GB2521275A

GB2521275A - Apparatus and method for engine fuel systems

Info

Publication number: GB2521275A
Application number: GB1422023.0A
Authority: GB
Inventors: Stephen Grieve
Original assignee: ENGYM SERVICES Ltd
Current assignee: ENGYM SERVICES Ltd
Priority date: 2013-12-11
Filing date: 2014-12-11
Publication date: 2015-06-17
Also published as: GB201321884D0

Abstract

Disclosed are apparatus and methods for treating internal combustion engines, and in particular the fuel systems of engines, in order to improve efficiency and reduce pollution. The apparatus comprises a reservoir 2 containing a cleaning composition and a delivery line 20 which may be connected to a fuel system of an engine. The cleaning compositions may be delivered to the fuel system to remove deposits which can block fuel lines, injectors, housings, pumps and the like. The present system is particularly suited to diesel engines, but could also be used in petrol engines. The apparatus also suitably contains a fuel cleaning device and optionally an agitator to agitate fuel in a tank.

Description

Apparatus and Method for Engine Fuel Systems The present invention relates to apparatus and methods for treating internal combustion engines, and in particular the fuel systems of engines, in order to improve efficiency and reduce pollution. The apparatus of the present invention is adapted to deliver cleaning compositions to the fuel system to remove deposits which can block fuel lines, injectors, housings, pumps and the like. The present system is particularly suited to diesel engines, but could also be used in petrol engines.

Background of the Invention

During the operation of any internal combustion engines deposits and contamination build up on all the major engine components. This is particularly noticeable within the fuel management systems, with harmful deposits building up on the fuel injectors and other critical components. Untreated these contaminants can seriously impede engine performance and reduce the effective working life of an engine. They can also have a detrimental impact on the fuel combustion, making it less economical and more polluting to run the engine.

Over time the fuel inside the system can also become contaminated with water and microbes, and it is advisable to remove these from the fuel system to improve the overall fuel combustion rate as well as reduce the contamination of the fuel management system.

Furthermore, it is desirable to remove such contaminants from fuel storage vessels.

Various fuel additives are marketed which are alleged to clean fuel systems. However, there is little clear evidence for their efficacy, and it would appear that their effects are marginal.

There remains a need for apparatus and methods to effectively restore the fuel systems of internal combustion engines.

Statements of the Invention

In a first aspect the present invention provides an apparatus for cleaning the fuel system of an engine, the apparatus comprising: -a reservoir adapted to contain a cleaning composition; and -a delivery line connectable to the fuel system to deliver the cleaning composition from the reservoir to the fuel system of the engine.

Preferably the engine is an internal combustion (IC) engine, such as a diesel or petrol (gasoline) engine, but the apparatus in principle could be used with any engine which runs on liquid hydrocarbon fuels.

Preferably the apparatus comprises a return line connectable to the fuel system of the engine to receive cleaning composition returning from the fuel system. Suitably the cleaning composition is returned to the reservoir.

Preferably the delivery line is adapted to deliver the cleaning composition to the fuel line of the engine fuel system at a point between the primary fuel pump (typically located at or near the fuel tank) and the fuel delivery system of the engine, e.g. the fuel injection system or carburettor or the like, whereby fuel is processed for introduction to the combustion chamber of the engine.

The term fuel injection system' is used in a broad sense to relate to any of the diverse systems used to introduce fuel directly into the combustion chamber of an IC engine. It thus includes true injection systems such as direct injection system which inject fuel directly into the combustion chamber (e.g. common rail injection systems), and indirect injection systems, such as multi-point fuel injection, where injection happens in the intake tract or cylinder port.

Suitably the reservoir stores the cleaning fluid at atmospheric pressure, or close thereto.

The cleaning fluid is pressurised for delivery to fuel system using a suitable pump.

Alternatively the apparatus is adapted to store the cleaning composition at pressure. For example, the reservoir may store the fuel at a pressure of from 0.5 bar to 5 bar, more typically from 0.75 to 2 bar, and typically approximately 1 bar (pressures are given as a value above normal atmospheric pressure). This allows the cleaning composition to be delivered at an appropriate pressure without the need for a pump in the apparatus. In general this is less preferred than using a pump, but in some circumstances, e.g. where a compressed air line is readily available, it may be preferred.

Preferably the reservoir is adapted to contain at least 2 litres of cleaning composition, suitably from 5 litres to 20 litres, and typically about 10 litres. The overriding consideration is that the reservoir should contain enough cleaning composition to complete the intended cleaning operation.

Preferably the reservoir is at least partially filled with a cleaning composition.

Preferably the reservoir comprises a pressure release valve to allow pressure to be released if it rises above a predetermined level, for example 5 bar. This prevents a build-up of pressure leading to rupture of the reservoir. In preferred embodiments the reservoir is typically non-pressurised, but pressure above atmospheric can originate from the heat expansion rate of the returning fuel and also the function of de-pressurising the system directly to the reservoir on power down mode. Any concerns about over pressurisation are addressed by the function of the pressure relief valve, situated in the reservoir body.

Preferably the reservoir comprises a measurement device to measure the amount of cleaning composition present in the reservoir. Suitable measuring systems are well known in the art, and include conventional fuel tank level sensors, e.g. those commercially available from IFM Electronics Ltd, UK or Gentech International Ltd UK.

The apparatus suitably comprises a pressurising means which is adapted to pressurise the cleaning composition to a desired pressure. Suitably the apparatus comprises a pump which pressurises the cleaning composition. Suitable pumps are well known in the art, and examples include conventional fuel pumps. This pump can suitably be located in the delivery line.

Alternatively the cleaning composition can be pressurised in the reservoir. This can be achieved by, for example, pumping air into the header space in the reservoir. Alternatively, a separate pressurising means can be used to pressurise the reservoir, e.g. a compressed air line in a workshop or the like.

Preferably the reservoir is an external reservoir, i.e. it is located outside of an enclosure holding the various pumps, filters and other parts of the apparatus. This is desirable to permit easy access to the reservoir, e.g. for filling or cleaning, but also as a safety feature as the reservoir is highly unlikely to be punctured or otherwise damaged in the case of a malfunction in the apparatus, e.g. catastrophic failure of a pump or a pressurised line/vessel.

Preferably the apparatus comprises a pressure control means adapted to maintain the pressure of cleaning composition in the delivery line. Suitably the pressure of the cleaning composition is matched to the normal operating pressure of the fuel system provided by its fuel pump. Where the cleaning composition is to be administered to the engine as it is running it is often very important that if the delivery pressure of the cleaning composition is substantially matched to the normal fuel pressure as this will prevent the ECU controlling the engine from preventing operation of the engine -the ECU typically cuts off the engine if the fuel pressure is not within an acceptable range. The relevant fuel pump /system pressure varies between engines. The typical range is from 1 bar to 4 bar, more typically from 1 bar to 2 bar in typical applications.

Pumps or the like can be used to modulate the pressure of the treatment composition in the delivery line. Suitably a cleaning composition pump (e.g. as described above) is located in the delivery line to apply a suitable pressure to the cleaning composition. It is preferred that such a pump is adjustable to alter the pressure exerted on the cleaning composition.

Alternatively, the pressure control means can simply comprise maintaining a suitable pressure in the reservoir so that the pressure of the treatment composition delivered to the fuel system is within the required range. Pressure control valves and the like can also be used to modulate the pressure of the cleaning composition if required.

Suitably the apparatus comprises a pressure measuring means to measure the operating pressure of the fuel system of an IC engine. Such a pressure measuring means is suitably adapted to be attached to the fuel system when pressurised by the fuel pump of the fuel system. It measures the pressure in fuel system and this pressure can then be used to set the pressure control means of the apparatus.

This procedure is suitably carried out by connecting the delivery line of the apparatus to the direct supply line coming from the fuel tank via the in-tank electric pump. The in-coming pressure is measured via a pressure sensor located in the device delivery line, which in turn relays the information to the HMI/PLC for control of the pressure control means; this is described further below.

Suitably the pressure measuring means is provided in the delivery line for the cleaning composition. The delivery line can thus be attached to the fuel system, e.g. via a T-piece and the engine startedlignition turned on to engage the fuel pump of the fuel system. The pressure measuring means measures the native' pressure of the fuel system. A record of the native pressure is retained for use in setting up the apparatus for the cleaning process.

When determining the native pressure the apparatus is configured to prevent the fuel travelling up the delivery line, e.g. using a one-way valve which only permits flow in the intended direction. This prevents fuel from flowing up the delivery line under the pressure applied by the engine's fuel pump.

An additional or alternative system for determining the native pressure of the system comprises a pressure sensor which is provided in a remote unit. The remote unit can suitably be in communication with the apparatus via a wired or wireless connection, e.g. an umbilical cable or a Bluetooth connection. The remote unit has suitable interface means to allow it to be connected to the fuel system and thus measure the native pressure. The measured pressure is then used to configure the apparatus, as described previously.

Whichever specific manner of measuring the native pressure is used, it is a significant advantage of the present invention that it allows the native pressure of any given fuel system to be measured, and the apparatus configured to match that pressure. Typically this is achieved using a PLC which controls operation of the apparatus, and which can receive details of the native pressure and then set the pump of the apparatus to substantially match the native pressure. This avoids the need to maintain a list of all vehicle fuel system pressures (which is prone to becoming out of date) or to carry out a trial and error approach to finding a suitable pressure. Furthermore, measuring the native pressure of a fuel system can be useful in identifying problems in the pressurisation of fuel system, e.g. as a result of a worn or faulty pump, e.g. if the measured native pressure is significantly different from an expected value.

Another possibility is the provision of an in-line pressure sensor permanently in the fuel system of the engine which constantly or selectively measures the native pressure. Such sensors are commercially available, e.g. part number PT9554 from IFM Electronics.

Suitable pressure sensors for use in the pressure measuring means are well known in the art. Examples of suitable sensors include piezoresistive absolute pressure sensors and cavity pressure sensors. It is preferred that the sensors are ratiometric with power supply to sensor.

The apparatus of the present invention can thus be readily configured to mirror the pressure of the fuel system of the engine.

Preferably the apparatus of the present invention comprises at least one filter adapted to filter the cleaning composition. Conventional fuel filters are suitable for this purpose in the present invention.

