WO2010084358A2

WO2010084358A2 - An electrolysis device for generating hydrogen and oxygen for use in improving the combustion of hydrocarbon fuel

Info

Publication number: WO2010084358A2
Application number: PCT/GB2010/050104
Authority: WO
Inventors: Paul O'neill; Ken Cain; John Maynard
Original assignee: Htogo Limited
Priority date: 2009-01-23
Filing date: 2010-01-25
Publication date: 2010-07-29
Also published as: WO2010084358A3; GB0901221D0

Abstract

An electrolysis device (1) for generating hydrogen and oxygen for use in improving the combustion of hydrocarbon fuel comprises a housing (3) containing an electrolysis cell (5), and electronic control means (7) to provide an electric current to the cell (5). The device (1) further comprises sediment reduction means operative to reduce the sediment that accumulates in the cell (5) such that the device (1) can be used with tap or sea water without an electrolyte so as to generate hydrogen and oxygen gas from the tap or sea water. A hydrocarbon combustion unit comprising such a device is also provided.

Description

AN ELECTROLYSIS DEVICE FOR GENERATING HYDROGEN AND OXYGEN FOR USE IN IMPROVING THE COMBUSTION OF

HYDROCARBON FUEL

The present invention relates to an electrolysis device for generating hydrogen and oxygen for use in improving the combustion of hydrocarbon fuel, and particularly but not exclusively relates to such a device for use with a combustion unit such as a vehicle internal combustion engine or a boiler for heating a building or the like.

A typical internal combustion engine is powered by a hydrocarbon fuel such as petrol, diesel or liquefied petroleum gas. Internal combustion engines however, do not completely combust the fuels used, resulting in reduced efficiency and pollutants that are expelled into the atmosphere.

Pollution from internal combustion engines is a well known problem and many remedies have been proposed. It is known that adding hydrogen and oxygen gases into the fuel stream can increase efficiency and decrease the pollution caused by the incomplete combustion of hydrocarbon fuels.

Electronic devices have been proposed for generating hydrogen and oxygen gas, the device comprising an electrolysis cell adapted to be immersed in a liquid usually comprising distilled water and a suitable electrolyte. However, this means that special supplies of treated water are required with electrolytes that are often dangerous, environmentally harmful, or unpleasant to use.

Prior electrolysis cells typically use electrolytes such as concentrated sodium hydroxide (NaOH) or potassium hydroxide (KOH) to facilitate the transfer of ions across the aqueous solution and thereby the process of electrolysis. However the electrolytes commonly used can be corrosive if used with an internal combustion engine and can be hazardous to health.

When used with internal combustion engines, prior electrolysis devices typically use the alternator output to detect if it is generating electrical power and hence the engine is running. However this can be difficult and problematic. It is a time consuming task and can also cause a charge fault indication due to excess current draw. This may make installation difficult and may contravene manufacturer's warranty conditions.

According to one aspect of the invention there is provided an electrolysis device for generating hydrogen and oxygen for use in improving the combustion of hydrocarbon fuel, the device comprising a housing containing an electrolysis cell, and electronic control means to provide an electric current to the cell, the device further comprising sediment reduction means operative to reduce the sediment that accumulates in the cell such that the device can be used with tap or sea water without an electrolyte so as to generate hydrogen and oxygen gas from the tap or sea water.

The sediment reduction means may comprise water pre-treatment means operative to pre-treat the water so as to render the water more suitable for electrolysis prior to the water entering the electrolysis cell.

Preferably the water pre-treatment means comprises a filter.

Preferably the filter comprises a multistage filter.

The multistage filter may include a fine particle filter operative to remove larger particles including sediment and rust. The multistage filter may include an activated carbon filter operative to absorb chlorine.

The multistage filter may include an ion exchange resin filter operative to reduce the amount of unwanted trace metals.

The multistage filter may include an ultra fine mesh filter. Additional filters can be used as required depending on the type and quality of water being used.

The filter may be in the form of a removable filter cartridge that can be removed from the device and replaced when required.

The sediment reduction means may comprise metal components in the electrolysis cell, the metal components having had anticorrosion pre- treatment.

Preferably the pre-treatment comprises a chemical pre-treatment of the metal components.

The metal components may comprise stainless steel components. The metal components may additionally or alternatively comprise components electrochemically plated with nickel, platinum, platinum alloy, or mixed metal oxide.

Alternatively plates formed from a plastics material could be used, the plates comprising a conductive filler. One embodiment uses polypropylene plates containing carbon particles to provide electrical conductivity. The sediment reduction means may comprise the electronic control means when operative to generate an electric current such as to reduce the sediment.

Preferably the electronic control means generates an electric current to the electrolysis cell utilising at least one of pulse width modulation, phase lock loop and current modulation circuitry.

The electronic control means may be operative according to a cleaning cycle operative to apply a high frequency cleaning current to the electrolysis cell to dislodge sediment from the cell. The frequency range may be between 15kHz and 40OkHz.

Preferably the cleaning current is an ultrasonic frequency current.

The electronic control means may comprise a polarity reverser operative to sequentially vary the polarity of the current to the cell. This has the effect of reducing the amount of sediment by placing back into solution a proportion of the sediment.

The electronic control means may comprise an acoustic identification unit operative to acoustically identify the resonant frequency of the cell, the electronic control means being operative to provide an electric current at the identified resonant frequency to the cell.

The electronic control means may comprise a sensor operative to generate a signal indicative of when an internal combustion unit with which the device is used is running, the electronic control means sending an electric current to the electrolysis cell only when the signal is received. The sensor may comprise an acoustic sensor operative to generate the signal when the noise of the internal combustion unit running is detected.

The sensor may comprise a vacuum sensor operative to generate the signal when a vacuum generated when the internal combustion unit is running is detected.

Preferably the cell comprises a plurality of spaced apart plates, the plates being mounted on at least one support bar in the housing, the support bar passing through a nodal point on each plate, that is, a point having the minimum interference with any resonance of the plate.

The cell may comprise a plurality of sets of spaced apart plates, each set of plates being electrically isolated from the next by an insulating plate.

