Claims
- 1. A reciprocating pump for liquids, said pump comprising: a cylinder including outer walls providing a closed interior compartment having opposed ends, a piston assembly having a dispensing end and an opposed end, said piston assembly being movably mounted within said compartment for movement in opposed linear directions along the central axis of the piston assembly and cylinder between the opposed ends of the closed interior compartment, a sealing member between said piston assembly and said cylinder to maintain a dynamic fluid seal between the piston assembly and said cylinder as said piston assembly is moved in said opposed linear directions between said opposed ends of said closed interior compartment, said sealing member separating said interior compartment into a dispensing chamber and a reservoir chamber; said dispensing end of the piston assembly being kept in the dispensing chamber during movement of the piston assembly in said opposed linear directions, a linear magnetic drive including an armature on the piston assembly and a stator cooperating with the armature and providing a linearly moving magnetic field, a power supply for imparting 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 moving the piston assembly in said opposed linear directions; a valve-controlled inlet conduit communicating with the dispensing chamber of the interior compartment for directing liquid into the dispensing chamber to fill the volume of the dispensing chamber as the piston assembly moves through a swept volume in one linear direction through a liquid-receiving suction stroke; a valve-controlled outlet conduit communicating with the dispensing chamber of the interior compartment for directing pumped liquid out of the dispensing chamber as the piston assembly is moved through a swept volume in a direction opposed to said one linear direction through a liquid dispensing stroke, an energy storage and release media for storing energy as a result of the movement of the piston assembly through the suction stroke by the magnetic force imparted to the piston assembly by the linear magnetic drive in the direction of the suction stroke and for releasing the stored energy to said piston assembly as the piston assembly is moved through said dispensing stroke by the combined force provided by the release of the stored energy and by the magnetic force imparted to the piston assembly by the linear magnetic drive in the direction of the dispensing stroke.
- 2. The pump of claim 1, wherein said energy storage and release media at least partially fills the reservoir chamber.
- 3. The pump of claim 1, being hermetically sealed.
- 4. The pump of claim 2, being hermetically sealed.
- 5. The pump of claim 1, wherein said energy storage and release media is elastically compressive or extensible for storing energy as a result of the movement of the piston assembly through said suction stroke.
- 6. The pump of claim 2, wherein said energy storage and release media includes a gaseous substance.
- 7. The pump of claim 6, further including an additional energy storage and release means for storing energy derived from motion of the piston assembly in said suction stroke and for releasing the stored energy to the piston assembly as the piston assembly is moved in said dispensing stroke.
- 8. The pump of claim 6, wherein said gaseous substance is non-condensible and is not a vapor of the liquid being pumped, including means for supplying and discharging said gaseous substance from the pump and control means for maintaining a desired gas inventory in the pump.
- 9. The pump of claim 6, wherein said gaseous substance is partially composed of vapor of the liquid being pumped and is partially composed of a non-condensible gas that is not a vapor of the liquid being pumped, including means for supplying and discharging controlled amounts of said non-condensible gas to said pump.
- 10. The pump of claim 6, wherein said piston assembly is disposed in said cylinder such that the reservoir chamber is substantially filled with a gaseous substance in a region occupied by the opposed end of the piston assembly as said piston assembly moves through both said suction and dispensing strokes .
- 11. The pump of claim 10, wherein said gaseous substance is composed solely of vapor of the liquid being pumped.
- 12. The pump of claim 10 for pumping a liquefied gas, wherein said cylinder includes heat-insulating means at a region of the dispensing chamber to maintain said liquid to be pumped at a desired cold temperature to maintain said liquid state; heating means at a region of the reservoir chamber to maintain said reservoir chamber at a desired warm temperature to maintain at least a portion of the reservoir chamber volume in a gaseous state; the pressure of the gas in said reservoir chamber being maintained below the critical pressure of the gas.
- 13. The pump of claim 10 for pumping a cryogenically liquefied gas, wherein said cylinder includes heat-insulating means at a region of the dispensing chamber to maintain said liquid to be pumped at a desired cold temperature to maintain said liquid state; heating means at a region of the reservoir chamber to maintain said reservoir chamber at a desired warm temperature to maintain at least a portion of the reservoir chamber volume in a gaseous state; the pressure of the gas in said reservoir chamber being maintained substantially at or above the critical pressure of the gas.
- 14. The pump of claim 1, wherein said linear magnetic drive includes a programmable microprocessor for controlling the operation of the power supply to adjustably control movement of the piston assembly.
