Self-priming adapter apparatus and method

Abstract

Some embodiments of the invention provide a self-priming adapter system including a pump inlet receiving liquid mixed with air, a pump coupled to the pump inlet, and a self-priming adapter coupled to the pump. The self-priming adapter includes a separation chamber. The separation chamber includes one or more baffles to substantially separate the air from the liquid. The self-priming adapter system also includes a recirculation line coupled to the self-priming adapter to return the liquid to the pump inlet. Some embodiments of the invention provide a self-priming adapter for use with existing pumps of any type. Some embodiments of the invention provide a method of self-priming a pump using a self-priming adapter.

Description

RELATED APPLICATIONS

This application claims priority under 35 U.S.C. § 119 to U.S. Provisional Patent Application No. 60/841,295 filed on Aug. 30, 2007, the entire disclosure of which is incorporated herein by reference.

BACKGROUND

Centrifugal pumps are often used in agricultural sprayer systems to pump liquid from a tank to a boom for distribution. Centrifugal pumps can be subject to air locks due to loss of prime. Self-priming pumps have been designed to attempt to increase the priming capabilities of centrifugal pumps. However, conventional self-priming pumps include complex and heavy castings that serve as the input manifold of the centrifugal pump. Also, conventional self-priming pumps generally must be mounted vertically, which limits the configurations in which the pump can be installed. In addition, conventional self-priming pumps generally lower the performance of the pump to below its standard performance level.

SUMMARY

Some embodiments of the invention provide a self-priming adapter system including a pump inlet receiving liquid mixed with air, a pump coupled to the pump inlet, and a self-priming adapter coupled to the pump. The self-priming adapter includes a separation chamber. The separation chamber includes one or more baffles to substantially separate the air from the liquid. The self-priming adapter system also includes a recirculation line coupled to the self-priming adapter to return the liquid to the pump inlet. Some embodiments of the invention provide a self-priming adapter for use with existing pumps of any type. Some embodiments of the invention provide a method of self-priming a pump using a self-priming adapter.

Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a self-priming adapter system according to one embodiment of the invention.

FIG. 2 is a side view of the self-priming adapter system of FIG. 1.

FIG. 3 is a perspective view of a self-priming adapter system according to another embodiment of the invention.

FIGS. 4A, 4B, and 4C are perspective, front, and side views of a separation chamber for use with the self-priming adapter system of FIGS. 1 and 2.

FIG. 5 is a perspective view of a self-priming adapter system according to another embodiment of the invention.

FIG. 6 is another perspective view of the self-priming adapter system of FIG. 5.

FIG. 7 is a partial cross-sectional front view of the self-priming adapter system of FIGS. 5 and 6.

FIG. 8 is a partial cross-sectional perspective view of the self-priming adapter system of FIGS. 5 and 6.

FIG. 9 is a partial cross-sectional front view of a self-priming adapter system including a check valve.

FIGS. 10A, 10B, 10C, and 10D are perspective, top, cross-sectional side, side, and cross-sectional front views of a separation chamber according to one embodiment of the invention.

FIG. 11 is a front view of a separation chamber according to one embodiment of the invention including baffles and anti-vortex screens.

FIG. 12 is a graph of priming times for a self-priming adapter having two inch baffles according to one embodiment of the invention.

FIG. 13 is a graph of priming times for a self-priming adapter having anti-vortex screens according to one embodiment of the invention.

FIG. 14 is a data table that includes test priming rate data.

FIG. 15 is a graph of a self-priming rate of a pump fitted with the self-priming adapter of FIG. 5.

FIG. 16 is a graph of flow, liquid pump pressure, and rotational frequency over time for a pump fitted with a self-priming adapter.

FIG. 17 is a graph of pump lift capacity data for several pump models with and without self-priming adapter systems according to some embodiments of the invention.

DETAILED DESCRIPTION

Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings.

