GB2483073A

GB2483073A - A carbonator for beverages with cooling means surrounding the carbonator tank

Info

Publication number: GB2483073A
Application number: GB201014116A
Authority: GB
Inventors: Klaus Wiemer; Heinz Altenbach
Original assignee: IMI Cornelius UK Ltd
Current assignee: Marmon Foodservice Technologies UK Ltd
Priority date: 2010-08-24
Filing date: 2010-08-24
Publication date: 2012-02-29
Anticipated expiration: 2030-08-24
Also published as: GB201014116D0; GB2483073B

Abstract

In one aspect, a carbonator tank has a cooling coil (71, Fig.7) extending around the tank. In another aspect, a tubular heat exchanger surrounds an outer surface of the tank for heat transfer between the liquid in the carbonator and the fluid in the heat exchanger. In a third aspect, the carbonator has a pre-coil wrapped around the tank and at least one of the pre-coil and the cooling coil are in contact with the outer surface of the tank and with the other coil. The tank may have a bowl 37a and a lid 37b. The lid 37b is provided with an inlet 39 for still water, an inlet 41 for carbonating gas and an outlet 43 for carbonated water. The water inlet 41 is connected to a supply line 48 that includes the pre-cool coil 49 that is wrapped around and contacts an outer surface of the cooling coil 71. Coolant in cooling coil 71 cools the still water delivered to the tank in the pre-cool coil 49 and the carbonated water in the tank.

Description

CARBONATOR

The present invention concerns improvements in or relating to apparatus for producing carbonated water also known as soda water.

Carbonators for producing carbonated water are well known and typically comprise a tank in which still water is carbonated by the addition of a carbonating gas. The carbonating gas is typically carbon dioxide but other gases or mixtures of gases may be used. For example nitrogen may be used in place of carbon dioxide and it will be understood the terms "carbonated" and "carbonating gas" are used herein for convenience to include all gases and mixtures of gases and are non-limiting as to the use of any particular gas or mixture of gases.

It is known to employ a water bath to cool the carbonated water in the tank by heat exchange with water in the bath. For this the carbonator tank is positioned in the water bath so that the water covers the tank. The water in the bath may be cooled by a refrigeration system including an evaporator that is also positioned in the water bath so that the water covers the evaporator. The water is usually circulated in the bath by an agitator. It is also known to cool the incoming water supply to the carbonator tank by heat exchange with water in the water bath by positioning a pre-cool coil within the water bath so that the water covers the pre-cool coil.

In the known arrangement employing a water bath, it is necessary to maintain the water level in the bath so as to cover the carbonator tank, evaporator and, where provided, pre-cool coil. For example, the water level within the bath may change due water loss caused by spillage and/or from evaporation and/or due to water gain by condensation from ambient air. Controlling the water level adds to costs. In addition, the temperature of the water in the bath may change due to heat gain from the agitator, especially if an agitator having a submersible motor is employed, increasing the cooling load on the evaporator and adding to costs. With such known arrangement, the water bath tends to be quite large to accommodate the carbonator tank, evaporator, pre-cool coil and agitator and requires a large space in which to install the water bath.

Also, due to the size, the water bath is not easy to handle and manoeuvre, especially when filled with water. As a result, installation of the water bath in areas where space is restricted can be difficult and, when filled with water, movement of the water bath may be impossible.

The present invention seeks to provide a solution to these problems.

According to one aspect of the present invention there is provided apparatus comprising a carbonator tank in which still water can be carbonated to produce carbonated water, and means externally of the tank for cooling still water supplied to the tank and/or carbonated water in the tank, the cooling means including a cooling coil extending around the tank.

Preferably, the cooling coil contains a cooling fluid and is configured for heat exchange between the cooling fluid and the still water and/or the carbonated water. The cooling fluid may be a gas or a liquid.

Preferably, the cooling fluid is a refrigerant. Containing the cooling fluid in a cooling coil that extends around the tank avoids the use of a water bath and may result in a carbonator unit that is smaller, more compact and lighter than previous units employing a water bath. As a result, installation of the unit may be facilitated.

Heat exchange between the cooling fluid and the still water may be provided by contact between the cooling coil and a pre-cool coil containing the still water externally of the tank. The pre-cool coil preferably extends around the tank.

