comprises a centrifugal pump.

6. A pump comprising:

a housing having 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; and

an anti-airlock impeller configured on the shaft, the anti-airlock impeller having 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 also having 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.

7. A pump according to claim 6, wherein the set of axially curving vane extensions are 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:

A' = D * cosf at) * e ^~bt

y = D * sm(cEf) * _and

z = h— ctⁿ 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.

8. A pump according to claim 6, wherein the radially curving vanes are 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 is configured to force the liquid below the pump to move axially into the pumping chamber and into the radially curving vanes to be pumped.

9. A pump according to claim 6, wherein the pump is a centrifugal pump.

10. A centrifugal pump comprising:

submerging in any liquid to be pumped underneath the centrifugal 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;

the radially curving vanes are 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 is configured to force the liquid below the centrifugal pump to move axially into the pumping chamber and into the radially curving vanes to be pumped; and

the set of axially curving vane extensions being 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^~bc _^

y = D * sin( t) * and

z = h— ctⁿ 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.

1 1 . Apparatus according to claim 1 , wherein the set of axially curving vane extensions are configured with an axial vane curvature that is generated through the use of parametric equations in a Cartesian x, y, z, coordinate system.

12. Apparatus according to claim 1 1 , wherein the parametric equations in the

Cartesian x, y, z, coordinate system include t as a sweep parameter.

13. A pump according to claim 6, wherein the set of axially curving vane extensions are configured with an axial vane curvature that is generated through the use of parametric equations in a Cartesian x, y, z, coordinate system.

14. Apparatus according to claim 13, wherein the parametric equations in the Cartesian x, y, z, coordinate system include t as a sweep parameter.