FIGS. 1 and 2 illustrate a self-priming adapter system 10 according to one embodiment of the invention. The self-priming adapter system 10 can include a pump 12, a self-priming adapter 14, a pump outlet 16, a recirculation line 18, a pump inlet 20, and an air outlet 22. In some embodiments, the self-priming adapter system 10 can also include a recirculation valve 24, a pump outlet valve 26, a liquid tank inlet valve 28, a fill line valve 30, and a tank valve 32. In some embodiments, the self-priming adapter system 10 can also include a clean liquid tank line 34, a boom outlet line 36, a tank line 38, a pump outlet line 40, a fill line 42, and a self-priming adapter inlet line 44. In some embodiments, the self-priming adapter system 10 can include a number of connectors, such as T-fittings 46, 48, 50.

In some embodiments, the self-priming adapter system 10 can protect the pump 12 from a dry run condition. In some embodiments, an automated system (not shown) can be used to prevent dry-run conditions, which are detrimental to centrifugal pumps. In some embodiments, the self-priming adapter system 10 can be used with any centrifugal pump (such as an open or closed impeller centrifugal pump) to convert a standard pump to a self-priming pump 12. In some embodiments, the self-priming adapter system 10 can convert existing pumps to on-load sprayers. In some embodiments, the self-priming adapter system 10 can provide fast self-priming rates. The self-priming adapter 14 can be used with other suitable types of pumps, not only centrifugal pumps.

The self-priming adapter system 10 can provide a path for liquid (e.g., liquid) to circulate through the pump 12. The self-priming adapter 14 can include a separation chamber 54 that can allow entrained air to percolate out of the liquid being circulated and can release air back to the atmosphere. The liquid can return back to the pump inlet 20, in order to evacuate air from the pump inlet 20. In some embodiments, the self-priming adapter 14 can provide fast self-priming capabilities to any closed impeller centrifugal pump.

When circulated liquid enters the impeller of the pump 12 with air present, the air can be entrained into the liquid, increasing its volume. The liquid can then be carried through the pump 12 to the separation chamber 54. In some embodiments, the separator chamber 54 can hold enough volume of liquid to fill the cavity of the pump 12 and the pump inlet 20. When the pump 12 is restarted, liquid can circulate through the pump 12 and can be directed into the separator chamber 54, where the velocity of the liquid can be slowed to a point where air bubbles can percolate up to the top and out of the air outlet 22, thereby evacuating air from the pump inlet 20. In a properly-sized separation chamber 54, liquid flow can slow to the point where entrained air can percolate upward and out toward the atmosphere. The liquid can be pulled back toward the pump inlet 20, which may be at negative pressure. The separation chamber 54 can allow for recirculation of pumping liquids so that the pump inlet 20 can be evacuated of air. In other words, the separation chamber 54 is used to separate air bubbles from the liquid being circulated. In some embodiments, the self-priming adapter system 10 can be gravity fed to help avoid air locks in the lines.

Once all the air has been evacuated from the pump inlet 20 and the pump 12 has been primed, the recirculation line 18 can be closed. Once the recirculation line 18 is closed, the pump 12 can operate according to its normal pumping operation. If the recirculation line 18 is not closed, a large drop in performance output can occur.

By increasing the amount of liquid circulating through the self-priming adapter system 10, priming rates can be increased. Priming rates can range from no priming with circulation flow less than three gallons per minute to one foot per second in a two inch hose with 40 gallons per minute of circulation flow (e.g., see FIG. 16). The size/volume of the separator chamber 54 can be increased as the circulation flow increases. The size, shape, and position of the separator chamber 54 can be chosen to properly fill the pump 12 at startup. Also, in some embodiments, the size of a manifold of the pump 12 chosen for a particular application can be minimized in order to minimize the amount of liquid necessary to initiate priming and increase priming efficiency. In some embodiments, the self-priming adapter system 10 can allow for the pump 12 to be mounted in tight configurations. In some embodiments, various orientations of the pump 12 can be applied and the self-priming adapter 14 and its separator chamber 54 can be mounted some distance (e.g., three meters) away from the pump 12 while continuing to provide self-priming capabilities. Also, the volute leading to the pump outlet 16 can be rotated if desired for a particular configuration. In addition, the pump inlet 20 can be raised from the position that would be necessary for a conventional self-priming pump.

