GB2272942A

GB2272942A - Conditioning hydrocarbon fuel.

Info

Publication number: GB2272942A
Application number: GB9321216A
Authority: GB
Inventors: Stephen Anthon Sherwood-Rogers
Original assignee: SHERWOOD ROGERS STEPHEN ANTHON
Current assignee: SHERWOOD ROGERS STEPHEN ANTHON
Priority date: 1992-11-27
Filing date: 1993-10-14
Publication date: 1994-06-01
Anticipated expiration: 2013-10-14
Also published as: GB9321216D0; GB2272942B; GB9224857D0

Abstract

Fuel combustion efficiency is improved by passing a hydrocarbon fuel containing at least 0.1 per cent by volume of water through a constant or oscillating magnetic field. Subsequently the fuel is passed through an electrical field resulting from a potential difference arising between two dissimilar materials such as mild steel and a tin alloy. Domed alloy bodies 18 are located between steel filter mesh 20 downstream of a permanent magnet 16. A fuel filter (26, Fig. 2) may be located upstream the magnet and alloy bodies in a container 10 with a tap for water removal. The magnet and alloy bodies may be mounted for oscillation in the container (30, Fig. 3) to remove heavy oil deposits in light oil supplied to the container. Alloy compositions and magnetic field values are given in the specification. <IMAGE>

Description

METHOD AND APPARATUS FOR IMPROVING FUEL COMBUSTION EFFICIENCY The present invention relates to a method and an apparatus for improving fuel combustion efficiency and may be used with hydrocarbon fuels, for example, in conjunction with internal combustion engines of the spark ignition or compression ignition type and in conjunction with other forms of fuel combustion.

It is known from GB-A-2 155 993 to apply a magnetic field to fuel in the flow path of the fuel to an internal combustion engine, the direction of the magnetic field being substantially orthogonal to the flow of fuel. A magnetic field of the order of 4000 Gauss is said to improve fuel consumption by some 3 to 5 per cent. It is also known from GB-A-1 079 698 that passing fuel, particularly a relatively heavy fuel oil, over an alloy of lead, tin, mercury and antimony improves fuel combustion efficiency. In practice, pellets of the alloy are suspended in the fuel tank in a cage of perforated mild steel or wire mesh.

These two known methods for improving fuel combustion efficiency have been combined in EP-A-o 399 801 according to which the combustion efficiency of fuel can be improved by some 10 per cent if an additive in the form of an alloy of tin, antimony, lead and mercury is located within the magnetic field of a magnet. There is a suggestion that a steel member may confer further advantages, but this is not considered to be essential. In practice, the magnetic member is arranged in the flow of fuel to one side of the alloy such that the fuel first passes over the alloy, albeit within the magnetic field of the magnet, and subsequently passes over the magnet.

The two known methods for improving fuel combustion efficiency have also been combined in GB-A-2 247 919 according to which fuel first passes over a tin alloy and subsequently passes the pole faces of a magnet, the magnetic field being configured such that the tin alloy is substantially unaffected by the magnetic field.

Although the mechanisms by which fuel combustion efficiency are improved have not been fully understood, I have found that the prior art proposals do not fully exploit the potential of the various mechanisms for improving fuel combustion efficiency.

It is therefore an object of the present invention to provide a more effective method and apparatus for improving fuel combustion efficiency.

According to one aspect of the present invention there is provided a method for improving fuel combustion efficiency comprising the steps of: passing a hydrocarbon fuel containing at least 0.1 per cent by volume of water through a magnetic field; and subsequently passing the fuel through an electrical field resulting from a potential difference arising between two dissimilar materials.

According to a second aspect of the present invention there is provided an apparatus for improving fuel combustion efficiency comprising: a housing defining a fuel flow path between a fuel inlet and a fuel outlet of the housing; means for generating a magnetic field within the housing; and an electrosynthesis unit disposed in the fuel flow path downstream of the magnetic field and comprising two dissimilar materials which, in use, create an electrical field through which the fuel flows, the electrical field resulting from a potential difference arising between the two dissimilar materials.

