WO2016046519A1

WO2016046519A1 - Fuel delivery apparatus and method

Info

Publication number: WO2016046519A1
Application number: PCT/GB2015/052603
Authority: WO
Inventors: Trevor John Poulter
Original assignee: Mechtronic Ltd
Current assignee: Mechtronic Ltd
Priority date: 2014-09-22
Filing date: 2015-09-09
Publication date: 2016-03-31
Anticipated expiration: 2017-03-22
Also published as: EP3197825A1; GB201416730D0

Abstract

Liquid fuel delivery apparatus (10) comprising: a plurality of fuel inlet conduits (12a-d) having a first end and a second end, each conduit being connectable via its first end to a respective fuel storage vessel (14a-d), a fuel outlet conduit (22) in fluid communication with said second ends of the fuel inlet conduits, a flow control apparatus (48a-d) configured with respect to each fuel inlet conduit to be selectively changeable between an open condition in which fuel flow through the respective conduit in a first flow direction from said first end to said second end is permitted and a closed condition in which fuel flow through the respective conduit in the first direction is prevented, each said fuel inlet conduit further comprising a fuel return port (52a-d), and a detection device (54a-d); the apparatus having a fuel dispensing configuration in which fuel can flow from said first end to said second end of a fuel inlet conduit and a fuel return configuration in which a fuel return flow can pass through said fuel return port and from said fuel return port in a second flow direction through said fuel inlet conduit towards said first end, and wherein in said fuel return configuration said detection device is configured to detect a transition of the fuel return flow from a fuel of a first type to a fuel of a second type when said transition is proximate said fuel return port.

Description

Fuel Delivery Apparatus and Method

[0001] This invention relates to an apparatus and method for dispensing fluid from a tank, compartment or container. More particularly, embodiments of the present invention relate to apparatus and methods for dispensing liquid fuel, notably a hydrocarbon fuel, from a tanker vehicle.

[0002] In particular embodiments the present invention relates to apparatus and methods for recovering fuel contained in a delivery hose. Embodiments of the invention relate to methods of preparing a fuel delivery apparatus for dispensing a second fuel after dispensing of a first fuel by the apparatus, and to apparatus configured for such dispensing. More especially embodiments of the present invention relate to apparatus and methods for the recovery of a first fuel from a delivery hose prior to the delivery of a second fuel through said hose. In embodiments of the invention the fuel recovered from the delivery hose can be returned to a tank or tank compartment of a tanker vehicle from which it was drawn.

BACKGROUND

[0003] It is common practice for hydrocarbon fuels to be delivered to a place of use or storage by a fuel tanker vehicle. The fuel tanker vehicle is commonly a road-going vehicle (a lorry or truck) but can be a railway (railroad) vehicle. The tanker vehicle can typically include a fuel tank configured to contain the hydrocarbon fuel which is dispensed into the fuel tank at a fuel source (such as a refinery or bulk storage facility). The hydrocarbon fuel is transported in the fuel tank to a destination, typically an end user or retailer of the hydrocarbon fuel and is dispensed from the fuel tank of the tanker vehicle into a destination storage tank.

[0004] The fuel tank of the tanker vehicle can be divided into a plurality of discrete compartments. On any given tanker delivery journey, each tank compartment can (but will not necessarily) contain a different type of fuel. Different types of fuel can be, by way of example, automotive fuel oils such as petroleum (gasoline) and diesel, kerosene and paraffinic oils, domestic or commercial heating oil and the like. It is important that different types of fuel are not mixed, or at least that any mixing of different types of fuel is minimised as far as possible.

[0005] In a typical known arrangement for delivery of fuel from the fuel tank of the tanker vehicle, fuel from a given compartment is directed through a common manifold and from the manifold through a delivery hose to a destination storage tank. Thus at different times, different fuels from the respective tank compartments pass through the common manifold and the delivery hose. [0006] At each fuel delivery typically a measured amount of fuel is dispensed from the tank compartment to the destination storage tank. A metering device can be provided to determine the amount of fuel dispensed to the destination storage tank. Thus, a customer can be charged in accordance with the amount of fuel delivered to the destination storage tank.

[0007] However, after each delivery fuel remains in the delivery hose downstream of the manifold, in particular between the manifold and a delivery outlet end portion (e.g. nozzle) at a delivery end of the delivery hose. In some arrangements the delivery outlet end portion can include a flow control valve which can be closed to stop the flow of fuel through the delivery hose. A typical volume of such remaining fuel ("retained fuel") contained in the delivery hose after a delivery is of the order of 100-150 litres.

[0008] The presence of such retained fuel in the delivery hose presents challenges. If a subsequent fuel delivery is of a different (second) type of fuel (that is, of a type different to the retained fuel), the retained fuel in the delivery hose must be removed from the hose so that it is not dispensed to the destination of the second fuel. Otherwise, the retained fuel from the delivery hose will become mixed with the second type of fuel in the destination storage tank. As noted, it is highly desirable to avoid mixing of fuels as far as possible. Given that a typical fuel delivery from a tank compartment of a tanker vehicle can be as little as 200 litres, a retained amount of fuel in the delivery hose of around 100 litres can represent a very significant proportion of the delivered volume of fuel, and this further emphasises the importance of avoiding mixing of fuels. A further important consideration is that different fuels may be taxable at different rates. It is therefore essential that a customer receives a required volume of fuel and that the received volume consists of only one type of fuel, so that applicable tax can be correctly paid. By way of example, in the UK regulations can require under or over dispensing of fuels (depending of relative tax rates of the sequentially dispensed fuels) to ensure that there is no underpayment of tax.

[0009] In order to address the above problem, fuel tankers can be provided with a return path by which retained fuel contained in the delivery hose can be returned to the tank compartment from which it was originally drawn. Typically a specific return inlet can be provided upstream of the manifold with a flow path from the inlet along which retained fuel is caused to flow back the tank compartment from which it was originally drawn. To achieve this, the delivery outlet end portion (e.g. dispensing nozzle) of the dispensing hose is connected to the return inlet. Second fuel is dispensed from a second tank

compartment, usually via the manifold, into the delivery hose. The second fuel displaces the retained fuel contained in the dispensing hose, causing the retained fuel to exit the delivery hose through the delivery outlet end portion and into the return inlet. When the retained fuel has been displaced from the delivery hose, dispensing of the second fuel is stopped. The delivery hose should thus contain (substantially) only the second fuel. The delivery nozzle can be detached from the return inlet and the apparatus is then ready for delivery of the second fuel to its destination storage tank.

[0010] Generally, the delivery hose has a sufficiently narrow diameter such that mixing of the fuels at the interface in the delivery hose between the retained fuel and the second fuel is minimal.

[0011] The amount of second fuel which is dispensed for displacing the retained fuel should be sufficient to displace all the retained fuel from the dispensing hose. An excess amount of second fuel will cause second fuel to enter the tank compartment of the first (retained) fuel. An insufficient amount of the second fuel will result in dispensing of some of the retained fuel with the second fuel. In both cases, an undesired mixing of fuels occurs.

