O'KEEFFE ROBERT (GB)
| US3555312A | 1971-01-12 | |||
| US3294989A | 1966-12-27 | |||
| EP1548919A2 | 2005-06-29 | |||
| DE554959C | 1933-07-27 | |||
| DE555413C | 1932-07-28 |
| CLAIMS 1. A pump comprising a working fluid inlet, a working fluid outlet coupled to the working fluid inlet by a conduit and located above the working fluid inlet, and a buoyant fluid inlet arranged on the conduit, and characterised by further comprising an electromagnetic field generating unit operable to provide an electromagnetic field within the conduit. 2. The pump of claim 1 , wherein the electromagnetic field generating unit is arranged between the working fluid inlet and the working fluid outlet. 3. The pump of claim 1 or 2, wherein the electromagnetic field generating unit comprises an electrically conductive coil. 4. The pump of claim 3, wherein the electrically conductive coil comprises more than one turn. 5. The pump of claim 3 or 4, wherein the electrically conductive coil comprises less than 200,000 turns, preferably less than 10,000 turns, more preferably less than 5,000 turns, for example less than 2,000 turns. 6. The pump of any one of claims 3, 4 or 5, wherein the electrically conductive coil comprises more than 500 turns, for example more than 1 ,000 turns. 7. The pump of any one of claims 3-6, wherein electrically conductive coil comprises 1 ,000, 2,000 turns or a number of turns in the range 1 ,000 to 2,000. 8. The pump of any one of claims 3-7, wherein the electrically conductive coil comprises a length in the range 1 cm to 1000cm. 9. The pump of any one of claims 3-8, wherein the electrically conductive coil comprises a length of 30cm. 10. The pump of any preceding claim, wherein the electromagnetic field generating unit is arranged around the conduit. 1 1. The pump of any preceding claim, wherein the electromagnetic field generating unit comprises a signal generator coupled to an electrically conductive coil. 12. The pump of any preceding claim, wherein the electromagnetic field generating unit of is arrangable, in use to provide a time varying electromagnetic field. 13. The pump of any preceding claim, wherein the electromagnetic field generating unit is arrangable, in use to provide a time varying electromagnetic field at a working frequency. 14. The pump of any preceding claim, wherein the electromagnetic field generating unit is arrangable, in use to provide a repeating periodic variation of electromagnetic field strength over time, at a working frequency. 15. The pump of any preceding claim, wherein the electromagnetic field generating unit is arrangable, in use to provide a square, sawtooth or sinusoidal variation of electromagnetic field strength over time, at a working frequency. 16. The pump of any preceding claim, wherein the electromagnetic field generating unit is arrangable, in use to provide a swept frequency change in electromagnetic field strength. 17. The pump of any one of claims 13-16, wherein the working frequency is a resonant frequency of the working fluid. 18. The pump of any one of claims 13-17, wherein the working frequency is a resonant frequency of buoyant fluid introduced into the conduit. 19. The pump of any one of claims 13-18, wherein the working frequency is a resonant frequency of bubbles of buoyant fluid introduced into the working fluid. 20. The pump of any one of claims 13-19, wherein the working frequency is in a range bounded at its lower end by subsonic frequencies. 21. The pump of any one of claims 13-20, wherein the working frequency is in a range bounded at its upper end by the ultrasonic range. 22. The pump of any one of claims 13-21 , wherein working frequency is in the range OHz to 20kHz. 23. The pump of any one of claims 13-22, wherein the working frequency is up to 1 kHz, preferably up to 500Hz, more preferably up to 100Hz. 24. The pump of any one of claims 13-22, wherein the working frequency is at least 1 Hz, preferably at least 5Hz, preferably at least 10Hz. 25. The pump of any one of claims 13-23, wherein the working frequency is in the range OHz to 100Hz. 26. The pump of any one of claims 13-24, wherein the working frequency is 10 Hz. 27. The pump of any preceding claim, wherein the electromagnetic field generating unit is arranged in use to produce an electromagnetic field within the conduit above the buoyant fluid inlet only. 28. The pump of any one of claims 1-27, wherein the electromagnetic field generating unit is arranged in use to produce an electromagnetic field within the conduit below the buoyant fluid inlet only. 29. The pump of any one of claims 1-26, wherein the electromagnetic field generating unit is arranged in use to produce an electromagnetic field both above and below the buoyant fluid inlet. 