The fuel flow path may cross the magnetic lines of force of the magnetic field, and advantageously the fuel may flow substantially perpendicular to the magnetic lines of force.

The magnetic field may have a strength in the range of 800 to 1400 (preferably 1100) Gauss.

The magnetic field may alternate or oscillate at one or more frequencies. The magnetic field may oscillate at one or more relatively low frequencies, for example at one or more frequencies less than 100 Hz. Such a frequency may conveniently be derived from an A.C. mains frequency.

Additionally or alternatively, the magnetic field may oscillate at one or more frequencies in the range from 10 to 200 MHz.

The flow rate of the fuel through the electrical field is preferably such that pressure differences within the fuel are not sufficient to give rise to separation and the evolution of gases from the fuel.

The dissimilar materials that give rise to the electrical field may be mild steel and a tin alloy. The tin alloy may have the following composition: 65 to 85 (preferably 75) per cent by weight tin 7 to 17 (preferably 12) per cent by weight antimony O to 10 (preferably 5) per cent by weight mercury 1 to 5 (preferably 3) per cent by weight lead 0 to 6 (preferably 3) per cent by weight copper together with trace elements, incidental constituents and impurities. The trace elements may comprise elements from the lanthanide series such as caesium, but it is important that any such trace elements should not significantly degrade, for example by more than 5 per cent, the galvanic effect of the alloy. Part of the surface of the alloy may be oxidised.The area of the oxidised surface relative to the rate of flow past the surface may be such that there is at least 60 mm2 of oxidised surface for each litre/minute flow rate of fuel.

The mild steel may be in the form of at least two mesh elements having substantially the same dimensions as the internal dimensions of the housing. The tin alloy may be in the form of a plurality of domed bodies arranged between each two mesh elements, the domed bodies being disposed such that, in use, they present a substantially planar face towards the inflowing fuel and such that the domed portion thereof extends in the downstream direction of the fuel flow path. The tin alloy may be encased in a mesh of mild steel. The effect of encasing the tin alloy in the mild steel mesh may be such as to isolate the tin alloy from the magnetic field.

The fuel may pass through a filter prior to or subsequent to its passage through the magnetic field. Where the fuel passes through a filter subsequent to its passage through the magnetic field, the filter may comprise the mesh elements.

Means may be provided for agitating the electrosynthesis units within the housing.

For a better understanding of the present invention and to show more clearly how it may be carried into effect reference will now be made, by way of example, to the accompanying drawings in which: Figure 1 is a cross-sectional view through one embodiment of an apparatus according to the present invention for improving fuel combustion efficiency; Figure 2 is a cross-sectional view through a second embodiment of an apparatus according to the present invention for improving fuel combustion efficiency; and Figure 3 is a cross-sectional view through a third embodiment of an apparatus according to the present invention for improving fuel combustion efficiency.

The apparatus shown in Figure 1 comprises a generally cylindrical housing 10, for example of mild steel, provided with mild steel end closures 12, 14 which may be threaded or welded on the ends of the housing 10. A fuel inlet pipe 13 is connected to end closure 12 and a fuel outlet pipe 15 is connected to end closure 14. Positioned within the housing 10 adjacent to the end closure 12 is a magnet 16 which preferably gives rise to a magnetic field strength of some 800 to 1400 (most preferably 1100) Gauss. In the illustrated embodiment, the magnet 16 is a bar magnet arranged substantially perpendicular to the axis of the housing 10 such that fuel passing around the magnet 16 flows generally perpendicular to the magnetic lines of force.Other forms of magnet can be employed, such as an annular magnet or multiple bar magnets, but where a permanent magnet is employed it is advantageous that the magnet is arranged such that the fuel flows across the magnetic lines of force. I have found that the use of two magnets, with the major flow path for the passing between the magnets can give rise to a more advantageous magnetic field than in the case of a single bar magnet. It may also be desirable to enclose the magnet or magnets in a mesh so as to contain and direct the magnetic field.

