GB2602878A

GB2602878A - Electrolysis unit

Info

Publication number: GB2602878A
Application number: GB2116524.6A
Authority: GB
Inventors: Callwood Johnathan
Original assignee: Clean Combustion Ltd; Clean Comb Ltd
Current assignee: Clean Combustion Ltd; Clean Comb Ltd
Priority date: 2020-11-17
Filing date: 2021-11-16
Publication date: 2022-07-20
Also published as: GB202018067D0; GB202116524D0

Abstract

An electrolysis unit 10 comprises a container having a casing 11 for containing electrolyte. In said container an anode 22 and a plurality of cathodes 12 are provided. Each cathode has a tubular shape, said cathodes being axially aligned so that one cathode tube surrounds at least a part of another cathode tube. Said tubes being spaced to define annular chambers 13 for the electrolyte. Magnet(s) (figures 21,21a 89) may also form part of the electrolysis unit and a pulse width modulator control. The unit can be used for the production of Brown’s gas (HHO) as an addition to an internal combustion engine (ICE).

Description

ELECTROLYSIS UNIT

This invention relates to an electrolysis unit and particular, though not exclusively, to an electrolysis unit for electrolysing hydrogen and oxygen from an electrolyte such as a solution of sodium (potassium hydroxide) hydroxide.

The invention further provides an air intake system for an internal combustion engine or an oil burner assembly and comprising the use of said electrolysis unit.

A disadvantage of many known electrolysis units is that they are expensive to manufacture or have a relatively low efficiency in terms of both output per unit volume of space occupied by the unit or the electrical energy required for their operation.

An object of the present invention is to provide an improved electrolysis unit in which at least some of the disadvantages of known electrolysis units are mitigated or overcome.

According to one aspect of the present invention there is provided an electrolysis unit comprising a container comprising a casing for containing electrolyte and within said container an anode and a plurality of cathodes, each cathode being of a tubular shape, said tubular cathodes being substantially axially aligned such that one cathode tube surrounds at least a pad of another cathode tube and said tubes being spaced to define therebetween an annular chamber for the electrolyte.

Preferably the anode is supported relative to the casing to extend within the innermost of the cathode tubes.

The anode may in the form of a rod and may be positioned to extend substantially centrally through the innermost cathode tube. Alternatively the anode may be of a tubular shape.

An innermost chamber for electrolyte may be defined by the space between the anode and innermost cathode tube. An outermost electrolyte chamber may be defined by the space between an outermost cathode tube and the casing.

Optionally the casing may be of electrically conductive material and may be employed as a cathode. The casing may be insulated from but provide support for an anode connection The spacing between surfaces defining a first chamber may be greater than the spacing between surfaces defining a second chamber which lies outwards of and surrounds said first chamber. The electrolysis unit may comprise three or more concentric chambers and each of the chambers outwards of the innermost may be of successively decreasing radial extent compared with the radial extent of the adjacent inwardly positioned chamber.

The spacing between surfaces defining a chamber typically may be between 2mm and 25mm, preferably between 8mm and 20mm. A spacing of 15mm is believed to be particularly beneficial for minimising the current taken by the electrolysis unit and thus the heat generated.

The invention envisages that typically the cathode tubes (and an anode if tubular) and the casing will each be of a cylindrical shape but other cross-sections such as a square, hexagonal or octagonal cross-section may be employed.

The tubes preferably are supported relative to the casing by end support plates, preferably each formed of electrically non-conductive material. The end plates may be substantially wholly formed from non-conductive material, or may comprise a coating of non-conductive material for contact with the ends of tubes, or may support insulating material positioned between the tubes and plate(s).

The tubes may each be of equal length. Alternatively they may be of different lengths.

The electrolysis unit may comprise at least two pairs of cathode tubes with the two tubes of each pair being of the same length and having spaced apart confronting surfaces which define therebetween an annular chamber, and the tubes of one said pair each being of a greater length than the tubes of the or each other said pair. Three or more pairs of equal length tubes may be arranged in a series in which the tubes of each pair positioned outwards of another pair are of a greater length than the surrounded pair. Alternatively they may be arranged such that the tubes of each outer pair are of a smaller length than the pair which they surround.