30. The pump of any preceding claim, comprises a supply means arranged to provide a working fluid to the working fluid inlet. 31. The pump of any preceding claim comprises a working fluid. 32. The pump of claim 31 , wherein working fluid substantially fills the conduit. 33. The pump of any preceding claim, wherein the conduit is closed to the atmosphere between the working fluid inlet and the working fluid outlet. 34. The pump of any preceding claim, wherein conduit is a pipe. 35. The pump of any preceding claim, wherein the conduit is of circular cross-section. 36. The pump of any preceding claim, wherein the conduit is of internal diameter of 5cm to 10cm. 37. The pump of any preceding claim, operable with magnetically active working fluid. 38. The pump of any preceding claim, wherein the working fluid is a liquid. 39. The pump of any preceding claim, wherein the working fluid comprises an electrolyte solution. 40. The pump of any preceding claim, wherein the working fluid comprises an aqueous salt solution. 41. The pump of any preceding claim, wherein the working fluid comprises an aqueous gel. 42. The pump of any preceding claim, wherein the working fluid comprises a magnetically active liquid and comprises magnetically active particles. 43. The pump of any preceding claim, wherein the working fluid comprises magnetically active particles in suspension. 44. The pump of any preceding claim, wherein the working fluid comprises ferromagnetic particles. 45. The pump claim 44, wherein the magnetically active particles comprise iron particles or particles containing an iron compound. 46. The pump of any one of claims 42-44, wherein the magnetically active particles comprise a protective coating. 47. The pump of claim 46, wherein the protective coating forms a barrier around the magnetically active particles to render them chemically inert with respect to the working fluid. 48. The pump of claim 46 or 47, wherein the protective coating forms a barrier around the magnetically active particles to prevent coalescence of the magnetically active particles. 49. The pump of any preceding claim, wherein the working fluid comprises a liquid metal. 50. The pump of claim 49, wherein the working fluid comprises liquid ferromagnetic metal. 51. The pump of any preceding claim, wherein the working fluid comprises an electrorheological fluid. 52. The pump of any preceding claim, wherein the working fluid comprises a ferrofluid. 53. The pump of any preceding claim, wherein the working fluid comprises a magnetic ionic liquid. 54. The pump of any preceding claim, wherein the buoyant fluid comprises a gas. 55. The pump of claim 54, wherein the buoyant fluid comprises air. 56. The pump of any preceding claim comprises a buoyant fluid introduction means arranged in use to supply buoyant fluid through the buoyant fluid inlet. 57. A method of operating a pump comprising a working fluid inlet, a working fluid outlet coupled to the working fluid inlet by a conduit and located above the working fluid inlet, working fluid within the conduit, and a buoyant fluid inlet arranged on the conduit, and further comprising an electromagnetic field generating unit arranged to provide an electromagnetic field to working fluid within the conduit, the method comprising supplying buoyant fluid to the working fluid through the buoyant fluid inlet while providing an electromagnetic field to working fluid using the electromagnetic field generating unit. 58. The method of claim 57, wherein the pump comprises further features electromagnetic field generating unit as described above in relation to the pump of claims 1-29. 59. The method of claim 57 or 58, comprises operating the a pump comprising the features of any one of claims 1-56 in accordance with the operability described above in claims 1-56. 60. A pump or method substantially as herein described, with particular reference to the accompanying drawings. |
Field of the Invention
The present invention relates to pumps and to pumping methods. Background to the Invention
Airlift pumps are known as a useful way of raising liquids in particular applications. As with all pumping applications, improving pump efficiency is important.
The present invention aims to address at least one disadvantage associated with the prior art, whether identified herein, or otherwise.
Summary of the Invention
In a first aspect the present invention provides a pump comprising a working fluid inlet, a working fluid outlet coupled to the working fluid inlet by a conduit and located above the working fluid inlet, and a buoyant fluid inlet arranged on the conduit, and characterised by further comprising an electromagnetic field generating unit to provide an electromagnetic field within the conduit.