Positioned within the housing 10 downstream of the magnet 16 is a plurality of electrosynthesis units which comprise in the illustrated embodiment a plurality of domed bodies 18 arranged between two layers of mild steel mesh 20. The layers of mild steel mesh are generally circular and are dimensioned so as to have substantially the same diameter as the internal diameter of the housing 10, the layers of mesh being arranged substantially perpendicular to the axis of the housing. Particularly with relatively heavy fuel oils and with blended fuel oils, the mild steel mesh may act as a fuel filter. I have found that the nature of the mesh can be helpful in maximising the effectiveness of the electrosynthesis unit in that small radius surfaces can be helpful in enhancing the effect of the electrical field.

The mesh can be made, for example, of a perforated plate, a filamentary material, or an expanded metal material. In addition to its association with the electrical field, the mesh can act as a physical filter in respect of particulate contaminants in the fuel and/or as an adsorption and/or absorption filter.

The domed bodies 18 are arranged such that they present a substantially planar face towards the end closure 12 and the inflowing fuel and such that the dome extends towards the end closure 14 and the outflowing fuel. This is believed not only to assist in the flow of fuel past the domed part of the domed bodies, but additionally to maintain the planar surface as free as possible from deposits and to improve the response to the electrical field.The domed bodies 18 are made of a tin-based alloy having the following composition: 65 to 85 (preferably 75) per cent by weight tin 7 to 17 (preferably 12) per cent by weight antimony 0 to 10 (preferably 5) per cent by weight mercury 1 to 5 (preferably 3) per cent by weight lead 0 to 6 (preferably 3) per cent by weight copper together with trace elements, incidental constituents and impurities. The trace elements may comprise elements from the lanthanide series such as caesium, but it is important that any such trace elements should not significantly degrade, for example by more than 5 per cent, the galvanic effect of the alloy. The copper, for example, is believed to be particularly useful when the electrosynthesis unit is being used in conjunction with fuel having a relatively high sulphur content.

The domed bodies are manufactured by casting the alloy in shallow domed moulds such that the planar metal surface of the cast molten alloy is exposed to the atmosphere. This gives rise to oxidation of the planar surface and the creation of an oxide surface.

I have found that a small degree of movement between the domed bodies 18 and the mesh 20 can be helpful in maintaining good metal-to-metal contact and in maximising the electrical field.

The apparatus operates in two ways to improve fuel combustion efficiency, the two improvements be interrelated so as to provide a greater overall improvement than the sum of the two methods independently. As the fuel enters the housing 10, it first encounters the magnetic field created by the magnet 16. The magnetic field of a permanent magnet is aligned such that the fuel flows across the lines of magnetic force and this is believed to cause an effect on the diamagnetic hydrogen atoms in the hydrocarbon fuel and possibly also in the water molecules within the fuel so as to align the molecules in a favourable orientation. Where an oscillating electromagnet is employed, orientation of the magnetic field is not as important. For this effect to be significant, it is important that the apparatus is located relatively close to the point of combustion.The electrosynthesis unit should be not more than 2 minutes of linear flow rate from the point at which the fuel is injected or inducted into the combustion chamber. It is not sufficient for the apparatus to be positioned within a fuel tank, for example.

After the fuel has passed through the magnetic field, or at least a part of the magnetic field, it enters the electrosynthesis units. For electrosynthesis to take place it is essential that the fuel contains a proportion of water in an amount at least 0.1 per cent by volume. Many hydrocarbon fuels are naturally hygroscopic and absorb moisture from the atmosphere and as such they may already contain water, for example in an amount up to 2 per cent by volume. The dissimilar materials, in the illustrated embodiment mild steel and tin alloy, making up the electrosynthesis units are believed to give rise to an electrical field resulting from a potential difference between the two materials in a form of galvanic action and this in turn gives rise to the presence of free hydrogen and oxygen radicals in the fuel.The presence of free radicals, particularly of oxygen, at the point of combustion results in more complete combustion of the fuel than would otherwise occur and this in turn gives rise to further advantages as will be explained in more detail hereinafter. Depending on the magnetic properties of the materials of the electrosynthesis units and on the magnetic configuration of the apparatus, the fuel may or may not be subjected to a magnetic field as is passes through the electrosynthesis units.