The end plates may be provided with grooves each to receive an end of a respective one of the tubes. Alternatively, and particularly if the cathode tubes are not all of the same length, one or each end plate may have a stepped form thereby to provide a plurality of shoulders each to engage with and provide location for a respective one of the cathode tubes. One or more of said shoulders may be employed to engage with one of a pair of cathode tubes of equal length.

The annular electrolyte chambers preferably are in fluid communication with one another such that an equal level of electrolyte will be maintained in each chamber. The cathode tubes may be provided with one or more apertures to permit flow of electrolyte between the chambers.

The cathode tubes may be substantially permanently non-removably secured within the casing. Optionally the construction of the casing may be arranged to ensure that the anode may be readily replaced.

An uppermost of the end support plates for the cathode tubes preferably is formed with pluralities of spaced vent passages whereby gases generated by electrolysis pass upwards from the chambers to a collection zone provided between the upper support plate and a top plate or cover of the casing. Said top plate or cover may be provided with an outlet passage. Said outlet passage may have secured thereto or be indirectly connected to an exhaust pipe such as one of a spiral shape which allows condensate to fall back into the electrolysis unit. Alternatively the outlet may, for example, connect to an in-line drier.

The top plate or cover may be of a kind readily removable and replaceable thereby to permit re-filling or topping up of the electrolyte.

The present invention further provides an air intake system for an internal combustion engine or oil burner assembly and comprising an electrolysis unit in accordance with the present invention and arranged whereby gases generated by the electrolysis unit are introduced into and mixed with the fuel just prior to combustion within the engine or oil burner.

The electrolysis unit may comprise at least one magnet for enhancing operation of the unit to generate hydrogen by improving current density between the anode and cathode.

The or each magnet may be a permanent magnet or may be an electro magnet.

The electrolysis unit may comprise a tubular anode that surrounds a centrally positioned magnet, for example a rod shaped magnet. Additionally or alternatively the outermost cathode tube or the casing may be surrounded by a tubular magnet, for example in the form of a sleeve that extends around the casing of the electrolysis unit.

The electrolysis unit may comprise a centrally positioned magnet, such as a rod magnet, and a ferrous element, such as an iron tube, positioned over the outermost tube The electrolysis may comprise a centrally positioned ferrous element, such as an iron ferrite rod, and a tubular magnet positioned over the outermost tube.

The electrical supply to the electrolysis unit may be a constant DC supply but preferably is a pulsed supply. Preferably a pulse width modulator (PVVM) control unit is provided to provide a current flow, such as of a saw tooth profile, between the anode and cathode. Preferably the supply has a frequency of between 300 Hz and 1800Hz. More preferably the frequency is in the range of 1200Hz plus or minus 10%. A frequency of 1200Hz is found to have a particularly good beneficial effect.

In the case of use of the electrolysis unit with an internal combustion engine the electrical supply to the electrolysis unit may be derived from operation of the internal combustion engine, for example from a generator or alternator or a battery which is charged via an alternator or generator.

Although the invention is directed primarily to an electrolysis unit for use in electrolysing hydrogen and oxygen, it is to be understood that it may be employed to generate hydrogen for use with proton exchange membrane cells which generate electricity.

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying diagrammatic drawings in which:-Figure 1 is a longitudinal sectional view of an electrolysis unit in accordance with a first embodiment of the present invention; Figure 2 is a plan view of the lower plate of the unit of Figure 1; Figure 3 is a side view of the plate of Figure 2; Figure 4 is a section on the line A-A of Figure 2; Figure 5 is a plan view of a upper plate of the unit of Figure 1; Figure 6 is a side view of the plate of Figure 5; Figure 7 is a section on the line A-A of Figure 5 Figure 8 is a side view of a top plate of the unit of Figure 1; Figure 9 is a plan view of the plate of Figure 8; Figure 10 is a section on the line A-A of Figure 9; Figure 11 is a sectional view substantially similar to that of Figure 1 and showing a modification of the first embodiment; Figure 12 is a longitudinal sectional view of an electrolysis unit in accordance with a second embodiment of the present invention.

