Combination carbonator, soda pump and water agitator

A combined agitator (30), carbonator (10) and soda pump arrangement (23, 24) for dispensing beverages uses a magnetic drive coupling (28, 29). The carbonator coolant tank (15) in which the agitator (30) works has an optional ice bank chiller (20).

FIELD OF THE INVENTION
 The present invention generally concerns beverage dispensing equipment and
 in particular such equipment having a combined agitator, carbonator and
 soda pump arrangement using a magnetic drive coupling.
 BACKGROUND OF THE INVENTION
 Beverage dispensing equipment relative to the provision of carbonated
 beverages is well understood. Such beverages may include a syrup mixed
 with carbonated water (also known as soda). Such equipment which provides
 for such beverages typically have associated with them a carbonator for
 mixing carbon dioxide gas with water. The carbonator body may have
 surrounding it a reservoir containing a chilled coolant. For example, the
 carbonator may be located within an ice bank cooled water bath which
 chills the carbonator and its contents as well as the water to be
 carbonated. As is known, the ice bank is formed on an evaporator located
 with the water bath which evaporator is cooled by the operation of a
 mechanical refrigeration system. Examples of such arrangements are
 described in GB 2 307 975A and U.S. Pat. No. 5,399,300.
 In practice, the carbonator may be closely adjacent to or remote from the
 beverage dispense point i.e., the point where a valve or tap is operated
 to dispense the beverage into a glass or similar container from which the
 consumer will drink the beverage. If the carbonator is remote from the
 dispense point, the soda may be kept chilled on its journey from the
 carbonator by ensuring that the supply tube is held within a thermally
 insulating sleeve which is sometimes known as a python.
 A continuing problem with prior art carbonators concerns their ability to
 rapidly form carbonated water of the desired level of carbonation to
 adequately provide for needed volumes thereof during periods of high drink
 demand.
 A further problem concerns the ability of the cooling equipment to provide
 for good heat exchange between the ice bank and the carbonator tank and
 the water or syrup coils wherein the water in the bath serves as the
 thermal exchange medium there between. Typically, agitators are used to
 stir the water in the bath tank to ensure proper heat exchange between the
 water and the ice bank and, in turn, the carbonator and coils. However, an
 agitator includes a separate motor and presents further equipment and
 energy consumption cost.
 Carbonators also require a water pump to pump the flat or non-carbonated
 water therein and to pump the carbonated water therefrom to the dispense
 point. Such pumps also represent further cost and complexity.
 Accordingly, it would be desirable to have an improved carbonator that can
 produce large volumes of properly carbonated water. And it also would be
 desirable to accomplish the foregoing in a manner that provides for good
 heat exchange between the carbonator and the cooling medium there around
 and do so in a manner that is cost efficient. It would further be
 desirable to provide for such heat exchange and for the pumping of water
 to and from the carbonator that does not require separate motors for each
 such function.
 BACKGROUND OF THE INVENTION
 According to one aspect of the invention, a carbonator is provided for use
 in beverage dispense, said carbonator comprising:
 means for retaining a first liquid to be carbonated, said retaining means
 essentially comprising a closed tank having associated an entry for said
 first liquid and an associated exit for said first liquid when carbonated;
 means for admitting carbon dioxide gas under pressure into said retaining
 means; pump means for said first liquid located within said retaining
 means, said pump means having drive means located externally of said
 retaining means, said pump means being driven via a magnetic coupling
 between the pump means and the drive means;
 a reservoir in which said retaining means is located, said reservoir being
 adapted to hold a second liquid which surrounds at least part of said
 retaining means, and agitation means located below the retaining means for
 agitating said second liquid, said agitation means being directly
 connected with the said drive means.
 A passageway may be provided through the retaining means through which
 passes a shaft extending from the drive means to the agitation means. The
 drive means may be located above the retaining means. The magnetic
 coupling between the pump means and the drive means may comprise two
 components, one of which is within the retaining means and coupled with
 the pump impeller, with the other component extending within the reservoir
 below the retaining means. This second component is typically attached to
 the lower portion of the shaft. The agitation means for the second liquid
 is typically located on said shaft below said latter component of the
 magnetic coupling. Means may be provided attached to the pump impeller for
 agitating the first liquid within the retaining means.