It is believed that the effect of the electrical field is particularly important in combination with the two-fold nature of the surface of the domed bodies 18, with the planar surface being oxidised and the domed surface being essentially metallic. It is believed that the oxide surface, in the presence of free oxygen radicals resulting from the effect of the electrical field on molecules of water in the fuel, oxidises alkene (CH2n) components of the fuel to reduce soot and smoke, while the metallic surface interacts with the copper and iron ions of impurities so as to improve the combustion quality of the fuel. The electrical field is additionally believed to modify alkyne (CnH2n2) components of the fuel that tend to give rise to predetonation during combustion of the fuel.

The materials comprising the electrosynthesis units as described can be exchanged for other suitable materials which give rise to a potential difference and thus an electric field, for example copper may be substituted for mild steel.

The flow rate of the fuel over the domed bodies 18 is important. It is not essential that the flow of fuel over the domed bodies is laminar, but the flow rate should not be so great as to create pressure differences within the fuel which could give rise to separation and the evolution of gases and the consequent creation of cavities in the fuel around the domed bodies. This has a deleterious effect on the electrosynthesis process.

Moreover, the flow rate of the fuel relative to the area of the oxide surface of the domed bodies 18 is important.

There should preferably be at least 60 mm2 of oxide surface for each litre/minute flow rate of fuel.

I have found that the use of a magnetic field at the inflow end of the container enhances the separation of the free radicals of hydrogen and oxygen and thus delays the decay of these radicals during the passage of the fuel from the housing 10 to the point of combustion. The effect of the present invention on combustion efficiency, compared with untreated fuel is to reduce the emission of unburnt hydrocarbons by up to 50 per cent, to reduce carbon monoxide emissions by up to 50 per cent and to reduce the emissions of nitrogen oxides by up to 20 per cent. The present invention is more effective in relation to turbocharged internal combustion engines than it is with naturally-aspirated internal combustion engines because the more complete combustion results in a higher volume of exhaust gases.This in turn causes the turbo-charger to run faster and thus to blow more air into the combustion chamber. This results in even more air being available for combustion and further improves the combustion efficiency.

In addition to the reduced levels of pollution, there is a reduction in fuel consumption generally in the range from 5 to 7 per cent and an increase in engine power. The more complete combustion reduces the build-up of carbon within an internal combustion engine and the greater volume of exhaust gases lead to reduced exhaust gas temperatures.

These both assist in increasing the service life of an internal combustion engine.

As an alternative to providing a constant magnetic field, for example due to a permanent magnet positioned within the housing, an alternating or oscillating magnetic field may be provided, for example by means of an electromagnet positioned within or adjacent to the housing.

Conveniently, the magnetic field may oscillate at mains frequency, that is 50 Hz, but it may be advantageous for the magnetic field to oscillate at a somewhat higher frequency, for example in the range from 10 to 200 MHz. It is believed that the use of a magnetic field which oscillates or alternates at one or more frequencies at the inflow end of the container further enhances the separation of the free radicals of hydrogen and oxygen and thus further delays the decay of these radicals during the passage of the fuel from the housing to the point of combustion.

The present invention can be employed in conjunction with a wide range of hydrocarbon fuels ranging from petroleum and diesel fuels as used in automobiles and goods vehicles through to fuel oils (light fuel oils, intermediate fuel oils and some heavy fuel oils in addition to blended fuels) such as may be used in high speed diesel trains and in marine environments.

Where the present invention is to be employed in conjunction with a relatively low power engine, such as an automobile engine or a goods vehicle engine, an apparatus generally similar to that described in relation to Figure 1 may be incorporated into a fuel filter as illustrated in Figure 2. The same reference numerals are used in Figure 2 as in Figure 1 to denote the same or similar components.