The coils may be arranged one on top of the other such one coil contacts an outer surface of the tank and the other coil contacts an outer surface of the cooling coil or vice versa. Alternatively, the coils may be arranged side by side so that both coils contact the outer surface of the tank.

Alternatively, one of the coils may be arranged inside the other coil so that the outer coil contacts an outer surface of the tank.

In one arrangement, the cooling coil and pre-cool coil are arranged one on top of the other with the inner coil contacting the outer surface of the tank and the outer coil contacting the inner coil. The inner coil may be the cooling coil containing the cooling fluid and the outer coil may be the pre-cool coil containing the still water or vice versa. One or more additional coils may be provided on top of the outer coil with each additional coil being arranged on top of another coil. Additional coils may be a cooling coil or a pre-cool coil. Cooling coils and pre-cool cool coils may alternate with each other. The coils may extend for all or part of the length of the carbonator tank. The carbonator tank may be of round section although other shapes are possible, for example an oval section. One or more coils may be of round section. Alternatively or additionally, one or more coils may be of non-round section to increase the area of contact with the carbonator tank and/or with another coil.

Contacting surfaces of the coils may be configured to mate with each other to increase the area of contact.

In another arrangement, the cooling coil and pre-cool coil are arranged so that both coils contact the outer surface of the tank with turns of one coil separating turns of another coil along the length of the tank. The turns of one coil may alternate with the turns of another coil. The coils may extend for all or part of the length of the carbonator tank. One or more additional coils may be provided on top of the cooling coil and pre-cool coil with each additional coil being arranged on top of another coil.

Additional coils may be a cooling coil or a pre-cool coil. The carbonator tank may be of round section although other shapes are possible, for example an oval section. One or more coils may be of round section.

Alternatively or additionally, one or more coils may be of non-round section to increase the area of contact with the carbonator tank and/or with another coil. Contacting surfaces of the coils may be configured to mate with each other to increase the area of contact.

In another arrangement, the cooling coil and pre-cool coil form a twin coil -one within the other -arranged so that the outer coil contacts the outer surface of the tank. The inner coil may contain the cooling fluid with the still water contained between the coils or vice versa. The twin-coil may extend for all or part of the length of the carbonator tank. The carbonator tank may be of round section although other shapes are possible, for example an oval section. The outer coil of the twin-coil may be of round section. Alternatively, the outer coil may be of non-round section to increase the area of contact with the carbonator tank.

The inner coil may be of round or non-round section.

According to another aspect of the present invention there is provided apparatus comprising a carbonator and a tubular heat exchanger surrounding and contacting an outer surface of the carbonator for heat transfer between a liquid within the carbonator and a fluid within the heat exchanger.

The tubular heat exchanger may comprise one or more tubes wrapped around the carbonator. The or each tube may form a helical or spiral coil around the carbonator. The tubular heat exchanger may comprise two tubes, one containing cooling fluid and the other containing liquid for supply to the carbonator. The tubes may be separate and may be wrapped in separate coils one on top of the other or side by side. Alternatively, the tubes may be combined one within the other and may be wrapped in a one coil. The or each tube may be wrapped more than once around the carbonator.

According to another aspect of the present invention there is provided apparatus for carbonating water including a tank having an inlet for still water and an outlet for carbonated water, a cooling coil and a pre-cool coil wrapped around the tank with at least one of the coils in contact with an outer surface of the tank and with the other coil.

The cooling coil may form part of a loop for circulating a coolant to cool the carbonated water in the tank. The pre-cool coil may form part of a supply line for delivering still water to the inlet of the tank.

The cooling coil may be coiled around and contact the outer surface of the tank and the pre-cool coil may be coiled around and contact the cooling coil. Alternatively, the cooling coil and pre-cool coil may be coiled around and contact the outer surface of the tank.

Other features, benefits, applications and uses of the invention will be apparent from the description herein of exemplary embodiments.