The sediment reduction means may comprise a sloping internal floor of the housing to enable sediment to collect at the lowest part of the floor. The housing may comprise a drain plug at the lowest point of the sloping internal floor.

The housing may comprise a baffle arranged to be above the water level in use of the electrolysis cell, the baffle being operative to resist water from entering the gas outlet pipe from the electrolysis cell, if the device were to be moved violently.

The baffle may comprise a primary baffle plate mounted across the top of the electrolysis cell, the baffle plate comprising at least one aperture through which gas can escape in use of the device.

The baffle may further comprise at least one sub-baffle plate arranged in a non-parallel manner with the primary baffle plate, the sub-baffle plate comprising at least one aperture through which gas can escape in use of the device.

The device may comprise a hydrogen sensor operative to generate an output signal indicative of the levels of hydrogen gas in the vicinity of the device, the electronic control means being operative to cut the electricity supply to the electrolysis cell when the output signal indicates that the levels of hydrogen gas in the vicinity of the device have reached a predetermined level.

The electrolysis cell may comprise a cell module that can be removably mounted in the housing. The cell module may comprise at least two of the following components: electrically conductive electrolysis plates, electrically insulating plates between at least some of the electrolysis plates; power bars connected to the electrolysis plates which in use conduct electricity to the plates; and an electrically insulating mounting rod on which the electrolysis plates are mounted.

Some or all of the connections to the device may be located on a side wall of the housing. Preferably all of the primary connections to the device are located on the same side wall of the housing. The primary connections include any of an air inlet, an electrolyte inlet, a hydrogen gas outlet, and the electrical connections to the electrolysis cell.

The device may comprise an inlet air filter arranged in the housing to function as a water overflow outlet.

According to a further aspect of the invention there is provided an electrolysis device for generating hydrogen and oxygen for use in improving the combustion of hydrocarbon fuel, the device comprising a housing containing an electrolysis cell, and electronic control means to provide an electric current to the cell to generate hydrogen and oxygen when an electrolyte is contained in the electrolysis cell, the device further comprising vibration means operative to dislodge bubbles of gas that attach to parts of the cell as part of the electrolysis process.

The vibration means may comprise an ultrasonic transducer operative to induce ultrasonic pressure waves within the electrolysis cell.

The electronic control means may comprise frequency adjustment means operative to adjust the output frequency of the ultrasonic transducer and thus the frequency of the ultrasonic pressure waves.

More than one ultrasonic transducer may be provided. The or each ultrasonic transducer may be aligned with an axis of the electrolysis cell.

According to another aspect of the invention there is provided an electrolysis device for generating hydrogen and oxygen for use in improving the combustion of hydrocarbon fuels, the device comprising a housing containing an electrolysis cell, the device further comprising electronic control means comprising an acoustic identification unit operative to acoustically identify the resonant frequency of the cell and to provide an electric current at the identified resonant frequency to the cell so as to generate hydrogen and oxygen gas from liquid in which the electrolysis cell is immersed in use.

According to a further aspect of the invention there is provided an electrolysis device for generating hydrogen and oxygen for use in improving the combustion of hydrocarbon fuels, the device comprising a housing containing an electrolysis cell, the electrolysis cell comprising at least two electrodes, the device further comprising electronic control means operative to provide an electric current of sequentially varying polarity to the electrodes so as to generate hydrogen and oxygen gas from liquid in which the electrolysis cell is immersed in use.

According to a yet further aspect of the invention there is provided a hydrocarbon combustion unit comprising the device of any one of the other aspects of the invention.

The hydrocarbon combustion unit may comprise an internal combustion engine for a vehicle, or a static generator.

The hydrocarbon combustion unit may comprise a boiler for a building.

According to a yet further aspect of the invention there is provided a water pre-treatment device for use with an electrolysis device of the type that generates hydrogen and oxygen for use in improving the combustion of hydrocarbon fuel, the water pre-treatment device comprising a filter container comprising a water inlet operative to be connected to a water source, and a water outlet operative to be connected to a water reservoir of the type to deliver water to the electrolysis device in use, the filter container further comprising a filter operative to filter the water so as to render the water more suitable for electrolysis.

Preferably the filter comprises a multistage filter.

The multistage filter may include a fine particle filter operative to remove larger particles including sediment and rust.

The multistage filter may include an activated carbon filter operative to absorb chlorine. The multistage filter may include an ion exchange resin filter operative to reduce the amount of unwanted trace metals.

Other aspects of the present invention may include any combination of the features or limitations referred to herein.

The present invention may be carried into practice in various ways, but embodiments will now be described by way of example only with reference to the accompanying drawings in which:

Figure 1 shows a schematic diagram of a device in accordance with the present invention;

Figure 2 shows an exploded part sectional perspective view of a device in accordance with the present invention;

Figure 3 shows a side view of the device of Figure 2;

Figure 4 shows an end view of the device of Figures 2 and 3;

Figure 5 is a perspective view of the device of Figures 2 to 4 but with the majority of the components removed; Figure 6 is a perspective view of the device of Figures 2 to 5 showing only the housing and electrolysis cell;

Figures 7a, 7b & 7c show plan, end and side views of part of the device of Figures 2 to 6;

Figure 8 shows a plan view of the device of Figures 2 to 7;

Figure 9 shows a schematic diagram of the functionality of the electronic control means comprising part of the device in accordance with the present invention;

Figure 10 shows a schematic diagram of a polarity switching circuit comprising part of the electronic control means of Figure 9;

Figure 11 shows a side view of a further device in accordance with the present invention;

Figure 12 shows an end view of the further device of Figure 11 ;

Figures 13a, 13b & 13c show plan, end and side views of part of the further device of Figures 11 and 12;

Figure 14 is a schematic side view of a solenoid valve comprising part of the devices of Figures 1 to 13;

Figures 15 a, 15b show schematic side views of two examples of a water filtration unit comprising part of the devices of Figures 1 to 13, whilst Figure 15c shows a removable water filter comprising part of the water filtration units; Figure 16 is a schematic side view of a hydrogen sensor comprising part of the devices of Figures 1 to 13;

Figure 17 is a schematic perspective view of an ultrasonic transducer unit comprising part of the devices of Figures 1 to 13;

Figure 18 shows a side view of a modified device in accordance with the present invention;

Figure 19 shows schematic plan view of the modified device of Figure 18;

Figure 20 shows a side view of a sub assembly of the modified device of Figures 19 and 20;

Figure 21 shows a space plate of the modified device of Figures 18 to 20;

Figure 22 is a side view of the modified device of Figures 18 to 21 with the sub assembly of Figure 20 removed;

Figure 23 is a plan view corresponding to Figure 22;

Figure 24 is front view of a further modified device in accordance with the present invention; and

Figure 25 is a side view of the further modified device of Figure 24.