Figure 2 shows a housing 10 which is provided at one end thereof with an end closure 12 and a fuel inlet pipe 13.

The other end of the housing is closed by an integral domed portion 22 which is provided with a reservoir 24 for accumulating any concentrations of water molecules that are of sufficient size to sink to the bottom of the housing and with a tap for removing the water from the reservoir 24 from time to time. A fuel outlet pipe 15 is positioned towards the bottom of the housing 10. Arranged within the housing 10 is a fuel filter element shown diagrammatically at 26, a bar magnet 16 positioned beneath the filter element 26, and an electrosynthesis unit comprising a plurality of domed bodies 18 arranged between two layers of mild steel mesh 20. The magnet 16 and the electrosynthesis unit may be secured in the embodiment of Figure 2 to the lower end of the filter element 26 so as to be replaceable therewith, although this is not essential.

Where the present invention is to be used in conjunction with heavy fuel oils and heavy blended fuel oils, the fuel builds up deposits on the electrosynthesis units over time and it is necessary to clean the units regularly. In marine environments, the usual method of cleaning fuel filters is to shut off the supply of heavy fuel oil and to flush the filter by passing a light, and more expensive, fuel oil through the filter until the deposits have been dissolved or washed away. The light fuel oil, which has been contaminated with heavy fuel oil deposits, is mixed with the heavy fuel oil remaining in the fuel tank.

Clearly in the present situation it is desirable to reduce the volume of light fuel oil required to clean the internal components, particularly the electrosynthesis units, of the apparatus. I have found this can be effected by agitating the electrosynthesis units relative to the light fuel oil.

This can be achieved, for example, by passing the light fuel oil repeatedly through the housing in opposite directions or, preferably, by moving the electrosynthesis units up and down while the housing if filled with the light fuel oil. I have found this latter alternative particularly effective and economical in cleaning deposits of heavy fuel oil from the electrosynthesis units because the repeated agitation between the electrosynthesis units and the light fuel oil improves the cleaning operation and because the amount of relatively expensive light fuel oil required is reduced to a minimum.

One way in which the electrosynthesis units can be agitated in the housing is illustrated in Figure 3 where a housing 30 is provided with upper and lower end closures 32, 34 respectively. A fuel inlet pipe 36 is provided in the side of the housing towards the upper end thereof, while a fuel outlet pipe 38 is provided in the side of the housing 30 towards the lower end thereof. Positioned within the housing 30 is a cage 40, for example of mild steel, the cage providing support for a plurality of layers of mesh 42 having arranged between adjacent layers a plurality of domed bodies 44 oriented such that they present a planar face towards the end closure 32 and the inflowing fuel.

Positioned at the upper end of the cage 40 is a bar magnet 46. In order to permit the cage, and thus the electrosynthesis units, to be agitated within the housing 30, the upper end of the cage 40 is provided with a ring 48 which, in a lower position of the cage 40, bears by way of a sealing ring 50 against an annular collar 52 formed on the inner surface of the housing 30 so as to prevent the passage of fuel around the electrosynthesis units. The ring 48, and thus the cage 40, is coupled to a yoke 54 by way of diametrically opposed pivotable couplings 56, and the yoke 54 is in turn connected to a rod 58 which extends out of the housing 30 by way of an aperture 60 formed in the upper end closure 32 and through which the rod 58 passes in a substantially fluid-tight manner.A handle 62 is pivotably connected to the free end of the rod 58, the handle 62 also being pivotably mounted on the upper end closure 32 such that up and down movement of the free end of the handle 62 causes the cage 40 to move up and down within the housing 30. Other features of the apparatus shown in Figure 3 are substantially identical to the apparatus illustrated in and described with reference to Figure 1.

When it is desired to clean heavy fuel oil deposits from the electrosynthesis units, the flow of heavy fuel oil is shut off and the housing is filled with light fuel oil.