The invention will now be described in more detail by way of example only with reference to the accompanying drawings wherein: Figure 1 shows a schematic layout of a system employing apparatus embodying the invention; Figure 2 is a perspective front view of apparatus shown in Figure 1; Figure 3 is a perspective rear view of the apparatus shown in Figure 2; Figure 4 is a perspective side view of the apparatus of Figures 2 and 3 with parts of the housing removed to show the internal components; Figure 5 shows a schematic layout of the apparatus shown in Figures 1 to 4; Figure 6 shows the carbonator tank of the apparatus; Figure 7 shows assembly of the cooling coil and pre-cool coil to the carbonator tank, Figure 8 shows the carbonator tank, cooling coil and pre-cool coil assembled; Figures 9 to 24 show alternative arrangements of the cooling coil and pre-cool coil of the carbonator shown in Figures 3 and 4.

Apparatus 1 according to a first embodiment of the invention is shown in Figure 1 connected to a water supply line 3 for potable still (uncarbonated) water, to a gas supply line 5 for carbonating gas such as carbon dioxide, and to a product delivery line 7 for delivering still water or carbonated water to a remote dispense font 9 such as a tap according to user selection. The font 9 is connected to the apparatus 1 by a wire link 11 for controlling operation of the apparatus 1 according to user selection via a manually operable control knob 13 on the font 9 for dispense of still water or carbonated water from an outlet 15. In a modification, the wire link 11 may be replaced by a wireless link or may provide a back-up for a wireless link. The gas supply line 5 may be connected to any suitable source (not shown) of carbonating gas such as a gas cylinder fitted with a regulator valve for controlling gas pressure. A visual and/or audible warning may be provided when the gas cylinder needs to be replaced. The water supply line 3 may be connected to the mains water supply or any other suitable source of potable still water and may include a filter (not shown) for removing impurities from the water.

Referring now to Figures 2, 3 and 4, the apparatus 1 comprises a rectangular casing 19 having a rear wall provided with a water inlet connector 21 for connection to the water supply line 3, a gas inlet connector 23 connectable to the gas supply line 5 and a product outlet connector 25 connectable to the product delivery line 7. Also provided in the rear wall is a power inlet 27 with a socket for connecting an electrical power supply to the apparatus 1. Both sidewalls of the casing 19 are provided with air inlet grilles 29a, 29b and a front wall of the casing 19 is provided with an air outlet grille 31. The front wall is also provided with a manually operable temperature control knob 33 for adjusting the temperature of the still water or carbonated water delivered to the font 9 and an LED panel 35 with LED lamps and a rear mounted controller.

Mounted within the casing 19, the apparatus 1 includes a carbonator tank 37, a carbonator pump 39, and a cooling system 41.

As shown schematically in Figure 5, the carbonator tank 37 comprises a cylindrical bowl 37a and a head or lid 37b. The head 37b is provided with an inlet 39 for still water, an inlet 41 for carbonating gas and an outlet 43 for carbonated water. The outlet 43 is in the form of a tube that extends close to the bottom of the carbonator bowl 37a and is connected by a line 45 to a valve block 47 including the product outlet connector 25.

The inlet 39 is connected to the water inlet connector 21 by a line 48 that includes the pump 39 and a water pre-cool coil 49. A check valve 51 in the inlet 39 prevents back-flow of water. The inlet 41 is connected to the gas inlet connector 23 by a line 53. A check valve 55 in the inlet 41 prevents back-flow of gas.

A T-connector 57 downstream of the pre-cool coil 49 splits the line 48 for connection to the inlet 39 to the carbonator tank 37 and to the valve block 47. The valve block 47 is operable to supply still water from line 48 or carbonated water from line 45 to the product delivery line 7 according to user selection. In some applications, the valve block 47 may also be configured to supply a mixture of still water and carbonated water to the product outlet 7. The ratio of still water and carbonated water in a mixture may be adjustable according to user selection.

The valve block 47 may include flow control means for one or both of the still water and carbonated water supplied from lines 45, 48 to the delivery line. The flow control means may be adjustable. In this embodiment, separate screw adjusters 58a, 58b are provided for the lines 45 and 48 respectively. The flow control means may be set on installation.

The head 37b of the carbonator tank 37 further includes a safety valve 57 and a level probe assembly 59. The safety valve 57 is operable to release excess pressure from a headspace 61 within the carbonator tank 37. The level probe assembly 59 includes a pair of probes 59a, 59b for monitoring water level in the carbonator tank 37 and controlling addition of water to the carbonator tank 37. In use, water is added to the carbonator tank 37 when the water level falls to a minimum level as detected by one probe 59a until an upper level is reached as detected by the other probe 59b.