Referring initially to Figure 1 , a device 1 comprises an electrolysis cell housing 3 in which is mounted an electrolysis cell 5. The cell 5 is provided in use with an electric current generated by an electronic control unit 7. Water is fed to the cell 5 through a water inlet 8 from a water reservoir 9 via a water pump 11 and a water level sensor 13 is provided to activate or deactivate the water pump 11 as required. A replaceable water filter 10 is provided between reservoir 9 and pump 11. When an electric current is provided to the cell 5, hydrogen and oxygen molecules are released from the water and these bubble up through the water and escape the housing 3 through a gas outlet 15.

Referring additionally to Figures 2 to 8, the housing 3 is generally oblong in this example and in this example comprises a sloping floor 17 the lowermost part of which is provided with a drain plug 19.

The cell 5 comprises a plurality of spaced apart conductive rectangular plates 21 arranged in sets 22, each set 22 being mounted on two parallel stainless steel rods 23 that extend from front to back of the cell 5. In this example each set 22 has ten plates 21 although any other number of plates 21 and sets 22 could be used, depending on the gas output required. Each plate 21 is spaced from the next by a respective stainless steel spacer 25 mounted on the rods 23. Each set 22 of plates 21 is separated from the next by an insulating plate 28 that extends across the housing 3 so as to isolate one set 22 from the other. The insulating plate 28 may be an integral part of the housing 3 or may be a separate component mounted to the sets 22 of plates 21. A stainless steel electrically conductive link 30 connects the two sets 22 of plates 21 together. Nylon lock nuts 26 are provided at each end of the rods 23 to clamp the plates 21 and spacers 25 together. The insulating plate 28 has apertures 32 that enable fluid to flow from one side of the plate 28 to the other so that the electrolyte level is maintained at the same height on both sides of the plate 28. The cell 5 is mounted on the housing 3 by two parallel horizontally extending nylon support bars 27 that extend between the sides of the housing 3. Nylon washers 29 are provided on the bars 27 between each plate 21 and the washers 29 are doubled up on each side of the insulating plate 28. The cell 5 is secured to the bars 27 by four nylon nuts 31.

The first and last plate 21 of the cell 5 are each provided with a respective power bar 33 that extends vertically to the top of the housing 3, the power bars 33 in use conducting an electric current to the cell 5.

The housing 3 further comprises a baffle 35 comprising a perforated plate mounted in the housing 3 so as to be spaced above the cell 5, the power bars 33 extending through the baffle 35 in this example. The baffle 35 comprises a central circular aperture 36 through which extends the water level sensor 13 operative to generate a signal indicative of the water level in the housing 3.

The housing 3 further comprises a lid 39 that seals shut the housing 3. The water inlet 8 is provided through one part of the lid 39 and the gas outlet 15 is provided through another part of the lid 39. The gas outlet 15 is provided with a flash back arrestor or water bubbler to prevent ignition of the gas occurring in the gas outlet 15.

An air inlet 45 extends through, in this example, a side wall of the housing 3 and may be provided with an air filter (not shown) .

The water inlet 8 is in communication with the outlet of the water pump 11 , the pump 11 being controlled by the electronic control unit 7 in response to the signal generated by the water level sensor 13. The electronic control unit 7 is powered by an electric power supply which may be generated by the internal combustion unit electrical system with which the device 1 is used, or may be independently generated from a stand alone battery or generator such as a solar panel.

The electronic control unit 7 comprises a sensor 47 operative to generate a signal indicative of whether or not the internal combustion unit is on and so whether or not the electronic control unit 7 is to generate a current for the cell 5. The electronic control unit 7 sends an electrical current to the cell 5 when the unit 7 receives a signal from the sensor 47 indicative that the internal combustion unit is running.

The electronic control unit 7 further comprises an acoustic sensor 49 operative to generate a signal indicative of the acoustic level within the housing 3. The signal is used by the control unit 7 to vary the electric current generated so that resonance within the housing 3 is achieved.

The electronic control unit 7 is also connected to a device status display 51 either by a wired or wireless connection. The display 51 may thus be remote from the electronic control unit 7 and is operative to provide information to the user of the device 1 on the operation of the device 1.

The display 51 comprises a remote enclosure containing a device status panel with light emitting diodes, dials, or other visible and/or audible means of providing information on the operational status of the device, suitable for being mounted in a suitable position for the driver or operator. The electronic control unit (ECU) 7 comprises an external enclosure containing electronic circuits operative to:

a. control the supply of electrical energy to the device 1

b. determine if the internal combustion unit is running

c. control supply of water from the reservoir 9 to the housing 3

d. generate and transmit information on the status of the device lto the external status display 51 ;

e. provide optional data links to external devices such as engine management and tracking systems.

f. Control supply of electrical energy to the optional low temperature heater

g. Generate an appropriate signal voltage to oxygen sensor equipment if required; and

h. Interface with external devices such as a lap top computer to allow the transfer of data in either direction.

The device 1 uses a modular structure so that different components such as the electrolysis cell 5, electronic control unit (ECU) 7 and water reservoir 9 can be mounted separately in the most appropriate locations in any given application.

The components may use stainless steel, aluminium or high impact plastic (such as ABS for example) outer cases to protect them from potential damage if the device 1 is located in an exposed position. The outer cases can be locked and thermally insulated to additionally protect the components against low temperatures.

