Self-priming adapter apparatus and method
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.
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.
BACKGROUNDCentrifugal 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.
SUMMARYSome 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
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.
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
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
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.
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.
Type: Application
Filed: Aug 30, 2007
Publication Date: Apr 17, 2008
Inventor: John Lang (Inver Grove Heights, MN)
Application Number: 11/897,523
International Classification: F04D 9/02 (20060101);