Suitably, the electromagnetic field generating unit is arranged between the working fluid inlet and the working fluid outlet. Suitably, the electromagnetic field generating unit is arranged around the conduit. Suitably, the electromagnetic field generating unit comprises an electrically conductive coil. Suitably, the electrically conductive coil is arranged around the conduit. Suitably, the electrically conductive coil comprises more than one turn. Suitably, the electrically conductive coil comprises less than 200,000 turns, preferably less than 10,000 turns, more preferably less than 5,000 turns, for example less than 2,000 turns. Suitably, the electrically conductive coil comprises more than 500 turns, for example more than 1 ,000 turns. Suitably, the electrically conductive coil comprises 1 ,000, 2,000 turns or a number of turns in the range 1 ,000 to 2,000. Suitably, the electrically conductive coil comprises a length in the range 1 cm to 1000cm. Suitably, the electrically conductive coil comprises a length of 30cm. Suitably, the electromagnetic field generating unit comprises a signal generator coupled to an electrically conductive coil. Suitably, the electromagnetic field generating unit is arrangable, in use to provide a time varying electromagnetic field. Suitably, the electromagnetic field generating unit is arrangable, in use to provide a time varying electromagnetic field at a working frequency. Suitably, the electromagnetic field generating unit is arrangable, in use to provide a repeating periodic variation of electromagnetic field strength over time, at a working frequency. Suitably, the electromagnetic field generating unit is arrangable, in use to provide a square, sawtooth or sinusoidal variation of electromagnetic field strength over time, at a working frequency. Suitably, the the electromagnetic field generating unit is arrangable, in use to provide a swept frequency change in electromagnetic field strength. Suitably, the working frequency is a resonant frequency of the working fluid. Suitably, the working frequency is a resonant frequency of buoyant fluid introduced into the conduit. Suitably, the working frequency is a resonant frequency of bubbles of buoyant fluid introduced into the working fluid. Suitably, the working frequency is in a range bounded at its lower end by subsonic frequencies. Suitably, the working frequency is in a range bounded at its upper end by the ultrasonic range. Suitably, the working frequency is in the range OHz to 20kHz. Suitably, the working frequency is up to 1 kHz, preferably up to 500Hz, more preferably up to 100Hz. Suitably, the working frequency is at least 1 Hz, preferably at least 5Hz, preferably at least 10Hz. Suitably, the working frequency is in the range OHz to 100Hz. Suitably, the working frequency is 10 Hz.
Suitably, the electromagnetic field generating unit is arranged in use to produce an electromagnetic field within the conduit above the buoyant fluid inlet. Suitably, the electromagnetic field generating unit is arranged in use to produce an electromagnetic field within the conduit below the buoyant fluid inlet. Suitably, the electromagnetic field generating unit is arranged in use to produce an electromagnetic field both above and below the buoyant fluid inlet.
Suitably, the pump comprises a supply means arranged to provide a working fluid to the working fluid inlet. Suitably, the pump comprises a working fluid. Suitably, the working fluid substantially fills the conduit. Suitably, the conduit is closed to the atmosphere between the working fluid inlet and the working fluid outlet. Suitably, the conduit is a pipe. Suitably, the conduit is of circular cross-section. Suitably, the conduit is of internal diameter of 5cm to 10cm. Suitably, the working fluid is magnetically active. Suitably, the working fluid is a liquid. Suitably, the working fluid comprises an electrolyte solution. Suitably, the working fluid comprises an aqueous salt solution. Suitably, the working fluid comprises an aqueous gel. Suitably, the magnetically active liquid comprises magnetically active particles. Suitably, the working fluid comprises magnetically active particles in suspension. Suitably, the working fluid comprises ferromagnetic particles. Suitably, the magnetically active particles comprise iron particles or particles containing an iron compound. Suitably, the magnetically active particles comprise a protective coating. Suitably, the protective coating forms a barrier around the magnetically active particles to render them chemically inert with respect to the working fluid. Suitably, the protective coating forms a barrier around the magnetically active particles to prevent coalescence of the magnetically active particles. Suitably, the working fluid comprises a liquid metal. Suitably the working fluid comprises liquid ferromagnetic metal. Suitably, the working fluid comprises an electrorheological fluid. Suitably, the working fluid comprises a ferrofluid. Suitably, the working fluid comprises a magnetic ionic liquid. Suitably, the buoyant fluid comprises a gas. Suitably, the buoyant fluid comprises air. Suitably, the pump comprises a buoyant fluid introduction means arranged in use to supply buoyant fluid through the buoyant fluid inlet.
