Description of Invention
[0001] This invention relates to a beverage dispensing system and more particularly to a
               system in which the beverage is stored e.g. in a cellar, and delivered to a dispensing
               head, for example, on a bar.
 
            [0002] Conventionally, in a cellar of a public house or the like, a chiller is provided,
               which is operative to cool one, but usually a plurality of lines each of which conveys
               a different beverage to a or a plurality of dispensing heads on the bar. A particular
               chiller will not, however, be able to provide adequate cooling for an unlimited number
               of beverages. Thus, if the number of beverage dispensing heads requiring cooling increases
               above a maximum, for example if the public house or the like is extended to include
               an additional bar, the existing chiller may not have the capacity to provide adequate
               cooling for all of the dispensed beverages. Typically, when this occurs, the existing
               chiller is replaced by a new, larger capacity chiller.
 
            [0003] Moreover, where a plurality of beverages are chilled in a common chiller, the temperatures
               of each of the beverages as dispensed, will tend to be about the same. In the case
               of the plurality of beverages each being beer for example, each dispensed beer may
               thus be dispensed with the same temperature typically in the order of 6°C to 8°C.
               However, the producers of some beers specify an optimum temperature for drinking the
               beer, and such optimum temperatures may vary from one beer to another. Also the common
               chiller may be required to chill soft drinks which typically are required to be served
               at colder temperatures than at least some beers.
 
            [0004] From an economic point of view, and because space may be restricted, it is not usually
               viable to provided a plurality of chillers in a cellar for each of a plurality of
               beverages to be dispensed, or at least it is undesirable so to do.
 
            [0005] It is known from GB2205638A to finely adjust the temperature of beverages supplied
               to a bar along a common insulated pipeline by means of a plurality of water filled
               heat exchanger module one of which is located adjacent the dispense point of each
               beverage. The temperature of the water in each module, and hence the temperature of
               the dispensed beverage, is finely adjusted by passing cooling water through the module
               in response to a temperature sensor which detects the temperature of water in the
               module. In one embodiment of the system described in GB2205638A, the central chiller
               is partitioned so that it contains two volumes of liquid coolant, each of which has
               its own re-circulating pump, both volumes of coolant being cooled using the same refrigeration
               unit. Coolant from one volume is circulated around the insulated pipeline to cool
               all of the beverages, whilst coolant from the other volume is circulated around the
               water filled modules. Thus, by virtue of this system, the different beverages may
               be dispensed at different temperatures.
 
            [0006] According to a first aspect of the invention we provide a beverage dispensing system
               including a dispensing head for dispensing the beverage at a point of delivery at
               a temperature in a desired delivery temperature range, a first cooling apparatus which
               cools the beverage to a temperature below the ambient temperature at the point of
               delivery and outside the desired delivery temperature range, an upstream heat exchanger
               to which the cooled beverage is supplied and in which heat is exchanged with the beverage
               to change the temperature of the beverage to lie in the desired delivery temperature
               range, a beverage supply conduit extending between the heat exchanger and the dispensing
               head for supplying the beverage to the dispensing head, and there being a second cooling
               apparatus which is separate from the first cooling apparatus, including a coolant
               delivery conduit for delivering a coolant to the heat exchanger, and a control device
               for controlling the flow of coolant to the heat exchanger in accordance with an input
               indicative of the temperature or changes in temperature, of the beverage in or downstream
               of the heat exchanger.
 
            [0007] Thus in a system in accordance with the first aspect of the invention, the cooling
               provided by a system with an inadequate existing chiller, or cooling apparatus may
               be improved without the need to replace the existing chiller, simply by the addition
               of a second chiller and a heat exchanger circuit. Thus, the cost of upgrading an existing
               beverage dispensing system is substantially reduced.
 
            [0008] Moreover, a common chiller may be provided for example in a location remote from
               the dispensing head or heads, such as in a cellar, for chilling each of a plurality
               of different beverages to a common temperature, whilst each beverage may have its
               own heat exchanger, for example provided close to the dispensing head, e.g. below
               a bar, and the temperature of each individual beverage as dispensed, may thus be adjusted
               e.g. by operation of the control device, to lie within the desired delivery temperature
               range for that beverage.
 