A filter is preferably provided between the reservoir and the end of the delivery line. This prevents contaminants that might accumulate in the reservoir progressing to the fuel system of the IC engine.

Preferably a filter is provided between the reservoir and the cleaning composition pump.

This prevents contamination present in the reservoir reaching the cleaning composition pump where it could damage or block the pump.

Preferably a filter is provided downstream of the cleaning composition pump. This is desirable to ensure that, should the cleaning composition pump malfunction, any debris emanating from the pump is not able to pass into the fuel system of the IC engine. Such debris could, at worst, cause catastrophic damage to the fuel system of the engine, or at least partially clog the fuel filter(s) of the engine.

Preferably the delivery line is provided with one or more pressure and or flow measuring devices. These can be used to measure the pressure and/or flow of the cleaning composition as it passes down the delivery line.

Preferably the delivery line is provided with a pressure release valve to allow the pressure in the fuel system to be relieved. This can be achieved by releasing the pressure to the reservoir or the return line, e.g. via a suitable pressure release line.

Preferably the delivery line comprises a safety shutoff valve, which can operate to prevent flow out of the outlet, e.g. is the case of malfunction or an emergency stop. The safety shutoff valve is preferably located downstream of the pump. If a pressure release valve is provided in the delivery line, then the safety shutoff valve is preferably located upstream of the pressure release valve.

Preferably the reservoir comprises a measurement device to measure the level of the cleaning composition within the reservoir. The measurement device conveniently allows the amount of cleaning composition consumed against time, which gives a robust fuel consumption measure. This can be utilised instead of, or in addition to, flow meters in the delivery line or the like.

Preferably the apparatus comprises an emergency stop system which allows for the various operations of the apparatus to be halted when required. The emergency stop system can suitably cut the power to the various pumps of the apparatus and optionally operate one or more safety valves, e.g. to shut off flow and/or release pent-up pressure.

Preferably the apparatus comprises a remote emergency stop unit. This allows a user to stop the apparatus, e.g. in the case of malfunction, even when not in proximity to the device.

For example, an emergency stop button can be provided on an unit which is connected to the apparatus via a cable or via a wireless connection (e.g. Bluetooth). A user may well have to move away from the apparatus during a cleaning process, e.g. to carry out other maintenance operations, and having a remote emergency stop allows the user to do this but retain the ability to shut the apparatus down rapidly and without approaching it, if needed.

The apparatus can suitably be provided with a fuel cleaning device adapted to filter a fuel supply stored in a storage vessel. Suitably the fuel cleaning device comprises a fuel inlet line adapted to receive fuel from the fuel supply, a filter adapted to remove contamination from the fuel, and a return line to return the filtered fuel to the fuel supply.

The fuel storage vessel can be the fuel tank of a vehicle, or it can be a fixed bulk store of fuel. Fuel tanks in general are prone to becoming increasingly contaminated over time as contaminants present in fuel (e.g. water and particulates) or microbial deposits accumulate in the tank. It is therefore desirable to remove such contaminants to prevent them entering the fuel system of an engine.

The fuel cleaning device can suitably be adapted to passively receive, filter and return fuel to the fuel supply through action of the fuel pump of the fuel system of the engine or a pump associated with the storage vessel.

Preferably, however, the fuel cleaning device is provided with a pump to actively draw and return the fuel from the fuel supply.

The fuel cleaning device suitably comprises a high flow transfer pump which passes the fuel through a fuel cleaner unit.

Preferably the pump is located downstream of the filter such that it draws fuel through the filter rather than pushing it through. This is of particular benefit in the case of filtration systems which use centrifugal fuel cleaning, which are used in some preferred embodiments of the present invention.

Preferably the fuel cleaning device is provided with a pressure release valve to allow the pressure built up in the fuel cleaning device downstream of the pump to be relieved. This can be achieved by releasing the built up pressure back into the flow line coming from the fuel supply, i.e. upstream of the pump. This allows for recirculation through the pump to occur.

Various fuel cleaner units are available commercially.

A multi stage fuel cleaner unit is particularly suitable for the present invention, e.g. which provides centrifugal separation and membrane filtration. A suitable three stage fuel cleaning unit can provide the following cleaning stages: -Separation: As fuel enters into the filter assembly; it moves through a turbine centrifuge and spins off large solids and water droplets which fall to the bottom of a collection bowl.

-Coalescing: Small water droplets bead-up along the sides of the chamber and on the element, once heavy enough these too fall into the bottom of the collection bowl.

-Filtration: Algae, rust and dirt are then filtered from the fuel by the filter elements, e.g. hydrophobic filter elements -as such elements are waterproof they are much more effective and long lasting than water absorbing elements.

Thus, water is removed from the fuel and gathers in one or more inspection bowls to be drained at the end of the procedure and a membrane filter then serves to trap further contamination.

Suitable the fuel cleaner unit has at least two membranes in sequence, wherein the membranes successively decrease in pore size, thus providing more stringent filtration as the fuel passes through the cleaner. For example, the membrane filtration sequence starts with a 35 micron gauge filter which then reduces to a 2 micron gauge membrane to trap even the smallest contaminants. 2 micron gauge is most commonly used filter in common rail systems in production to date.

An exemplary fuel cleaner unit for use in the present invention is the 1000FH from Racor/Parker.

The fuel cleaning device can be controlled by the HMI/PLC to specific cycle times appertaining to levels of contamination and fuel quantity. It is also incorporated into an emergency shutdown facility within the device control.

The apparatus can further comprise an agitation device to agitate the fuel within a fuel storage tank. The agitation device suitably comprises a pressurisable system which is adapted to direct a pressurised flow of fluid into the tank via a suitable nozzle. For example, the agitation device can be used to deliver a stream of compressed air into a fuel tank to agitate any deposits within the tank and encourage them to become suspended. The suspended deposits are then able to pass through the inlet to the filter of the fuel cleaning device. This means that deposits which would normally by retained on at the bottom or adhered on surfaces of the tank are removed from the tank, thus preventing future contamination. Alternatively the agitation device could direct a pressurised flow of fuel to the tank, e.g. fuel could be taken from the reservoir within the tank, pressurised and then used to agitate the fuel within the tank etc. Alternatively, a mechanical agitator (e.g., a spinning pad or the like) could be used, but this is typically less preferred.

The agitation device can suitably comprise a pressure release valve to permit excess pressure generated by an air compressor to be vented, e.g. when the pressure rises over 2 bar.

Preferably the agitation device is at least partially housed within an enclosure. Providing the agitation device within such an enclosure has the desirable effect of mechanically separating the compressor and associated systems from the fuel/cleaning composition systems, which would be important, for example, in the case of catastrophic failure of the compressor or a pressurised air-line.

The apparatus suitably comprises appropriate electronic control systems to monitor and control operation of the apparatus, and a human/machine interface (HMI) to allow a user to control the various functions of the device.

Appropriate control systems are known in the art, and typically comprise a suitable programmable logic circuit (PLC) which communicates with a user via the HMI, e.g. a touch screen controller or computer. A stylus is to be used in conjunction to prevent screen damage through contamination.

Suitably all active components of the apparatus (e.g. pumps, pressure sensors, flow meters and the like) are connected to the PLC. This allows the PLC to monitor operation of the device and make any necessary adjustments, issue warnings or alarms, or terminate operation of the device if needed, e.g. in the case of malfunction.

The apparatus of the present invention is suitably adapted to monitor various parameters of operation in order to achieve one or more of the following: evaluate the effectiveness of an engine cleaning operation, evaluate the progress of an engine cleaning operation, adjust operational features of an engine cleaning operation; stop operation of the apparatus in the case of malfunction and/or provide feedback to a user on the properties of the engine.

In a simple example, the apparatus is configured to monitor the consumption of the cleaning composition during a cleaning operation. The total amount of cleaning composition consumed can be taken as an indicator of progress of the cleaning operation. Changes in the rate of consumption of the cleaning composition can be taken as an indicator in changes in the condition of an engine, e.g. increased usage may indicate improved operation of a badly contaminated fuel injection system (e.g. because is blockage reduction), and in other cases a reduction in usage of the composition could represent an increase in efficiency of an engine. Additional parameters can be measured to assist with more detailed interpretation.

Suitably the apparatus can be adapted to measure at least the amount of cleaning composition in the reservoir (this can be achieved, for example, using a level meter in the reservoir). Suitably the apparatus is adapted to measure the rate of flow of the cleaning composition to the engine, from the engine, or both to and from the engine (e.g. using flow meters).

In a second aspect of the present invention there is a provided an apparatus as set out above connected to the fuel system of an engine.

Suitably the engine is an internal combustion (IC) vehicle engine, e.g. the engine of a car, van, lorry/truck, boat or the like.

Suitably the engine is a diesel engine or a petrol (gasoline) engine.

In the present aspect the delivery line is suitably connected to the fuel supply line of the engine. It is preferably connected at a point between the primary fuel pump of the vehicle and the fuel delivery system, e.g. fuel injector, and its associated hardware. Preferably the delivery line is connected immediately after the primary fuel pump, and can suitably be connected to the fuel line at the point where it is normally connected to the downstream end of the fuel pump or, in the case of an in-tank pump, at the exit from the tank.

Thus the delivery line is suitably connected upstream of the injection system and high pressure (HP) fuel pump. Preferably it is attached upstream of any pressure regulating valves or fuel temperature sensors present in the fuel system.

The apparatus is configured to substantially match the pressure which the primary fuel pump conventionally applies to the fuel system, which is typically between 0.5 and 1.5 bars.

The return line of the device can be attached at any suitable point after the fuel delivery system. For example, the return line can be connected where the fuel line of the fuel system reaches the fuel tank. This maximises the amount of the fuel system which is exposed to the cleaning composition.

Optionally the fuel tank of the fuel system can be connected to the fuel cleaning device. For example, the fuel inlet line of the fuel cleaning device can be attached to the output from the primary fuel pump, and the return line of the cleaning device can be connected to the fuel inlet of the tank. For a vehicle fuel tank, the inlet/outlet lines of the fuel cleaning device are preferably brought into fluid communication with the fuel via the filler neck aperture.

The fuel tank can also be provided with the fuel agitator device.