The cage 40 carrying the electrosynthesis units is then agitated in the light fuel oil within the housing 30 by moving the handle up and down so as to create a complementary movement of the cage 40. This causes deposits of heavy fuel oil to be dissolved and washed away and the relatively small amount of light fuel oil containing the heavy fuel oil deposits can be passed back to the fuel tank. If necessary, the operation can be repeated to further clean the electrosynthesis units, but even repeated cleaning will still use a relatively small amount of light fuel oil compared with the amount used when flushing light fuel oil through the housing to clean the electrosynthesis units.

Claims

1. A method for improving fuel combustion efficiency comprising the steps of: passing a hydrocarbon fuel containing at least 0.1 per cent by volume of water through a magnetic field; and subsequently passing the fuel through an electrical field resulting from a potential difference arising between two dissimilar materials.

2. A method according to claim 1, wherein the fuel flow path crosses the magnetic lines of force of the magnetic field.

3. A method according to claim 2, wherein the fuel flows substantially perpendicular to the magnetic lines of force.

4. A method according to claim 1, 2 or 3, wherein the magnetic field has a strength in the range of 800 to 1400 Gauss.

5. A method according to claim 4, wherein the magnetic field has a strength of substantially 1100 Gauss.

6. A method according to any preceding claim, wherein the magnetic field oscillates at one or more frequencies.

7. A method according to claim 6, wherein the magnetic field oscillates at one or more relatively low frequencies.

8. A method according to claim 7, wherein the magnetic field oscillates at one or more frequencies less than 100 Hz.

9. A method according to claim 6, 7 or 8, wherein the magnetic field oscillates at one or more frequencies in the range from 10 to 200 MHz.

10. A method according to any preceding claim, wherein the flow rate of the fuel through the electrical field is such that pressure differences within the fuel are not sufficient to give rise to separation and the evolution of gases from the fuel.

11. A method according to any preceding claim, wherein the dissimilar materials that give rise to the electrical field comprise mild steel and a tin alloy.

12. A method according to claim 11, wherein the tin alloy has the following composition: 65 to 85 per cent by weight tin 7 to 17 per cent by weight antimony O to 10 per cent by weight mercury 1 to 5 per cent by weight lead O to 6 per cent by weight copper together with trace elements, incidental constituents and impurities.

13. A method according to claim 12, wherein the tin alloy has substantially the following composition: 75 per cent by weight tin 12 per cent by weight antimony 5 per cent by weight mercury 3 per cent by weight lead 3 per cent by weight copper together with trace elements, incidental constituents and impurities.

14. A method according to claim 12 or 13, wherein the trace elements comprise elements from the lanthanide series.

15. A method according to claim 14, wherein the trace elements comprise caesium.

16. A method according to any one of claims 11 to 15, wherein part of the surface of the alloy is oxidised.

17. A method according to claim 16, wherein the area of the oxidised surface relative to the rate of flow past the surface is such that there is at least 60 mm2 of oxidised surface for each litre/minute flow rate of fuel.

18. A method according to any one of claims 11 to 17, wherein the mild steel is in the form of at least two mesh elements having substantially the same dimensions as the dimensions of the fluid flow path.

19. A method according to claim 18, wherein the tin alloy is in the form of a plurality of domed bodies arranged between each two mesh elements, the domed bodies being disposed such that, in use, they present a substantially planar face towards the inflowing fuel and such that the domed portion thereof extends in the downstream direction of the fuel flow path.

20. A method according to claim 18 or 19, wherein the tin alloy is encased in a mesh of mild steel.

21. A method according to any one of claims 18 to 20, wherein tin alloy is isolated from the magnetic field by the mesh.

22. A method according to any preceding claim and including the step of passing the fuel through a filter prior to or subsequent to its passage through the magnetic field.

23. A method according to claim 22 when dependent upon any one of claims 18 to 21, wherein the fuel passes through the filter subsequent to its passage through the magnetic field and the filter comprises the mesh elements.

24. A method according to any preceding claim and including the step of agitating the electrosynthesis units.

25. A method for improving fuel combustion efficiency according to claim 1 and substantially as hereinbefore described with reference to Figure 1, Figure 2 or Figure 3 of the accompanying drawings.