Optimal characteristics and designs of the separation chamber 54 can be developed, for example, using a formula for sizing the separation chambers 54 to meet pump 12 flow capacities. In some embodiments, as the pump 12 capacity increases, the amount of circulation flow required to achieve fast priming rates also increases. In some embodiments, the top of the separation chamber 54 can be mounted to be substantially level with a top portion of an impeller eye within the pump 12. In some embodiments, providing liquid to the pump inlet 20 at ten gallons per minute or more (e.g., liquid from a fresh liquid tank) can allow the pump to prime as well.

As shown in FIG. 2, in one embodiment, the maximum self-priming adapter 14 height can be substantially no higher than the bottom of the fill port in the fill line valve 30. Also, the minimum self-priming adapter 14 height can be substantially no lower than a top portion of the pump inlet 20 (e.g., a top portion of a casting on the pump inlet 20). In some embodiments, the maximum hose length between the pump 12 and the self-priming adapter 14 can be about three meters. In some embodiments, the air outlet 22 can have a minimum diameter of 25 mm. In some embodiments, the air outlet 22 can extend ½ meter above the self-priming adapter 14. However, in some embodiments, the air outlet 22 (or vent line) can be eliminated.

FIG. 3 illustrates another embodiment of a self-priming adapter system 10, including a pump 12, a self-priming adapter 14, a recirculation line 18, a vent line 22, a clean liquid tank line 34, a boom outlet line 36, a tank line 38, a fill line 42, and a self-priming adapter inlet line 44. In some embodiments, as shown in FIG. 3, “Y” fittings (e.g., 45 degree fittings) can be used to reduce pressure drop through the self-priming adapter system 10 for faster fill rates.

FIGS. 4A, 4B, and 4C illustrate a self-priming adapter 14 according to one embodiment of the invention. The self-priming adapter 14 can include a tank 52 that creates the separation or stilling chamber 54. In one embodiment, the tank 52 can be substantially cylindrical. The self-priming adapter 14 can include an inlet port 56, an outlet port 58, and an air vent port 60. The self-priming adapter 14 can also include one or more baffles 62. In one embodiment, a baffle 62 includes a first wall 64, a second wall 66, a back wall 68, and a floor 70. In one embodiment, the first wall 64 and the second wall 66 can be diagonal with respect to sides of the tank 52. Including baffles 62 in the separation chamber 54 can improve priming performance. In some embodiments, priming rates with baffles 62 can be two to three times faster than conventional self-priming pumps.

FIGS. 5-9 illustrate another embodiment of a self-priming adapter system 10, including a pump 12, a self-priming adapter 14, a pump outlet 16, a recirculation line 18, a pump inlet 20, and an air outlet 22. The self-priming adapter 14 can include a tank with substantially semi-circular sides. In some embodiments, the self-priming adapter 14 can include a flapper 72. The flapper 72 in the separation chamber 54 can prevent liquid from shooting through the separation chamber 54 during priming and can rotate to allow liquid to flow unobstructed out of the separator chamber 54 to a filter (not shown) and/or a boom (not shown).

FIG. 9 illustrates the self-priming adapter system 10 with a check valve 74 in the recirculation line 18. As shown in FIG. 9, the check valve 74 can be closed when the flapper 72 is open. In one embodiment, a tank line 38 (as shown in FIG. 1) can be coupled to a tank of an agricultural sprayer (not shown). When the tank of the agricultural sprayer becomes empty, the check valve 74 can open, allowing liquid to begin to circulate from the separator chamber 54 to the pump inlet 20. In some embodiments, once the pump 12 is primed, pressure can increase in the separation chamber 54. In some embodiments, a sensor (not shown) can sense the increased pressure and cause the check valve 74 to close the recirculation line 18 to the pump inlet 20. In some embodiments, the check valve 74 can operate at relatively low pressures (e.g., 20 PSI). In some embodiments, the check valve 74 can be a manual or electronic shut-off valve. In some embodiments, the self-priming adapter system 10 can automatically control the self-priming adapter 14 circulation with an electronic valve.