            [0009] Thus for a bar for example serving several different beverages, each individual beverage
               may be dispensed at a temperature in a desired delivery temperature range appropriate
               for the particular beverage. The heat exchanger for the or each beverage physically
               may be relatively small and thus a plurality of such heat exchangers may be accommodated
               close to the dispensing head or heads, because the heat exchanger need only be capable
               of cooling the beverage, where the beverage supplied to the heat exchanger is below
               the ambient temperature at the point of delivery, further to a temperature in the
               desired delivery temperature range.
 
            [0010] Preferably the first cooling apparatus includes a first refrigeration unit for reducing
               the temperature of a beverage in the first cooling apparatus, and the second cooling
               apparatus includes a second refrigeration unit for reducing the temperature of a coolant
               in the second cooling apparatus.
 
            [0011] The second cooling apparatus may also be provided close to the dispensing head, e.g.
               below a bar.
 
            [0012] Preferably the first cooling apparatus is provided remote from the dispensing head,
               for example in a cellar.
 
            [0013] The control device may be adapted to respond to the input by increasing the flow
               of coolant to the heat exchanger where it is desired to increase cooling of the beverage
               in the heat exchanger, and to reduce, including even stopping altogether, the flow
               of coolant to the heat exchanger where it is desired to reduce cooling of the beverage
               in the heat exchanger.
 
            [0014] The heat exchanger may include a heating device, so that in the event that the temperature
               of the beverage supplied to the heat exchanger is below the desired delivery temperature
               range, the beverage may be heated to increase the temperature of the beverage which
               passes into the beverage supply conduit, to a temperature within the desired delivery
               temperature range.
 
            [0015] Such a heating device may include a simple electrical resistance heater, or any other
               desired device for heating the beverage flowing through the heat exchanger. Of course
               during such heating the control device may stop the flow of coolant to the heat exchanger.
 
            [0016] The second cooling apparatus may include a refrigerated container containing a single
               phase liquid such as glycol, the glycol being circulated as the coolant to the heat
               exchanger of the system, and returned to the container. The control device may in
               one example include a control valve, which may be driven from a stepper motor or another
               kind of motor, which valve controls the flow of coolant to the heat exchanger and
               is capable of diverting at least a proportion of the flowing coolant to a by-pass
               without the coolant passing to the heat exchanger, depending on the input. Alternatively,
               a speed-control pump may be used, to vary the rate of coolant flow to the heat exchanger.
               However the control device may otherwise control the flow of coolant to the heat exchanger,
               for example by varying the quantity of coolant being pumped from the refrigerated
               container, or otherwise. The control valve, alternatively, may be a binary switching
               valve, removing the requirement of a motor.
 
            [0017] The heat exchanger may be of any desired suitable kind but preferably is a solid
               body of a material with a high thermal capacity and/or a high heat conductivity, such
               as metal, especially aluminium, there being provided in the body, a cooling passage
               e.g. in the form of a coil, for the coolant, and a passage, which may again be a coil,
               for the beverage. As will be understood by those skilled in the relevant field, a
               high thermal capacity is desirable so that the heat exchanger is able to store thermal
               energy. Such a body is thus cooled to a temperature in the desired delivery temperature
               range, by the coolant, and the flowing beverage may quickly be cooled as it passes
               through the body.
 
            [0018] Where a heating device is provided, this may conveniently be a heating element which
               may be embedded in the body of the heat exchanger, or may surround the body of the
               heat exchanger, thus rapidly to heat the body to a temperature in the desired delivery
               temperature range where the temperature of the beverage supplied to the heat exchanger
               is below the temperatures in the desired delivery temperature range.
 
            [0019] Preferably the control device includes a manually adjustable control so that an optimum
               serving temperature for the beverage within the desired delivery temperature range
               may be set.
 
            [0020] The system preferably includes a plurality of dispensing heads, each dispensing head
               being provided with a heat exchanger, the second cooling apparatus including a plurality
               of coolant delivery conduits for delivering coolant to each of the heat exchangers.
 
            [0021] In this case, the system may further include a plurality of control devices, one
               control device for controlling the flow of coolant to each heat exchanger.
 