26. An apparatus for improving fuel combustion efficiency comprising: a housing defining a fuel flow path between a fuel inlet and a fuel outlet of the housing; means for generating a magnetic field within the housing; and an electrosynthesis unit disposed in the fuel flow path downstream of the magnetic field and comprising two dissimilar materials which, in use, create an electrical field through which the fuel flows, the electrical field resulting from a potential difference arising between the two dissimilar materials.

27. An apparatus as claimed in claim 26, wherein the means for generating a magnetic field is disposed such that, in use, the fuel flows across the magnetic lines of force generated by the magnetic field generating means.

28. An apparatus as claimed in claim 27, wherein the means for generating a magnetic field is disposed such that, in use, the fuel flows substantially perpendicular to the magnetic lines of force generated by the magnetic field generating means.

29. An apparatus as claimed in claim 26, 27 or 28, wherein the magnetic field has a strength in the range of 800 to 1400 Gauss.

30. An apparatus as claimed in claim 29, wherein the magnetic field has a strength of substantially 1100 Gauss.

31. An apparatus as claimed in any one of claims 26 to 30, wherein the magnetic field is adapted to oscillate at one or more frequencies.

32. An apparatus as claimed in claim 31, wherein the magnetic field is adapted to oscillate at one or more relatively low frequencies.

33. An apparatus as claimed in claim 32, wherein the magnetic field is adapted to oscillate at one or more frequencies less than 100 Hz.

34. An apparatus as claimed in claim 31, 32 or 33, wherein the magnetic field is adapted to oscillate at one or more frequencies in the range from 10 to 200 MHz.

35. An apparatus as claimed in any one of claims 26 to 34, wherein the dissimilar materials that give rise to the electrical field comprise mild steel and a tin alloy.

36. An apparatus as claimed in claim 35, wherein the tin alloy has the following composition: 65 to 85 per cent by weight tin 7 to 17 per cent by weight antimony O to 10 per cent by weight mercury 1 to 5 per cent by weight lead O to 6 per cent by weight copper together with trace elements, incidental constituents and impurities.

37. An apparatus as claimed in claim 36, wherein the tin alloy has substantially the following composition: 75 per cent by weight tin 12 per cent by weight antimony 5 per cent by weight mercury 3 per cent by weight lead 3 per cent by weight copper together with trace elements, incidental constituents and impurities.

38. An apparatus as claimed in claim 36 or 37, wherein the trace elements comprise elements from the lanthanide series.

39. An apparatus as claimed in claim 38, wherein the trace elements comprise caesium.

40. An apparatus as claimed in any one of claims 35 to 39, wherein part of the surface of the alloy may be oxidised.

41. An apparatus as claimed in any one of claims 35 to 40, wherein the mild steel is in the form of at least two mesh elements having substantially the same dimensions as the internal dimensions of the housing.

42. An apparatus as claimed in claim 41, wherein the tin alloy is in the form of a plurality of domed bodies arranged between each two mesh elements, the domed bodies being disposed such that, in use, they present a substantially planar face towards the inflowing fuel and such that the domed portion thereof extends in the downstream direction of the fuel flow path.

43. An apparatus as claimed in claim 41 or 42, wherein the tin alloy is encased in a mesh of mild steel.

44. An apparatus as claimed in any one of claims 41 to 43, wherein the tin alloy is isolated from the magnetic field by the mild steel mesh.

45. An apparatus as claimed in any preceding claim and including a fuel filter disposed upstream or downstream of the magnetic field.

46. An apparatus as claimed in claim 45 when dependent upon any one of claims 41 to 45, wherein the fuel filter is disposed downstream of the magnetic field and comprises the mesh elements.

47. An apparatus as claimed in any one of claims 26 to 46 and including means for agitating the electrosynthesis units within the housing.

48. An apparatus for improving fuel combustion efficiency as claimed in claim 26 and substantially as hereinbefore described with reference to, and as shown in, Figure 1, Figure 2 or Figure 3 of the accompanying drawings.