As shown in Figure 6, the probes 59a, 59b are located in a "quiet" zone of the tank defined by an internal baffle 62 separate from the inlets 39, 41 so that the water level monitored by the probes 59a, 59b is not affected by any turbulence that may be created by the addition of still water and/or carbonating gas to the carbonating tank 37. The baffle 62 is preferably generally V-shaped in plan view and preferably includes the outlet tube through which carbonated water is delivered to the valve block 47. The baffle 62 preferably includes a transverse plate 62a at the lower end and the outlet tube extends below the plate 62a. The baffle 62 may be attached at the upper end to the head 37b of the carbonator tank 37 by any suitable means. For example the baffle 62 and head 37b may be made of plastics materials with co-operating formations that engage with a snap fit.

With reference again to Figure 4, the cooling system 41 employs a refrigerant circuit including a condenser 63, a compressor 65 and an evaporator 67. The condenser 63 is cooled by air that is drawn into the casing 19 through the inlet grilles 29a, 29b by a fan 69 and is directed over the condenser before exiting from the outlet grille 31 at the front of the casing. As shown the condenser 63 is angled towards the front wall of the casing 19 and defines with the sidewalls of the casing 19 an air tunnel 70 to confine and direct the air flow towards and through the outlet grille 31.

With reference now to Figures 7 and 8, the evaporator 67 comprises a coil 71 that is wound around and contacts the external surface of the carbonator tank 37 over substantially the whole length of the tank 37.

The pre-cool coil 49 is wound around and contacts the external surface of the evaporator coil 71 over substantially the whole length of the tank 37.

The tubes forming the coils 49, 71 may be wound slightly undersize and then unwound to increase the internal diameter for assembly on the carbonator tank 37. On assembly the coils 49, 71 are allowed to spring back to provide a tight fit that may give better contact between the coils 49, 71 and between the coil 71 and tank 37 for heat exchange.

The carbonator bowl 37a, pre-cool coil 49 and evaporator coil 71 are made of materials having a high thermal conductivity, for example metal or alloy, to promote heat transfer between refrigerant in the evaporator coil 71 and still water in the pre-cool coil 49 and carbonated water in the carbonator bowl 37a Tubing for the potable water pre-cool coil 49 may be of copper or stainless steel, while the refrigerant evaporator coil 71 may be of aluminium as it can be readily extruded and post formed.

Some plastics materials may also be suitable for one or both of the pre-cool coil and evaporator coil although generally the inferior thermal conductivity of many plastic materials compared to metal or alloy materials may make them less preferred.

To improve heat transfer, between the coils 49, 71 and between the coil 71 and the carbonator bowl 37a, a thermally conducting material may be employed in the spaces between the coils 49, 71 and the carbonator bowl 37a. For example, the assembly of the tank 37 and coils 49, 71 may be dipped in a bath of molten solder that fills substantially completely the spaces so as to increase the area for heat transfer between refrigerant in the evaporator coil 71 and still water in the pre-cool coil 49 and between refrigerant in the evaporator coil 71 and carbonated water in the carbonator bowl 37a. Other heat conducting materials may be employed.

To reduce heat exchange with the surrounding ambient air and further improve efficiency, the assembly of the carbonator tank 3?, evaporator coil 71 and pre-cool coil 49 is surrounded by a jacket 73 of thermally insulating material. The jacket 73 may be pre-formed, for example from a plastics material such as polystyrene, to fit around the assembly or may be formed in situ around the assembly, for example from a plastics material such as polyurethane.

In use, still water in the pre-cool coil 49 and carbonated water in the tank 37 may be cooled to substantially the same temperature by heat exchange with refrigerant in the evaporator coil 71 so that the temperature of the still water or carbonated water delivered to the font for dispense is substantially the same. The user can adjust the temperature by means of the control 33 on the front wall of the casing 19.

In the above-described embodiment, the pre-cool coil 49 is wrapped around the evaporator coil 71. Other arrangements of the coils are possible.

For example, in a modification shown in Figure 9, both coils are wound around and contact the outer surface of the carbonator tank 37 with each turn of the pre-cool coil 49 alternating with the turns of the evaporator coil 71. In another modification shown in Figure 10, the evaporator coil 71 is positioned between two pre-cool coils 49a,49b with the inner pre-cool coil 49a contacting the outer surface of the carbonator tank 37.