            [0022] According to a second aspect of the invention we provide a method of dispensing a
               beverage at a temperature in a desired delivery temperature range at a point of delivery
               from a dispensing head, the method including cooling the beverage using a first cooling
               apparatus to a temperature below the ambient temperature at the point of delivery
               and outside the desired delivery temperature range, supplying the beverage to an upstream
               heat exchanger, operating a control device to control the flow of a coolant from a
               second cooling apparatus which is separate from the first cooling apparatus to the
               heat exchanger along a coolant delivery conduit which delivers the coolant to the
               heat exchanger in accordance with an input indicative of the temperature or changes
               in temperature of the beverage in or downstream of the heat exchanger, whereby in
               the heat exchanger, heat is exchanged with the beverage to change the temperature
               of the beverage supplied thereto to lie in the desired delivery temperature range,
               and supplying the beverage to the dispensing head from the heat exchanger via a beverage
               supply conduit.
 
            [0023] The method of the second aspect of the invention may include operating a heating
               device to increase the temperature of the beverage, where supplied to the heat exchanger
               at a temperature below the desired delivery temperature range, during which heating
               device operation, the flow of coolant to the heat exchanger may be at least reduced
               to a minimal flow, and preferably is stopped altogether.
 
            [0024] According to a third aspect of the invention we provide a method of upgrading a beverage
               dispensing system including a dispensing head for dispensing the beverage at a point
               of delivery, a first cooling apparatus for cooling the beverage to a temperature below
               the ambient temperature at the point of delivery, and a beverage supply conduit extending
               between the first cooling apparatus and the dispensing head for supply cooled beverage
               to the dispensing head, wherein the method includes the steps of inserting a heat
               exchanger in the beverage supply conduit, so that beverage from the first cooling
               apparatus passes through the heat exchanger before entering the dispensing head, adding
               a second cooling apparatus, the second cooling apparatus being adapted to supply a
               coolant to the heat exchanger.
 
            [0025] Thus, by virtue of this aspect of the invention, the performance of a beverage dispensing
               system with an inadequate chiller may be improved without the need to replace the
               existing chiller.
 
            [0026] Preferably, the method further includes the step of providing a control device for
               controlling the flow of coolant to the heat exchanger in accordance with an input
               indicative of the temperature or changes in temperature of the beverage in or downstream
               of the heat exchanger.
 
            [0027] Specific and non-limiting embodiments of the invention will now be described, by
               way of example only, with reference to the accompanying drawing which is a schematic
               view of a beverage dispensing system in accordance with the invention.
 
            [0028] Referring to the drawing, a beverage dispensing system 10 is shown for delivering
               beverage, in the example beer, at a point of delivery, via a dispensing head 12. The
               system shown is particularly for a public house, hotel or the like, having a bar where
               one or more dispensing head 12 is located. The beer is stored in a remote location
               such as a cellar where there is a first cooling apparatus 14, a chiller 14 for example
               of the kind including an ice bank, through which the beer passes in a cooling coil
               for example. The beer may be passed through the cooling coil by virtue of a pump,
               preferably located upstream of the chiller 14, or it may pass through the coil as
               a result of its own pressure, via an insulated conduit 16, typically with other conduits
               containing different beverages, to the bar and thus to a dispensing head 12.
 
            [0029] Thus the beer which passes from the cellar will be at a temperature below ambient
               temperature, typically in the range 6°C to 8°C, and usually provided that the dispensing
               head 12 is not a very large distance from the chiller 14, the serving temperature
               of the beer dispensed would be close to the chilled temperature.
 
            [0030] In a conventional system, the beer in the conduit, adjacent the head 12, may be cooled
               by recirculated cooling water, so that chilled beer is always available for serving
               at the dispensing head 12 even if the beer is not served continuously.
 
            [0031] Typically, the chiller 14 is used to cool a beverage or beverages to be dispensed
               from a plurality of dispensing heads, and a chiller 14 of an appropriate capacity
               to chill the volume of beverage it is envisaged will be dispensed when the system
               is set up is chosen. If, however, the volume of dispensed beverage increases significantly,
               for example if, the public house, hotel or the like is extended and the number of
               beverage dispensing heads increases, or if the performance of the chiller 14 has deteriorated
               with age, the existing chiller 14 may not be capable of providing adequate cooling.
 
