Patent Application
20100183464
The current disclosure is directed to a water pump that provides affordable access to safe water. In underdeveloped and developing nations, one consistent need is the need for access to safe water. Traditional hand pumps are often expensive to construct and made up of steel components that make transport, shipping and construction costly. In addition, such traditional pumps often fail. Some statistical reports indicate that forty percent of all hand pumps fail and are abandoned within two years of installation. This number is reported to rise to ninety percent in three years. The failure of hand-operated pumps is due to a variety of causes. A large number of inoperative hand pumps result from damaged or failed O-rings that are utilized in traditional pumps. In order to replace damaged O-rings, replacement parts must be available and the equipment needed to pull pump units from the well likewise must be available. Local communities in impoverished areas are often unsuccessful in their attempts at pump repair because of either the lack of the parts or the inability to pull the pump unit with steel risers from the well. Thus, there is a continuing need for a more reliable hand pump that can be utilized in underdeveloped and impoverished areas that will provide a supply of water and that is efficient and reliable.
The current disclosure is directed to a water pump that utilizes commonly available materials, requires no electrical means to fabricate or actuate and will operate longer than prior art hand-operated pumps, since traditional wear components are not used. The pump is compact and will enable water recovery from a broad range of existing well casings. The pump will benefit developing and impoverished nations by providing affordable access to safe water. The water pump will operate for more cycles than traditional water pumps that utilize O-rings and steel risers. Components of the pump of the current disclosure are constructed with PVC and no steel risers are utilized. Construction of the water pump of the current disclosure is simpler, faster and requires less equipment than traditional pumps since PVC is lighter and easier to work with than steel risers.
The water pump of the current disclosure may be positioned in a cased, or uncased well. The water pump has an outer housing with a reciprocating plunger assembly disposed therein. A proximity bushing is affixed in the housing through which the plunger assembly reciprocates. A first check valve is attached to the bottom or first end of the housing and will allow water to be drawn therethrough into the housing, but will prevent the expulsion of water from the housing through the first check valve. A second check valve is attached to a first, or lower end of the plunger assembly and is positioned inside the housing. The second check valve at the lower end of the plunger assembly will allow water in the housing to pass therethrough into the plunger assembly but will prevent water from passing from the plunger assembly through the second check valve into the housing.
In operation, the plunger is reciprocated in the housing. The proximity bushing is positioned around the plunger assembly and the interaction between the proximity bushing and the plunger assembly will create a negative pressure when the plunger is pulled upwardly. The negative pressure will draw water through the first check valve into the housing. At the top of the reciprocation stroke the plunger will be urged downwardly and water in the housing will be pushed upwardly through the second check valve into the plunger assembly. The reciprocal movement is repeated and water will pass from the plunger assembly upwardly through a riser to the surface where it can be discharged through a fitting. The proximity bushing may be comprised of PVC, but is preferably comprised of nylon, UHMW, or Kynar®. The plunger assembly may be comprised of PVC.
The water pump 10 of the current disclosure comprises a housing 12 with a plunger assembly 14 disposed therein. Housing 12 includes an upper, or guide cylinder 16 having upper end 18 and lower end 20 connected to a lower, or pressure cylinder 22 having upper and lower ends 24 and 26, respectively. Lower end 26 of pressure cylinder 22 may be referred to as the first end thereof, and is also the first, or lower end of housing 12. Guide cylinder 16 is connected to pressure cylinder 22 with a coupling 28. Guide cylinder 16, pressure cylinder 22 and coupling 28 may be, for example, PVC, and may be connected with adhesives, or may be threadedly connected. Coupling 28 has a radially inwardly extending shoulder 29 positioned between lower end 20 of guide cylinder 16, and upper end 24 of pressure cylinder 22.
A reducer bushing 30 is connected to pressure cylinder 22 at the lower end 26 thereof with a coupling 32. A nipple, or pipe stub 34 is attached to reducer bushing 30, which is in turn connected to a first check valve 36, which may be, for example, a foot valve 36. Foot valve 36 is a check valve designed to allow flow upward therethrough and through nipple 34 into pressure cylinder 22, but will prevent flow in the opposite direction. Foot valve 36 may be, for example, a flapper valve comprised of PVC
A coupling 40, which may be referred to as upper coupling 40, is connected to guide cylinder 16 at upper end 18 thereof and has a reducer bushing 42 attached thereto. Reducer bushing 42 is connected by threads, or other known means, to a suspension pipe 44 used to suspend water pump 10 in the well. Suspension pipe 44 is preferably comprised of PVC.
Plunger assembly 14 comprises a primary riser pipe 50 having upper end 52 and lower end 54. Lower end 54 may be referred to as a first end of primary riser pipe 50, and is the first or lower end of plunger assembly 14. Primary riser pipe 50 may comprise a plurality of connected tubulars, for example upper primary riser pipe 51 and lower primary riser pipe 53. A riser coupling 56 is connected to primary riser pipe 50 at upper end 52 thereof, and is also connected to a secondary riser pipe 58. Primary riser 50 and secondary riser 58 may be referred to as riser assembly 59. Secondary riser pipe 58 may comprise a plurality of connected tubulars that will extend to the surface and will be connected to a plunger arm as described hereinbelow with respect to
A reducer bushing 62 is attached to upper primary riser 51 at a lower end 55 thereof. Reducer bushing 62 is connected to a coupling 64, which is in turn connected to a lower primary riser 53 at an upper end 66 thereof. Lower primary riser 53 has outer surface 68 and lower end 54, and has coupling 72 connected thereto.