If larger amounts of hydrogen gas are required for the combustion device, for example an HGV engine, multiple devices 1 can be linked together with the outer case.

The electrolysis plates 21 may be manufactured from 0.9mm thick steel. The steel may be mild steel or stainless steel and may be electrochemically plated with a suitable metal or metal alloy depending on the type and quality of water being used. Different grades of stainless steel and different plate dimensions are envisaged. The SAE grades most commonly used in the preferred embodiments are 316 and 304.

Every metal component may be treated to a specific anti corrosion pre- treatment process prior to assembly, depending on the type of water to be used. This involves degreasing and cleaning to remove grease and any other deposits and contaminating.

The components are then treated in a solution of 25%-45% by volume nitric acid at ambient temperature for twenty to forty minutes. They are then rinsed in clean water. The water is changed and they are rinsed again. They are then dried in a warm oven dryer.

Once the components have been treated they are handled very carefully during the assembly process so that the surfaces remain uncontaminated.

The device 1 is operative to use plain tap or salt water if necessary without the use of electrolytes. It is desired in electrolysis to maintain the ionic transfer capability of the water essential for gas production but minimise the possibility that undesirable compounds in the water can come out of solution during the process of electrolysis and accumulate as sediment and reduce the efficiency of the process. For example, many tap waters can contain significant concentrations of dissolved metallic salts that can precipitate out of solution. To prevent this, the water inlet 8 incorporates pre-treatment means comprising an appropriate water filter 10 to filter out the undesirable components in the water being used. The specification of the water filter 10 can vary depending on the type of water being used in the electrolysis cell 5. For example, in one embodiment the filter 10 includes the following sub filters:

a fine particle filter which removes larger particles including sediment and rust; an activated carbon filter operative to absorb chlorine and reduces it by up to 80%; an ion exchange resin filter operative to reduce the amount of unwanted trace metals, and also to reduce calcium carbonate by up to 70%; and an ultra fine mesh filter.

The water filter 10 is part of sediment reduction means and either comprises an integral part of the housing 3 itself or is a remote component in communication with the housing 3, depending on the amount of space available to install the device 1.

The current device 1 can use distilled water or plain tap water or salt water with no electrolyte, and/or sodium sulphate (Na₂SO₄) which is an electrolyte that is inert and generally regarded as non toxic and so not considered as harmful to internal combustion units or human health. The current device can also use an electrolyte containing potassium hydroxide (KOH) dissolved in water to facilitate electrolysis. The device 1 can allow a relatively small concentration of potassium hydroxide to be used such as, for example, less than 10% by weight.

If sodium sulphate is used, it can be added in varying concentrations depending on the type of water being used, the gas output requirement and the likely average operating temperature. With either electrolyte, the preferred method to determine the required concentration of electrolyte is to add the electrolyte in powder form into the water in the electrolysis cell until the optimum gas output is determined. The electrolyte is not consumed in the electrolysis process and remains dissolved in solution.

The gases generated by the electrolysis cell 5 pass from the aqueous solution and out of the housing 3 via the gas outlet 15 and flash-back arrestor or the small water filter container generally known as a 'bubbler¹.

When used with internal combustion engines the gases are preferably drawn into the inlet manifold by the induction stroke of the engine. In other applications a gas pump may be required.

To allow the process to take place without creating a vacuum within the electrolysis cell 5, outside air is drawn in during the process via the air inlet 45 with the attached air filter. The air inlet 45 is located just above the desired maximum water level in the housing 3 and also serves as an emergency water overflow in the event of a malfunction by the water level sensor 13 or water pump 11. This prevents the level of water within the housing 3 reaching such a high level that it would be possible for the water to be drawn into an internal combustion engine or other internal combustion unit connected to the gas outlet 15. The perforated baffle 35 above the maximum water level prevents the possibility of water splashing into the gas outlet 15 and then being drawn into the internal combustion unit.

Referring additionally to Figures 9 and 10, the ECU 7 contains the electronic circuits that control the device 1. These circuits can include discrete logic or be an intelligent system driven via software. While most of the monitoring routines and control routines described can be provided in discrete logic, it can be useful, cost effective and flexible to use an intelligent controller.

Electrical pulses are sent into the cell 5 and are produced by a pulse width modulation circuit controlled by the ECU 7. The pulsed current can improve production of hydrogen and oxygen gas as compared to a non-pulsed current. At one or more frequencies, the electrolysis cell 5 can produce an optimum amount of gas and these frequencies are generally referred to as resonant frequencies.

An acoustic and/or ultrasonic sensor 49 is/are used in addition to a phase lock loop (PLL) circuit 63 to identify the resonant frequency.

In some applications the electronic control unit 7 can be selected to supply a simple direct current to the plates, controlled so as not to exceed a specified maximum amperage and voltage.

The electronic control unit 7 preferably comprises a PIC 18F family programmable micro processor 61 used to coordinate the main functions of the device 1 as follows with reference to the device 1 being used with an internal combustion engine. Referring additionally to Figure 9, a summary of the data signals is as follows:

A - engine on signal

B - acoustic resonance detection signal C - frequency scanning and acoustic data

D - frequency and gating control

E - current feedback from cell

F - current control

G - low water signal H - water pump on signal

I - alarm signal

J - system status output

K - external interface

L - optional oxygen sensor output M - optional thermostat low temperature signal

N - optional heater on signal

In the event the device 1 is fitted to equipment that has oxygen sensors incorporated, the processor can be programmed to send out the appropriate signal voltage to the oxygen sensor ranging from 0.1V to IV. This will ensure that the engine management system does not over compensate with fuel due to the addition of hydrogen and oxygen in the combustion chamber from the electrolysis cell. The device 1 should not generate gases if the connected internal combustion engine, boiler or other combustion unit is not operating as this could lead to an accumulation of inflammable gas within the combustion unit.

The engine on sensor 47 may measure battery voltage to detect the charging condition and thereby whether the engine and alternator are running. Further examples of the sensor 47 include an acoustic sensor to detect the sound of the internal combustion unit running, or a vacuum sensor operative to detect a vacuum generated when the internal combustion unit is running. The engine on sensor 47 may alternatively comprise a Hall effect transducer connected around the alternator output to generate a signal if the transducer detects the presence of a current.