            [0032] In this case, typically the existing chiller would be replaced with a new, higher
               capacity, chiller, at significant expense. In accordance with the invention, however,
               the performance of an existing beverage dispensing system may be enhanced without
               the need to replace the existing chiller 14.
 
            [0033] Moreover, the chiller 14 typically would chill several different beverages which
               ideally are required to be served at temperatures within unique desired delivery temperature
               ranges. For example, one beer may ideally be served at a temperature in the range
               5°C to 7°C whilst another beer or other beverage may be required to be served at a
               temperature in the range 8°C to 10°C. In accordance with the invention, the temperature
               of the beer or other beverage may be adjusted as the beverage flows from the chiller
               14 to the dispensing head 12, to lie in a desired delivery temperature range.
 
            [0034] To effect this, the system 10 includes a second cooling apparatus 18 which preferably
               has a cooling capacity significantly smaller than that of the chiller 14 and a heat
               exchanger 22 through which cooled beverage from the chiller 14 flows prior to entering
               a dispensing head 12. The second cooling apparatus 18 is entirely separate from the
               central chiller 14 in that it includes its own refrigeration unit for reducing the
               temperature of the coolant in the cooling apparatus 18.
 
            [0035] The second cooling apparatus 18 may be of any desired type, such as a refrigerated
               container 19 containing a single phase liquid such as glycol or a glycol/water mix
               20 which is cooled by evaporating/expanding refrigerant (not shown), the glycol or
               glycol/water mix 20, being a coolant which as described below, may be circulated to
               the heat exchanger 22 to cool the beverage. Whilst it will be appreciated that the
               system may include a plurality of dispensing heads, for simplicity, a system including
               only one will be described below.
 
            [0036] The cooling apparatus 18 thus includes a cooling circuit which includes a coolant
               delivery conduit 23 to the heat exchanger 22, a coolant return conduit 24 from the
               heat exchanger 22 back to the container 19, and a by-pass conduit 26 with there being
               a diverter control valve 27 which controls the flow of the coolant 20 as between the
               heat exchanger 22 and the by-pass 26.
 
            [0037] The diverter valve 27 is a component of a flow control device which includes an electronic
               controller 30, the diverter valve 27 being stepper or other motor driven, or otherwise
               being electrically actuable, under the control of the electronic controller 30, which
               signals the valve 27 as required, along a control line 31.
 
            [0038] The heat exchanger 22 in this example is a solid body, such as a block of a highly
               heat conductive material, such as aluminium or another metal, there being provided
               in the body, a cooling passage e.g. in the form of a coil, for the coolant 20, and
               a passage, which may again be a coil, for the beverage from the insulated conduit
               16 from the chiller 14.
 
            [0039] Embedded within the solid body of the heat exchanger 22, or surrounding the body,
               preferably a heating device 37 such as an electrically operable heating element is
               provided which when operated imparts heat into the solid body which may be exchanged
               to the flowing beverage, as described below. In another arrangement the heating device
               37 of the heat exchanger may be removed from the solid body.
 
            [0040] Also, either embedded in the solid body of the heat exchanger 22 or otherwise in
               a position to sense the temperature of beverage leaving the heat exchanger 22 and
               flowing to the dispensing head 12 along a beverage supply conduit 35, there is a temperature
               sensor 38 which provides an input to the electronic controller 30 of the flow control
               device, which responds to the input by controlling the diverter valve 27, and operation
               of the heater device 37 of the heat exchanger 22.
 
            [0041] Operation of the system 10 will now be described.
 
            [0042] First, in the case of the temperature of the beverage from the chiller 14 being supplied
               to the heat exchanger 22 being higher than the desired delivery temperature or range
               of acceptable temperatures in a desired temperature range, the temperature sensor
               38 providing the input to the electronic controller 30 of the flow control device
               will indicate that further cooling of the beverage flowing from the chiller 14 is
               required. This may be because the chiller 14 is working at or close to its maximum
               cooling capacity, and/or because no beverage has been dispensed for some time, and
               thus beverage in the insulated conduit 16 from the cellar, has warmed; and/or because
               of high ambient temperatures. The electronic controller 30 signals the diverter valve
               27 to divert coolant, or more coolant, to the heat exchanger 22 thus to further cool
               the beverage flowing through the heat exchanger 22, to or at least towards a temperature
               within the desired delivery temperature range.
 