Figure 13 is a longitudinal sectional view of an electrolysis unit in accordance with a third embodiment of the present invention, Figure 14 is a side view of the closure assembly and cover plate of the unit of Figure 13; Figure 15 is a section on the line A-A of Figure 16; Figure 16 is a plan view of the spacer plate of Figure 14; Figure 17 is side view of the upper cover plate of the electrolysis unit of Figure 14; Figure 18 is a plan view of the cover plate of Figure 17; Figures 19a to 19c are respectively two side views and a perspective view of a separation curtain of the electrolysis unit of Figure 13; Figures 20a and 20b show respectively a rod magnet and lines of magnetic flux from the magnet when in situ within an electrolysis unit; Figures 21a and 21b show respectively a sleeve magnet and lines of magnetic flux from the magnet when in situ around an electrolysis unit, and Figure 22 is a cross sectional view, in a plane similar to that of Figure 1, of an electrolysis unit in accordance with a fourth embodiment of the invention.

An electrolysis unit 10 (see Figure 1) comprises an outer cylindrical casing 11 which supports and, within which are mounted, four concentric cylindrical tubes 12 which are axially aligned with one another and define therebetween three annular chambers 13, an outer chamber 13a and an inner chamber 13b.

The tubes 12 are supported relative to the casing 11 by lower and upper spacer plates 14, 15.

The lower spacer plate 14 (see Figures 2 to 4) has an outer cylindrical face 16 with a diameter corresponding to the inner diameter of the casing 11. An upper face 17 of the plate 14 has formed therein a plurality of concentric annular grooves 18 each dimensioned to receive a lower end of a respective one of the tubes 12.

The upper spacer plate 15 (see Figures 5 to 7) also has a cylindrical outer face of a diameter corresponding to the inner diameter of the casing. A lower face 19 is provided with a plurality of annular grooves 20 which correspond in size and position with the grooves on the lower spacer plate so as each to receive and support an upper end of a respective one of the tubes 12.

Additionally the upper plate 15 is formed with a plurality of vent passages 21, these being arranged in five circumferentially extending groups with the passages of each group circumferentially spaced and each group being positioned to align with a respective one of the five annular chambers 13, 13a, 13b.

The four cylindrical tubes 12 and casing 11 are intended, in use, to serve as cathodes, and a suitable material for forming the tubes, and also the casing 11, is type 316L stainless steel. Other suitable materials include electrically conductive materials such as titanium and other types of stainless steel.

An anode is provided in the form of a central rod 22 which extends axially within the innermost tube 12. A suitable material for the anode is type 316L stainless steel but other materials such as titanium and other types of stainless steel may be employed.

The anode 22 has a lower end which locates in a blind bore 23 formed centrally in the upper face of the lower support plate 14. The upper region of the anode extends upwards through an aperture 24 provided centrally in the upper support plate 15.

The diameters of the cylindrical tubes 12 and casing 11 and the initial diameter of the anode are selected such that the outer two chambers 13, 13a have a first and equal radial extent which is smaller than the radial extent of the other two chambers 13. The radial extent of said other two chambers 13 in turn is smaller than that of the inner chamber 13b. In this example the inner chamber has a radial extent of 15mm, the next two chambers 13 have a radial extent of 12mm and the outer two chambers 13, 13a have a radial extent of 10mm, In use, and with the electrolysis unit mounted vertically as shown in Figure 1, the annular electrolyte chambers contain NaOH. Slots (not shown) are provided in the lower region of each cylindrical tube 12 such that an equal level of electrolyte is maintained in each of the chambers 13, 13a, 13b Gases generated when a current flows between the anode and casing, via the four intermediate cathode tubes and the electrolyte, exit from the chambers 13,13a,13b via the respective groups of vent passages 21 to a collection chamber 30 which is defined by the space between an upper surface 31 of the upper support plate 15 and a lower face 33 of a top plate 32.