FIGS. 10A-10E illustrate a self-priming adapter 14 according to one embodiment of the invention. The self-priming adapter 14 can include a tank 52 that creates a separation or stilling chamber 54. In one embodiment, the tank 52 can include side walls having the shape of half an octagon. The self-priming adapter 14 can include an inlet port 56, an outlet port 58, and an air vent port 60. The self-priming adapter 14 can also include one or more baffles 62. In one embodiment, a baffle 62 includes a first wall 64, a second wall 66, and a floor 70. In some embodiments, the first wall 64 and the second wall 66 can be substantially vertical and can extend parallel to one another along the length of a top portion of the tank 52. In some embodiments, the self-priming adapter 14 can include suitable wall-mount brackets.

FIG. 11 illustrates another embodiment of a self-priming adapter 14, including one or more anti-vortex screens 76. The use of anti-vortex screens 76 can improve priming smoothness. In some embodiments, the anti-vortex screens 76 are removable for cleaning. FIG. 11 illustrates one embodiment of the invention in which the separation chamber 54 of the self-priming adapter 14 can include two inch baffles 62 and anti-vortex screens 76 at a four foot lift height. As shown in FIG. 11, air bubbles are generally confined to an upper portion of the separation chamber 54. However, without baffles 62, air bubbles are generally free to chum about and are easily entrained in the recirculation flow that is used for priming, resulting in surging and loss of priming capabilities. FIG. 12 illustrates a graph of priming times for a self-priming adapter having two inch baffles 62, while FIG. 13 illustrates a graph of priming times for a self-priming adapter that does not have baffles 62. A tray-like baffle 62 can be welded into the top portion of the self-priming adapter 14 to keep some of the violent air-entrained turbulence from pulsing toward the bottom of the self-priming adapter 14. Raising the sides of the baffle 62 to two inches can increase the smoothness of the priming operation, without decreasing priming times (e.g., see FIG. 12). Adding the anti-vortex screen 76 on a bottom portion of the self-priming adapter 14 can reduce priming times by 15 to 20 seconds, in some embodiments. Removing the baffle 62 can increase surging. Without a baffle 62, the pump 12 may not be able to prime at higher RPMs due to 6 foot surges in the pump inlet 20 (e.g., see FIG. 4).

In some embodiments, the self-priming adapter system 10 can be used to provide protection from pump failure due to unexpected dry-run conditions. For example, some embodiments of the self-priming adapter system 10 can function automatically to prevent dry-run conditions.

The self-priming adapter system 10 can be retrofitted to an existing pump, including most manufacturers' centrifugal pump products. The self-priming adapter system 10 can be retro-fitted to provide the same protection to positive displacement pumps. The self-priming adapter system 10 can allow existing sprayers to be retrofit and have self-priming capabilities for on-loading or on-board loading sprayer tanks.

The self-priming adapter system 10 can be used for mobile equipment that operates on steep grades (e.g., agricultural sprayers, DOT roadway de-icing equipment, etc.).

The self-priming adapter system 10 can provide a protective feature for unattended equipment everywhere (e.g., industrial applications).

The self-priming adapter system 10 can allow centrifugal pumps to be mounted in tight-fitted configurations, while maintaining priming capabilities. For example, the separator chamber 54 can be mounted in a nearby remote location and a volute or standard pump housing of the pump 12 can be rotated to increase the functionality of system design and maintain the benefit of reduced pressure loss in system plumbing.

In some embodiments, including a self-priming adapter system 10 does not compromise centrifugal pump performance due to the inefficiencies present in a conventional self-priming chamber. In other words, the pump 12 of the self-priming adapter system 10 maintains its standard performance levels. Complex, difficult, and heavy casting patterns for conventional self-priming chambers that must be mounted vertically are no longer needed with the self-priming adapter system 10, according to some embodiments of the invention.

One embodiment of the self-priming adapter system 10 was tested including a six meter (19.7 ft) priming lift height, a six meter hose length, a 50.6 mm (two inch) suction hose diameter, and a two minute maximum time to prime hose. A fork lift, cage, and a ten foot ladder were used to test the self-priming adapter system 10 to specifications that require a 22 foot height with 50 feet of two inch hose. Increasing the hose length can add approximately 30 to 40 seconds to overall priming time.

In one embodiment, the pump 12 can operate at 4000-5000 RPM for good priming. Slower speeds yield longer priming times, but can also yield smoother operation. Slowing down the RPM can stop a surging effect due to lower recirculation rates. In one embodiment, the self-priming adapter system 20 can include a 1¼ inch hose for the pump outlet 16, the recirculation line 18, and the pump inlet 20 in order to provide smooth operation. However, different sized hose can produce different priming speeds (e.g., faster or slower priming times) suitable for various applications.