In a variation of Figure 10, the pre-cool coil 49 could be positioned between two evaporator coils. Other configuration and arrangements of multiple pre-cool and/or evaporator coils will be apparent to those skilled in the art.

As thus far described, the coils 49, 71 are constructed from round tubes having a substantially circular cross-section. It will be appreciated that round tubes, even in intimate contact, provide only an infinitely thin line of contact with each other and with the carbonator tank. We may improve contact as described above by partially or completely filling the gaps between the tubes and the carbonator tank. However, this increases material costs and also the weight of the assembly which may be undesirable for some applications and uses of the invention, for example portable versions for domestic use where the apparatus should desirably be compact and easy to lift and manoeuvre for installation such as in a cupboard under a sink.

As an alternative to filling the gaps or possibly to reduce the size of any gaps and thus the amount of material required to fill such gaps, we may employ tubes having different cross-sections chosen to increase the area of contact.

For example, Figure 11 shows a variation in which the evaporator coil 71 is flattened to have a D' shape in cross-section that is wound around the carbonator tank 37 so that the flattened surface contacts the external surface of the carbonator tank 37 to improve heat transfer. Figures 12 and 13 show application of the same principle to the arrangements shown in Figures 9 and 10.

As an alternative to winding the evaporator coil(s) 71 and pre-cool coil(s) 49 separately as described above, we may employ a tube-in tube arrangement.

For example, Figure 14 shows a tube-in-tube coil 75 where the inner tube 77 may contain the refrigerant with the still water contained between the inner tube 77 and the outer tube 79 or vice versa. Although a single coil is shown, multiple coils may be employed. Also in Figure 14, both tubes are of circular cross-section and Figure 15 shows a variation in which the outer tube 79 is flattened to a "D" shape in cross-section to improve contact with the carbonator tank 37 as described previously.

Other shapes and configurations of one or more pre-cool coils and evaporator coils may be employed to improve contact between the coils and/or with the carbonator tank.

For example, Figure 16 shows an inner coil 81 of "obround" cross-section and an outer coil 83 of "D" cross-section. The inner coil 81 has flat surfaces on opposite sides that contact the outer surface of the carbonator tank 37 and the flat surface of the outer coil 83 respectively.

Figure 17 shows a variation of Figure 16 where both coils 81, 83 are of "obround" cross-section. Figure 18 shows another variation where the inner coil 81 is of "obround" cross-section with a concave recess 81a in the outer face to receive an outer coil 83 of circular cross-section. The inner coil in Figures 16 to 18 may be the evaporator coil and the outer coil the pre-cool coil or vice versa.

Figures 19 to 21 show modifications of Figures 16 to 18 where the rounded ends of the "obround" sections are flattened to produce a rectangular section with square corners.

Figure 22 and Figure 23 show further examples of cross-sections that may be employed for the pre-cool and evaporator coils to improve contact between the coils. In Figure 22, the inner coil 85 is of "D" cross-section and the outer coil 87 is profiled to mate with the radii of two adjacent turns of the inner coil 85. In Figure 23, the inner coil 85 is profiled to have a "T" cross-section providing a flat inner surface contacting the carbonator tank 37 with adjacent turns of the coil 85 providing a recess 85a mating with an outer coil 87 of circular cross-section. As above the inner coil may be the evaporator coil and the outer coil the pre-cool coil or vice versa.

It will be appreciated that many more shape options exist and that the function of the inner and outer tubes may be interchanged between pre-cool and evaporator. Extra layers of tube, either of round or co-operative profile may be added to add more coil length to either the pre-cool coil, evaporator coil, or both.

Figure 24 shows an arrangement having three coils with the inner coil 89 being of "D" section, the outer coil 91 of circular cross-section and the centre coil 93 profiled to mate with both coils. The centre coil 93 may be the pre-cool coil and the inner and outer coils 89, 91 the evaporator coils or vice versa.

Manufacturing tubes having a special profile such as shown in the preceding examples may be achieved by drawing, extrusion or rolling either initially or from a round conventional tube. However it is known that, in the process of coiling to surround the carbonator tank, deformation of the profile can occur, especially where the tube may have walls perpendicular to the surface of the carbonator. We may seek to use such distortion as part of the forming process to achieve the desired shape or use forming techniques to overcome or mitigate the effects of distortion by any of the following: * Development of tube profile(s) such that distortion results in the final desired shape.