On receipt of an engine on signal A from the engine on sensor 47, the processor 61 sends a gating instruction D to the phase locked loop (PLL) circuit 63. This is the command that controls the frequency and on/off ratio of the square wave current pulses to the electrolysis cell 5. Acoustic resonance signals B are passed from the acoustic sensor 49 to the PLL circuit 63, which then sends frequency scanning and acoustic data C to the processor 61.

The processor 61 uses this information to redefine the frequency and gating control signal D that is passed via a polarity reverser circuit 65 to the electrolysis cell 5. Using feedback E from the polarity reverser circuit 65, the processor 61 also controls the current F to the cell 5 up to a predefined maximum.

The processor 61 also monitors the water level in the electrolysis cell 5 and when it receives a low water signal G from the water level sensor 13 it sends an activation signal H to the water pump 11. Water from the reservoir 9 is then pumped into the electrolysis cell 5, and continues to be pumped until the water level sensor 13 signals a high level. The processor 61 activates a timer for this function. If the high level signal is not detected, the fill function will time out and the pump will stop and an alarm signal will be sent to the system display. The safety function is incorporated to ensure that the cell is not overfilled due to a faulty level sensor. If the water level does not increase within a pre-selected time, the processor 61 sends an alarm signal I to be displayed on the system status display 51 to signify that the water reservoir 9 is empty or there is a malfunction.

Using a Bluetooth^® interface or other appropriate wireless protocol, the processor 61 also sends status signals J to the remote system status display.

The processor 61 also provides an interface for external inputs and outputs K. The interface may include a data channel for the transfer of archived system performance such as live or archived system information, the downloading of new programs for the processor 61 , A/D converters to convert analogue signals to digital signals, and a multiplexer to expand the number of channels that can be monitored.

External ports provide capability to receive digital inputs such as from the vehicle's engine management system and tracking equipment, input from remote computers for software upgrades or interrogation, parallel digital inputs from, for example, on/off devices such as relays or reed switches; and parallel analogue inputs from for example temperature sensors and pump current sensors. Outputs from external ports include: parallel digital outputs such as to relays and to the power regulator; and serial digital outputs such as to the engine management system, tracking system and to ports for communication with diagnostic computers. An interface with the vehicle's on-board computer allows the controller to read the engine' s operating parameters (rpm, speed, mass air flow, throttle position, for example.)

The device status display 51 can be mounted remotely from the electrolysis cell 5 to give the operator or driver information on the status of the device 1.

The device status display 51 can be connected to the ECU 7 by wire.

In some applications such as vehicle installations it may be difficult to physically connect the status display 51 to the ECU 7 and it may be more appropriate to use a wireless technology such as Bluetooth.

The status display 51 may comprise coloured light emitting diode (LED) indicators showing two or more status conditions. For example a green light indicates the device 1 is operating correctly. A red light can indicate a fault such as, for example, the device 1 requires more water. This LED is triggered from the processor 61 when there is a low water signal from the water level sensor 13 and should switch off after a few seconds once the water pump 11 has filled the housing 3 to the maximum level. If the red LED fails to go out this indicates to the operator or driver that the device 1 requires more water in the reservoir 9. The red LED also illuminates if there is no signal from the processor 61 indicating there has been a processor or other electrical fault. The red LED could also illuminate if the level sensor caused a 'time out' from the ECU 7.

The LEDs may be augmented or replaced with one or more gauges showing the status of the device 1. An audible buzzer may be provided where it is critical that the operator is aware of the status of the device 1. The device 1 incorporates an optional heater in the form of PVC insulated heating tape surrounding the water reservoir, the water pump, the electrolysis cell and the connecting hoses. The heating tape is energised when the processor 61 receives a low temperature signal from the thermostat, for example when the temperature is 1 °C.

Despite the use of an appropriate water filter and passivated stainless steel components, it is still possible that sediment will accumulate at the bottom of the electrolysis cell 5. The sloping internal floor 17 comprises a further part of the sediment control means and encourages the accumulation of sediment at the drain plug 19 to ensure effective flushing of the cell 5 during regular maintenance.

To further minimise the production and accumulation of sediment, the polarity of the electrodes in the electrolysis cell 5 can be reversed on a regular basis, again, depending on the type of feed water used.

With reference to Figure 10, the polarity reverser 65, which comprises a further part of the sediment control means, comprises a 20-amp double changeover relay to change the polarity of the anode and cathode. As sediment is deposited only at one electrode, by reversing the polarity, this has the effect of returning precipitated sediment deposits back into solution and thereby reducing the overall amount. The frequency of reversal can vary depending on the operating conditions and quality of water being used. As an example only, the polarity of the electrodes may be reversed every five minutes of operation although this can vary depending on the type of water used.

An audible tone can often accompany the introduction of electrical pulses into the electrolysis cell 5. One indication that the frequency of these pulses is at a resonant frequency is through a marked increase in loudness of the tone. The acoustic sensor 49 in the form of an ultrasonic or acoustic transponder is used to measure this acoustic change to identify acoustically the resonant frequency for the cell 5 at that time. The resonant frequency can change depending on several factors such as the type and quantity of water, and/or operating temperature of the electrolysis cell 5. This information is fed back to the PLL circuit 63 and processor 61 from where the pulse frequency is adjusted accordingly.

It will be appreciated that the position of the mounting bars 27 relative to the plates 21 is such that the bars 27 are at 90° to the plane of the plates 21 and pass through a nodal point in each plate 21 so as to minimise contact between adjacent plates 21 and so as to have the minimum interference with the resonance of the plates 21.

To ensure there is not an accumulation of sedimentary deposits on the electrolysis plates 21 , the processor 61 can periodically instruct the ultrasonic transducer to emit a short ultrasonic 'cleaning' pulse into the electrolysis cell 5, again, depending on the type of feed water used.