[0012] However, it is not currently possible consistently and/or accurately to determine the correct amount of the second fuel which is dispensed to displace the retained (first) fuel. Conventional practice is to determine at the time of manufacture the volume of the delivery hose and to assume that the determined volume corresponds to the volume of retained fuel after each delivery. The metering device can then be used to meter an amount of the second fuel (to displace the retained fuel back to the tank compartment from which it was originally drawn) equal to determined volume of the delivery hose. However this method is fraught with possible inaccuracies such as changes over time and use in the volume of the delivery hose and operator inattention and errors.

[0013] The present invention seeks to ameliorate or overcome one or more of the above problems.

BRIEF SUM MARY OF THE DISCLOSURE

[0014] In accordance with a first aspect of the present invention there is provided a liquid hydrocarbon fuel delivery apparatus comprising:

a plural number of fuel inlet conduits having a first end and a second end, each said conduit being connectable via its first end to a respective fuel storage vessel, each said fuel inlet conduit further comprising a fuel return port,

a fuel outlet conduit in fluid communication with said second ends of the fuel inlet conduits

flow control apparatus configured with respect to each fuel inlet conduit to be selectively changeable between an open condition in which fuel flow through the respective conduit in a first flow direction from said first end to said second end is permitted and a closed condition in which fuel flow through the respective conduit in the first direction is prevented,

and

a detection device

the apparatus having a fuel dispensing configuration in which fuel can flow from said first end to said second end of a fuel inlet conduit and a fuel return

configuration in which a fuel return flow can pass through said fuel return port and from said fuel return port in a second flow direction through said fuel inlet conduit towards said first end,

wherein in said fuel return configuration said detection device is configured to detect a transition of the fuel return flow from a fuel of a first type to a fuel of a second type when said transition is proximate said fuel return port.

[0015] In some preferred embodiments the apparatus can further comprise a fuel delivery hose having a first end and a delivery end portion, said first end connected to said fuel outlet conduit and said delivery end portion including a connection arrangement connectable for fuel delivery to a destination fuel storage vessel and for fuel return flow to a fuel return port.

[0016] In the simplest arrangement, said connection of the delivery end portion can be simple insertion of the delivery end portion into a receiving inlet opening of the destination fuel storage vessel. However, such an arrangement can be unsuitable for delivering volatile hydrocarbon fuels. Hence in more preferred arrangement, the connection arrangement is adapted to engage a complementary formation of the destination fuel storage vessel to form a substantially fluid tight seal. Suitably, the connection

arrangement can include a screw threaded portion configured to engage a complementary screw threaded formation of the receiving inlet opening of the destination fuel storage vessel. An alternative arrangement can be a bayonet type coupling. In any of the above arrangements, said delivery end portion can be, or can include a portion, in the form of a nozzle. In particularly preferred arrangements the connection arrangement is adapted to engage a corresponding complementary formation of the fuel return port to form a substantially fluid tight seal for return of retained fuel to its respective tank compartment. Again, the connection arrangement can include a screw threaded portion configured to engage a complementary screw threaded formation of a receiving inlet opening of a fuel return port. An alternative arrangement can be a bayonet type coupling.

[0017] According to a second aspect of the present invention there is provided a fuel delivery vehicle comprising a plural number of fuel storage vessels for containing different types of liquid hydrocarbon fuel, and a liquid hydrocarbon fuel delivery apparatus according to the first aspect, each respective fuel inlet conduit being connected via its first end to a respective fuel storage vessel. The respective fuel storage vessels can be tank compartments of a tank of the delivery vehicle.

[0018] In some preferred embodiments the detection device can comprise a colour sensor configured to determine a difference in colour between the fuel of the first type and the fuel of the second type.

[0019] In ideal arrangements, the detection device can be arranged as closely as possible to the union formed (for the return of retained fuel) between the connection arrangement and the fuel return port. Design constraints are likely in practical

embodiments to dictate, however, that the detection device cannot be disposed exactly at said union.

[0020] In some preferred embodiments the detection device can be disposed on, in, or proximate the fuel return port.

[0021] In some preferred embodiments the detection apparatus can be disposed on, in or proximate the delivery end portion of the fuel delivery hose.

[0022] In some preferred embodiments the apparatus or fuel delivery vehicle can further comprise a fuel delivery manifold, said manifold having a common manifold chamber with which the second end of each of the plural number of fuel inlet conduits and the fuel outlet conduit are in fluid communication.

[0023] In some preferred embodiments the flow control apparatus can comprise respective flow control valves arranged in the fuel inlet conduits downstream of the location of the fuel return port and upstream of the second ends of the fuel inlet conduits, with respect to the first flow direction.

[0024] In some preferred embodiments the flow control apparatus can be configured in a first dispensing condition of the apparatus to permit flow of a selected first fuel through a selected one of the plural number of fuel inlet conduits and through the fuel outlet conduit and in a second dispensing condition to permit flow of a selected other fuel through a selected other one of the plural number of fuel inlet conduits and through the outlet conduit. Preferably the apparatus is so configured that these first and second dispensing conditions cannot occur simultaneously.

[0025] In some preferred embodiments the flow control apparatus can be configured in a fuel return configuration to permit flow of fuel of a first type in the second flow direction through the fuel return port of a first fuel inlet conduit and simultaneously to permit flow of a fuel of a second type different to the first type in the first direction through a fuel inlet conduit other than the first fuel inlet conduit and through the outlet conduit. [0026] In some preferred embodiments the flow control apparatus can be configured in the fuel return configuration to prevent flow of the fuel of a first type from the fuel return port through the second end of the first inlet conduit.

[0027] In some preferred embodiments the detection device can be configured to generate a signal on detection of said transition of the fuel flow from a fuel of a first type to a fuel of a second type and, in response to said signal from the detection device, the flow control apparatus can be configured to stop or prevent flow of said fuel of the second type.

[0028] In some preferred embodiments the detection device can be configured to generate a signal on detection of said transition of the fuel flow from a fuel of a first type to a fuel of a second type and, in response to said signal from the detection device, the flow control apparatus can be configured to stop or prevent flow of said fuel of a second type different to the first type through said fuel inlet conduit other than the first fuel inlet conduit.

[0029] In some preferred embodiments, the apparatus can further include a controller, in particular an electronic controller. The controller can receive said signal from the detection device and, in response to said signal from the detection device, can cause the flow of fuel of the second type to be stopped. Thus, the controller can cause the flow control apparatus to stop the flow of the second fuel.

[0030] The controller can, in embodiments of the invention, control other aspects of the operation of the invention. Such control can be responsive to one or more operator inputs or can be responsive to operation steps or stages in the operation of the apparatus. Such operation steps or stages can include, by way of example, delivery of a determined amount of fuel to a destination storage tank or initiating a flow of fuel of a second type after the manifold is emptied of fuel of the first type. In embodiments, the controller can control the operation of the flow control apparatus and/or any one or more of the flow control valves of the apparatus.