- 15. The pump of claim 14, wherein said programmable microprocessor can adjustably control the operation of the power supply to control 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.
- 16. The pump of claim 14, wherein said programmable microprocessor adjustably controls motion of the piston assembly to provide a time delay of motion between successive cycles of the piston assembly, each cycle including both a suction stroke and a dispensing stroke of the piston assembly.
- 17. The pump of claim 14, wherein said programmable microprocessor adjustably controls motion of the piston assembly to provide a time delay of motion at one or more of various locations within any cycle of the piston assembly, each cycle including both a suction stroke and a dispensing stroke of the piston assembly.
- 18. The pump of claim 14, further including a piston assembly position sensor providing an electrical feed back signal to the programmable microprocessor.
- 19. The pump of claim 14, wherein said programmable microprocessor adjustably controls the time duration of movement of the piston assembly during the suction stroke and the time duration of movement of the piston assembly during the dispensing stroke.
- 20. The pump of claim 19, wherein said programmable microprocessor adjustably controls the time duration of movement of the piston assembly during the suction stroke to be less than the time duration of movement of the piston assembly in the dispensing stroke.
- 21. The pump of claim 1, wherein said linear magnetic drive includes a stator and armature, said stator being located adjacent and outside of the cylinder and said armature being located on said piston assembly inside said cylinder.
- 22. The pump of claim 2, wherein said linear magnetic drive includes a stator and armature, said stator being located adjacent and outside of the cylinder and said armature being located on said piston assembly inside said cylinder.
- 23. The pump of claim 2, further including a liquid sump in communication with the valve-controlled inlet conduit for supplying liquid to the pump.
- 24. The pump of claim 23, wherein said sump is completely filled with said liquid.
- 25. The pump of claim 23, wherein said sump is partially filled with said liquid and includes a ullage space having a compressible media therein.
- 26. The pump of claim 25, wherein said ullage space includes a thermal insulation with anti-convection and anti-conduction properties.
- 27. The pump of claim 25, including a thermally conductive element for assisting in maintaining the liquid in the sump at a desired elevation.
- 28. The pump of claim 25, wherein said sump includes a vent line, a valve and liquid float for operating said valve to maintain the liquid in the sump at a desired elevation.
- 29. The pump of claim 25, including conduit means connecting the discharge from said pump to a bottom wall section of the sump through a removable and sealed connection.
- 30. The pump of claim 25, including conduit means connecting the discharge from said pump through the sump ullage space.
- 31. The pump of claim 1, wherein the reservoir chamber includes a bellows section therein, said energy storage and release media communicating with said bellows section, said bellows sections being moved by the suction stroke of the piston assembly to store energy in said energy storage and release media.
- 32. The pump of claim 31, wherein said energy storage and release media is a gaseous substance filling said bellows section, said bellows section being a member located in the reservoir chamber.
- 33. The pump of claim 31, wherein said bellows section is an end section of the reservoir chamber and said energy storage and release media engages an outer wall of the bellows section.
- 34. The pump of claim 33, wherein said bellows section is filled with a liquid.
- 35. A reciprocating pump for liquids, said pump comprising: a cylinder including outer walls providing a closed interior compartment having opposed ends, a piston assembly having a dispensing end and an opposed end, said piston assembly being movably mounted within said compartment for movement in opposed linear directions along the central axis of the piston assembly and cylinder between the opposed ends of the closed interior compartment, a sealing member between said piston assembly and said cylinder to maintain a dynamic fluid seal between the piston assembly and said cylinder as said piston assembly is moved in said opposed linear directions between said opposed ends of said closed interior compartment, said sealing member separating said interior compartment into a dispensing chamber and a reservoir chamber; said dispensing end of the piston assembly being kept in the dispensing chamber during movement of the piston assembly in said opposed linear directions, a linear magnetic drive generating a linearly moving magnetic field for moving the piston assembly in said opposed linear directions; a valve-controlled inlet conduit communicating with the dispensing chamber of the interior compartment for directing liquid into the dispensing chamber to fill the volume of the dispensing chamber as the piston assembly moves through a swept volume in one linear direction through a liquid-receiving suction stroke; a valve-controlled outlet conduit communicating with the dispensing chamber of the interior compartment for directing pumped liquid out of the dispensing chamber as the piston assembly is moved through a swept volume in a direction opposed to said one linear direction through a liquid dispensing stroke, an energy storage and release media including a gaseous substance in a location for storing energy as a result of the movement of the piston assembly through the suction stroke and for releasing the stored energy to said piston assembly as the piston assembly is moved through said dispensing stroke and control means for maintaining the desired 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 said dispensing stroke.