The apparatus of the present invention can suitably be provided in kit form, along with a supply of cleaning composition.

In a further aspect the present invention provides a method of cleaning the fuel system of an engine. The method comprises connecting an apparatus as set out above to the fuel system of an engine, and operating the apparatus to thereby delivering a cleaning composition to the fuel system of the engine.

The method may thus comprise: -providing an engine having a fuel system; -providing an apparatus as described above; -delivering a cleaning composition to the fuel system, whereby the cleaning composition passes through at least a portion of the fuel system and removes contaminants therefrom; and -optionally, returning the cleaning composition which has passed through the cleaning composition to the apparatus.

The cleaning composition is delivered to at least the fuel delivery system of the engine, i.e. the system which delivers the fuel in appropriate quantities to the combustion chamber. In particular, the cleaning composition is preferably delivered to at least the fuel injection system of an engine comprising such a fuel delivery system.

The method this comprises connecting the delivery line of the apparatus upstream of the fuel delivery system and connecting the return line of the apparatus downstream of the fuel delivery system.

Preferably the method comprises running the engine while the cleaning composition is delivered to the fuel system.

Preferably the method comprises using the cleaning composition as a fuel source to run the engine. This allows the cleaning composition to pass completely through the fuel system of the engine to the combustion chamber(s). This means that the cleaning composition is able to enter into, and pass through, for example, the fuel rail and injectors and the like, which are parts of the fuel system often at least partially occluded by contaminants.

It is a preferred feature of the present invention that the engine is run using the cleaning composition in substantially pure form. That is to say, that the engine is not run on a conventional fuel which has an additive added thereto, but rather where the cleaning composition is the sole (or at least major) fuel source. Thus the method preferably comprises running the engine for at least a portion of the cleaning cycle using the cleaning composition as the sole fuel source. It will be apparent that there will be traces of normal fuel left in the fuel system which will be mixed with the cleaning composition to some extent, but this will only be relatively small amounts, and will be massively diluted in the total volume of the cleaning composition -where fuel is mixed with the cleaning composition in this way it is only considered a minor fraction, and the cleaning composition is still considered substantially pure.

Thus the method comprises running the engine for a period of time on a fuel source comprising at least 90%, more preferably 95%, most preferably 99% or higher of cleaning composition; correspondingly there is less than 10%, 5% or 1% of the normal fuel present for the relevant period. The period of time is preferably at least 5 minutes, preferably at least 10 minutes, and more preferably at least 20 minutes.

In order for this to occur, it will be apparent that the cleaning composition must be combustible (it will therefore typically be hydrocarbon-based), and have generally comparable combustion characteristics to the normal fuel of the vehicle. In the case of a diesel engine, the cleaning composition preferably has a cetane number of from 40 or higher, preferably from about 51 to 60 as measured in accordance with EN ISO 5165.

Various cetane number modifying additives are known in the art which can be used to modify the cetane number of a cleaning composition, e.g. alkyl nitrates (principally 2-ethylhexyl nitrate) and di-tert-butyl peroxide (DTBP).

A suitable composition for use in the present invention comprises: -70 to 75% by volume of a C7 to C12 petroleum distillate (e.g. white spirit); -20 to 25% by volume of a Ce to C16 petroleum distillate (e.g. kerosene); and -0.5 to 1% by volume of tetrachloroethylene.

This composition has been demonstrated to allow effective cleaning when used in the manner described in the present application.

It is, however, preferred that the cleaning composition has a flash point of 60 CC or higher.

A more preferred cleaning composition comprises: -95% to 99% by volume 06 to 016 petroleum distillate, for example de-aromatised kerosene (e.g. Product no BAS D220-235, Banner Chemicals Ltd, UK) -1% by volume tetrachloroethylene (e.g. Product name Perklone Ext, Banner Chemicals Ltd. UK) This cleaning composition has a flashpoint of over 60 °C and a high level of cleaning efficacy.

Other formulations of cleaning composition could, of course be selected by the skilled person based on the teaching herein and his common general knowledge.

The method comprises running the engine using the cleaning composition as a fuel source for a suitable time period for cleaning to occur. Obviously the amount of time required will depend on the amount of cleaning to be performed, the level of contamination present, the type of contamination present, the type of engine, etc. Thus one cannot define specific time periods for all situations. However, experimental work suggests that time period of from 20 minutes to 1 hour results in a suitable level of cleaning for most engines, including diesel engines in commercial vehicles.

The level of cleaning which has been achieved can be quantified by comparing fuel efficiency and pollutant levels in exhaust gases before and after cleaning. Techniques to do this are well known in the art.

Additionally, by monitoring changes of flow rate of the cleaning composition as cleaning progressed, or by measuring fuel flow rates before and after cleaning, an indication of the amount of cleaning which has occurred can be determined.

The method preferably comprises matching the delivery pressure of the cleaning composition to the native pressure of the engine fuel system. Suitably this can be achieved by measuring the native pressure of the fuel system of the engine and matching the delivery pressure of the cleaning composition to this. However, this can also be achieved by setting the delivery pressure to an appropriate level for the engine type without performing the measuring step, e.g. using a database of pressures for various engines. Exact numerical correspondence of pressures is not required, but the match should be close enough to allow the ECU to permit the engine to run.

The pressure of the cleaning composition can conveniently be set to a desired level using a pump with a variable output pressure to control the pressure in the delivery line.

Suitably the method comprises filtering the cleaning composition within the apparatus to remove contaminants.

Suitably the method comprises cleaning the fuel supply present in a fuel storage vessel (e.g. the fuel tank of a vehicle or an external fuel storage tank) using a fuel cleaning device provided in the apparatus of the present invention.

This can suitably involve connecting an inlet line of the fuel cleaning device to the outlet from the primary fuel pump of the vehicle (or any other suitable location) and attaching the return line to a suitable point of the fuel system upstream of the fuel tank.

As mentioned above, for a vehicle fuel tank it is preferred that the inlet/outlet lines of the fuel cleaning device are preferably brought into fluid communication with the fuel via the filler neck aperture.

The fuel to be cleaned can be moved through the fuel cleaning device by a pump which is provided in the fuel cleaning device.

Agitation of fuel supply can be carried out using a fuel agitation device, e.g. which can be provided as part of the apparatus.

Specific Description of Embodiments of the Invention The present invention will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which: -Fig 1 shows a schematic representation of an apparatus according to the present invention; and -Fig 2 shows a schematic representation of a typical common rail injection fuel system; -Fig 3 shows a schematic of an apparatus according to the present invention and suitable circuitry; -Fig 4 shows a schematic of another apparatus according to the present invention and

suitable circuitry;

-Fig 5 shows a flow diagram operation of the fuel cleaning mode of the present device; and -Fig 6 shows a flow diagram operation of the fuel system cleaning mode of the present device.

-Fig 7 shows typical variability of speed in the steady state runs, test run at 50 mile/h, unmodified vehicle and standard fuel; -Fig 8 shows typical variability of speed in the steady state runs test run at 50 mile/h, modified vehicle and treated fuel; -Fig 9 shows a comparison of fuel consumption of standard vehicle and fuel versus modified vehicle with treated fuel; -Fig 10 shows a comparison of carbon dioxide emission levels of standard vehicle and fuel versus modified vehicle with treated fuel; -Fig 11 shows oxygen emission levels of standard vehicle and fuel versus modified vehicle with treated fuel; -Fig 12 shows nitrogen oxide emission levels of standard vehicle and fuel versus modified vehicle with treated fuel; -Fig 13 shows sulphur dioxide emission levels of standard vehicle and fuel versus modified vehicle with treated fuel; -Fig 14 shows CO emission levels of standard vehicle and fuel versus modified vehicle with treated fuel; -Fig 15 shows uHC emission levels of standard vehicle and fuel versus modified vehicle with treated fuel; -Fig 16 shows smoke levels of standard vehicle and fuel versus modified vehicle with treated fuel; and -Fig 17 shows a schematic of another apparatus according to the present invention and

suitable circuitry.

In normal operation any internal combustion engine is prone to certain problems arising from the burning of fossil fuels as a power source: -Components directly involved in combustion such as fuel flow lines, intake valves, spray injectors and combustion chambers see the build-up of deposits such as carbon, tar and varnishes under normal running conditions.

-This is expected over the lifetime of a vehicle or plant equipment but can seriously impact on engine performance and cause engine breakdown.

-The impact of this build up is to reduce performance and efficiency whereby more fuel is needed to develop the power needed.

-Emissions levels increase due to less efficient engine performance and incomplete combustion.

-Fuel can become contaminated, especially when bulk storage is utilised. This has the impact of clogging the fuel system and filters thereby reducing performance, creating significant wear on engine components and increasing the fuel needed to operate the engine.

-Contamination has a significant impact on emission levels. This type of problem is expected to become more prevalent as the levels of biodiesel in pump fuel increases to levels of over 20%. Biodiesel has the added complication of introducing feedstock waste and micro-organisms into the engine fuel system.

-Biodiesel causes specific problems including: increased deposits on the injectors resulting in misfiring or difficult starting, deposit build up in the injector pump causing a reduction in power and misfiring, lubrication oil becomes diluted resulting in a loss of oil pressure and worn bearings, poor starting in cold weather due to filter clogging.

Whilst engine technology has advanced over recent years, improving fuel economy and emissions, and alternative fuel sources are slowly emerging, there is still a need to burn fossil fuel to power engines. This is unlikely to change for the foreseeable future, with only electric powered vehicles offering an alternate option; these electric vehicles have significant limitations, especially with range, and are unlikely to become a credible alternate for quite some time.

The present invention is aimed at reducing fuel consumption and reducing pollutants improve our environment, also and has specific benefits within the biodiesel uptake.

This apparatus of the present invention acts to remove deposits that have built up on the fuel system components using a chemical cleaning solution. A specific, proprietary cleaning solution is described below. The apparatus is connected to an engine's fuel system flow (i.e. from the fuel tank to the engine) and return (i.e. from the engine back to the tank) lines and a cleaning chemical is pumped through the system under nominal operating pressure. The chemicals clean the fuel system components, in many cases returning them to nearly new condition. The apparatus is then disconnected so no permanent modification is made to the engine.