[0031] In some preferred embodiments, with said delivery end component of the fuel delivery hose connected to the fuel return port of a first fuel inlet conduit and said fuel delivery hose containing a residual amount of a first fuel, said flow control apparatus can be configurable to permit a flow of a second fuel in said first direction through a fuel inlet conduit other than said first inlet conduit such that the second fuel displaces the first fuel in the fuel delivery hose.

[0032] According to a third aspect of the present invention there is provided a method of preparing a fuel delivery apparatus for delivery of a fuel of a second type after delivery of a fuel of a first type different from said second type, said fuels being liquid hydrocarbon fuels, the method comprising displacing residual fuel of the first type contained in a fuel delivery hose from said delivery hose with said fuel of the second type, detecting when a transition between said fuel of the first type and said fuel of the second type is proximate a downstream end of the fuel delivery hose and stopping fuel flow in said fuel delivery hose in response to detection of said transition. In carrying out this method, the downstream end of the fuel delivery hose can be connected to a return flow path for the fuel of the first type, whereby the residual fuel of the first type can be returned to a storage tank for fuel of the first type.

[0033] In some preferred embodiments of this method the fuel delivery apparatus can be an apparatus according to the first aspect of the invention.

[0034] In some preferred embodiments of this method, the fuel delivery apparatus can be mounted to, or can be a part of, a fuel delivery vehicle and the fuel delivery vehicle can convey said fuel between a first delivery location and one or more subsequent delivery locations. The fuel delivery vehicle can comprise a plural number of fuel storage vessels for containing different types of fuel, and a liquid hydrocarbon fuel delivery apparatus. The respective fuel storage vessels can be tank compartments of a tank of the delivery vehicle.

[0035] In some preferred embodiments said detecting a transition between said fuel of the first type and said fuel of the second type can further comprise generating a detection signal on detection of said transition of the fuel flow from a fuel of a first type to a fuel of a second type and, in response to said signal from the detection device, stopping or preventing flow of said fuel of the second type.

[0036] In some preferred embodiments, said detection signal can be received by a controller, in particular an electronic controller. The controller can receive said signal and, in response to said signal from the detection device, can cause the flow of fuel of the second type to be stopped. In embodiments, the controller can cause a flow control apparatus to stop the flow of the second fuel.

[0037] The controller can, in embodiments of the invention, control other aspects of the operation of the invention. Such control can be responsive to one or more operator inputs or can be responsive to operation steps or stages in the operation of the apparatus. Such operation steps or stages can include, by way of example, delivery of a determined amount of fuel to a destination storage tank or initiating a flow of fuel of a second type after the manifold is emptied of fuel of the first type. In embodiments, the controller can control the operation of the flow control apparatus and/or any one or more of the flow control valves of the apparatus. [0038] In some preferred embodiments said detecting a transition between said fuel of the first type and said fuel of the second type can comprise detecting a colour change between said fuel of the first and second types.

[0039] In some preferred embodiments said apparatus can comprise a plural number of fuel inlet conduits having a first end and a second end, each said conduit being connected via its first end to a respective fuel storage vessel, and a fuel outlet conduit in fluid communication with said second ends of the fuel inlet conduits, and the method can comprise dispensing said fuel of the second type from a second fuel storage vessel via a second fuel inlet conduit and said fuel outlet conduit to said fuel delivery hose to displace said residual fuel of the first type and directing said residual fuel of the first type from said fuel delivery hose via a first fuel inlet conduit to a first fuel storage vessel.

[0040] In some preferred embodiments the method can include the step of, prior to initiating dispensing of said fuel of the second type, connecting a said downstream end of the delivery hose to a fuel return port of said first fuel inlet conduit.

[0041] In some preferred embodiments said first fuel storage vessel can be the fuel storage vessel from which the residual fuel of the first type was dispensed.

[0042] In some preferred embodiments the method can include the step of dispensing fuel of the first type from a first fuel storage vessel via said fuel delivery hose to a first fuel destination storage vessel, prior to displacing residual fuel of the first type contained in the fuel delivery hose from said delivery hose with said fuel of the second type.

[0043] In some preferred embodiments the method can include the step of, after stopping fuel flow in said fuel delivery hose in response to detection of said transition, connecting said downstream end of the delivery hose to a second fuel destination storage vessel and dispensing fuel of the second type into said second fuel destination storage vessel via said fuel delivery hose.

[0044] In some preferred embodiments the method can further comprise displacing residual fuel of the second type contained in the fuel delivery hose from said delivery hose with a different liquid hydrocarbon fuel, detecting when a transition between said fuel of the second type and said different fuel is proximate a downstream end of the fuel delivery hose and stopping fuel flow in said fuel delivery hose in response to detection of said transition. Said detecting a transition between said fuel of the second type and said different fuel can comprise detecting a colour change between said fuel of the first and second types.

[0045] In some preferred embodiments said steps of (a) displacing residual first fuel contained in a fuel delivery hose from said delivery hose with said second fuel and (b) dispensing first fuel from a first fuel storage vessel via said fuel delivery hose to a first fuel destination storage vessel, prior to displacing residual first fuel contained in a fuel delivery hose from said delivery hose with said second fuel can be (i) temporally spaced (ii) carried out at geographically the same or separate locations and/or (iii) carried out by different operators of the apparatus. The respective steps (a) and (b) can be temporally spaced by minutes (for example at least 10 or 20 or 30 minutes), or hours, depending, for example, on the time taken for a delivery vehicle bearing an apparatus according to the invention to move from a first delivery location to a second delivery location. Said geographically separate locations can be different delivery locations for the delivery vehicle.

[0046] In some preferred embodiments said steps of (a) stopping fuel flow in said fuel delivery hose in response to detection of said transition and (b) connecting said downstream end of the delivery hose to a second fuel destination storage vessel and dispensing fuel of the second type into said second fuel destination storage vessel via said fuel delivery hose can be (i) temporally spaced (ii) carried out at geographically the same or separate locations and/or (iii) carried out by different operators of the apparatus. The respective steps (a) and (b) can be temporally spaced by minutes (for example at least 10 or 20 or 30 minutes), or hours, depending, for example, on the time taken for a delivery vehicle bearing an apparatus according to the invention to move from a first delivery location to a second delivery location. Said geographically separate locations can be different delivery locations for the delivery vehicle.

[0047] In some preferred embodiments said steps of (a) dispensing second fuel into said second fuel destination storage vessel via said fuel delivery hose and (b) displacing residual second fuel contained in the fuel delivery hose from said delivery hose with a different liquid hydrocarbon fuel can be (i) temporally spaced (ii) carried out at

geographically the same or separate locations and/or (iii) carried out by different operators of the apparatus. The respective steps (a) and (b) can be temporally spaced by minutes (for example at least 10 or 20 or 30 minutes), or hours, depending, for example, on the time taken for a delivery vehicle bearing an apparatus according to the invention to move from a given delivery location to a subsequent delivery location. Said geographically separate locations can be different delivery locations for the delivery vehicle.

[0048] In some preferred embodiments a detecting device disposed on, in, or proximate a fuel return port of a fuel inlet conduit can detect when a transition between said first fuel and said second fuel is proximate a downstream end of the fuel delivery hose.

