Claims
- 1. A method for pumping a liquid including the steps of:(a) providing a pump including a piston assembly mounted for reciprocating movement in a closed interior compartment of a piston cylinder having opposed closed ends, the piston assembly including a dispensing end and an opposed end; (b) generating a linearly moving magnetic field for reciprocating the piston assembly within the cylinder through a dispensing stroke and a suction stroke, respectively; (c) providing a sealing member between the piston assembly and piston cylinder to maintain a dynamic fluid seal between the piston assembly and piston cylinder during the entire linear dispensing and return strokes of said piston assembly, said sealing member dividing said interior compartment into a dispensing chamber housing the liquid to be dispensed and a reservoir chamber; (d) introducing liquid to be pumped into the dispensing chamber; (e) maintaining the liquid in the cylinder at a level such that a lower surface of the sealing member and the dispensing end of the piston assembly are maintained within the liquid throughout the length of the dispensing and suction strokes of the piston assembly; and (f) providing an energy storage and release media in a location for storing energy when the piston assembly is moved through the suction stroke and for imparting the stored energy to the piston assembly as the piston assembly is moved through the dispensing stroke.
- 2. The method of claim 1, including the step of providing the energy storage and release media in the reservoir chamber of the interior compartment.
- 3. The method of claim 1, including the step of generating the linearly moving magnetic field through an electronic power supply controlled by a programmable microprocessor.
- 4. The method of claim 1, including the steps of determining the position of the piston assembly within the cylinder and controlling the linearly moving magnetic field in response to that determination.
- 5. The method of claim 1, including the step of generating the linearly moving magnetic field with a linear magnetic drive employing a stator and armature, the stator being located adjacent and outside of the piston cylinder of the pump and the armature being located on the piston assembly inside the piston cylinder to thereby create an air gap between the inner surface of the stator and the outer surface of the armature in which the outer wall of the piston cylinder is disposed.
- 6. The method of claim 2, wherein said energy storage and release media includes a gaseous substance.
- 7. The method of claim 6, including the step of establishing and maintaining a defined, liquid/vapor interface in the reservoir chamber between the liquid and the gaseous substance during operation of the pump.
- 8. The method of claim 6, including the step of filling the reservoir chamber with said gaseous substance to a level such that the opposed end of the piston assembly is in said gaseous volume during the entire dispensing and suction strokes of said piston assembly.
- 9. The method of claim 6, wherein the gaseous substance is non-condensible and is not a vapor of the liquid being pumped, including the steps of supplying and discharging controlled amounts of said non-condensible gaseous substance to said pump.
- 10. The method of claim 6, wherein the gaseous substance is a vapor of the liquid being pumped.
- 11. The method of claim 6, wherein the gaseous substance is partially composed of vapor from the liquid being pumped and is partially composed of a non-condensible gas that is not a vapor of the liquid being pumped, including the steps of supplying and discharging controlled amounts of said non-condensible gas to said pump.
- 12. The method of claim 1, including the step of modulating the linear moving magnetic field during the pumping operation to vary the motion of the piston assembly.
- 13. The method of claim 12, wherein varying the motion of the piston assembly includes varying one or more of the length of stroke of the piston assembly in each linear direction, the time period of the stroke of the piston assembly in each linear direction, the cyclic rate of reciprocation of the piston assembly including the position, velocity and acceleration of the piston assembly throughout the entire path of movement of the assembly in the opposed linear directions at every point in time of that cyclic motion.
- 14. The method of claim 13, including the step of providing different time durations for the dispensing stroke and the suction stroke, respectively.
- 15. The method of claim 13, including the step of providing a time delay of motion between successive reciprocating cycles of the piston assembly, each reciprocating cycle including one dispensing stroke and one suction stroke.
- 16. The method of claim 13, including the step of providing a time delay of motion at one or more of various locations within any cycle of the piston assembly, each cycle including one dispensing stroke and one suction stroke.
- 17. The method of claim 1, including the step of providing liquid to be pumped into the piston cylinder from a liquid sump.
- 18. The method of claim 17, including the step of maintaining the liquid level in the sump at a desired elevation.
- 19. The method of claim 17, including the step of partially filling the sump with the liquid to be pumped and including a compressible media in a ullage space within the sump.
- 20. The method of claim 2, including the step of insulating the outer cylinder of the pump in a region of the dispensing chamber to maintain the liquid to be pumped at a desired cold temperature and heating a region of the reservoir chamber to maintain said region of said reservoir chamber at a desired warm temperature and maintaining the pressure of the gas in the reservoir chamber below the critical pressure of the gas.
- 21. The method of claim 20, wherein the liquid to be pumped is a liquefied gas.
- 22. The method of claim 20, wherein the liquid to be pumped is a cryogenically liquefied gas.