The top plate 32 is shown in more detail in Figures 8 to 10 and also is made of stainless steel. The top plate has a lower face 33 provided with a boss 34 into which the top end of the anode 22 is a close fit. The plate 32 additionally comprises an upper face 35 provided with an anode terminal 37 for connection of the anode 22 to the positive side of the external electrical supply via the top plate 32. Connection to the negative side of the external electrical supply is via a cathode terminal 36 provided on the casing 11 and which may be employed also for mechanically attaching the unit to, for example, a vehicle body.

A gas exit port 38 extends from the top plate for connection via spiral pipe 44 to an internal combustion engine air intake.

The top plate also is provided with a safety valve 39.

To ensure a fluid seal for the electrolyte a bottom plate 40 is welded to the casing 11. At the top of the unit the top plate 32 is sealingly secured firmly but releasably relative to the top end of the casing 11 by an electrically nonconductive annular gasket 41 of a substantially T shape section and a snap shut type closure band 42. The band is held in place by a lever type closing mechanism (not shown). The leg portion of the T shape of the gasket provides electrical insulation between the casing 11 and the top plate 12. The head section provides insulation of the band 42 from the top plate 32.

The upper and lower support plates 14, 15 and top plate 32 are formed from an electrically non-conductive material such as nylon.

In use, in conjunction with an internal combustion engine of a vehicle the cathode terminal is connected to the negative terminal of the vehicle electrical supply, typically via the vehicle chassis, and the anode terminal is connected to the positive side of the vehicle electrical supply. When a current flows between the anode and cathode terminals hydrogen and oxygen electrolyses from the electrolyte and exits via port 38 as a supply of Hho (i.e. a mix of hydrogen and oxygen and known also as Brown's gas) to be mixed with fuel or combustion air just prior to combustion. The gas from the electrolysis unit thereby facilitates a reduction of fuel consumption and lowering of emission by acting as a catalyst within the combustion process, by increasing burn velocity and lowering combustion temperature.

Figure 11 is a sectional view substantially similar to that of Figure 1 but showing an upper cover plate in the form of a modified lid closure 45 and a threaded outlet 46.

Figure 12 shows an electrolysis unit 50 in accordance with a second embodiment.

The electrolysis unit 50 is of a construction substantially similar to that of the first embodiment with the exception of the upper and lower plates 51, 52 and the cathode tubes 53.

The upper and lower spacer plates have respective lower and upper faces 54, 55 which are stepped so as to provide cylindrical shoulder surfaces 56 against which ends of the tubes 53 are located. The tubes are of progressively increasing length from the innermost tube to the outermost.

Additionally there is shown in Figure 12 an exhaust pipe 57, corresponding to that of Figure 1, is secured to the outlet port 58. The pipe 57 is of a spiral shape so as to allow condensate to fall back into the electrolysis unit. However the provision of an exhaust of that shape is not essential and, for example, the function of the spiral exhaust may be provided alternatively by an inline drier.

In a third embodiment of the invention as shown in Figures 13 to 19 electrolysis unit 60 has upper and lower spacer plates 61,62 which are stepped in a manner similar to those spacer plates (51,52) of the second embodiment, but are formed with annular grooves 63,64 for retention of cathode tubes 70 and tubular separation curtains (membranes) 69.

The spacer plates 61,62 provide four annular, planar surfaces 65-68. The innermost surface 65 provides support for a single, innermost curtain tube 69. The other three surfaces 66-68 each provide support for a respective pair of a gas separation curtain 69 and a cathode tube 70 which are of equal length, and with each pair that surrounds another pair being of a greater length than the pair which it surrounds. The innermost tube 69 has a shorter length than the pair of equal length tubes 69, 70 by which it is surrounded.

Each gas separation membrane 69 (se Figures 19a to 19c) is a moulded plastics assembly of a cylindrically shaped fine wire mesh 90 mounted on a frame. The frame comprises two helicoidal supporting profiles 91,92 which are positioned one inside and the other outside the membrane such that the membrane is sandwiched therebetween. The supporting helicoidal profiles are supported in the lengthwise direction of the curtain by lengthwise extending supports 93. In use the membranes69 allow for the free passage therethrough of liquid and electrons but not gas. The helicoidal support profiles 91,92 serve also as flow deflectors and assist with efficient gas displacement.