[0049] In some preferred embodiments a detecting device disposed on, in, or proximate a downstream end of the fuel delivery hose can detect when a transition between said first fuel and said second fuel is proximate the downstream end of the fuel delivery hose. [0050] In some preferred embodiments the fuel delivery apparatus can be mounted on a vehicle and the vehicle can be moved from a given delivery location to a subsequent delivery location after displacing the fuel of the first type with the fuel of the second type and before dispensing the fuel of the second type to a destination storage tank.

[0051] In some preferred embodiments the fuel delivery apparatus can be mounted on a vehicle and the vehicle can be moved from a given delivery location to a subsequent delivery location after dispensing a fuel of the first type and prior to displacing said fuel of the first type with fuel of the second type.

[0052] In accordance with fourth embodiment of the invention there is provided a liquid hydrocarbon fuel delivery apparatus comprising:

a plural number of fuel inlet paths having a first end and a second end and each connectable at said first end to a respective one of the same plural number of fuel storage vessels

a fuel outlet path in fluid communication with said second ends of the fuel inlet paths

a fuel delivery hose having a first end and a delivery end, said first end connected to said fuel outlet path and said delivery end having a delivery nozzle connectable for fuel delivery to a destination fuel storage vessel and

flow control apparatus operable to permit flow of fuel through a selected fuel inlet path in a direction from said first end to said second end

each said fuel inlet path further comprising a fuel return port to which fuel return port the delivery nozzle is connectable and said fuel inlet path configurable to define, when the delivery nozzle is connected to the fuel return port, a fuel flow path permitting fuel flow from said fuel return port in a second flow direction towards said first end;

wherein the apparatus further comprises detection device arranged, when the delivery nozzle is connected to the fuel return port, proximate the hose delivery end, said detection device being operatively in detecting communication with the fuel flow and configured to detect a transition of the fuel flow from a fuel of a first type to a fuel of a second type. Said detecting device can preferably be in detecting communication with fuel within the fuel return port. Alternatively detecting device can preferably be in detecting communication with fuel within the delivery nozzle.

[0053] In some preferred embodiments the detection device can comprise a colour sensor configured to determine a difference in colour between the fuel of the first type and the fuel of the second type. [0054] In accordance with fifth embodiment of the invention there is provided a fuel delivery vehicle for the delivery of liquid hydrocarbon fuels, the vehicle comprising

a plural number of fuel storage vessels and

a delivery apparatus comprising

the same plural number of fuel inlet paths having a first end and a second end and each connected at said first end to a respective one of the fuel storage vessels

[0055] In some preferred embodiments the detection device can comprise a colour sensor configured to determine a difference in colour between the fuel of the first type and the fuel of the second type.

[0056] Further preferred embodiments of the fourth and fifth aspects of the invention can be substantially the same as, or analogous to, any of those above in relation to the first and second aspects of the invention.

[0057] In accordance with a sixth aspect of the invention there is provided a method of preparing a fuel delivery apparatus for delivery of a second liquid hydrocarbon fuel after delivery of a first liquid hydrocarbon fuel different from said second fuel, the method comprising connecting a delivery end component of a delivery end portion of a delivery hose to a fuel return port and providing a flow path from fuel return port to a first tank compartment containing the first liquid hydrocarbon fuel, providing a flow path from a second tank compartment containing the second liquid hydrocarbon fuel to an end of said delivery hose distal to said fuel delivery nozzle, displacing first fuel from said delivery hose with said second fuel such that the first fuel flows from said delivery hose to said first tank compartment, detecting that a transition between the first fuel and the second fuel is at a proximate the delivery nozzle, and stopping the flow of second fuel on said detection. Said detecting of a transition can preferably be within the fuel return port. Said detecting of a transition can preferably be within the delivery nozzle.

[0058] Further preferred embodiments of the sixth aspect of the invention can be substantially the same as, or analogous to, any of those above in relation to the third aspect of the invention.

[0059] For the avoidance of doubt it is noted that the present invention is not concerned with fuel tanks for vehicles from which tanks fuel is drawn and supplied to the vehicle engine for the purpose of propulsion of the vehicle. The present invention relates in its various aspects and embodiments to fuel tanks and/or fuel tank compartments and associated dispensing apparatus, the tanks and/or tank compartments serving to store and retain the fuel, typically during conveyance of the fuel from one location to another, no fuel being consumed from the tank and/or tank compartment during such period in which the fuel is stored or retained therein.

[0060] As used herein "proximate" can mean within a distance of not more than 50cm, in particular not more than 40 cm, such as not more than 30cm, or 20cm or not more 10cm or not more than 5cm. In some preferred embodiments, "proximate can relate to a range of from about 40cm to about 2cm, such as from about 30cm to about 2cm. Within the above definition, each occurrence herein of "proximate" need not relate to the same distance. By way of example, in a typical arrangement according to the invention, by arranging the detection device within about 50cm of the union between the return input port and the connection arrangement of the delivery hose mixing of different types of fuel can be limited to as little as 500ml, such as about 400ml, or 300ml or even 100ml, all of which amounts are far less than conventionally achieved and are trivial in relation to typical fuel delivery amounts.

BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Embodiments of the invention are further described hereinafter with reference to the accompanying drawings, in which: Figure 1 is a schematic illustration of one embodiment of an apparatus according to the present invention;

Figure 2 is a schematic illustration of a similar embodiment of an apparatus according to the present invention;

Figure 3 shows schematically a vehicle incorporating an apparatus according to the present invention;

Figure 4 shows a portion of an apparatus according to one embodiment of the invention; and

Figure 5 shows a portion of an apparatus according to another embodiment of the invention.

DETAILED DESCRIPTION

[0062] Referring in particular to Figures 1 and 2, apparatus 10 according to embodiments of the invention comprises a plural number of fuel inlet conduits 12a, 12b, 12c and (Fig 2) 12d (collectively fuel inlet conduits 12). Each fuel inlet conduit 12 is connected to a respective one of a plural number of tank compartments 14a, 14b, 14c (collectively tank compartments 14) of a fuel tank 16 (not shown in Fig 2). The fuel tank 16 is, in

accordance with embodiments of the invention, mounted on a vehicle 18 such as a road- going vehicle (lorry or truck) or a rail freight vehicle. The plural number of the fuel inlet conduits 12 is the same as the plural number of the tank compartments 14. In the particular example illustrated in Figures 1 and 3, the tank 16 has three tank compartments 14 and the apparatus 10 has three fuel inlet conduits 12. In the particular example illustrated in Figure 2, the apparatus 10 has four fuel inlet conduits 12 which can thus cooperate with a tank 16 (not shown) having four tank compartments. Other plural numbers of tank compartments 14 and fuel inlet conduits 12 can be provided, such as (without limitation) 2, 5, 6 or 8 tank compartments 14 and fuel inlet conduits 12.