The electronic control unit 7 has a built in thermal fuse link which can be reset. This fuse link ensures that the device 1 has protection against any power spikes. To protect the external combustion unit to which the device 1 is connected, a 20-amp in line fuse is fitted. The fuse is connected between the equipment battery positive terminal and the electrolysis cell 5. This will ensure that any power failure modes within the device 1 will not adversely affect the unit it is fitted to.

Referring now to Figures 11 to 13 a modified device 71 is shown with like features being given like references to that device 1 described above. The modified device 71 comprise a 'P' shaped housing 73 having a lower, relatively narrow leg portion 73A and an upper, relatively wide body portion 73B.

The electrolysis cell 5 is mounted in the leg portion 73A. The plates 21 of the cell 5 are relatively tall and narrow and thus two vertically spaced pairs of mounting bars 27 are provided: two towards the lower margin of the plates 21 and two towards the upper margin of the plates 21.

In this example one of the power bars 33 is cranked to as to exit the housing 73 through the body portion 73B.

It will be appreciated that any suitable shape of housing can be used as required to enable the device 1 to fit into the requisite space.

Likewise the various other components such as the water reservoir 9, water filter 10, the ECU 7, the water pump 11 and the device status display 51 can be mounted relative to the housing in any desired position which may be on the housing or remote from the housing.

Suitable snap fit connections can be used to connect the various components together either directly or via suitable conduits.

The housing 3, 73 can be made from any suitable material or materials one example of which is polypropylene.

The air and water inlets 8, 45 and the gas outlet 15 can be located in any desired position on the housing 3, 73 and this may be in the top or sides of the housing 3, 73 as required. Likewise, the power bars 33 can exit the housing 3, 73 at any desired position which may be the top or sides of the housing 3, 73 for example.

Referring to Figure 14, the water reservoir 9 feeds water (electrolyte) to the cell 5 via a water pump 11. The pump 11 is arranged in normal use to allow the water to free flow through it. A valve, such as for example a solenoid valve 79, may be provided between the pump 11 and the electrolysis cell 5. When activated the valve 79 opens to allow water to flow to the cell 5 under pressure from the pump 11. When deactivated, the valve 79 is closed such that water cannot flow to the cell 5 from the reservoir 9. This allows the reservoir 9 to be fitted in any position relative to the cell 5 without compromising the level of fluid in the cell 5. The valve 79 is controlled by the ECU 7.

Referring to Figure 15, the water filter 10 may comprise a removable filter cartridge 81 which may be screwed or clipped onto the inlet of the water reservoir 9. In Figure 15a, the filter cartridge 81 is mounted generally externally of the water reservoir 9, whereas in Figure 15b, the filter cartridge 81 is mounted generally internally of the water reservoir 9, in each case using a threaded or bayonet type connection.

With reference to Figure 15c, the filter cartridge 81 comprises a generally cylindrical filter body 82 having a frustro-conical outlet portion 83. A mesh inner container 84 is mounted inside the filter body 82 and is provided with a filter medium 85. An upper mesh screen 86 extends across the top of the filter medium 85 and a cartridge lid 87 seals the cartridge 81. The filter medium 85 can be of any suitable material or combination of materials such as granules or filter mesh as required. Referring additionally to Figure 16, a hydrogen sensor 89 may be provided that is controlled by the ECU 7. The hydrogen sensor 89 generates an output signal indicative of the level of hydrogen in an enclosed space, indicated notionally by 91 , in which the cell 5 is located. Such an enclosed space 91 may be, for example, the driver's cab of a truck, or the engine compartment of the vehicle if this was sealed such as might be the case for an amphibious vehicle.

The sensor 89 may be arranged to transmit the output signal to the ECU 7 when the concentration of hydrogen gas reaches a pre-determined level, for example 15000 parts per million. The level may be chosen to be higher than would be expected in normal use of the cell but below a level that could ignite from a spark. On receipt of such an output signal, the ECU 7 is operative to immediately cut the electrical supply to the cell 5 such that further hydrogen gas production by the cell is halted.

With reference to Figure 17, vibration means are provided to facilitate the removal of any bubbles of hydrogen that may have been generated by the cell 5 in use but which remain attached to the electrolysis plates of the cell 5 rather than floating away. The effect of such bubbles is that the area of the electrolysis plates that is available for electrolysis is reduced, thus reducing the level of usable hydrogen produced.

In this example the vibration means comprises a plurality of ultrasonic transducers 93 that are spaced around the outside of the walls of the cell 5. The ultrasonic transducers 93 generate high frequency vibrations through piezo-electric effects. These pulsed vibrations create ultrasonic pressure waves within the fluid contained in the cell, which facilitate removal of hydrogen bubbles from the electrolysis plates. This improves the efficiency of hydrogen gas production. The operating frequency of the transducers 93 can be adjusted to suit the configuration of the cell 5 in question, and in particular the size of cell 5 and the number of electrolysis plates employed. The ECU 7 may be operative to enable the frequency of the transducers 93 to be varied with the system in situ, in dependence upon the measured hydrogen gas output.

The number of ultrasonic transducers 93 can be varied as desired and indeed it is envisaged that only one transducer 93 may be used. The location of the, or each, transducer 93 can also be varied as required. In once example it would be possible to have a transducer 93 on each of the four sides of the cell 5, aligned with the axes of the cell 5.

Referring to Figures 18 to 23 a modified device 101 comprises a modified housing 103 and modified electrolysis cell 105. The overall features and function of the modified device 101 are as described above with reference to Figures 1 to 10. However, in the modified device 101 , the housing 103 is arranged such that the electrical connections to the power bars 33, and the connections to the water inlet 8, the gas outlet 15, and the air inlet 45 are all made on only one side of the housing 103. This facilitates assembly and maintenance and also helps to protect the connections from damage.

The modified electrolysis cell 105 comprises similar features to those described above with reference to Figures 1 to 10 but arranged such that the cell 105 comprises a cell module that can be preassembled, and then mounted as a single module on the housing 103.

In this example, the plates 21 are positioned sequentially as a positive then negative electrode in five sets 122 of four plates 21. 316-grade stainless steel is a preferred material for the plates 21 although other grades can also be used.