The impact of this cleaning process is immediate and significant: -Fuel flows more efficiently, the spray injectors fully atomise the fuel which is crucial in ensuring complete combustion of fuel in the chamber. This results in maximum power from the fuel.

-Since a very high proportion of the fuel is completely burnt during combustion the effect on emissions is significant with lower levels of un-burnt hydrocarbons being found and a reduction in undesirable pollutant gas output -A significant reduction in particulate emissions.

-Regular treatment of engines has the impact of prolonging the life of key components such as the injector spray arms which, when blocked, is often the cause of engine breakdown.

The apparatus has the secondary functionality of fuel conditioning. Fuel can be removed from a tank or storage vessel, passed through a centrifugal and filtration mechanism which acts to remove microbial, water and other contamination types.

Contamination of fuel has serious impacts including; reduced filter life, coalescer malfunction, engine wear due to variations in fuel flow, corrosion of the fuel system, corrosion of injectors, high fuel consumption and increased emissions.

A flow meter can be incorporated into the apparatus to allow for accurate assessment of the treatment composition flow rate. This flow rate can give an indication of the degree of fouling and contamination within the fuel management system. Once the cleaning process has been run an improvement in the fuel flow rate should be observed. It can also show how much fuel is wasted in engine idling and warm up when flow rate is compared between a cold start and fully warmed up.

A preferred alternative to the use of a flow meter is that changes in the level of cleaning composition can be measured by a fuel level measurement device in the fuel reservoir. This can then be compared against elapsed time to measure consumption and thus engine efficiency. Suitable level measure sensors are available commercially from IFM Electronics Ltd, UK, for example.

The treatment of an engine's fuel system (and optionally its fuel tank) can conveniently take place during normal vehicle or plant servicing. An added feature of the apparatus can be an engine diagnostic capability provided by diagnostic software applied via a laptop interface.

This will allow operators to effectively manage the entire servicing and cleaning procedures.

An exemplary apparatus is shown in Fig 1. The apparatus comprises a reservoir 2, in the form of a tank, with an opening at the top ito allow the reservoir to be filled with a cleaning composition. The reservoir has a drain 3, which allows for emptying of the reservoir to remove waste composition, e.g. after a cleaning operation has been concluded.

The apparatus comprises an outlet to a delivery line 20, which allows the cleaning fluid to leave the reservoir towards the engine. A filter 5 is provided in the delivery line immediately downstream of the reservoir to filter the cleaning composition.

A pump 8 is provided in the delivery line downstream of the filter 5. The pump is a conventional fuel pump, e.g. a Walbro GSL 392. The pump should typically be a low spark transfer pump, ideally able to run from of domestic electric supply. It should be chemical resistant and capable of variable speed control, ideally resistive to bio diesel up to B30. The pump acts to pressurise the cleaning composition. The pump is controlled by the programmable logic circuit (PLC) 18 in order to provide the correct pressure and/or flow rate of the cleaning composition, as will be described in more detail below.

First and second pressure sensors 9 are provided downstream of the pump 8. These can be any suitable pressure sensors for use in fuel systems, e.g. IFM PT9554 pressure sensors are suitable. Between the pressure sensors is a dump valve 10 (e.g. a Murphy Pry 50 valve) located in the delivery line and connected to a pressure release line 22 which leads to the reservoir 2. The dump valve 10 is operable to release the pressure in the delivery line, e.g. after a cleaning operation is complete. The dump valve is operated by the PLC 18. The pressure sensors 9 measure the pressure both upstream and downstream from the shuttle valve. This allows the PLC to monitor pressure in the delivery line and thereby adjust the operation of the pump 8 to control the pressure and monitor operation of the shuttle valve 10 to dissipate system pressure.

Below the second pressure sensor 9 is a second filterS. This filter has a principle role in ensuring that there is no possibility of debris from the pump, which can be released as a result of wear or malfunction, reaching the fuel system of the engine.

The filters 5 are capable of filtering bio diesel and are capable of sustaining a pressure of 3.5 bar. There are many filters on the market that may be adopted to suit end user preferences.

Downstream of the second filter there can be provided a flow meter 11, which is able to monitor the flow through the delivery line 20. This allows the PLC to monitor consumption of the cleaning composition provided in the reservoir 2, and also to monitor for changes in flow as the cleaning process proceeds. This latter observation is a useful indicator of successful treatment of the fuel system. An alternative, and preferred method can adopted, as described previously. This involves using a measuring device in the reservoir to monitor the level of the cleaning composition, and the consumption of cleaning composition against time can be used to determine consumption of the cleaning composition.

The delivery line then comprises suitable interface means to allow connection of the delivery line to the fuel system of a vehicle. Suitable interface means comprise push fit fuel line connectors, optionally with step-up or step-down adaptors, if required to accommodate different fuel line diameters.

An exemplary common rail diesel fuel injection system 30 is illustrated in Fig 2. The delivery line suitably connects at a point 32 after the primary fuel pump 36, but before the high pressure (HP) fuel pump 38. A return line is connected via a suitable interface means at a point 34 after the injection rail 40, typically before or at the point the fuel line reaches the fuel tank 42.

Suitable interface means for various engine/fuel systems will be stored on a database to allow a user to determine the appropriate connector for a particular vehicle or engine type.

The return line 24 of the apparatus discharges into the reservoir 24, returning any unused cleaning solution (and fuel from the engine fuel system lines present at the beginning of the cleaning process) to the reservoir. The returning cleaning solution is the recycled through the system. A flow meter can be provided in the return line 24 to allow the PLC to monitor the amount of cleaning composition returned to the reservoir and thus monitor consumption of the composition; this is useful to monitor for efficiency of the engine and to monitor the amount of cleaning solution used or left in the system.

In the delivery line 20 there is preferably provided a third pressure sensor 26, immediately upstream of the interface. Preferably this is associated with a non-return valve upstream (not shown) which prevents the flow of fluid back up the delivery line. This pressure sensor 26 is used to measure the native' pressure of the fuel system, i.e., the pressure exerted by the primary fuel pump 36 in operation. To achieve this, the interface is connected to the fuel system. The ignition system of the engine is then turned on so as to power up the primary fuel pump. This will apply the native pressure to the pressure sensor 26. This is recorded by the PLC and will later be used to set the appropriate pressure applied by the pump 8.

In use the apparatus is connected to the fuel system 30 as discussed above. The relevant pressure is taken. The vehicle fuel pump is then preferably deactivated, e.g. by removing the relevant fuse, relay or by providing a loop of fuel line to return pumped fuel to tank.

The connection is then modified (if necessary) to permit the delivery line to deliver the cleaning composition into the fuel system 30, flowing towards the injection system. The pump 8 is activated by the PLC 18 to apply the appropriate pressure to the fuel line. The engine ignition is then activated and the engine is started. Because the pressure exerted by pump 8 mirrors the native pressure of the fuel system, the engine control unit (ECU) of the engine does not detect any error and allows the engine to start and run as normal.

It is preferred that vehicle fuel filters are replaced to ensure a clean free supply of cleaning composition to the fuel system. If the pipe connection is before filter assembly of the engine fuel system, this will prevent any residual contamination being washed through the filter into the injection system. 21.

The cleaning composition then flows into the engine fuel system 30 and cleans the various deposits and contamination therefrom. The cleaning solution is able to dissolve deposits that would not be dissolved by fuel, even fuel which has a cleaning additive provided. By providing a neat' cleaning composition, the present invention thus provides for a level of cleaning rigour which is far better than any known system.

The cleaning composition acts a replacement surrogate fuel' for the engine. It is thus important that the composition is able to be burned by the engine, and has appropriate combustion properties. Most diesel engines can successfully burn fuels with a cetane number of 40 or higher, with cetane numbers of 51 to 60 being typically preferred (see EN ISO 5165 for calculation methodology). For petrol engines a cleaning composition preferably has an octane no of 90 or higher (RON), more preferably from 92 to 102 RON.

A suitable cleaning composition for a diesel engine comprises: -99% by volume de-aromatised kerosene distillate (Product no BAS 0220-235, Banner Chemicals Ltd, UK) -1% by volume tetrachloroethylene (Product Perklone Ext, Banner Chemicals Ltd, UK) The specifications of BAS D220-235 is set out in Table 1

Table I

PROPERTY QUALITY TEST METHOD TYPICAL

REQUIREMENT REFERENCE LEVELS

MIN MAX

DENSITY at 15°C (gJml) 0.800 0.820 ASTM D1298 0.810 COLOUR (Saybolt) +30 ASTM D 156 +30 BOILING RANGE: °C ASTM D 86 INITIAL POINT 218 222 DRY POINT _______ 240 232 FLASH POINT: °C 1P 170 93 AROMATICS %wt 0.1 max UV ANILINE POINT °C ASTM D 611 80 VAPOUR PRESSURE @20°C hPa: 0.1 BENZENECONTENTppm GC -<100 SULPHUR CONTENT-ppm --ASTM D 3120 <1 VISCOSITY @20 °C mm2/s 2.7 2.7 DOCTOR TEST IP 30 Negative As the cleaning composition passes through the fuel system it removes deposits of carbon, tar, biofilms and varnishes within the fuel system. These are generally dissolved and then are burnt as they are carried into the combustion chamber. It has been found that a critical area of cleaning is in the injector body itself. It has been found that the nozzle of the injector is not generally prone to blocking as the high pressures and the very narrow diameters involved tend to keep the nozzle clear. However, within the body of the injector deposits can accumulate which leads to poor fuel delivery to the nozzle and consequently poor fuel delivery and atomisation. This in turn leads to poor combustion, lack of power and an increase in particulate (soot) emissions.

Cleaning composition which is not used for combustion is returned to the reservoir via the return line 24.

The delivery and return lines are suitably conventional 8mm internal diameter fuel hoses.

Such lines allow sufficient flow and are compatible with the cleaning composition. They also allow for easy interconnection to engine fuel systems, using step-up or step-down adaptors if required.

The cleaning process is continued for as long as is required to clean the engine fuel system to a suitable level. It has been found that cleaning times of from 20 minutes to 1 hour are typically adequate for commercial vehicle diesel engines.