[0063] Each fuel inlet conduit 12 has a first end 12a', 12b', 12c' 12d' which connects (directly or indirectly) to its respective fuel tank compartment 14a, 14b, 14c (14d, not shown), such that, when required, fuel can flow from the respective tank compartment 14 into the associated fuel inlet conduit 12. A flow control valve 20a, 20b, 20c, 20d is conveniently arranged near said first end 12a', 12b', 12c', 12d' and proximate the respective tank compartment 14a, 14b, 14c, 14d. Flow control, valves 20a, 20b, 20c 20d can be parts or components of the respective tank compartments 14a, 14b, 14c, 14d. Flow control valves 20a, 20b, 20c, 20d are individually and selectively transformable between a closed condition in which fuel cannot flow from the respective tank compartment 14 into the associated fuel inlet conduit 12 and an open condition in which such fuel flow can occur.

[0064] Each fuel inlet conduit 12 also has a second end 12a", 12b", 12c" 12d" distal to the first end 12a', 12b', 12c', 12d'. Second ends 12a", 12b", 12c", 12d" connect (directly or indirectly) to a fuel outlet conduit 22. In some preferred arrangements, second ends 12a", 12b", 12c", 12d" of the fuel inlet conduits 12 are in fluid communication with a common manifold 30 and fuel outlet conduit 22 extends from the manifold 30.

[0065] Flow control apparatus is arranged to control the flow of fuel between each fuel inlet conduit 12 and fuel outlet conduit 22. In some preferred embodiments where the fuel inlet conduits communicate with manifold 30, flow control apparatus is arranged to control the flow of fuel between each fuel inlet conduit 12 and the manifold 30. The flow control apparatus can conveniently comprise a flow control valve 48a, 48b, 48c, 48d (collectively, flow control valves 48) for each respective fuel inlet conduit 12. The flow control valves 48a, 48b, 48c, 48d are conveniently arranged in the respective fuel inlet conduits 12 between the first ends 12a', 12b', 12c', 12d' and the second ends 12a", 12b", 12c", 12d". Also conveniently the respective flow control valves can be arranged nearer to second ends 12a", 12b", 12c", 12d" than to first ends 12a', 12b', 12c', 12d' such as adjacent second ends 12a", 12b", 12c", 12d". Each flow control valve 48a, 48b, 48c, 48d is individually and selectively transformable between a closed condition in which fuel cannot flow through the fuel inlet conduit 12 from the first end 12a', 12b', 12c', 12d' to the second end 12a", 12b", 12c", 12d" and an open condition in which such fuel flow can occur. Flow control apparatus (in particular respective valves 48a, 48b, 48c, 48d) can be user controlled and/or can be controlled automatically such as by means of an apparatus controller 40 which can control aspects of the operation of the apparatus 10.

[0066] Fuel outlet conduit 22 connects in use (directly or indirectly) to a fuel delivery hose 24 which for storage can conveniently be arranged around a drum 26 and can be extended from the drum 26 for use in delivering fuel. Fuel delivery hose 24 can terminate at its downstream or delivery end 32 at a delivery outlet end portion which can be a nozzle or other suitable coupling or connecting device 28 for allowing delivery of fuel therethrough into an inlet of a destination fuel storage tank indicated generally at 34. Destination storage tank 34 as such is not a part of the apparatus of the invention. Destination storage tanks suitable for hydrocarbon fuels as such are well known in the art and need not be described further. Delivery outlet end portion 32 can conveniently include a flow control valve 36 suitable for initiating and stopping the flow of fuel through the hose 24. Flow control valve 36 can be user controlled and/or can be controlled automatically such as by means of the overall apparatus controller 40. Delivery outlet end portion 32 can conveniently further include a non-return valve 38. In typical arrangements, fuel delivery hose 24 can have a length of about 45m and a diameter of about 30 to 40mm.

[0067] Fuel outlet conduit 22 can thus extend from a manifold 30 to an upstream end of the delivery hose 24. Fuel outlet conduit 22 can include other apparatus and devices for facilitating fuel delivery as necessary and appropriate. For example, a gas extractor 42 can be arranged at least partly within or downstream (conveniently immediately downstream) of the manifold 30. Gas extractor 42 serves to remove unwanted gas (typically air bubbles) from the fuel. Collected gas can be vented such as via a vent valve or valve arrangement 42A. Fuel outlet conduit 22 can include a fuel pump 44. A metering device 46 can also conveniently be provided in fuel outlet conduit 22 to measure the amount of fuel dispensed by the apparatus 10. Manifold 30 and or gas extractor 42 can include sensors 50a, 50b configured to determine the presence or absence of fuel at selected locations. The sensor or sensors 50a, 50b can communicate with controller 40 via suitable wired or wireless communication indicated generally as 50C.

[0068] Thus, for fuel delivery a tank compartment 14 containing the fuel required for delivery is selected. For the purposes of exemplification, tank compartment 14a is deemed to be selected and the delivery hose 24 is deemed initially to be empty of fuel. In general terms, to allow dispensing of fuel from tank compartment 14a, valve 20a (if present) and valve 48a are placed in their open condition. Opening of the valves 20a, 48a can be effected under the control of apparatus controller 40, such as in response to an input to the apparatus controller 40 (via, say, a push button or touch screen) by an operator identifying tank compartment 14a as that required for delivery and that delivery should be initiated. Opening of the valve 48a (and valve 20a if present) provides a flow path for the fuel in the tank compartment 14a from the tank compartment 14a through the fuel inlet conduit 12a to the manifold 30 and then to the fuel outlet conduit 22. Flow of fuel through the fuel outlet conduit 22 can be effected or assisted as required by pump 44. Flow of fuel continues through the fuel outlet conduit 22 and then the delivery hose 24. Fuel exits the delivery hose 24 via the fuel outlet end portion 32 and enters the destination storage tank 34. Delivery of fuel is continued until the required delivered volume has been achieved, as can be indicated by metering device 46, at which point the flow of fuel is terminated by closure of a relevant valve, notably valve 36 and valve 20a.

[0069] Thus, after delivery of fuel from tank compartment 14a to the destination storage tank, a quantity of the fuel is retained in the fuel outlet conduit 22 and the delivery hose 24 and measures are required to prevent, so far as possible, dispensing of such retained fuel when a second fuel is dispensed from another tank compartment (unless, of course, the second fuel is the same as the retained fuel). [0070] To this end, the apparatus of embodiments of the invention is provided with a return fuel path by which such retained fuel can be returned to the tank compartment from which is was dispensed, in the present example tank compartment 14a. Each fuel inlet conduit 12a, 12b, 12c, 12d can have a respective return inlet (fuel return port) 52a, 52b, 52c, 52d (collectively return inlets 52) to which the fuel outlet end portion 32 of the delivery hose 24 is connectable (note Figures 4 and 5) and through which, when the delivery hose 24 is so connected and when required, fuel can flow from the delivery hose into the associated fuel inlet conduit 12a, 12b, 12c, 12d. Return inlets 52a, 52b, 52c, 52d can include a respective valve 52a', 52b', 52c', 52d' (collectively vales 52') each of which is individually and selectively transformable between a closed condition in which fuel cannot flow through the respective return inlet 52 and an open condition in which fuel can flow through the respective return inlet 52. Valves 52a', 52b', 52c', 52d' can in preferred embodiments remain in their closed condition at substantially all times. A valve 52a', 52b', 52c', 52d' can be in its open condition only when retained fuel is returned through its respective return inlet 52a, 52b, 52c, 52d.