            [0043] Desirably, the second cooling apparatus 18 is located very close to the heat exchanger
               22 and dispensing head 12, e.g. beneath the bar, so that such additional cooling may
               be achieved very rapidly, before any significant volume of beverage at a temperature
               outside the desired delivery temperature range, has been dispensed.
 
            [0044] As the temperature sensor 38 determines that the temperature of the beverage being
               dispensed has been cooled to a temperature within the desired delivery temperature
               range, the electronic controller 30 may signal the diverter valve 27 to close or progressively
               to reduce the flow of coolant to the heat exchanger 22 so that the beverage is not
               over-cooled in the heat exchanger 22.
 
            [0045] It will be appreciated that the electronic controller 30 may be operated to respond
               to the input from the temperature sensor 38 according to an algorithm, so that the
               rate of change of temperature of the beverage can be determined, perhaps with some
               predictive effect, so that the temperature of the beverage being dispensed can very
               accurately be controlled. Other inputs to the electronic control which may be taken
               into consideration are the ambient temperature at the point of delivery at the dispensing
               head 12, historic information concerning the volume of beverage dispensed, and the
               temperature of the beverage attained by the chiller 14.
 
            [0046] In a second case, the temperature of the beverage supplied to the heat exchanger
               22 from the chiller 14 may be below the desired delivery temperature range for the
               particular beverage. This may be because of overly efficient cooling by the chiller
               14 working below its maximum cooling capacity, or because of low ambient temperatures,
               or otherwise.
 
            [0047] In this case, the electronic controller 30 would signal the diverter valve 27 to
               divert all or substantially all the coolant flowing in the cooling circuit to flow
               into the by-pass 26 and thus not to pass to the heat exchanger 22. Also, the heating
               element 37 may be operated to impart heat to the overly cooled beverage, so that the
               temperature of the beverage which passes into the beverage delivery conduit 35 and
               thus to the dispensing head 12 is increased to a temperature in the desired delivery
               temperature range.
 
            [0048] It will be appreciated that during dispensing of the beverage at the dispensing head
               12, the flow control device may actively control both the diverter valve 27 and the
               heating element 37 as required to achieve and maintain a desired delivery temperature.
 
            [0049] By virtue of the invention, there is no requirement to recirculate beverage from
               adjacent the dispensing heat 12 to the chiller 14; the chiller 14 may be further away
               from the bar (or at least the dispensing head 12) without compromising the delivery
               temperature of the beverage.
 
            [0050] As mentioned above, the system may include a plurality of dispensing heads 12 which
               dispense a plurality of different beverages. In this case, preferably each dispensing
               head 12 is provided with its own heat exchanger 22, each heat exchanger 22 being supplied
               with coolant from the second cooling apparatus 18. All of the beverages are, however,
               cooled using the chiller 14.
 
            [0051] Preferably each heat exchanger 22 is provided with a control device, as this enables
               a user to set a different desired delivery temperature for each dispensing head 12,
               which is particularly advantageous where a different beverage is dispensed from each
               dispensing head 12.
 
            [0052] Thus, by virtue of the invention, a common chiller 14 may be provided for chilling
               a plurality of different beverages which may then each be dispensed at temperature
               in an individual desired delivery temperature range. Because a heat exchanger 22 is
               only required for one beverage, is may physically be small and thus readily accommodated
               in the vicinity of the dispensing head 12, e.g. beneath the bar.
 
            [0053] It should be appreciated that a single heat exchanger 22 may be used to adjust the
               temperature of a beverage dispensed from a plurality of dispensing heads 12, provided
               that these are each not too far from the heat exchanger 22. It should also be appreciated
               that a single controller 30 may be used to control flow of coolant to a plurality
               of heat exchangers 22, provided that the desired delivery temperatures of each of
               the various beverages passing through the heat exchangers 22 is the same.
 
            [0054] If the range of desired delivery temperatures for the various dispensed beverages
               is too wide then it may be preferable to provide a third cooling apparatus, the second
               cooling apparatus 18 supplying coolant at a first temperature to some of the heat
               exchangers 22, and the third cooling apparatus supplying coolant at a second temperature
               to the remainder of the heat exchangers 22. Alternatively each heat exchanger 22 may
               be provided with its own cooling apparatus.
 