Suitable electronic control systems (embodying the PLC) for the apparatus comprise a motherboard (e.g. a Gigabyte BS5M-HD3) to which is connected: -A CPU (e.g. Intel Pentium G2020) -Disk drive (e.g. Crucial V4 64GB SSD) -Ram (e.g. Crucial 2GB DDR3) -I/O Card (e.g. National Instruments PCIe 6320) -Touch screen display (e.g. Microtouch C170055) The various pressure sensors, pumps etc. are connected to the motherboard to allow them to report or be controlled, as appropriate. Suitable software/firmware is provided for the apparatus to be operated.

The apparatus of the present invention may also comprise other features such as a pressure trip (e.g. IFM PK5524), temperature trip, and/or level sensor for safety and/or operational considerations.

Shutoff valves for use in the present invention are suitably pilot operated 2-port solenoid valves, e.g. those available from SMC Pneumatics Ltd (Milton Keynes, UK) under part number VXD21 40A-04F-5D01. Other valves could of course be used.

The dump valve is suitably a Murphy PRV 50 valve although, again, other dump valves could of course be used.

This summarises the core functionality of the apparatus of the present invention. However, the apparatus can have additional functionality, as discussed below.

In one preferred embodiment the apparatus comprises a fuel cleaning device, also known as a fuel polishing device or fuel conditioning unit. This device comprises an inlet to receive fuel from a storage tank (e.g. a vehicle fuel tank), a filter system to remove contaminants and an outlet to return the cleaned fuel to the tank, optionally via a temporary store. Preferably the fuel cleaning device comprises a pump to circulate the fuel through the filter system, e.g. a Marco 164-003-iC pump, which is preferably located downstream of the filter so as to draw the fuel through the filter. The filter system is intended to remove particulates and water contamination in particular. Fuel polishing kits are available for cleaning fuel supplies, e.g. IPU mobile fuel polishing kits (e.g. product FB500 from Industrial Power Units Ltd., Churchbridge, UK) or the 1000FH turbine diesel cleaning unit from Racor. Such commercially available kits can be readily incorporated into the apparatus of the present invention. Fig 5 shows a flow chart illustrating operation of the fuel cleaning device.

Combining engine cleaning and fuel cleaning functionality in a single apparatus provides significant operational advantages. For example, the apparatus of the present invention is able to clean the fuel system of an engine and, while the fuel tank is disconnected during the fuel system cleaning process, the contents of the fuel tank can be cleaned at the same time.

Furthermore, cleaning of the fuel can be achieved without the need for complete emptying of the fuel tank to another vessel, as the fuel can be drawn from the tank and returned to the tank without in a cyclical fashion. Cleaning of the contents of a fuel tank is of particular importance in the case of engines which are be left for protracted periods without being used, for example some marine engines or generators. In these cases the fuel can become contaminated, e.g. as a result of the growth of microbes and associated accumulation of biofilm, which is a particular problem with biodiesels. If the fuel is not cleaned, it typically leads to rapidly dirtying of the fuel system (e.g. clogging filters and injectors) once the engine is started, thus at least partially negating the benefits of cleaning the fuel system of the engine.

In another preferred embodiment the apparatus comprises agitation means to agitate the contents of the storage tank. Suitably this comprises an air compressor (e.g. Gast 71 Ri 42-POOl B-D3O1X) to provide a source of pressurised air, and a suitable applicator with a nozzle to deliver a stream of compressed air to the tank, and an air line connecting the compressor to the nozzle. In a simple embodiment the applicator can be a simple flexible hose. This has the effect of agitating the contents of the tank to bring settled contaminants into suspension, and also allows the surfaces of the tank to be scoured to remove adherent deposits, such as biofilms or the like. Other agitations systems can be used, but are typically less preferred. For example, the agitator can extract fuel from the tank, pressurise it, and direct it back into the tank under pressure to agitate the contents of the tank and scour its surfaces. Mechanical agitators such as rotating pad or the like could also be used.

Figure 3 shows an exemplary schematic of a further apparatus according to the present invention and suitable circuitry.

Notable in the embodiment shown in Figure 3 is the addition, relative to the embodiment shown in Fig 1, of further safety features in the form of an emergency stop system 50, two safety valves 52 and 54, which stop flow of fuel/cleaning composition when activated, and a dump valve 56 which dumps pressurised cleaning composition back to the reservoir 58, e.g. at normal shutdown or in an emergency stop. This dump valve is a very significant safety feature as it means that the system is depressurised at the end of the process and/or if a problem is encountered. If the pressure was not released then there could be safety issues with pressurised cleaning composition being ejected when connectors are de-coupled. The embodiment in Fig 3 automates the depressurising system which reduces the risk of human error.

The emergency stop system can be activated automatically where the control systems detect a problem and/or manually where a user has need to activate it.

As can be seen, the apparatus comprises a power and control enclosure which houses the various electronic systems 80, and which is connected to an external AC supply. It is a significant safety benefit if the power and control systems and the cleaning composition handling systems can be isolated from each other. By isolating the power and control systems from the cleaning composition handling systems it significantly reduces risk of fire should there be a fault with either system.

The agitator system 70 comprises an agitator pump 72 (air compressor) and a compressed air line 74 leading to a nozzle (not shown).

A fuel cleaning device 60 comprises a fuel polishing unit 62 and a fuel pump 64 and a safety shutoff valve 54. The safety shutoff valve 54 is connected to the emergency stop system, which allows operation of the fuel cleaning system to be halted if required by tripping the emergency stop system. In normal running, the fuel is pumped from the tank through the polishing unit and then back to the tank. If the emergency stop is pressed, the fuel pump will stop and also safety valve 54 would close meaning that no fuel could leave the system; this also occurs if power was cut or removed from the apparatus.

The dump valve 52 in the cleaning composition supply line is a 3-way valve which has a default position to direct flow to the reservoir, i.e. absent a control signal which causes the valve to direct flow to the outlet. This is a significant safety feature as it means that the apparatus is adapted to safely recycle cleaning composition or release stored pressure in the cleaning composition to the reservoir when required. When a suitable control signal is applied, i.e. when the cleaning process is in correct operation, the dump valve directs flow to the outlet and thus to the engine fuel system.

Fig 4 shows another embodiment of an apparatus according to the present invention. This embodiment is even more preferred than the two previous versions discussed, and includes additional refinements and safety features.

The agitator system 70 is provided in a compressor enclosure within the apparatus. This is an additional safety feature and mechanically isolates the compressor and associated systems from the fuel/cleaning composition systems. An air safety valve 76 is provided in line with the output of the compressor, which is set to 2 bar. If the pressure between the pump and the air outlet connection builds and exceeds the set pressure, the air safety valve will open and the pressure shall be safely vented through a silencer (not shown).

An additional feature in the fuel cleaning system of this embodiment has been added to further improve safety. If there is no connection made to the tank and the system is set to run, a pressure would build up against the output connector which could become problematic. An overpressure valve 64 has been fitted, which is a mechanical valve (i.e. with no electrical control). This is designed to open at 5 bar of pressure, which releases excessive built up pressure back into the polishing unit, and would continually loop until the pressure falls below 5 bar or the pump is halted.

In normal running, the cleaning composition (and residual fuel) is pumped from the engine fuel system into the reservoir 58, out of the reservoir through the filters and pressure sensors and back to the engine fuel system. If the emergency stop is pressed, the fuel pump will stop and also safety shutoff valve 52 would close meaning no fuel would pass out of the apparatus. At the same time the dump valve 56 shall open directing any pressurised cleaning composition back into the reservoir 58. An overpressure valve 57 is provided and operates in an analogous way to the overpressure valve 64 in the fuel cleaning device, directing flow into the return line from the engine fuel system and back into the reservoir.

In the embodiment of Fig 4 a tank level sensor 59 is shown associated with the reservoir 58, which monitors the level of cleaning composition in the reservoir.

Notably, in the embodiment of Fig 4 the reservoir is separated and isolated from the power and control systems and the cleaning composition handling systems. This provides a further safety feature in that the reservoir, which contains a comparatively large amount of flammable cleaning composition, is separated from the main electrical components and from the cleaning composition handling systems. This minimises the risk that a fault with the power and control systems or the cleaning composition handling systems could result in rupture of the reservoir and/or ignition of the contents of the reservoir.

Fig 17 shows another embodiment of an apparatus according to the present invention, which is a modification of the device shown in Fig 4. In this embodiment there is provided an external (remote) pressure sensor 90 and an external emergency stop button 92.

The pressure sensor 90 is adapted to connect to the fuel system 30 of the engine to be treated, and is connected by a suitable cable to the PLC (wireless communication systems could be used). This allows the native fuel system pressure of the vehicle to be determined and the pressure of the apparatus set to match the native pressure, as discussed above.

Providing the pressure sensor for measuring the native fuel pressure as an external, remote system has benefits in terms of convenience and safety.

Providing the emergency stop bufton an external, remote-operable button has benefits, particularly in terms of safety, but also in terms of convenience. By providing a remote emergency stop, a user can stop the device from a remote location, e.g. if he is conducting another piece of work on the engine or vehicle, or if remote operation is preferred from a safety point of view. Typically a cable is used to connect the emergency stop button to the apparatus, rather than a wireless communication system, because problems of connectivity can be essentially eliminated. However, a wireless system may be appropriate in some cases.

Exemplary Specific Operating Procedures for a Diesel Vehicle -Basic vehicle / plant checks will be carried out in advance of carrying out the process to ensure there are no underlying problems.

-The process suitably begins with an inspection of the vehicle/plant fuel tank by use of a borescope camera to determine contaminant levels.

-The fuel is then agitated using compressed air (at e.g. 2 bar) prior to being pumped through the fuel conditioning unit integrated into the cleaning device. This passes the fuel through a range of filters from 10 micron down to 2 micron which removes contaminants and via centrifugal action water is also removed -Care is taken to avoid over agitating fuel to avoid a foaming effect in the fuel.

-Observe closely for overspill of fuel.

-Once the fuel is reconditioned it is returned to the fuel tank.

-The process of cleaning and purging the fuel system then follows.

-The device is connected to the fuel flow and return hoses and the system is pressurised.

-In the first operation it may be necessary to measure the vehicle/plant delivery pressure from the primary (e.g. in tank) fuel pump. This is done by the device via a pressure sensor incorporated in the cleansing composition delivery line. This information will be displayed on the interface screen and the delivery pressure will be adjusted to suit the system pressure. This information is required by the vehicle powertrain control module (ECU) to allow the vehicle to start/run.