[0071] Thus, for the return of the retained fuel from the delivery hose 24 to the tank compartment 14 from which the retained fuel was dispensed a fuel flow path is provided from the delivery hose 24 via the appropriate return inlet 52 and fuel inlet conduit 12 to the appropriate tank compartment 14. For the return of retained fuel to the appropriate tank compartment 14, there must be no flow path for the retained fuel from the fuel inlet conduit 12 to the manifold 30 or fuel outlet conduit 22. Hence the respective flow control valve 48 of the fuel inlet conduit 12 through which the retained fuel is returned is maintained in a closed condition.

[0072] In the present example, the retained fuel in the fuel outlet conduit 22 and the delivery hose 24 is derived from tank compartment 14a and is therefore to be returned to tank compartment 14a. The return flow path from the delivery hose 24 is therefore via return inlet 52a and fuel inlet conduit 12a. Flow control valve 48a is maintained in its closed condition during return of the retained fuel to tank compartment 14a.

[0073] When the retained fuel is to be returned to its tank compartment, a flow of a second fuel from a different tank compartment (14c, for example) is provided. To provide the flow of second fuel from tank compartment 14c, valves 20c and 48c are opened so that the second fuel can flow through fuel inlet conduit 12c to manifold 30 and from manifold 30 to fuel outlet conduit 22. Second fuel from tank compartment 14c can thus pass into the fuel outlet conduit 22 and the delivery hose 24, and in so doing displaces the retained fuel. The retained fuel and (thereafter) the second fuel may be caused to pass through the fuel outlet conduit 24 and the delivery hose 24 with the assistance of pump 44. Because the delivery hose 24 and fuel outlet conduit are of relatively narrow diameter, such as 30 to 40mm, for example 32 to 38mm, any mixing of the retained and first fuels which may occur at their interface is negligible. Thus the second fuel displaces the retained fuel from the fuel outlet conduit 22 and the delivery hose 24 and the retained fuel flows via the return inlet 52a and the fuel inlet conduit 12a to the tank compartment 14a.

[0074] When returning retained fuel to the tank compartment 14 from which it was dispensed, the flow of fuel towards that tank compartment 14 should preferably not continue to the extent that the second fuel reaches the respective fuel inlet conduit 12 and most preferably the amount of second fuel which enters the return inlet 52 should be minimal. This is to prevent or minimise mixing of the second fuel with fuel from the tank compartment to which the retained fuel has been returned. Such mixing could occur, for example, when fuel is subsequently dispensed from that tank compartment if second fuel is, erroneously, contained in the fuel inlet conduit 12 associated with the tank compartment 14 to which retained fuel has been returned. In an ideal arrangement, substantially none of the second fuel should exit the fuel outlet end portion 32 and substantially all of the retained fuel should exit the fuel outlet end portion 32. Such an ideal arrangement may not be practically achievable, but embodiments of the present invention can achieve a result advantageously close to the ideal.

[0075] In the specific example as above, the flow of second fuel which is drawn from tank compartment 14c displaces retained fuel from the fuel outlet conduit 22 and the delivery hose 24 so that the retained fuel is returned to the tank compartment 14a. The flow of second fuel can be stopped before the second fuel reaches the fuel inlet conduit 12a, preferably as the second fuel reaches the return inlet 52a and most preferably immediately before any of the second fuel exits the fuel outlet end portion 32. The flow of second fuel can be stopped by closure of one or both of valves 20c and 48c and (if used) by stopping the pump 44.

[0076] Clearly it is desirable for as much of the retained fuel as possible to be displaced from the delivery hose 24 by the second fuel. As noted above, the prior art apparatus and methods are incapable of providing or achieving the required degree or precision or accuracy in determining when the flow of second fuel is to be stopped.

[0077] Embodiments of the present invention provide sensors 54a, 54b, 54c, 54d associated in some embodiments respectively with the return inlets 52a, 52b, 52c, 52d. One such embodiment is shown in Figure 4. The sensors 54a, 54b, 54c, 54d are configured and arranged to detect the boundary or interface between the retained fuel and the second fuel as fuel flows through the return inlet 52a, 52b, 52c, 52d. Expressed differently, the sensor 54a, 54b, 54c, 54d can interrogate the interior of the return inlet 52a, 52b, 52c, 52d and can determine when the boundary between the retained fuel and the second fuel moves through the return inlet 52a, 52b, 52c, 52d.

[0078] In some preferred embodiments, the sensors 54a, 54b, 54c, 54d are colour sensors which can detect a difference in colour between the retained fuel and the second fuel. On detecting the boundary or interface between the retained fuel and the second fuel, the flow of fuel through the delivery hose 24 is stopped. In some preferred embodiments, the sensor 54a, 54b, 54c, 54d is arranged to provide a signal on detecting said boundary or interface and the flow of fuel is stopped when such signal is provided. The signal can be transmitted (e.g. electronically via a wire, or wirelessly) to controller 40 which can then cause the pump 44 to be stopped and the valves 20, 48 to be closed, as appropriate.

[0079] Colour sensors as such are well known in the art and on the basis of the present disclosure the provision of a suitable colour sensor is within the capability of the person skilled in the art of electronic componentry. In one preferred arrangement the colour sensor can comprise light emitting diodes emitting in rapid sequence red, green and blue light and sensor arrangements configured to detect the emitted light after the light has passed through the fuel. An absorbance spectrum of the fuel may be determined and compared with a look up table to determine the identity of the fuel. A change of identified fuel equates to detection of the transition between different fuel types. Processing of data obtained from the sensor and comparison with a look up table can be carried out by an electronic apparatus controller.

[0080] In an alternative embodiment, sensors 54a, 54b, 54c, 54d are not provided in association with the respective return inlets 52a, 52b, 52c, 52d. In these embodiments, a sensor 54, which in preferred embodiments can be a colour sensor, is provided in association with fuel outlet end portion 32, and preferably as near to the outlet end of the fuel outlet end portion 32 as can reasonably be achieved. One such embodiment is shown in Figure 5. In this arrangement the sensor 54 is arranged to provide a signal on detecting said boundary or interface between the retained fuel and the second fuel and the flow of fuel is stopped when such signal is provided. Expressed differently, the sensor 54 can interrogate the interior of the fuel outlet end portion 32 and can determine when the boundary between the retained fuel and the second fuel approaches the exit outlet of the fuel outlet end portion 32 and can generate a signal accordingly. The signal can be transmitted (e.g. electronically via a wire, or wirelessly) to controller 40 which can then cause the pump 44 to be stopped and the valves 20, 48 to be closed, as appropriate.