Electrically insulating, in this example polypropylene, insulating plates 128 separates each set 122 of plates 21 from the next. The insulating plates 128 are machine cut to fit the interior of the housing 103, which ensures each set 122 of plates 121 is in its own compartment. The plates 21 of each set 122 are connected together by stainless steel rod 30 that extends through an upper part of each plate 21 at a pre-determined height. This arrangement ensures that "rogue" currents are eliminated and each set 122 of plates 121 has limited losses.

Each insulating plates 128 is provided with a cut-away 128 A at the bottom portion to allow self-levelling of the electrolyte within the housing 103 , between sets 122. This can be seen with reference to Figure 21.

The baffle 35 is mounted at a predetermined height on the power bars 33 directly above the plates 21. In this example two smaller sub- baffles 35A, 35 B are mounted on top of the baffle 35 at right angles to the main baffle 35. The sub-baffles 35 A, 35B are rectangular baffle plates provided with spaced apart circular venting apertures.

The baffles 35 , 35 A, 35B are all drilled at pre-determined points to allow maximum gas flow, but minimise water movement.

A lid 39 for the housing 103 is then placed on top of power bars 33 and sits flush on top of the two sub-baffles 35 A, 35B and also along an upper, interior lip 103A of the housing 103 where it is secured using nylon nuts and bolts. The lid 139 sits below the upper margin of the enclosure 103. An upper enclosure cover 140 is provided to close the enclosure 103 and to protect the upper parts of the power bars 33, the gas outlet 15, water inlet 8, and air inlet 45, where they project through the lid 139 prior to exiting the enclosure 103 through one of the sides of the enclosure 103.

This above described arrangement allows the cell 105 to be assembled as a module outside of the enclosure 103 prior to being located in the enclosure 103 and secured using the lid 39.

It is envisaged that any suitable number of plates and sets of plates may be used as required, and that the above described arrangements are examples only.

With reference to Figures 24 and 25 a further modified device 201 has identical components to the modified device of Figures 18 to 23 but the shape of the enclosure 203 is taller and narrower so as to represent a device for mounting where space is limited. In this example four sets 122 of plates 121 are provided.

Claims

1. An electrolysis device for generating hydrogen and oxygen for use in improving the combustion of hydrocarbon fuel, the device comprising a housing containing an electrolysis cell, and electronic control means to provide an electric current to the cell, the device further comprising sediment reduction means operative to reduce the sediment that accumulates in the cell such that the device can be used with tap or sea water without an electrolyte so as to generate hydrogen and oxygen gas from the tap or sea water.

2. The electrolysis device of claim 1 wherein the sediment reduction means comprises water pre-treatment means operative to pre-treat the water so as to render the water more suitable for electrolysis prior to the water entering the electrolysis cell.

3. The electrolysis device of claim 1 or claim 2 wherein the water pre- treatment means comprises a filter.

4. The electrolysis device of claim 3 wherein the filter comprises a multistage filter.

5. The electrolysis device of claim 4 wherein the multistage filter includes a fine particle filter operative to remove larger particles including sediment and rust.

6. The electrolysis device of claim 4 or claim 5 wherein the multistage filter may include an activated carbon filter operative to absorb chlorine.

7. The electrolysis device of any one of claims 4 to 6 wherein the multistage filter may include an ion exchange resin filter operative to reduce the amount of unwanted trace metals.

8. The electrolysis device of any one of claims 4 to 7 wherein the multistage filter includes an ultra fine mesh filter.

9. The electrolysis device of any one of claims 3 to 8 wherein the filter comprises a removable filter cartridge that can be removed from the device and replaced when required.

10. The electrolysis device of any one of the preceding claims wherein the sediment reduction means comprises metal components in the electrolysis cell, the metal components having had anticorrosion pre- treatment.

11. The electrolysis device of claim 10 wherein the pre-treatment comprises a chemical pre-treatment of the metal components.

12. The electrolysis device of claim 10 or claim 11 wherein the metal components may comprise stainless steel components.

13. The electrolysis device of any one of claims 10 to 12 wherein the metal components comprise components electrochemically plated with nickel, platinum, platinum alloy, or mixed metal oxide.

14. The electrolysis device of any one of claims 1 to 10 wherein the sediment reduction means comprises plates formed from a plastics material, the plates comprising an electrically conductive filler.

15. The electrolysis device of claim 14 wherein the sediment reduction means comprises polypropylene plates, the filler comprising carbon particles to provide electrical conductivity.

16. The electrolysis device of any one of the preceding claims wherein the sediment reduction means comprises the electronic control means when operative to generate an electric current such as to reduce the sediment.

17. The electrolysis device of claim 16 wherein the sediment reduction means comprises the electronic control means generates an electric current to the electrolysis cell utilising at least one of pulse width modulation, phase lock loop and current modulation circuitry.

18. The electrolysis device of any one of the preceding claims wherein the electric control means is operative according to a cleaning cycle wherein a high frequency cleaning current is applied to the electrolysis cell to dislodge sediment from the cell.

19. The electrolysis device of claim 18 wherein the frequency range of the high frequency cleaning current is between 15kHz and 40OkHz.

20. The electrolysis device of any one of the preceding claims wherein the cleaning current is an ultrasonic frequency current.

21. The electrolysis device of any one of the preceding claims wherein the electronic control means comprises a polarity reverser operative to sequentially vary the polarity of the current to the cell.

22. The electrolysis device of any one of the preceding claims wherein the electronic control means comprises an acoustic identification unit operative to acoustically identify the resonant frequency of the cell, the electronic control means being operative to provide an electric current at the identified resonant frequency to the cell.

23. The electrolysis device of any one of the preceding claims wherein the electronic control means comprises a sensor operative to generate a signal indicative of when an internal combustion unit with which the device is used is running, the electronic control means sending an electric current to the electrolysis cell only when the signal is received.

24. The electrolysis device of claim 23 wherein the sediment reduction means comprises sensor comprises an acoustic sensor operative to generate the signal when the noise of the internal combustion unit running is detected.