-A database incorporating manufacturer system pressures will be stored in the device to assist in the safe operation of accessing and adjustments necessary.

-The cleansing/purging additive is then passed through the complete fuel system at a pressure not detrimental to system connections. Dependant on the system the fuel filter can be replaced pre-or post-cleansing cycle. This is to reduce filter contamination being introduced to the fuel system.

-The cleansing cycle time can determined by the level of emissions which are measured at the tail pipe at the start of the process and which can vary considerably between applications.

-During the cycle contaminates are removed from the system and passed through a series of filters incorporated within the device ensuring a clean supply of additive.

-At the cycle elapsed time, monitored and displayed by the human interface system, all system connections are reassembled to the original specification so as not to invalidate manufacturer's warranty.

Fig 6 shows a flow chart illustrating the fuel system cleaning method.

Real-World Examples of Treating a Vehicle Engine Test I

Summary

Testing was carried out at the Intertek Tickford Ltd Vehicle Emission Test Laboratory in Milton Keynes, on behalf of Engym Services Ltd. The purpose of the tests was to quantify any improvements that may occur, following a process carried out on a diesel fuelled vehicle. A used Ford Transit 85 T260 van was tested, using the EC169212008 test standard, in an as received condition, immediately after the process and then again after 27Omiles of mixed use. The tests showed: -The average fuel consumption improvement on the combined drive cycle was 7.2% (change from 35.00mpg to 37.52mpg achieved after mileage accumulation.

-The best fuel consumption improvement on the combined drive cycle is 8.01% (change from a low of 34.84mpg to a high of 37.63mpg achieved after mileage accumulation) -see appendix A -The highest overall improvement was seen in the urban drive cycle; 9.09% (change from 29.81mpg to 32.52mpg achieved after mileage accumulation) -see appendix A. -The average CO2 was reduced by 6.8% -The exhaust particulates were reduced by 86.0%.

1. Introduction

Intertek Tickford were requested by Engym Services Ltd to quote for chassis dyno based vehicle emission and fuel consumption testing to determine the effect of a fuel treatment process they are developing. This report outlines the test procedure and summarises the results of a series of tests run on a used Ford Transit.

2. Emission Test Laboratory The Intertek Tickford Emission Test Laboratory is equipped with a MRW twin roll chassis dynamometer and Horiba 9000 emission bench, with Constant Volume Sampling (CVS) system. The system retains dilute exhaust gas in sample bags for post-test analysis. The chassis dynamometer is designed to simulate the on road behaviour of the test vehicle, using a combination of inertia weights and an electrical absorber. A windscreen mounted monitor displays the drive trace to be followed by the driver. This also indicates the points at which gear changes should be performed and is controlled by a test control computer that also records data from the emission bench and chassis dynamometer.

3. Test Method The test vehicle was installed into the test laboratory with the driven wheels on the chassis dynamometer rollers. The dynamometer control system was set to the appropriate road load model (RLM) and the exhaust tailpipe was connected to the CVS system. The vehicle was tested as received, using forecourt grade diesel fuel, with a preconditioning run followed by a test on three subsequent days as outlined in the European test procedure EC/69212008 (Euro 5). On completion of the initial batch of tests, representatives of Engym Services Ltd attended Intertek Tickford, and carried out, under confidence, a cleaning process on the vehicle as set out above.

This cleaning process was the direct cleaning method described above, run for 30 mins and used a cleaning composition comprising: -74.5% by volume white spirit; -24.5 by volume kerosene; and -1% by volume of tetrachloroethylene.

The test sequence was then repeated on each vehicle. Following this the vehicle was driven for 270 miles on a varied route of motorways, A roads and urban routes. The vehicle was then retested. A preconditioning run and two tests, on subsequent days, were completed.

The average of the baseline, post process tests and post mileage accumulation tests were used to make comparisons.

Each test was run using the Euro drive cycle to establish the Urban, Extra Urban and overall Fuel Consumption and Regulated Exhaust Emissions (CO, CO2. THC, NOx) including particulate mass. During the test the exhaust gases were collected and analysed using the dilute gas bag methods and carbon balance fuel consumption calculated.

4. Test Results CO 02 TiC NDx P&hc41aSs MPu 023 2134 I0O3 0277 S1 LL_____..__.

Past Prtess: 2' JO!1! .i it OThS k2O 411$5 205 JS'7.

Post Procns t VQ Sos kJN'TS C JHC NOH PrflcuL* n Is»=1 ____ S< 27,i27 oiaã o' I 6C [-I [i3 [63 J72

5. Conclusions

With regard to fuel consumption: -The average fuel consumption improvement on the combined drive cycle was 7.2% (change from 35.00mpg to 37.52mpg achieved after mileage accumulation.

-The best fuel consumption improvement on the combined drive cycle is 8.01% (change from a low of 34.48mpg to a high of 37.63mpg achieved after mileage accumulation).

-The highest overall improvement was seen in the urban drive cycle; 9.09% (change from 29.81mpg to 32.52mpg achieved after mileage accumulation).

With regard to regulated exhaust emissions: -The average CO2 was reduced by 6.8%.

-The exhaust particulates were reduced by 86.0%.

Test 2

Summary

Testing was carried out at the Intertek Tickford Ltd Vehicle Emission Test Laboratory in Milton Keynes, on behalf of Engym Services Ltd. The purpose of the tests was to quantify any improvements that may occur, following a process carried out on a diesel fuelled vehicle. A used Ford Transit 100 T280 van was tested, using the EC/69212008 test standard, in an as received condition, immediately after the process and then again after 265 miles of mixed use. The tests showed: -The average fuel consumption improvement on the combined drive cycle was 4.0% change from 35.47mpg to 36.91mpg achieved after mileage accumulation.

-The best fuel consumption improvement on the combined drive cycle is 4.76% (change from a low of 35.27mpg to a high of 36.95mpg achieved after mileage accumulation).

-The highest overall improvement was seen in the urban drive cycle; 8.03% (change from 29.40mpg to 31.76mpg achieved after mileage accumulation).

-The average C02 was reduced by 3.7%.

-The exhaust particulates were reduced by 75.3%.

1. Introduction

3. Test Method The test vehicle was installed into the test laboratory with the driven wheels on the chassis dynamometer rollers. The dynamometer control system was set to the appropriate road load model (RLM) and the exhaust tailpipe was connected to the CVS system. The vehicle was tested as received, using forecourt grade diesel fuel, with a preconditioning run followed by a test on three subsequent days as outlined in the European test procedure EC/69212008 (Euro 5). On completion of the initial batch of tests, representatives of Engym Services Ltd attended Intertek Tickford, and carried out, under confidence, a cleaning process on the vehicle as set out above (this was identical to the direct cleaning process carlied out in Test 1). The test sequence was then repeated on each vehicle. Following this the vehicle was driven for 265 miles on a varied route of motorways, A roads and urban routes. The vehicle was then retested. A preconditioning run and two tests, on subsequent days, were completed.

Each test was run using the Euro drive cycle to establish the Urban, Extra Urban and overall Fuel Consumption and Regulated Exhaust Emissions (00, 002, THC, NOx) including particulate mass. During the test the exhaust gases were collected and analysed using the dilute gas bag methods and carbon balance fuel consumption calculated.

4. Test Results Pr PrtGfl _______ _______ _______ ___________ Cons _____ ____ LNtS CD C02 I NC Nth Partcuksn sPG f3 LNUS CO C02 tHC flO Pcdtun MP

I

_______________ 0227 2a2r O' ces STh O22' 2Q J (J _______ I L 4!! 2fr L1L I E° Pfl.Prptns t Z8 ________ LNJS CO C02 T NC j Partsn 14L 2J,2$ $J uJ494.b91 I [Dance 37 -35 47 $0

5. Conclusions

With regard to fuel consumption: -The average fuel consumption improvement on the combined drive cycle was 4.0% (change from 35.47mpg to 36.91 mpg achieved after mileage accumulation.

-The best fuel consumption improvement on the combined drive cycle is 4.76% (change from a low of 35.27mpg to a high of 36.95mpg achieved post process).

With regard to regulated exhaust emissions: -The average CO2 was reduced by 3.7% -The exhaust particulates were reduced by 75.3%.

Conclusions

The two real world tests described above demonstrate the potential of the present invention to improve the performance of engines. A clear improvement in fuel economy was demonstrated after the test had been performed, and a very large improvement in particulate emissions was shown. Such a reduction of particulate emissions is particularly important in view of the health impact of such emissions, especially in an urban environment.

Various modifications can be made to the described apparatus and method without departing from the scope and spirit of the invention.

Description of Exemplary Control Systems and Operation of the Apparatus This document details the operation of the apparatus control software and the apparatus itself. The system has two main modes of operation, tank cleaning and engine cleaning.

There is also a requirement for an administrator level to perform maintenance tasks. The operation is described in relation to a truck, but other types of engines can of course be treated using the same general approach.

Tank CleaninQ Mode The tank cleaning mode utilises the high flow pump (e.g. Marco 164-003-iC) and the fuel polishing unit as well as the agitator pump to clean the contents of a fuel tank. The operation of this mode is summarised in Fig 4. Each of the functional steps in Fig 4 is detailed below, in this case in respect of a truck: Select Tank Cleaning From the main software the user selects to run the tank cleaning mode. This starts a "wizard" style step through process to run the tank cleaning operation.

Prompt-Enter Vehicle Details The first step of the process is to enter the truck details. An on screen keyboard is used for data entry. The user enters the registration of the truck, if it has already been processed by this unit the make and model will be brought up. If the truck has not been processed before the user will select the make and model from drop down menus. The size of the tank to be cleaned will be entered and from the volume a time to run the system for will be suggested, this time can be adjusted by the user to suit the condition of the tank. The user will be asked to confirm use of the agitator pump, a delay between activating the agitator and the pumping of the fuel can also be set. The user can also cancel the operation at this point and the system will go back to the main screen.

Prompt -Connect Piping The second stage of the wizard will show pictures of the pipes and the connections that need to be made and the user will be told to ensure they are connected correctly. The user can also cancel the operation at this point and the system will go back to the main screen.