A threaded fitting 74 is connected to coupling 72. A second check valve 76, which may be, for example, a poppet-type check valve is connected to fitting 74, and may be for example, threadedly connected to fitting 74. Check valve 76 may be comprised of materials known in the art, for example brass, but if size limitations permit, may also be comprised of PVC.
A proximity bushing 78 is disposed in housing 12 and is positioned between shoulder 29, and lower end 20 of guide cylinder 16. As such, proximity bushing 78 is seated on shoulder 29, and captured by guide cylinder 16 so that it is retained in housing 12. If desired, proximity bushing 78 may be positioned between shoulder 29 and upper end 66 of pressure cylinder 22. In such a case proximity bushing 78 will be seated against shoulder 29, and captured by pressure cylinder 22. An inner diameter 80 of proximity bushing 78 is closely received about outer surface 68 of lower primary riser 53, and may be sealingly received thereabout. Lower primary riser 53 is slidable in proximity bushing 78, and is received closely thereabout so that, as will be explained in more detail, a negative pressure is created in pressure cylinder 22 when plunger assembly 14, and more specifically lower primary riser 53 is pulled upwardly therethrough.
Pump 10 is shown schematically in
The operation of the pump 10 is as follows. Once pump 10 has been lowered to the desired level in wellbore 82, a handle 87 attached to secondary riser 58 may be moved to reciprocate lower primary riser 53 in housing 12.
As riser assembly 59 moves upwardly, lower primary riser 53 will move upwardly through proximity bushing 78, and the interaction therebetween causes negative pressure in a central opening 88 of pressure cylinder 22. Shoulder 29 preferably does not extend into central opening 88. Negative pressure in pressure cylinder 22 will cause foot valve 36 to move to an open position to allow water, or other liquid in wellbore 82, to move upwardly therethrough. Liquid will pass through nipple 34 into central opening 88 of pressure cylinder 22. Upward movement will cease when coupling 72, and specifically an upper end 90 thereof, engages proximity bushing 78. Proximity bushing 78 thus acts as a stop for upward movement. A screen 92 may be used with foot valve 36 to screen out particles, but pump 10 may be used and operated without screen 92.
Pressure cylinder 22 will fill, or partially fill with water due to the negative pressure. Once upward movement of the riser assembly 59 stops, and downward motion begins, foot valve 36 will close, and check valve 76 will move to an open position.
Downward movement of riser assembly 59 will urge check valve 76 to the open position and water will pass therethrough into riser assembly 59, and specifically into lower primary riser 53. Water will pass through coupling 72, lower primary riser 53, coupling 64, upper primary riser pipe 51, coupling 56 and secondary riser pipe 58 to the surface.
Upper and lower primary risers 51 and 53 define a flow passage 94 that will communicate water upwardly into secondary riser 58 which has a flow passage 96 therethrough, so that water is communicated to the surface. Flow passages 94 and 96 comprise flow passage 98 that delivers water to the surface. Reciprocating movement of lower primary riser 53 inside housing 12 may be generated manually by moving handle 87 which may be connected to secondary riser 58 with a fitting 100 which may have an opening 102 therein. Water may pass through opening 102 to be collected. As shown in
The reciprocating movement of lower primary riser 53 may have a predetermined stroke distance, or may be limited in its upward movement by the engagement of coupling 72 with proximity bushing 78, and in downward movement by engagement of coupling 64 with proximity bushing 78. Upward movement pulls water into pressure cylinder 22 and downward movement will cause water to pass through check valve 76 into lower primary riser 53, and ultimately to the surface and through opening 102 as described herein.
Proximity bushing 78 and outer surface 68 of lower primary riser 53 may have a minimal gap therebetween that may allow a small amount of water to pass therethrough. A weep hole 110 may be drilled through guide cylinder 16, so that water in guide cylinder 16 may exit therethrough and pass downwardly back into the water table.
Water pump 10 described herein provides a number of advantages over prior art water pumps. All of the components of the water pump 10 may be comprised of PVC. Proximity bushing 78 may instead comprise, for example, UHMW, nylon or Kynar®, and if size limitations dictate, check valve 76 may be a brass check valve. Water pump 10 thus eliminates the need for steel risers, which are more difficult and costly to transport, and more difficult to replace than PVC. Steel risers are not available in many countries, while PVC is readily available in most countries, so international shipping is not required.
In addition, there are no elastomeric O-rings used with water pump 10. Typical O-rings often become damaged, and cause the failure of prior art pumps. To replace prior art water pumps, the pump assembly, including steel risers, must be pulled which is a time-consuming and expensive process. Attempts to effectuate repairs in cases of failed O-rings is likewise time-consuming and expensive. The repair process often requires fishing tools to snare a pump rod and other downhole equipment, which often makes a repair cost and time prohibitive.
In controlled tests, water pump 10 has operated for approximately 3.2 million cycles, which conservatively translates into ten years of use. Water pump 10 is uniquely suited for use in underdeveloped countries since it may be constructed with readily available, inexpensive materials, and will operate for much longer periods of time than prior art pumps.
In
Use of two proximity bushings 78C allows for greater fluid resistance, and greater pressure with little increase in friction between moving parts.
Thus, it is seen that the apparatus and methods of the present invention readily achieve the ends and advantages mentioned as well as those inherent therein. While certain preferred embodiments of the invention have been illustrated and described for purposes of the present disclosure, numerous changes in the arrangement and construction of parts and steps may be made by those skilled in the art, which changes are encompassed within the scope and spirit of the present invention as defined by the appended claims.
This application incorporates by reference and claims the benefit of U.S. Provisional Application 61/146,225 filed on Jan. 21, 2009.
| Number | Date | Country | |
|---|---|---|---|
| 61146225 | Jan 2009 | US |