            [0055] Desirably, the electronic processor 30 includes a manual input control, so that a
               user may set the desired temperature, or desired temperature range, at which the beverage
               is to be dispensed.
 
            [0056] The system 10 may advantageously be applied to upgrading an existing beverage dispensing
               system which is providing inadequate cooling, without the need for replacing the existing
               cooling apparatus. This can be achieved by mounting a heat exchanger 22 in a beverage
               supply conduit to the or each dispensing head 12, and providing a further cooling
               apparatus 18 and cooling circuit to supply coolant to the heat exchanger 22. The additional
               cooling apparatus 18 supplements the cooling provided by the existing cooling apparatus
               14, and thus enhances the performance of the beverage dispensing system.
 
            [0057] Various other modifications may be made without departing from the scope of the invention.
 
            [0058] For example, the cooling apparatus 18 may of a different kind to that described,
               for example a conventional refrigerator with the coolant being refrigerant which is
               circulated to and from the heat exchanger 22.
 
            [0059] Instead of a diverter valve 27 to divert coolant to the by-pass 26, the flow of coolant
               to the heat exchanger 22 may otherwise be controlled, for example by controlling a
               coolant pump, which may be a variable displacement pump. The electronic controller
               30 may be provided close to the diverter valve 27 or coolant pump, and a single electronic
               controller 30 at least may be provided to control valves 27/pumps of a plurality of
               systems in a multi-system installation.
 
            [0060] In another embodiment, no heating device 37 may be provided, but the beverage may
               always be arranged to be supplied to the heat exchanger 22 at a temperature above
               the desired serving temperature, for example by suitable control of the chiller 14.
 
            [0061] Other modifications may be made without departing from the scope of the invention.
 
            [0062] The features disclosed in the foregoing description, or the following claims, or
               the accompanying drawings, expressed in their specific forms or in terms of a means
               for performing the disclosed function, or a method or process for attaining the disclosed
               result, as appropriate, may, separately, or in any combination of such features, be
               utilised for realising the invention in diverse forms thereof.
 
          
         
            
            1. A beverage dispensing system (10) including a dispensing head (12) for dispensing
               the beverage at a point of delivery at a temperature in a desired delivery temperature
               range, a first cooling apparatus (14) which cools the beverage to a temperature below
               the ambient temperature at the point of delivery and outside the desired delivery
               temperature range, an upstream heat exchanger (22) to which the cooled beverage is
               supplied and in which heat is exchanged with the beverage to change the temperature
               of the beverage to lie in the desired delivery temperature range, a beverage supply
               conduit (35) extending between the heat exchanger (22) and the dispensing head (12)
               for supplying the beverage to the dispensing head, and there being a second cooling
               apparatus (18), which is separate from the first cooling apparatus (14), including
               a coolant delivery conduit (23) for delivering a coolant to the heat exchanger (22),
               and a control device (27) for controlling the flow of coolant to the heat exchanger
               (22) in accordance with an input indicative of the temperature or changes in temperature
               of the beverage in or downstream of the heat exchanger (22).
 
            2. A beverage dispensing system (10) according to claim 1 wherein the first cooling apparatus
               (14) includes a first refrigeration unit for reducing the temperature of the beverage
               in the first cooling apparatus (14), and the second cooling apparatus (18) includes
               a second refrigeration unit for reducing the temperature of coolant in the second
               cooling apparatus (18).
 
            3. A system according to claim 1 or 2 wherein the heat exchanger (22) is provided close
               to the dispensing head (12).
 
            4. A system according to claim 1, 2 or 3 wherein the second cooling apparatus (18) is
               provided close to the dispensing head (12).
 
            5. A system according to any one of claims 1 to 4 wherein the first cooling apparatus
               (14) is provided remote from the dispensing head (12).
 
            6. A system according to any one of the preceding claims wherein the control device (27)
               is adapted to respond to the input by increasing the flow of coolant to the heat exchanger
               (22) where it is desired to increase cooling of the beverage in the heat exchanger
               (22), and to reduce the flow of coolant to the heat exchanger (22) where it is desired
               to reduce cooling of the beverage in the heat exchanger (22).
 