Prompt -Confirm Piping Secure The user will be asked to confirm that the piping is correctly secured. The user can also cancel the operation at this point and the system will go back to the main screen.

Prompt -Check Fuel Polishing Unit Pictures of the filter showing clean and dirty versions will be shown and the user will be asked to check that the fuel polishing unit is in good condition. The user can also cancel the operation at this point and the system will go back to the main screen.

RUN

The cleaning will run with a count down from the time set in the enter vehicle details step of the process. The user can end the operation early if required.

S

Store Log The system will log the information from the cleaning for future use.

Engine Cleaning Mode This mode of operation utilises the low flow pump (e.g. Walbro GSL 392) and the reservoir to clean the engine and add an additive to improve engine efficiency. The operation of this mode is summarised in Fig 5. Each of the functional steps in Fig 5 is detailed below, in this case in respect of a truck: Select Engine Cleaning From the main software the user selects to run the engine cleaning mode. This starts a wizard" style step through process to run the engine cleaning operation.

Prompt-Enter Vehicle Details The first step of the process is to enter the truck details. An on screen keyboard is used for data entry. The user enters the registration of the truck, if it has already been processed by this unit the make and model will be brought up. If the truck has not been processed before the user will select the make and model from drop down menus. The size of the engine to be cleaned will be entered and from the volume a time to run the system for will be suggested, this time can be adjusted by the user to suit the condition of the engine. A delay from engine start to flow monitoring can also be set to ensure the truck is at temperature before the monitoring begins. The starting pressure of the engine will be displayed, this will come from a database of engines, this pressure can be manually adjusted to suit a modified or not recognised engine. The user can also cancel the operation at this point and the system will go back to the main screen.

Prompt -Check Reservoir The user will be asked to confirm that the reservoir has a suitable level of fuel and additive for the truck engine to be cleaned. The user can also cancel the operation at this point and the system will go back to the main screen.

RUN

The pump will start and build up to start pressure of the truck engine using the feedback from the pressure and flow sensors. The user can also cancel the operation at this point and the system will go back to the main screen.

Prompt -Start Engine Once the pressure is correct the user will be asked to start the engine. The user can also cancel the operation at this point and the system will go back to the main screen.

CONTINUE

The system will circulate the fuel and additive into the engine. Once the delay time from start-up has passed the system will monitor the fuel usage to check the improvement in efficiency. Once the system has run for the predetermined time the user will be asked to turn off the engine. The system will then complete the cycle. The user can also cancel the operation at this point and the system will go back to the main screen.

Store Log The system will log the information from the cleaning for future use.

Administration Level As well as the above modes of operation an administration level will also allow the user (password protected level) to perform the following tasks: * Maintain the database of trucks * Download logs * Upgrade software * Maintain user accounts Further Testing, Including the Use of a Fuel Additive Composition

1 INTRODUCTION

Engym Services Ltd has developed an engine treatment procedure incorporating a fuel additive which is believed to reduce both fuel consumption and exhaust gas emissions. The company commissioned NFL to perform industry-standard vehicle tests to establish evidence of any improvements.

2 OBJECTIVE The objective of the project was to determine whether there was any significant reduction in fuel consumption and exhaust gas emissions due to the vehicle preparation and fuel treatment procedure adopted by Engym.

3 APPROACH The tests were undertaken in two stages: 1. Standard vehicle operating on standard fuel.

2. Modified vehicle operating on treated fuel.

At each stage the vehicle was operated at three steady state speed conditions and at two loads for each speed. Engym staff undertook the vehicle modification and the treatment of the fuel. Details of these tasks were not disclosed to NFL.

The test vehicle remained at the ETC building in a secure environment from delivery to the rolling road test cell throughout the complete test programme. It was not removed from the test site, except for being driven on the open road for a short period after the engine modification had been undertaken. A member of NEL staff was a passenger in the vehicle during this short drive.

4 TEST EQUIPMENT The vehicle used for the tests was a 2005 model year diesel Ford Transit 85T280, 1998cc, utilising a standard distributor pump type mechanical fuel injection system. The tests were carried out on a Consine Dynamics twin-drum chassis dynamometer operating in performance mode. For this mode of operation, loading is provided by an eddy current retarder. This retarder was operated in constant torque mode during the tests. A PC-controlled driver's aid unit was used to provide a visual reference of the target speed to the driver. The tests carried out were conducted at a series of steady speeds of 30, 40 and 50 mile/h. Fuel was supplied via a closed loop circulation system external to the vehicle. Fuel consumption was measured by a modified Hird-Brown gravimetric system which monitored the make-up flow to the closed loop. Exhaust emissions were measured using a Beckman CVS emissions system operating in raw gas mode. Non dispersive infra-red analysers were used to evaluate CC, CC2 and SO2 emissions. uHC emissions were measured by an FID device, NO emissions were measured by a chemiluminescent detector and C was measured by a paramagnetic detector. Raw gas tailpipe emissions were sampled from a location upstream of the CVS dilution point. An AVL 415 variable sampling smoke meter was used to determine variation in exhaust smoke concentration.

Thermocouples were fitted to record air inlet temperature, coolant temperature and fuel temperature.

5TEST PROCEDURE Prior to executing the tests the dynamometer was motored for a period of 30 minutes to stabilise bearing friction. The vehicle was then driven for sufficient time to enable the coolant temperature to stabilise. Steady-state measurements were initially recorded at a light road-load at 40 mile/h. This process was repeated at 50 mile/h and then at 30 mile/h with the same level of brake load. The test sequence was then repeated at a second, higher, road-load condition. This programme of six test points was then repeated in its entirety to provide two sets of baseline data. After the baseline tests were completed, Engym staff undertook two tasks: 1. A batch of diesel fuel was treated in preparation for further tests.

2. Modification was undertaken on the vehicle.

These tasks were undertaken at NEL premises and took approximately 90 minutes to complete. Details of these tasks were not disclosed to NEL. The standard fuel was then drained from the system and it was then flushed with the treated fuel. The system was drained again and refilled with the treated fuel. Following completion of the service procedures, the test vehicle was driven on the open road for approx 30 minutes prior to re-testing. A member of NEL staff was a passenger during the open road drive to verify no further work was undertaken. On completion of the fuel treatment process, the vehicle modification and the 30 minute drive, the tests carried out for the baseline measurements were repeated in their entirety with the modified vehicle and treated fuel. Figs 7 and 8 show exemplary traces for test runs at 50 mph for standard vehicl.

The treated fuel was a conventional forecourt diesel containing 5 ppt (0.5 % by volume) of a diesel fuel additive comprising: -73.5% by volume white spirit; -24.5 % by volume kerosene; and -2 % by volume 2-ethylhexyl nitrate.

The vehicle treatment was the same method as used in the Intertek Tickford tests 1 and 2 discussed above, i.e. the direct cleaning method, run for 30 mins, and used a cleaning composition comprising: -74.5% by volume white spirit; -24.5 by volume e.g. kerosene; and -1% by volume of tetrachloroethylene.

6 TEST RESULTS The test conditions used in the project are summarised in Table 2.

Table 2

Test poM Rad spsed mli&h Torque at toils Mm 1 40 75 2 50 _______________________ 3 75 4Th 50 139 * 139 The load figures represent the torque set and measured at rolls. This value was adjusted in each run to allow for the necessary corrections due to changes in ambient pressure and temperature. Typical variability of speed in the steady state runs is shown in Figures 7 and 8 for the 50 mile/h, 75 Nm torque condition. Some speed variability can be observed and a larger number of repeat runs would be required to ensure that the effect of this would be eliminated from the results. The vehicle service procedure and the fuel treatment were both undertaken at the same time, so it is not possible to separate the effects of these in the tests undertaken.

The results are reviewed briefly in two sections: * Fuel consumption * Emissions 6.1 Fuel Consumption Measurements Figure 9 shows the comparison of the average measured fuel consumption at each test condition. Two test runs were undertaken at each speed/load condition and the average of these two runs is shown. The results for the modified condition were recorded using treated fuel and the vehicle modification. At first sight it would appear that the modified vehicle with treated fuel has resulted in a reduction in fuel consumption at each condition evaluated. In percentage terms the reduction appears large (up to 14%); however care is required in the interpretation of the results. The error bars shown in the figure illustrate that the measurements were highly variable and the measurement variability was considerably larger than the apparent reduction in fuel flow rate. A comparison of the range covered by the error bars does, however, suggest a reduction in fuel consumption in four out of six test conditions evaluated. The degree of variability in the measurements, however, precludes any accurate evaluation of the magnitude of any reduction in fuel consumption. The calibrated accuracy of the fuel measurement system was better than 1%, and therefore the variability in the measurements is likely to be due to small changes in speed and load over the test condition.

Since only two sets of test data were recorded at each test condition it was not possible to carry out a meaningful statistical analysis of the data. Further work would be required to gather more data points, to enable confidence limits to be determined.

6.2 Emissions Measurement Exhaust gas emissions measurements are less obviously affected by instability in operating conditions due to the sample transport times, mixing in the exhaust collection pipe work and analyser response times. Figure 10 shows the comparative levels of CO measured with standard vehicle set up and the modified vehicle with treated fuel.

Figure 11 shows the same plot for exhaust gas oxygen levels. Although exhaust emissions are expressed as a volumetric fraction, if a significant reduction in fuel flow rate was achieved, it might be expected that a reduction in CO levels and an increase in residual oxygen would be apparent. No such changes are evident in figures 10 and 11. It should be noted that the CO figures are quoted as percentage concentration by volume, not as g/km.

Figure 13 suggests some reduction in SO2 levels with the modified vehicle and treated fuel.

Comparisons of CO emissions and uHC emissions with standard vehicle set up and modified vehicle with treated fuel are shown in Figures 14 and 15 and although these show reductions in emissions, all the values are at trace concentration levels, so no firm

conclusion can be drawn.

Figure 16 shows that there was a significant improvement in exhaust smoke concentration with modified vehicle and treated fuel (as expressed in terms of Filter Smoke Number -FSN).

7 CONCLUSIONS

1. Steady state fuel consumption and exhaust emissions measurements were carried out on a Ford transit vehicle operating (1) in standard form with standard pump fuel and (2) after engine cleaning and with diesel fuel treated with a fuel additive.