[0081] As noted above manifold 30 can be provided with sensors 50a and 50b. Sensor 50a is useful for determining whether the level of fuel in the manifold 30 is approaching a predetermined maximum level and is not directly relevant to the present invention (and as such could be omitted). Sensor 50b can determine when the level of fuel in the manifold 30 reaches a minimum level, or when the manifold 30 is drained of fuel. The ability to drain the manifold of fuel can be important in preventing or minimising mixing of the retained fuel and the second fuel. Sensor 50b can determine when the level of fuel in the manifold has fallen below a predetermined minimum level and can generate a signal accordingly. In response to the generated signal, the pump 44 can be stopped and/or other measures taken (such as the closure of valve 36) to prevent further fuel flow through the outlet conduit 22 and delivery hose 24. The generated signal can be received by controller 40 which can cause the pump to be stopped and/or the valve 36 to be closed.

[0082] After delivery of fuel to a destination storage tank 36, the fuel flow path

downstream of the valves 48 is full of retained fuel. That is, the manifold 30, fuel outlet conduit 22 and delivery hose 24 all are full of retained fuel. If, in this condition, dispensing of second (or subsequent) fuel from a tank compartment 14 (tank compartment 14d for example) is commenced, undesired mixing of the second fuel with the retained fuel can result. This can be because the flow of the second fuel establishes a direct flow path through the manifold from the respective valve 48 (48d in this example) to the fuel outlet conduit 22. Outside that flow path, the manifold still contains the retained fuel which then slowly mixes with the second fuel. Such mixing is highly disadvantageous, for the reasons noted above. To avoid such mixing, the manifold 30 is first drained of retained fuel before dispensing of the second (or subsequent) fuel commences. Sensor 50b can be used to determine when the manifold has been sufficiently drained. Thus, only after the manifold 30 has been drained is the dispensing of the second fuel from tank compartment 14 commenced. The interface between the retained fuel and the second fuel is thus confined to the fuel outlet conduit 22 and then to the delivery hose 24 and is necessarily therefore of small area, which minimises the mixing of the retained fuel and the second fuel.

[0083] Thus in a variation according to embodiments of the invention, the return of the retained fuel to the tank compartment 14 from which it was dispensed can proceed in two stages. In a first stage, the fuel outlet end portion 32 of the delivery hose 24 is connected to a respective return inlet 52a, 52b, 52c, 52d and retained fuel is transferred (e.g. by the action of pump 44) from the delivery hose via the return inlet 52 to the appropriate tank compartment 14 until the manifold is drained of retained fuel. In a subsequent second stage, dispensing of second fuel from a different tank compartment commences, and displacement of the retained fuel continues in the second stage until the interface between the retained fuel and the second fuel is detected by sensor 54. The second stage can follow immediately after the first stage without pause or interruption. For example, in response to the signal generated by sensor 50b indicating that the manifold is drained, the controller 40 can cause the relevant valves 20, 48 to be opened to commence dispensing of the second fuel.

[0084] As noted above, second fuel is dispensed from the appropriate tank compartment 14 until the interface between the second fuel and the retained fuel is detected by sensor 54, at which time the flow of second fuel is stopped. The fuel outlet end portion 32 of the delivery hose 24 can then be uncoupled or disconnected from the respective return inlet 52 and can subsequently be connected to a destination storage tank 34 for delivery of second fuel to that tank. After completion of the delivery, the second fuel contained in the fuel outlet conduit 22 and the delivery hose 24 is then "retained fuel" which can be returned to the tank compartment 14 from which it was dispensed in the same manner as described above so that a subsequent fuel can be dispensed from a different tank compartment 14 without mixing with the retained second fuel.

[0085] Throughout the description and claims of this specification, the words "comprise" and "contain" and variations of them mean "including but not limited to", and they are not intended to (and do not) exclude other moieties, additives, components, integers or steps. Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.

[0086] Features, integers, characteristics, compounds, chemical moieties or groups described in conjunction with a particular aspect, embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. The invention is not restricted to the details of any foregoing embodiments. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

[0087] The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

Claims

1. A liquid hydrocarbon fuel delivery apparatus comprising:

a plural number of fuel inlet conduits having a first end and a second end, each said conduit being connectable via its first end to a respective fuel storage vessel, a fuel outlet conduit in fluid communication with said second ends of the fuel inlet conduits

flow control apparatus configured with respect to each fuel inlet conduit to be selectively changeable between an open condition in which fuel flow through the respective conduit in a first flow direction from said first end to said second end is permitted and a closed condition in which fuel flow through the respective conduit in the first direction is prevented, each said fuel inlet conduit further comprising a fuel return port,

and

a detection device

the apparatus having a fuel dispensing configuration in which fuel can flow from said first end to said second end of a fuel inlet conduit and a fuel return configuration in which a fuel return flow can pass through said fuel return port and from said fuel return port in a second flow direction through said fuel inlet conduit towards said first end,

2. Apparatus as claimed in claim 1 further comprising a fuel delivery hose having a first end and a delivery end portion, said first end connected to said fuel outlet conduit and said delivery end portion comprising a delivery end portion including a connection arrangement connectable for fuel delivery to a destination fuel storage vessel and for fuel return flow to a fuel return port.

3. A fuel delivery vehicle comprising a plural number of fuel storage vessels for containing different types of fuel, and a liquid hydrocarbon fuel delivery apparatus as claimed in claim 1 or 2, each respective fuel inlet conduit being connected via its first end to a respective fuel storage vessel.

4. Apparatus as claimed in claim 1 or 2, or a fuel delivery vehicle as claimed in claim 3, wherein the detection device comprises a colour sensor configured to determine a difference in colour between the fuel of the first type and the fuel of the second type.

5. Apparatus as claimed in claim 1 , 2 or 4, or a fuel delivery vehicle as claimed in claim 3 or 4, wherein the detection device is disposed on, in, or proximate the fuel return port.

6. Apparatus as claimed in claim 2 or claim 4 when dependent on claim 2, or a fuel delivery vehicle as claimed in claim 3 or 4 when dependent on claim 2, wherein the detection apparatus is disposed on, in or proximate the delivery end portion of the fuel delivery hose.

7. Apparatus as claimed in claim 1 or 2 or any of claims 4 to 6, or a fuel delivery vehicle as claimed in any of claims 3 to 6, further comprising a fuel delivery manifold, said manifold having a common manifold chamber with which the second end of each of the plural number of fuel inlet conduits and the fuel outlet conduit are in fluid communication.

8. Apparatus as claimed in claim 1 or 2 or any of claims 4 to 7, or a fuel delivery vehicle as claimed in any of claims 3 to 7, wherein the flow control apparatus comprises respective flow control valves arranged in the fuel inlet conduits downstream of the location of the fuel return port and upstream of the second ends of the fuel inlet conduits, with respect to the first flow direction.

9. Apparatus as claimed in claim 1 or 2 or any of claims 4 to 8, or a fuel delivery vehicle as claimed in any of claims 3 to 8 wherein the flow control apparatus is configured in a first dispensing condition of the apparatus to permit flow of a selected first fuel through a selected one of the plural number of fuel inlet conduits and through the fuel outlet conduit and in a second dispensing condition to permit flow of a selected other fuel through a selected other one of the plural number of fuel inlet conduits and through the outlet conduit.