* Forming the assembled coils by squeezing within a shaped die' onto a mandrel so as to distort the tube profiles into cooperating shapes.

* As above but expanding the tube(s) into the shape of the mandrel/die by internal pressure or explosive forming. The relative distortion of a number of tubes could be controlled by pressure or explosive charge variation or by varying the tube wall thickness, hardness, diameter or material.

In any of the options above it may be possible to use the carbonator tank as the inner mandrel. Also the method of unwinding' the coil(s) and allowing them to spring back to grip the carbonator may be used.

In addition to providing the best possible mechanical fit' of the tubes and carbonator tank, it may still be possible to improve performance further by the use of conductive coatings such as the solder already mentioned earlier. These could include:- * Powder coating with a conductive plastic material.

* Dipping into a paint or lacquer with conductive properties.

* Casting into a block of aluminium or a conductive low melting point alloy.

* Coating in conductive grease or paste, possibly at elevated temperature such that the medium would flow into the gaps between the mating parts by capillary action.

* Enhancement of any of the processes by the use of pressure or vacuum to eliminate voids or gaps.

* The provision of an outer container of either rigid or flexible material to surround the coil/carbonator tank assembly and contain a fluid (liquid or powder/gel) heat transfer medium. For example water with or without a freeze point suppressant. The container could be, for instance a vacuum formed sleeve or a simple plastic bag secured at the top by a cable tie or similar device.

It will be understood that the invention is not limited to the embodiment above-described and that the benefits and advantages of positioning the cooling coil for the carbonator tank and the pre-cool coil for the still water supply externally of the carbonator tank has application to all types and constructions of carbonators for producing carbonated water from potable still water for human consumption. In some applications, the carbonator may be employed to supply a dispenser for mixing carbonated water with a concentrate such as syrup to produce a flavoured carbonated drink such as a cola.

Claims

CLAIMS1. Apparatus comprising a carbonator tank in which still water can be carbonated to produce carbonated water, and means externally of the tank for cooling still water supplied to the tank and/or carbonated water in the tank, the cooling means including a cooling coil extending around the tank.
2. Apparatus according to claim 1 wherein, the cooling coil contains a cooling fluid and is configured for heat exchange between the cooling fluid and the still water and/or the carbonated water.
3. Apparatus according to claim 2 wherein, the cooling fluid is a gas or a liquid.
4. Apparatus according to claim 3 wherein, the cooling fluid is a CO refrigerant.

CO
5. Apparatus according to any of claims 2 to 4 wherein, heat exchange between the cooling fluid and the still water is provided by contact between the cooling coil and a pre-cool coil containing the still water externally of the tank.
6. Apparatus according to claim 5 wherein, the pre-cool coil extends around the tank.
7. Apparatus according to claim 6 wherein, the coils are arranged one on top of the other.
8. Apparatus according to claim 6 wherein, the coils are arranged side by side.
9. Apparatus according to claim 6 wherein, one of the coils is arranged inside the other coil.
10. Apparatus according to claim 7 wherein, the cooling coil and pre-cool coil are arranged one on top of the other with an inner coil contacting an outer surface of the tank and an outer coil contacting the inner coil.
11. Apparatus according to claim 10 wherein, the inner coil is the cooling coil containing the cooling fluid and the outer coil is the pre-cool coil containing the still water or vice versa.
12. Apparatus according to claim 10 or claim 11 wherein, one or more additional coils are provided on top of the outer coil with each additional coil being arranged on top of another coil. Co
13. Apparatus according to claim 12 wherein, the one or more CO additional coils comprise a cooling coil or a pre-cool coil. (\J
14. Apparatus according to claim 12 or claim 13 wherein, cooling coils and pre-cool cool coils alternate with each other.
15. Apparatus according to any of claims 10 to 14 wherein, the coils extend for all or part of the length of the carbonator tank.
16. Apparatus according to any of claims 10 to 15 wherein, the carbonator tank is of round section.
17. Apparatus according to any of claims 10 to 16 wherein, one or more coils is of round section.
18. Apparatus according to any of claims 10 to 17 wherein, one or more coils is of non-round section.
19. Apparatus according to any of claims 10 to 18 wherein, contacting surfaces of the coils are configured to mate with each other.
20. Apparatus according to claim 8 wherein, the cooling coil and pre-cool coil are arranged so that both coils contact an outer surface of the tank with turns of one coil separating turns of another coil along the length of the tank.
21. Apparatus according to claim 20 wherein, the turns of one coil alternate with the turns of another coil.
22. Apparatus according to claim 20 or claim 21 wherein the coils CO extend for all or part of the length of the carbonator tank.