            7. A system according to any one of the preceding claims wherein the heat exchanger (22)
               includes a heating device (37) so that in the event that the temperature of the beverage
               supplied to the heat exchanger (22) is below the desired delivery temperature range,
               the beverage may be heated to increase the temperature of the beverage which passes
               into the beverage supply conduit, to a temperature within the desired delivery temperature
               range.
 
            8. A system according to claim 7 wherein the heating device (37) includes an electrical
               resistance heater.
 
            9. A system according to any one of the preceding claims wherein the control device (27)
               includes a control valve and the control valve is driven from a motor, which valve
               controls the flow of coolant to the heat exchanger (22) and is capable of diverting
               at least a proportion of the flowing coolant to a by-pass without the coolant passing
               to the heat exchanger (22), depending on the input.
 
            10. A system according to any one of the preceding claims wherein the heat exchanger (22)
               is a solid body of a material with a high heat conductivity, there being provided
               in the body, a cooling passage for the coolant, and a passage for the beverage.
 
            11. A system (10) according to claim 10 where dependant upon claim 7 wherein the heating
               device (37) is a heating element either embedded in the body of the heat exchanger
               (22), or surrounding the body of the heat exchanger (22).
 
            12. A system (10) according to any one of the preceding claims wherein the control device
               (27) includes a manually adjustable control to set an optimum serving temperature
               for the beverage within the desired delivery temperature range.
 
            13. A beverage dispensing system (10) according to any one of the preceding claims wherein
               the system (10) includes a plurality of dispensing heads (12), each dispensing head
               (12) being provided with a heat exchanger (22), the second cooling apparatus (18)
               including a plurality of coolant delivery conduits (23) for delivering coolant to
               each of the heat exchangers (22).
 
            14. A beverage dispensing system according to claim 16 wherein the system (10) further
               includes a plurality of control devices (27), one control device (27) for controlling
               the flow of coolant to each heat exchanger (22).
 
            15. A method of dispensing a beverage at a temperature in a desired delivery temperature
               range at a point of delivery, from a dispensing head (12), the method including cooling
               the beverage using a first cooling apparatus (14) to a temperature below the ambient
               temperature at.the point of delivery and outside the desired delivery temperature
               range, supplying the cooled beverage to an upstream heat exchanger (22), operating
               a control device (27) to control the flow of a coolant from a second cooling apparatus
               (18), which is separate from the first cooling apparatus (14), to the heat exchanger
               (22) along a coolant delivery conduit (23) which delivers the coolant to the heat
               exchanger (22) in accordance with an input indicative of the temperature or changes
               in temperature of the beverage in or downstream of the heat exchanger (22), whereby
               in the heat exchanger (22), heat is exchanged with the beverage to change the temperature
               of the beverage supplied thereto to lie in the desired delivery temperature range,
               and supplying the beverage to the dispensing head (12) from the heat exchanger (22)
               via a beverage supply conduit (35).
 
            16. A method according to claim 15 wherein the method includes operating a heating device
               (37) to increase the temperature of the beverage, where supplied to the heat exchanger
               (22) at a temperature below the desired delivery temperature range.
 
            17. A method according to claim 20 wherein during operation of the heating device, the
               flow of coolant to the heat exchanger (22) is at least reduced to a minimal flow,
               and preferably is stopped altogether.
 
            18. A method of upgrading a beverage dispensing system including a dispensing head (12)
               for dispensing the beverage at a point of delivery, a first cooling apparatus (14)
               for cooling the beverage to a temperature below the ambient temperature at the point
               of delivery, and a beverage supply conduit extending between the first cooling apparatus
               (14) and the dispensing head (12) for supply cooled beverage to the dispensing head
               (12), wherein the method includes the steps of inserting a heat exchanger (22) in
               the beverage supply conduit (35), so that beverage from the first cooling apparatus
               (14) passes through the heat exchanger (22) before entering the dispensing head (12),
               adding a second cooling apparatus (18), the second cooling apparatus (18) being adapted
               to supply a coolant to the heat exchanger (22).
 
            19. A method according to claim 18 wherein the method further includes the step of providing
               a control device (27) for controlling the flow of coolant to the heat exchanger (22)
               in accordance with an input indicative of the temperature or changes in temperature
               of the beverage in or downstream of the heat exchanger (22).