2. Fuel flow rate measurements indicated a reduction in fuel consumption when operating with the modified vehicle and treated fuel.

3. The fuel flow rate measurements were subject to a degree of variability and more data would be required to perform meaningful statistical analysis. Nonetheless, the overall results are indicative of improved engine performance.

4. Measured data was recorded on the vehicle after both cleaning and fuel modification. It was not possible to determine the separate contribution of the vehicle modification or of the treated fuel to any changes in performance.

5. A more extensive test programme would be required to accurately quantify the magnitude of the benefits offered by the vehicle modification and treated fuel.

Claims

Claims 1. An apparatus for cleaning the fuel system of an engine, the apparatus comprising: -a reservoir adapted to contain a cleaning composition; and -a delivery line connectable to the fuel system to deliver the cleaning composition from the reservoir to the fuel system of the engine.
2. The apparatus of claim 1 which comprises a return line connectable to the fuel system of the engine to receive cleaning composition returning from the fuel system.
3. The apparatus of claim 1 or 2 which is configured such that the cleaning composition is returned to the reservoir via a return line.
4. The apparatus of any preceding claim wherein the delivery line is adapted to deliver the cleaning composition to the fuel line of the engine fuel system at a point between the primary fuel pump and the fuel delivery system of the engine.
5. The apparatus of any preceding claim wherein the reservoir is adapted to store the cleaning fluid at atmospheric pressure.
6. The apparatus of any one of claims 1 to 4 wherein the apparatus is adapted to store the cleaning composition at elevated pressure.
7. The apparatus of any preceding claim wherein the reservoir is at least partially filled with a cleaning composition.
8. The apparatus of any preceding claim wherein the reservoir comprises a pressure release valve to allow pressure to be released if it rises above a predetermined level.
9. The apparatus of any preceding claim which comprises a measurement device to measure the amount of cleaning composition present in the reservoir.
10. The apparatus of any preceding claim which comprises a pressurising means which is adapted to pressurise the cleaning composition to a desired pressure for delivery to the fuel system.
11. The apparatus of claim 10 wherein the pressurising means comprises a pump adapted to pump at variable pressures.
12. The apparatus of any preceding claim wherein the reservoir is an external reservoir.
13. The apparatus of any preceding claim which comprises a pressure control means adapted to maintain the pressure of cleaning composition in the delivery line at a desired pressure.
14. The apparatus of any preceding claim adapted to match the pressure of the cleaning composition to the normal operating pressure of the fuel system to be cleaned.
15. The apparatus of any preceding claim which comprises a pump is which is adjustable to alter the pressure exerted on the cleaning composition to match the delivery pressure of the cleaning composition to the normal operating pressure of the fuel system to be cleaned.
16. The apparatus of any preceding claim which comprises a pressure measuring means to measure the operating pressure of the engine fuel system.
17. The apparatus of claim 16 wherein the pressure measuring means is provided in the delivery line for the cleaning composition.
18. The apparatus of claim 16 wherein the pressure measuring means comprises a pressure sensor which is provided in a remote unit.
19. The apparatus of any preceding claim which comprises at least one filter adapted to filter the cleaning composition.
20. The apparatus of claim 19 wherein the filter is provided between the reservoir and the outlet of the delivery line.
21. The apparatus of claim 19 or 20 wherein a filter is provided between the reservoir and the cleaning composition pump.
22. The apparatus of any one of claims 19 to 21 wherein a filter is provided downstream of the cleaning composition pump.
23. The apparatus of any preceding claim wherein the delivery line is provided with one or more pressure and/or flow measuring devices.
24. The apparatus of any preceding claim wherein the delivery line is provided with a pressure release valve to allow the pressure in the fuel system to be relieved.
25. The apparatus of any preceding claim wherein the delivery line comprises a safety shutoff valve, which can operate to prevent flow out of the outlet of the delivery line.
26. The apparatus of claim 25 wherein the safety shutoff valve is located downstream of the pump.
27. The apparatus of claim 25 or 26 wherein a pressure release valve is provided in the delivery line and the safety shutoff valve is located upstream of the pressure release valve.
28. The apparatus of any preceding claim which comprises an emergency stop system which allows for the various operations of the apparatus to be halted when required.
29. The apparatus of claim 28 which comprises a remote emergency stop controller.
30. The apparatus of any preceding claim which is provided with a fuel cleaning device adapted to filter a fuel supply stored in a storage vessel.
31. The apparatus of claim 30 wherein the fuel cleaning device comprises a fuel inlet line adapted to receive fuel from the fuel supply, a filter adapted to remove contamination from the fuel, and a return line to return the filtered fuel to the fuel supply.
32. The apparatus of claim 30 or 31 wherein the fuel cleaning device is provided with a pump to draw fuel from, and return fuel to, the fuel supply.
33. The apparatus of claim 32 wherein the fuel cleaning device comprises a high flow transfer pump which passes the fuel through a fuel cleaner unit.
34. The apparatus of any one of claims 30 to 33 wherein the fuel cleaning device is provided with a pressure release valve to allow the pressure built up in the fuel cleaning device downstream of the pump to be relieved.
35. The apparatus of any one of claims 30 to 34 which comprises a multi stage fuel cleaner unit which provides centrifugal separation and membrane filtration.
36. The apparatus of claim 35 wherein multi stage fuel cleaner unit provides separation, coalescence and filtration of the fuel.
37. The apparatus of any preceding claim which comprises an agitation device to agitate fuel within a fuel storage vessel.
38. The apparatus of claim 37 wherein the agitation device comprises a pressurisable system which is adapted to direct a pressurised flow of fluid into the storage vessel via a nozzle.
39. The apparatus of claim 38 wherein the agitation device is adapted to deliver a stream of compressed air into the storage vessel to agitate fuel within the tank.
40. The apparatus of any one of claims 37 to 39 wherein the agitation device can suitably comprise a pressure release valve to permit excess pressure generated by an air compressor to be relieved.
41. The apparatus of any one of claims 37 to 40 wherein the agitation device is at least partially housed within an enclosure to mechanically separate the compressor and associated systems from the fuel/cleaning composition systems.
42. The apparatus of any preceding claim which comprises electronic control systems to monitor and control operation of the apparatus, and a human/machine interface to allow a user to control functions of the apparatus.
43. The apparatus of claim 42 wherein all active components of the apparatus are connected to the electronic control systems.
44. A system comprising an apparatus according to any one of claims 1 to 43 connected to a fuel system of an engine.
45. A system according to claim 44 wherein the engine is a diesel engine or a petrol engine.
46. A system according to claim 44 or 45 wherein the delivery line is connected to the fuel supply line of the engine.
47. A system according to any one of claims 44 to 46 wherein the delivery line is connected upstream of the injection system and high pressure fuel pump.
48. A system according to any one of claims 44 to 47 wherein the apparatus is configured to substantially match the delivery pressure of the cleaning composition to the native pressure of the primary fuel pump.
49. A system according to any one of claims 44 to 48 wherein the return line of the device is connected to the fuel system at a point after the fuel delivery system.
50. A system according to any one of claims 44 to 49 wherein the fuel tank of the fuel system is connected to a fuel cleaning device.
51. A system according to any one of claims 44 to 50 wherein the fuel tank of the fuel system is provided with a fuel agitator device.
52. A kit comprising an apparatus according to any one of claims 1 to 43 with a supply of a suitable cleaning composition.
53. A method of cleaning the fuel system of an engine, comprising: -connecting an apparatus according to any one of claims 1 to 43 to the fuel system of an engine; and -operating the apparatus to thereby deliver a cleaning composition to the fuel system of the engine.
54. The method of claim 53 comprising: -providing an engine having a fuel system; -providing an apparatus according to any one of claims ito 43; -delivering a cleaning composition to the fuel system, whereby the cleaning composition passes through at least a portion of the fuel system and removes contaminants therefrom; and -optionally, returning the cleaning composition which has passed through the fuel system to the apparatus.
55. The method of claim 53 or 54 wherein the cleaning composition is delivered to at least a fuel injection system of the engine.
56. The method of any one of claims 53 to 55 which comprises connecting the delivery line of the apparatus upstream of the fuel delivery system and connecting the return line of the apparatus downstream of the fuel delivery system of the engine fuel system.
57. The method of any one of claims 53 to 56 wherein the cleaning composition is delivered to the fuel delivery system of the vehicle for at least 5 minutes, preferably at least 10 minutes, and more preferably at least 20 minutes.
58. The method of any one of claims 53 to 57 which comprises running the engine while the cleaning composition is delivered to the fuel system.
59. The method of claim 58 which comprises using the cleaning composition as a fuel source to run the engine.
60. The method of any one of claims 53 to 59 in the cleaning composition comprises: -70 to 75% by volume white spirit; -20 to 25% by volume kerosene; and -0.5 to 1% by volume tetrachloroethylene.
61. The method of any one of claims 53 to 59 in the cleaning composition comprises: -95% to 99% by volume kerosene (preferably de-aromatised); and -1% by volume tetrachloroethylene.
62. The method of any one of claims 53 to 61 which comprises comparing fuel efficiency and/or pollutant levels in exhaust gases before and after cleaning.
63. The method of any one of claims 53 to 62 which comprises monitoring the flow rate of the cleaning composition intermittently or continuously as cleaning progresses, or measuring fuel flow rates before and after cleaning.
64. The method of any one of claims 53 to 63 which comprises matching the delivery pressure of the cleaning composition to the native pressure of the engine fuel system.
65. The method of any one of claims 53 to 64 which comprises setting the delivery pressure of the cleaning composition to a desired level using a pump with a variable output pressure to control the pressure in the delivery line.
66. The method of any one of claims 53 to 65 which comprises filtering the cleaning composition to remove contaminants.
67. The method of any one of claims 53 to 65 which comprises cleaning the fuel supply present in a fuel storage vessel using a fuel cleaning device.
68. The method of claim 67 which comprises connecting an inlet line and a return line of the fuel cleaning device to suitable points in the fuel system.
69. The method of claim 67 or 68 in which the fuel to be cleaned is moved through the fuel cleaning device by a pump which is provided in the fuel cleaning device.
70. The method of any one of claims 53 to 69 in which agitation of fuel supply is carried out using a fuel agitation device.