In the second embodiment of the invention it was described that the end spacer plates 51,52 provide cylindrical shoulder surfaces 56 against which ends of the tubes are located. In the construction of Figures 13-18 the end spacer plates 61,62 similarly provide cylindrical shoulder surfaces but those surfaces are each aligned with annular groove 63 having a radial width corresponding to the radial thickness of the cathode tubes 70. Thus the innermost tube of each pair of tubes is supported at each end by both a cylindrical surface and by an annular groove 63.

Each of the annular surfaces 66-68 is formed between its radially inner and outer extremities with another retention groove 64 for locating an end of an outer tube, a gas curtain separation tube, of a respective one of the pairs of tubes 69, 70. The innermost planar surface 65 similarly is formed midway between its radially inner and outer extremities with a retention groove 64 for location of an end of the innermost curtain tube 69.

In this embodiment the tubes and anode 95 are uniformly spaced thereby to provide annular chambers 71 which are each of the same radial extent.

The upper spacer plate 61 is secured relative to the casing in a manner different from that of the first embodiment. In this embodiment the casing 73 is provided at the upper end with a retention ring 74 welded thereto. The upper spacer plate 61 provides a plurality of vent passages 75 which are substantially similar to the aforedescribed vent passages 21 of the first embodiment and also an outer retention formation 72 provided with apertures 84 which, in the assembly, are aligned with apertures in the retention ring 74 whereby the two components may be bolted together.

The upper spacer plate 61 is provided with a radially extending passage 76 which extends to the outer periphery of the region 72 for venting of gases from a collection chamber 77 defined by the space between the upper surface 78 of the upper spacer plate 61 and a lower surface 79 of a top plate 80.

The top cover plate 80 (see Figures 17 and 18) comprises a plurality of vent passages 81. In use hydrogen output of the electrolysis unit flows through the passages 81 directly to hydrogen cells (not shown) for the generation of electrical current. Retention apertures 82 allow the top plate 80 to be secured to corresponding threaded blind bores 83 in the upper spacer plate 61.

In a fourth embodiment of the present invention there is provide a modification of the first embodiment, as shown in outline by the Figures 20a, 20b and the Figures 21a, 21b.

In the modification 85 of Figures 20a and 20b the anode is tubular and surrounds a centrally positioned rod magnet 86 thereby to provide the unit with lines 87 of magnetic flux.

In the modification 88 of Figures 21a and 21b the construction of Figures 20a and 20b is provided with a plurality of sleeve magnets 89 instead of a central rod magnet. The sleeve magnets surround the casing of the unit thereby to provide lines 90 of magnetic flux.

The modification of Figures 20a and 20b is depicted in more detail by the cross-sectional view of Figure 22. In the unit 92 of Figure 22 a tubular anode 93 surrounds a stack of a plurality of short length rod shaped neodymium magnets 94. The anode is surrounded by a plurality of tubular cathodes 95 in a manner in accordance with the invention and an outer casing 96 that supports a ferrous casing sleeve 97.

Having regard to the foregoing it is to be appreciated that the electrolysis unit of the present invention may be of a durable and rugged construction. In consequence of the relatively large cathode surface area and preferred plate (i.e. tube) gap spacing it is able efficiently to produce significant amounts of gas for assisting in efficiency of a combustion process. The construction is readily scalable for example by suitable selection of the number of cathode tubes and their sizes so as to provide an output appropriate to the size of the internal combustion engine, oil burner assembly or other device with which the electrolysis unit is to be used. The electrolysis unit may be employed to generate hydrogen for use with PEM (proton exchange membrane) cells which generate electricity.