- 23. The method of claim 2, including the step of insulating the outer cylinder of the pump in a region of the dispensing chamber to maintain the liquid to be pumped at a desired cold temperature and heating a region of the reservoir chamber to maintain said region of said reservoir chamber at a desired warm temperature and maintaining the pressure of the gas in the reservoir chamber at or above the critical pressure of the gas.
- 24. The method of claim 23, wherein the liquid to be pumped is a liquefied gas.
- 25. The method of claim 23, wherein the liquid to be pumped is a cryogenically liquefied gas.
- 26. The method of claim 1, including the step of providing a bellows section in said reservoir chamber and communicating said energy storage and release media with said bellows section such that movement of the piston assembly through the suction stroke moves the bellows section to store energy in the energy storage and release media.
- 27. The method of claim 26, including the step of locating the bellows section inside the reservoir chamber and filling said bellows member with a gaseous substance, said gaseous substance being said energy storage and release media.
- 28. The method of claim 26, including the step of providing the bellows section as an end section of the reservoir chamber and engaging an outer wall of the bellows section with said energy storage and release media.
- 29. The method of claim 28, including the step of providing a spring member as the energy storage and release media.
- 30. The method of claim 28, including the step of filling the bellows section with a liquid.
- 31. A method for pumping a liquid including the steps of:(a) providing a pump including a piston assembly mounted for reciprocating movement in a closed interior compartment of a piston cylinder having opposed closed ends, the piston assembly including a dispensing end and an opposed end; (b) providing a linear magnetic drive including an armature and a stator, said stator being adjacent said armature and said armature being on said piston assembly for cooperating with the stator, (c) providing a modulating electric current to the stator for generating a linearly moving magnetic field that imposes a magnetic force on the piston assembly in opposed linear directions through said armature for reciprocating the piston assembly within the cylinder through a dispensing stroke and a suction stroke, respectively; (d) providing a sealing member between the piston assembly and piston cylinder to maintain a seal between the piston assembly and piston cylinder during the entire linear dispensing and return strokes of said piston assembly, said sealing member dividing said interior compartment into a dispensing chamber housing the liquid to be dispensed and a reservoir chamber; (e) introducing liquid to be pumped into the dispensing chamber; (f) maintaining the liquid in the cylinder at a level such that a lower surface of the sealing member and the dispensing end of the piston assembly are maintained within the liquid throughout the length of the dispensing and suction strokes of the piston assembly; and (g) providing an energy storage and release media in a location for storing energy when the piston assembly is moved by the magnetic force through the suction stroke and for releasing the stored energy to the piston assembly as the piston assembly is moved through the dispensing stroke by the combined force provided by the release of the stored energy and by the magnetic force imposed on the piston assembly in the direction of the dispensing stroke by the linear magnetic drive.
- 32. The method of claim 31, including the step of providing the energy storage and release media in the reservoir chamber of the interior compartment.
- 33. The method of claim 31, including the step of generating the linearly moving magnetic field in the stator through an electronic power supply controlled by a programmable microprocessor.
- 34. The method of claim 31, including the steps of determining the position ofthe piston assembly within the cylinder and controlling the linearly moving magnetic field in response to that determination.
- 35. The method of claim 31, including the steps of generating the linearly moving magnetic field with a linear magnetic drive employing a stator and armature, locating the stator adjacent and outside ofthe piston cylinder ofthe pump to thereby create an air gap between the inner surface of the stator and the outer surface of the armature in which the outer wall of the piston cylinder is disposed.
- 36. The method of claim 32, wherein said energy storage and release media includes a gaseous substance.
- 37. The method of claim 36, including the step of establishing and maintaining a defined, liquid/vapor interface in the reservoir chamber between the liquid and the gaseous substance during operation of the pump.
- 38. The method of claim 36, wherein the gaseous substance is a vapor of the liquid being pumped.
- 39. The method of claim 36, wherein the gaseous substance is partially composed of vapor from the liquid being pumped and is partially composed of a non-condensible gas that is not a vapor of the liquid being pumped, including the steps of supplying and discharging controlled amounts of said non-condensible gas to said pump.
- 40. The method of claim 31, including the step of modulating the linear moving magnetic field during the pumping operation to vary one or more of the length of stroke of the piston assembly in each linear direction, the time period of the stroke of the piston assembly in each linear direction, the cyclic rate of reciprocation of the piston assembly including the position velocity and acceleration of the piston assembly throughout the entire path of movement of the assembly in the opposed linear directions at every point in time of that cyclic motion.
- 41. The method of claim 40, including the step of providing different time durations for the dispensing stroke and the suction stroke, respectively.
- 42. The method of claim 40, including the step of providing a time delay of motion between successive reciprocating cycles of the piston assembly, each reciprocating cycle including one dispensing stroke and one suction stroke.
- 43. The method of claim 40, including the step of providing a time delay of motion at one or more of various locations within any cycle of the piston assembly, each cycle including one dispensing stroke and one suction stroke.