In a second aspect the present invention provides a method of operating a pump comprising a working fluid inlet, a working fluid outlet coupled to the working fluid inlet by a conduit and located above the working fluid inlet, working fluid within the conduit, and a buoyant fluid inlet arranged on the conduit, and further comprising an electromagnetic field generating unit arranged to provide an electromagnetic field to working fluid within the conduit, the method comprising supplying buoyant fluid to the working fluid through the buoyant fluid inlet while providing an electromagnetic field to working fluid using the electromagnetic field generating unit.
Suitably, the pump comprises further features electromagnetic field generating unit as described above in relation to the pump of the first aspect of the invention. Suitably, the method comprises operating the pump in accordance with the operability described above in relation to the pump of the first aspect of the invention.
Introduction to the Drawings
For a better understanding of the invention, and to show how embodiments of the same may be carried into effect, reference will now be made, by way of example, to the accompanying diagrammatic drawing in which:
Figure 1 shows a schematic view of pump according to an example embodiment of the present invention, the pump according to an example embodiment of the present invention arranged in use with an impulse turbine.
Description of Example Embodiments
Referring now to Figure 1 there is shown a schematic view of a pump according to an example embodiment of the present invention. The pump 1 comprises a working fluid inlet 2, a working fluid outlet 4 coupled to the working fluid inlet by a conduit 6. The working fluid outlet 4 is located above the working fluid inlet 2. The pump 1 further comprises a buoyant fluid inlet 8 arranged on the conduit 6 and an electromagnetic field generating unit 10 arranged to provide an electromagnetic field within the conduit 6. The electromagnetic field generating unit 10 comprises a coil 102 arranged between the working fluid inlet 2 and the working fluid outlet 6 and positioned around the conduit 6. In the example embodiment shown, the coil 102 comprises 1 ,000 turns over a length of 30cm, and the conduit is a pipe with 10cm inner diameter. The electromagnetic field generating unit 10 further comprises a signal generator 104 coupled to the coil 102 via a 50 Watt amplifier 108. Both the signal generator 104 and amplifier are powered from a power supply 106, which in the example embodiment shown comprises a 12 volt battery. The signal generator 104 produces a sinusoidal variation of electromagnetic field strength over time in the conduit 6 by virtue of the coil 102. The working frequency of the signal generator 104 is selected as a resonant frequency of working fluid 200 provided in the conduit 6, the working fluid being in this example embodiment a magnetically active liquid. The working frequency is 10Hz in the example embodiment shown.
The working fluid 200 in the example embodiment comprises an aqueous salt solution, here sodium chloride solution, and including a suspension of iron particles in the form of iron filings. The iron filings comprise a protective coating to render them chemically inert with respect to the sodium chloride solution. In the example embodiment shown the working fluid 200 is water including 2kg of iron in suspension and 10kg of dissolved sodium chloride.
The buoyant fluid in the example embodiment shown comprises a gas in the form or air. The pump 1 comprises a buoyant fluid introduction means in the form of a compressor 300 arranged in use to supply air through the buoyant fluid inlet 8. In the example embodiment shown the compressor 300 provides approximately two hundred litres of air per minute. The coil 102 is arranged just above the buoyant fluid inlet 8, with a 10m vertical run of conduit 6 above the coil 102. 60cm horizontal runs of conduit link the vertical runs of conduit 6 to the working fluid inlet 2 and working fluid outlet 4, and a 30cm horizontal run of conduit links the vertical runs of conduit 6 at the bottom of the pump 1.
By supplying buoyant fluid into the working fluid the pump 1 operates as an air-lift type pump. However, the present invention leads to increased pumping efficiency by virtue of the action of the electromagnetic field on the working fluid 200. The bubbles of buoyant fluid are increased in size by the effect of the electromagnetic field, which leads to increased pumping efficiency. The pump 1 is useful, for example in providing working fluid 200 to an impulse turbine I mounted in a collection tank T, as shown in Figure 1. It will be appreciated that the impulse turbine I and tank T are not elements of the pump shown schematically in Figure 1 by way of an example embodiment of the invention.
Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.
All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.
Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.
The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.