25. The electrolysis device of claim 23 wherein the sensor comprises a vacuum sensor operative to generate the signal when a vacuum generated when the internal combustion unit is running is detected.

26. The electrolysis device of any one of the preceding claims wherein the cell comprises a plurality of spaced apart plates, the plates being mounted on at least one support bar in the housing, the support bar passing through a nodal point on each plate, that is, a point having the minimum interference with any resonance of the plate.

27. The electrolysis device of any one of the preceding claims wherein the cell comprises a plurality of sets of spaced apart plates, each set of plates being electrically isolated from the next by an insulating plate.

28. The electrolysis device of any one of the preceding claims wherein the sediment reduction means comprises a sloping internal floor of the housing to enable sediment to collect at the lowest part of the floor.

29. The electrolysis device of any one of the preceding claims wherein the housing comprises a baffle arranged to be above the electrolyte level in use of the electrolysis cell, the baffle being operative to resist electrolyte from entering the gas outlet pipe from the electrolysis cell, if the device were to be moved violently.

30. The electrolysis device of claim 29 wherein the baffle comprises a primary baffle plate mounted across the top of the electrolysis cell, the baffle plate comprising at least one aperture through which gas can escape in use of the device.

31. The electrolysis device of claim 30 wherein the baffle further comprises at least one sub-baffle plate arranged in a non-parallel manner with the primary baffle plate, the sub-baffle plate comprising at least one aperture through which gas can escape in use of the device..

32. The electrolysis device of any one of the preceding claims further comprising a hydrogen sensor operative to generate an output signal indicative of the levels of hydrogen gas in the vicinity of the device, the electronic control means being operative to cut the electricity supply to the electrolysis cell when the output signal indicates that the levels of hydrogen gas in the vicinity of the device have reached a predetermined level.

33. The electrolysis device of any one of the preceding claims wherein the electrolysis cell comprises a cell module that can be removably mounted in the housing.

34. The electrolysis device of claim 33 wherein the sediment reduction means comprises at least two of the following components: electrically conductive electrolysis plates, electrically insulating plates between at least some of the electrolysis plates; power bars connected to the electrolysis plates which in use conduct electricity to the plates; and an electrically insulating mounting rod on which the electrolysis plates are mounted.

35. The electrolysis device of any one of the preceding claims wherein at least two of the connections to the device may be located on a side wall of the housing.

36. The electrolysis device of claim 35 wherein all of the primary connections to the device are located on the same side wall of the housing.

37. The electrolysis device of claim 35 or claim 36 wherein the primary connections include an air inlet, an electrolyte inlet, a hydrogen gas outlet, and the electrical connections to the electrolysis cell.

38. The electrolysis device of any one of the preceding claims comprising an inlet air filter arranged in the housing to function as a water overflow outlet.

39. An electrolysis device for generating hydrogen and oxygen for use in improving the combustion of hydrocarbon fuel, the device comprising a housing containing an electrolysis cell, and electronic control means to provide an electric current to the cell to generate hydrogen and oxygen when an electrolyte is contained in the electrolysis cell, the device further comprising vibration means operative to dislodge bubbles of gas that attach to parts of the cell as part of the electrolysis process.

40. The electrolysis device of claim 39 wherein the vibration means comprises an ultrasonic transducer operative to induce ultrasonic pressure waves within the electrolysis cell.

41. The electrolysis device of claim 40 wherein the electronic control means comprises frequency adjustment means operative to adjust the output frequency of the ultrasonic transducer and thus the frequency of the ultrasonic pressure waves.

42. The electrolysis device of any one of claims 39 to 41 wherein more than one ultrasonic transducer is provided.

43. The electrolysis device of claim 42 wherein at least one ultrasonic transducer is aligned with an axis of the electrolysis cell.

44. An electrolysis device for generating hydrogen and oxygen for use in improving the combustion of hydrocarbon fuels, the device comprising a housing containing an electrolysis cell, the device further comprising electronic control means comprising an acoustic identification unit operative to acoustically identify the resonant frequency of the cell and to provide an electric current at the identified resonant frequency to the cell so as to generate hydrogen and oxygen gas from liquid in which the electrolysis cell is immersed in use.

45. An electrolysis device for generating hydrogen and oxygen for use in improving the combustion of hydrocarbon fuels, the device comprising a housing containing an electrolysis cell, the electrolysis cell comprising at least two electrodes, the device further comprising electronic control means operative to provide an electric current of sequentially varying polarity to the electrodes so as to generate hydrogen and oxygen gas from liquid in which the electrolysis cell is immersed in use.

46. A hydrocarbon combustion unit comprising the device of any one of claims 1 to 45.

47. The unit of claim 46 wherein the hydrocarbon combustion unit comprises an internal combustion engine for a vehicle, or a static generator.

48. The unit of claim 46 wherein the hydrocarbon combustion unit comprises a boiler for a building.

49. A water pre-treatment device for use with an electrolysis device of the type that generates hydrogen and oxygen for use in improving the combustion of hydrocarbon fuel, the water pre-treatment device comprising a filter container comprising a water inlet operative to be connected to a water source, and a water outlet operative to be connected to a water reservoir of the type to deliver water to the electrolysis device in use, the filter container further comprising a filter operative to filter the water so as to render the water more suitable for electrolysis.

50. The water pre-treatment device of claim 49 wherein the filter comprises a multistage filter.

51. The water pre-treatment device of claim 50 wherein the multistage filter includes a fine particle filter operative to remove larger particles including sediment and rust.

52. The water pre-treatment device of claim 50 or claim 51 wherein the multistage filter includes an activated carbon filter operative to absorb chlorine.

53. The water pre-treatment device of any one of claims 50 to 52 wherein the multistage filter includes an ion exchange resin filter operative to reduce the amount of unwanted trace metals.

54. The water pre-treatment device of any one of claims 50 to 53 wherein the multistage filter includes an ultra fine mesh filter.

55. The water pre-treatment device of any one of claims 49 to 52 wherein the filter comprises a removable filter cartridge that can be removed from the device and replaced when required.