Claims

Claims 1. An electrolysis unit comprising a container comprising a casing for containing electrolyte and within said container an anode and a plurality of cathodes, each cathode being of a tubular shape, said tubular cathodes being substantially axially aligned such that one cathode tube surrounds at least a pad of another cathode tube and said tubes being spaced to define therebetween an annular chamber for the electrolyte.
2. An electrolysis unit according to claim 1 wherein the anode is supported relative to the casing to extend within the innermost of the cathode tubes.
3. An electrolysis unit according to claim 1 or claim 2 wherein the anode is the form of a rod and is positioned to extend substantially centrally through the innermost cathode tube.
4. An electrolysis unit according to claim 1 or claim 2 wherein the anode is of a tubular shape.
5. An electrolysis unit according to any one of the preceding claims wherein an innermost chamber for electrolyte is defined by the space between the anode and innermost cathode tube.
6. An electrolysis unit according to any one of the preceding claims wherein an outermost electrolyte chamber is defined by the space between an outermost cathode tube and the casing.
7. An electrolysis unit according to any one of the preceding claims wherein the casing is of electrically conductive material and is employed as a cathode.
8. An electrolysis unit according to any one of the preceding claims wherein the spacing between surfaces defining a first chamber is greater than the spacing between surfaces defining a second chamber which lies outwards of and surrounds said first chamber.
9. An electrolysis unit according to any one of the preceding claims wherein the electrolysis unit comprises three or more concentric chambers and each of the chambers outwards of the innermost is of a successively decreasing radial extent compared with the radial extent of the adjacent inwardly positioned chamber.
10. An electrolysis unit according to any one of the preceding claims wherein the spacing between surfaces defining a chamber is between 2mm and 25mm, preferably between 8mm and 20mm.
11. An electrolysis unit according to any one of the preceding claims wherein the tubes are supported relative to the casing by end support plates which are provided with grooves each to receive an end of a respective one of the tubes.
12. An electrolysis unit according to claim 11 wherein the cathode tubes are not all of the same length, and wherein one or each end support plate is of a stepped form thereby to provide a plurality of shoulders each to engage with and provide location for a respective one of the cathode tubes.
13. An electrolysis unit according to claim 11 or claim 12 wherein an uppermost of the end support plates for the cathode tubes is formed with pluralities of spaced vent passages whereby gases generated by electrolysis pass upwards from the chambers to a collection zone provided between the upper support plate and a top plate or cover of the casing.
14. An electrolysis unit according to any one of the preceding claims wherein the electrolysis unit comprises at least two pairs of cathode tubes with the two tubes of each pair being of the same length and having spaced apart confronting surfaces which define therebetween an annular chamber, and the tubes of one said pair each being of a greater length than the tubes of the or each other said pair.
15. An electrolysis unit according to any one of the preceding claims and comprising a plurality of electrolyte chambers, wherein said chambers are in fluid communication with one another such that an equal level of electrolyte will be maintained in each chamber.
16. An electrolysis unit according to claim 15 wherein the cathode tubes are provided with one or more apertures to permit flow of electrolyte between the chambers.
17. An electrolysis unit according to any one of the preceding claims wherein the cathode tubes are of substantially permanently non-removably secured within the casing.
18. An electrolysis unit according to any one of the preceding claims and comprising at least one magnet for enhancing operation of the unit to generate hydrogen by improving current density between the anode and cathode.
19. An electrolysis unit according to claim 18 wherein a said magnet is a permanent magnet
20. An electrolysis unit according to claim 18 or claim 19 wherein a said magnet is an electro magnet.
21. An electrolysis unit according to any one of claims 18 to 20 and comprising a tubular anode that surrounds a centrally positioned magnet, for example a rod shaped magnet.
22. An electrolysis unit according to any one of claims 18 to 21 wherein the outermost cathode tube or the casing is surrounded by a tubular magnet that extends around the casing of the electrolysis unit.
23. An electrolysis unit assembly comprising the combination of an electrolysis unit according to any one of the preceding claims and a pulse width modulator control unit for providing a profiled current flow between the anode and cathode.
24. An electrolysis unit assembly according to claim 23 wherein the supply has a frequency of between 300 Hz and 1800Hz, preferably in the range of 1200Hz plus or minus 10%.
25. An electrolysis unit assembly according to claim 23 or 24 or an assembly comprising an electrolysis unit according to any one of claims 1 to 22 wherein the electrolysis plate comprises a top plate or cover provided with an outlet passage which has secured thereto or is indirectly connected to which allows condensate to fall back into the electrolysis unit.