C)
23. Apparatus according to any of claims 20 to 22 wherein, one or more additional coils are provided on top of the cooling coil and pre-cool coil with each additional coil being arranged on top of another coil.
24. Apparatus according to claim 23 wherein, additional coils comprise a cooling coil or a pre-cool coil.
25. Apparatus according to any of claims 20 to 24 wherein, the carbonator tank is of round section.
26. Apparatus according to any of claims 20 to 25 wherein, one or more coils is of round section.
27. Apparatus according to any of claims 20 to 25 wherein, one or more coils is of non-round section.
28. Apparatus according to any of claims 20 to 27 wherein, contacting surfaces of the coils are configured to mate with each other.
29. Apparatus according to claim 9 wherein, the cooling coil and pre-cool coil form a twin coil -one within the other -arranged so that the outer coil contacts the outer surface of the tank.
30. Apparatus according to claim 29 wherein, the inner coil contains the cooling fluid with the still water contained between the coils or vice versa.
31. Apparatus according to claim 30 wherein, the twin-coil extends for CO all or part of the length of the carbonator tank.

CO
32. Apparatus according to claim 30 or claim 31 wherein, the (\J carbonator tank is of round section.
33. Apparatus according to any of claims 30 to 32 wherein, the outer coil of the twin-coil is of round section.
34. Apparatus according to any of claims 30 to 32 wherein, the outer coil is of non-round section.
35. Apparatus according to any of claims 30 to 34 wherein, the inner coil is of round or non-round section.
36. Apparatus according to any preceding claim wherein an outer container is provided to surround the coil/carbonator tank assembly and contain a fluid heat transfer medium.
37. Apparatus comprising a carbonator and a tubular heat exchanger surrounding and contacting an outer surface of the carbonator for heat transfer between a liquid within the carbonator and a fluid within the heat exchanger.
38. Apparatus according to claim 37 wherein, the tubular heat exchanger comprises one or more tubes wrapped around the carbonator.
39. Apparatus according to claim 38 wherein, the or each tube forms a helical or spiral coil around the carbonator.
40. Apparatus according to claim 37 wherein, the tubular heat exchanger comprises two tubes, one containing cooling fluid and the other CO containing liquid for supply to the carbonator.
41. Apparatus according to claim 40 wherein, the tubes are separate and wrapped in separate coils one on top of the other or side by side around the carbonator.
42. Apparatus according to claim 40 wherein, the tubes are combined one within the other and wrapped in one coil around the carbonator.
43. Apparatus according to any of claims 38 to 42 wherein, the or each tube is wrapped more than once around the carbonator.
44. Apparatus according to any of claims 38 to 43 wherein the or each tube is provided with a heat conductive coating.
45. Apparatus for carbonating water including a tank having an inlet for still water and an outlet for carbonated water, a cooling coil and a pre-cool coil wrapped around the tank with at least one of the coils in contact with an outer surface of the tank and with the other coil.
46. Apparatus according to claim 45 wherein, the cooling coil forms part of a loop for circulating a coolant to cool the carbonated water in the tank.
47. Apparatus according to claim 45 or claim 46 wherein, the pre-cool coil forms part of a supply line for delivering still water to the inlet of the tank.
48. Apparatus according to any of claims 45 to 47 wherein, the cooling coil is coiled around and contacts the outer surface of the tank and the pre-cool coil is coiled around and contacts the cooling coil. C)
49. Apparatus according to any of claims 45 to 47 wherein, the cooling coil and pre-cool coil are coiled around and contact the outer surface of the tank.
50. Apparatus substantially as hereinbefore described with reference to Figures 1 to 8 of the accompanying drawings.
51. Apparatus substantially as hereinbefore described with reference to Figures 1 to 8 of the accompanying drawings as modified by any of Figures 9 to 24 of the accompanying drawings.