FIG. 14 is a data table that includes test priming rate data for pumps and self-priming adapter systems 10 having multiple configurations. FIG. 16 illustrates a graph of flow, liquid pump pressure, and rotational frequency over time for a pump fitted with a self-priming adapter 14. FIG. 17 illustrates a graph of pump lift capacity data for several pump models with and without self-priming adapter systems 10. Curves 80, 82, 84, and 86 represent data for pumps used with a self-priming adapter system 10 according to some embodiments of the invention. Curves 90, 92, 94, and 96 represent data for conventional pumps and conventional self-priming pumps without the use of a self-priming adapter 14 according to some embodiments of the invention.

Various features and advantages of the invention are set forth in the following claims.

Claims

1. A self-priming adapter system comprising:

a pump inlet receiving liquid mixed with air;

a pump coupled to the pump inlet;

a self-priming adapter coupled to the pump, the self-priming adapter including a separation chamber, the separation chamber including at least one baffle to substantially separate the air from the liquid; and

a recirculation line coupled to the self-priming adapter to return the liquid to the pump inlet.

2. The self-priming adapter system of claim 1 wherein the at least one baffle includes a first wall, a second wall, and a floor mounted in a top portion of the separation chamber.

3. The self-priming adapter system of claim 2 wherein at least one of the first wall and the second wall is about two inches in height.

4. The self priming adapter system of claim 2 wherein the at least one baffle is mounted within the separation chamber in order to receive liquid from an inlet port; and wherein the at least one baffle is positioned between the inlet port and an outlet port.

5. The self-priming adapter system of claim 2 wherein at least one of the first wall and the second wall substantially extends a length of the separation chamber.

6. The self-priming adapter system of claim 1 wherein the separation chamber includes at least one anti-vortex screen.

7. The self-priming adapter system of claim 1 wherein the self-priming adapter includes at least one of a cylindrical tank, a semi-circular tank, and a half-octagonal tank.

8. The self-priming adapter system of claim 1 and further comprising at least one valve to open and close the recirculation line.

9. The self-priming adapter system of claim 8 wherein the at least one valve includes a check valve positioned in the recirculation line.

10. The self-priming adapter system of claim 8 and further comprising a pressure sensor that measures pressure in the separation chamber and indicates that the pump has been primed; and wherein the at least one valve closes the recirculation line after the pressure sensor indicates the pump has been primed.

11. A self-priming adapter for use with a pump having a pump inlet receiving liquid mixed with air and a recirculation line, the self-priming adapter comprising:

a tank including an inlet port and an outlet port;

a separation chamber within the tank; and

at least one baffle positioned within the separation chamber, the at least one baffle substantially separating the air from the liquid.

12. The self-priming adapter of claim 11 wherein the at least one baffle includes a first wall, a second wall, and a floor mounted in a top portion of the separation chamber.

13. The self-priming adapter of claim 12 wherein at least one of the first wall and the second wall is about two inches in height.

14. The self priming adapter of claim 12 wherein the at least one baffle is mounted within the separation chamber in order to receive liquid from the inlet port; and wherein the at least one baffle is positioned between the inlet port and the outlet port.

15. The self-priming adapter of claim 2 wherein at least one of the first wall and the second wall substantially extends a length of the separation chamber.

16. The self-priming adapter of claim 11 wherein the separation chamber includes at least one anti-vortex screen.

17. The self-priming adapter of claim 11 wherein the tank is least one of a cylindrical tank, a semi-circular tank, and a half-octagonal tank.

18. The self-priming adapter of claim 11 and further comprising a pressure sensor that measures pressure in the separation chamber and indicates that the pump has been primed.

19. A method of priming a pump, the method comprising:

receiving liquid mixed with air;

directing the liquid mixed with air over at least one baffle;

substantially separating the air from the liquid; and

returning the liquid to a pump inlet in order to prime the pump.

20. The method of claim 19 and further comprising directing the liquid mixed with air over at least one anti-vortex screen.