- 36. The pump of claim 35, wherein said energy storage and release media at least partially fills the reservoir chamber.
- 37. The pump of claim 35, being hermetically sealed.
- 38. The pump of claim 36, being hermetically sealed.
- 39. The pump of claim 35, further including an additional energy storage and release means for storing energy derived from motion of the piston assembly in said suction stroke and for releasing the stored energy to the piston assembly as the piston assembly is moved in said dispensing stroke.
- 40. The pump of claim 35, wherein said gaseous substance is non-condensible and is not a vapor of the liquid being pumped, said control means including means for supplying and discharging said gaseous substance from the pump for aiding in maintaining a desired gas inventory in the pump.
- 41. The pump of claim 35, wherein said gaseous substance is partially composed of vapor of the liquid being pumped and is partially composed of a non-condensible gas that is not a vapor of the liquid being pumped, said control means including means for supplying and discharging controlled amounts of said non-condensible gas to said pump.
- 42. The pump of claim 35, wherein said piston assembly is disposed in said cylinder such that the reservoir chamber is substantially filled with the gaseous substance in a region occupied by the opposed end of the piston assembly as said piston assembly moves through both said suction and dispensing strokes.
- 43. The pump of claim 35 for pumping a liquefied gas, wherein said cylinder includes heat-insulating means at a region of the dispensing chamber to maintain said liquid to be pumped at a desired cold temperature to maintain said liquid state; said control means including heating means at a region of the reservoir chamber to maintain said reservoir chamber at a desired warm temperature to maintain at least a portion of the reservoir chamber volume in a gaseous state and at a pressure below the critical pressure of the gas.
- 44. The pump of claim 35 for pumping a cryogenically liquefied gas, wherein said cylinder includes heat-insulating means at a region of the dispensing chamber to maintain said liquid to be pumped at a desired cold temperature to maintain said liquid state; said control means including heating means at a region of the reservoir chamber to maintain said reservoir chamber at a desired warm temperature to maintain at least a portion of the reservoir chamber volume in a gaseous state and at a pressure substantially at or above the critical pressure of the gas.
- 45. The pump of claim 35, wherein said linear magnetic drive is a poly phase linear motor including an electronic power supply and includes a programmable microprocessor for controlling the operation of the power supply to adjustably control movement of the piston assembly.
- 46. The pump of claim 45, wherein said programmable microprocessor can adjustably control the operation of the power supply to control 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.
- 47. The pump of claim 45, wherein said programmable microprocessor adjustably controls motion of the piston assembly to provide a time delay of motion between successive cycles of the piston assembly, each cycle including both a suction stroke and a dispensing stroke of the piston assembly.
- 48. The pump of claim 45, wherein said programmable microprocessor adjustably controls motion of the piston assembly to provide a time delay of motion at one or more of various locations within any cycle of the piston assembly, each cycle including both a suction stroke and a dispensing stroke of the piston assembly.
- 49. The pump of claim 45, further including a piston assembly position sensor providing an electrical feed back signal to the programmable microprocessor.
- 50. The pump of claim 45, wherein said programmable microprocessor adjustably controls the time duration of movement of the piston assembly during the suction stroke and the time duration movement of the piston assembly during the dispensing stroke.
- 51. The pump of claim 50, wherein said programmable microprocessor adjustably controls the time duration of movement of the piston assembly during the suction stroke to be less than the time duration of movement of the piston assembly in the dispensing stroke.
- 52. The pump of claim 35, wherein said linear magnetic drive includes a stator and armature, said stator being located adjacent and outside of the cylinder and said armature being located on said piston assembly inside said cylinder.
- 53. The pump of claim 35, wherein the reservoir chamber includes a bellows section therein, said gaseous substance being in said bellows section, said bellows section being moved by the suction stroke of the piston assembly to store energy in said gaseous substance.
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a Continuation Application of application Ser. No. 09/225,804, filed on Jan. 5, 1999 now U.S. Pat. No. 6,203,288 entitled Reciprocating Pumps with Linear Motor Driver and whose entire disclosure is incorporated by reference herein.
Not Applicable
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Continuations (1)
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Number |
Date |
Country |
Parent |
09/225804 |
Jan 1999 |
US |
Child |
09/811676 |
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US |