- 44. The method of claim 31, including the step of providing liquid to be pumped into the piston cylinder from a liquid sump.
- 45. The method of claim 44, including the step of partially filling the sump with the liquid to be pumped and including a compressible media in a ullage space within the sump.
- 46. The method of claim 32, including the step of insulating the outer cylinder of the pump in a region of the dispensing chamber to maintain the liquid to be pumped at a desired cold temperature and heating a region of the reservoir chamber to maintain said region of said reservoir chamber at a desired warm temperature and maintaining the pressure of the gas in the reservoir chamber below the critical pressure of the gas.
- 47. The method of claim 46, wherein the liquid to be pumped is a liquefied gas.
- 48. The method of claim 46, wherein the liquid to be pumped is a cryogenically liquefied gas.
- 49. The method of claim 32, including the step of insulating the outer cylinder of the pump in a region of the dispensing chamber to maintain the liquid to be pumped at a desired cold temperature and heating a region of the reservoir chamber to maintain said region of said reservoir chamber at a desired warm temperature and maintaining the pressure of the gas in the reservoir chamber at or above the critical pressure of the gas.
- 50. The method of claim 49, wherein the liquid to be pumped is a liquefied gas.
- 51. The method of claim 49, wherein the liquid to be pumped is a cryogenically liquefied gas.
- 52. The method of claim 32, including the step of providing a bellows section in said reservoir chamber and communicating said energy storage and release media with said bellows section such that movement of the piston assembly through the suction stroke moves the bellows section to store energy in the energy storage and release media.
- 53. A method for pumping liquid including the steps of:a. providing a pump including a piston assembly mounted for reciprocating movement in a closed interior compartment of a piston cylinder having opposed closed ends, the piston assembly including a dispensing end and an opposed end; b. generating a linearly moving magnetic field for reciprocating the piston assembly within the cylinder through a dispensing stroke and a suction stroke respectively; c. providing a sealing member between the piston assembly and piston cylinder to maintain a dynamic fluid seal between the piston assembly and piston cylinder during the entire linear dispensing and return strokes of said piston assembly, said sealing member dividing said interior compartment into a dispensing chamber housing the liquid to be dispensed and a reservoir chamber; d. introducing liquid to be pumped into the dispensing chamber; e. maintaining the liquid in the cylinder at a level such that a lower surface of the sealing member and the dispensing end of the piston assembly are maintained within the liquid throughout the length of the dispensing and suction strokes of the piston assembly; f. providing an energy storage and release media including a gaseous substance in a location for storing energy when the piston assembly is moved through the suction stroke and for imparting the stored energy to the piston assembly as the piston assembly is moved through the dispensing stroke; and g. controlling the volume and pressure of the gaseous substance in said location for storing a desired amount of energy as a result of the movement of the piston assembly through the suction stroke and for releasing said desired amount of stored energy to the piston assembly as the piston assembly is moved through the dispensing stroke.
- 54. The method of claim 53, including the step of providing the energy storage and release media in the reservoir chamber of the interior compartment.
- 55. The method of claim 53, including the step of generating the linearly moving magnetic field through an electronic power supply controlled by a programmable microprocessor.
- 56. The method of claim 53, including the step of generating the linearly moving magnetic field with a linear magnetic drive employing a stator and armature, the stator being located adjacent and outside of the piston cylinder of the pump and the armature being located on the piston assembly inside the piston cylinder to thereby create an air gap between the inner surface of the stator and the outer surface of the armature in which the outer wall of the piston cylinder is disposed.
- 57. The method of claim 54, including the step of filling the reservoir chamber with said gaseous substance to a level such that the opposed end of the piston assembly is in said gaseous volume during the entire dispensing and suction strokes of said piston assembly.
- 58. The method of claim 54, wherein the gaseous substance includes a non-condensible substance that is not a vapor of the liquid being pumped and wherein the step of controlling the volume and pressure of the gaseous substance includes the steps of supplying and discharging controlled amounts of said non-condensible gaseous substance to said reservoir chamber for storing energy in said pump.
- 59. The method of claim 57, including the step of providing liquid to be pumped into the piston cylinder from a liquid sump.
- 60. The method of claim 59, including the step of maintaining the liquid level in the sump at a desired elevation.
- 61. The method of claim 59, including the step of partially filling the sump with the liquid to be pumped and including a compressible media in a ullage space within the sump.
- 62. The method of claim 54, including the step of providing a bellows section in said reservoir chamber and communicating said gaseous substance with said bellows section such that movement of the piston assembly through the suction stroke moves the bellows section to store energy in said gaseous substance.
- 63. The method of claim 62, including the step of locating the bellows section inside the reservoir chamber.
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a divisional of application Ser. No. 09/225,804, filed Jan. 5, 1999, now U.S. Pat. No. 6,203,288.
US Referenced Citations (22)
Foreign Referenced Citations (1)
Number |
Date |
Country |
2903817 |
Aug 1990 |
DE |