10. Apparatus as claimed in claim 1 or 2 or any of claims 4 to 9, or a fuel delivery vehicle as claimed in any of claims 3 to 9, wherein the flow control apparatus is configured in a fuel return configuration to permit flow of fuel of a first type in the second flow direction through the fuel return port of a first fuel inlet conduit and simultaneously to permit flow of a fuel of a second type different to the first type in the first direction through a fuel inlet conduit other than the first fuel inlet conduit and through the outlet conduit.

11. Apparatus as claimed in claim 10 or a fuel delivery vehicle as claimed in claim 10 wherein the flow control apparatus is configured in the fuel return configuration to prevent flow of the fuel of a first type from the fuel return port through the second end of the first inlet conduit.

12. Apparatus as claimed in claim 1 or 2 or any of claims 4 to 1 1 , or a fuel delivery vehicle as claimed in any of claims 3 to 11 , wherein the detection device is configured to generate a signal on detection of said transition of the fuel flow from a fuel of a first type to a fuel of a second type and wherein the flow control apparatus is configured to prevent flow of said fuel of the second type in response to said signal from the detection device.

13. Apparatus as claimed in claim 10 or 1 1 , or a fuel delivery vehicle as claimed in claims 10 or 1 1 , wherein the detection device is configured to generate a signal on detection of said transition of the fuel flow from a fuel of a first type to a fuel of a second type and wherein the flow control apparatus is configured to prevent flow of said fuel of a second type different to the first type through said fuel inlet conduit other than the first fuel inlet conduit in response to said signal from the detection device.

14. Apparatus as claimed in claim 2 or in any of claims 4 to 13 when dependent on claim 2, or a delivery vehicle as claimed in any of claims 3 to 13 when dependent on claim 2 wherein, with said delivery end component of the fuel delivery hose connected to the fuel return port of a first fuel inlet conduit and said fuel delivery hose containing a residual amount of a first fuel, said flow control apparatus is configurable to permit a flow of a second fuel in said first direction through a fuel inlet conduit other than said first inlet conduit such that the second fuel displaces the first fuel in the fuel delivery hose.

15. A method of preparing a fuel delivery apparatus for delivery of a fuel of a second type after delivery of a fuel of a first type different from said second type, said fuels being liquid hydrocarbon fuels, the method comprising displacing residual fuel of the first type contained in a fuel delivery hose from said delivery hose with said fuel of the second type, detecting when a transition between said fuel of the first type and said fuel of the second type is proximate a downstream end of the fuel delivery hose and stopping fuel flow in said fuel delivery hose in response to detection of said transition.

16. A method as claimed in claim 15 wherein said detecting a transition between said fuel of the first type and said fuel of the second type comprises detecting a colour change between said fuel of the first and second types.

17. A method as claimed in claim 15 or 16 wherein said apparatus comprises a plural number of fuel inlet conduits having a first end and a second end, each said conduit being connected via its first end to a respective fuel storage vessel, and a fuel outlet conduit in fluid communication with said second ends of the fuel inlet conduits, the method comprising dispensing said fuel of the second type from a second fuel storage vessel via a second fuel inlet conduit and said fuel outlet conduit to said fuel delivery hose to displace said residual fuel of the first type and directing said residual fuel of the first type from said fuel delivery hose via a first fuel inlet conduit to a first fuel storage vessel.

18. A method as claimed in claim 17 including the step of, prior to initiating dispensing of said fuel of the second type, connecting a said downstream end of the delivery hose to a fuel return port of said first fuel inlet conduit.

19. A method as claimed in claim 17 or 18 wherein said first fuel storage vessel is the fuel storage vessel from which the residual fuel of the first type was dispensed.

20. A method as claimed in any of claims 15 to 19 including the step of dispensing fuel of the first type from a first fuel storage vessel via said fuel delivery hose to a first fuel destination storage vessel, prior to displacing residual fuel of the first type contained in the fuel delivery hose from said delivery hose with said fuel of the second type.

21. A method as claimed in any of claims 15 to 20 including the step of, after stopping fuel flow in said fuel delivery hose in response to detection of said transition, connecting said downstream end of the delivery hose to a second fuel destination storage vessel and dispensing fuel of the second type into said second fuel destination storage vessel via said fuel delivery hose.

22. A method as claimed in claim 21 further comprising displacing residual fuel of the second type contained in the fuel delivery hose from said delivery hose with a different liquid hydrocarbon fuel, detecting when a transition between said fuel of the second type and said different fuel is proximate a downstream end of the fuel delivery hose and stopping fuel flow in said fuel delivery hose in response to detection of said transition.

23. A method as claimed in claim 20 wherein said steps of (a) displacing residual first fuel contained in a fuel delivery hose from said delivery hose with said second fuel and (b) dispensing first fuel from a first fuel storage vessel via said fuel delivery hose to a first fuel destination storage vessel, prior to displacing residual first fuel contained in a fuel delivery hose from said delivery hose with said second fuel are (i) temporally spaced and/or (ii) carried out at geographically separate locations and/or (iii) carried out by different operators of the apparatus.

24. A method as claimed in claim 21 wherein said steps of (a) stopping fuel flow in said fuel delivery hose in response to detection of said transition and (b) connecting said downstream end of the delivery hose to a second fuel destination storage vessel and dispensing fuel of the second type into said second fuel destination storage vessel via said fuel delivery hose are (i) temporally spaced and/or (ii) carried out at geographically separate locations and/or (iii) carried out by different operators of the apparatus.

25. A method as claimed in claim 22 wherein said steps of (a) dispensing second fuel into said second fuel destination storage vessel via said fuel delivery hose and (b) displacing residual second fuel contained in the fuel delivery hose from said delivery hose with a different liquid hydrocarbon fuel are (i) temporally spaced and/or (ii) carried out at geographically separate locations and/or (iii) carried out by different operators of the apparatus.

26. A method as claimed in any of claims 14 to 25 wherein a detecting device disposed on, in, or proximate a fuel return port of a fuel inlet conduit detects when a transition between said first fuel and said second fuel is proximate a downstream end of the fuel delivery hose.

27. A method as claimed in any of claims 14 to 25 wherein a detecting device disposed on, in, or proximate a downstream end of the fuel delivery hose detects when a transition between said first fuel and said second fuel is proximate the downstream end of the fuel delivery hose.

28. A method as claimed in any of claims 15 to 27 wherein the fuel delivery apparatus is mounted on a vehicle and the vehicle is moved from a given delivery location to a subsequent delivery location after displacing the fuel of the first type with the fuel of the second type and before dispensing the fuel of the second type to a destination storage tank.

29. A method as claimed in any of claims 15 to 27 wherein the fuel delivery apparatus is mounted on a vehicle and the vehicle is moved from a given delivery location to a subsequent delivery location after dispensing a fuel of the first type and prior to displacing said fuel of the first type with fuel of the second type.

30. Apparatus as claimed in claim 1 or 2 or a vehicle as claimed in claim 3 substantially as hereinbefore described with reference to any of Figures 1 to 5.

31. Method as claimed in claim 15 substantially as hereinbefore described with reference to any of Figures 1 to 5.