 Optionally, the reservoir may contain means for chilling the second liquid.
 Such chilling means may include the evaporator portion of a refrigeration
 circuit. The evaporator may be in the form of a coiled tube which extends
 around the inside perimeter of the reservoir. The refrigeration system may
 be adapted to create and maintain an ice bank around the inside perimeter
 of the reservoir. Alternatively, the second liquid may be recirculated
 through a python to a remote chiller from where the second liquid is
 returned to the reservoir. The reservoir may be of a depth which
 substantially enables the retaining means to be covered with the second
 liquid or for the liquid to extend over a substantial portion of the
 external surface area of the retaining means. Within the reservoir there
 may be means for circulating a further liquid product and maintaining said
 further product chilled. Such further product could include a fruit or
 cola syrup.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
 One embodiment of the invention will now be described, by way of example
 only, with reference to the accompanying FIG. 1. A carbonator of the
 present invention for use with an associated beverage dispenser has a
 carbonator body 10 of cylindrical shape and made from stainless steel. The
 carbonator body has an upper end cap 12 and a lower end cap 13 which
 together with the body 10 provide means for retaining a body of water 11
 which is being carbonated. The lower end cap 13 is made of
 non-ferromagnetic material e.g. a plastics moulding, and the assembly is
 made pressure tight to accommodate the required degree of carbonation.
 Upper end cap 12 can also be made of plastic, as seen in U.S. Pat. No.
 5,792,391, which patent is incorporated herein by reference thereto, and
 both caps 12 and 13 can be secured to carbonated body cylinder 10 as seen
 therein.
 A central passageway having an annular wall 14 and a top fluid tight shaft
 seal 14a and a bottom fluid tight shaft seal 14b, extends vertically
 through the carbonator body 10. The carbonator body 10 is located within a
 coolant reservoir 15, the coolant typically being glycol or water based.
 The level of the coolant is shown by numeral 16.
 The carbonator body 10 has entry means 17 to enable fresh water to pass
 into the carbonator. An exit 18 for carbonated water extends through the
 wall of the lower end cap 13 and has tubing (shown schematically by dashed
 lines) which takes the carbonated water from the carbonator and transfers
 it to one or more associated beverage dispensers. A carbon dioxide gas
 inlet 19 is provided in the upper end cap 12 whereby carbon dioxide gas
 under pressure may be admitted into the carbonator body and into the water
 11 retained within said body 10.
 As seen in FIG. 1, an optional evaporator 20 is used to chill and/or freeze
 the coolant adjacent the inner walls of reservoir 15. This may create an
 ice bank whose inner perimeter is illustrated in dashed line at 21.
 Optional product coils 22, through which syrups or colas may pass and be
 chilled, are shown extending within the coolant in the reservoir 15.
 Within the annular carbonator body 10 is a pump housing 23 which is
 co-axial with central passageway 14. Within pump housing 23 is a pump
 impeller 24, again co-axial with central passageway 14, which may be
 driven to pump soda water from carbonator body 10 via exit 18. A vane 25
 is attached to the pump impeller 24 so that it rotates with it to agitate
 the water 11 within carbonator body 10 to assist in the absorption of
 carbon dioxide. The pump impeller 24 is driven indirectly by a motor 26
 positioned above the carbonator body 10. A drive shaft 27 extends
 downwardly from motor 26 through central passageway 14 and through dynamic
 seals 14a and 14b to below the level of the lower end cap 13. The indirect
 driving means is provided by magnetic drive components 28 and 29, first
 component 28 of which is attached to drive shaft 27 and extends radially
 therefrom closely adjacent to and below the bottom surface of the lower
 end cap 13. The second component 29 of the magnetic drive means extends
 annularly and is free to rotate within carbonator body 10 closely adjacent
 the upper surface of the lower end cap 13. The pump impeller 24 is
 attached to the second magnetic drive component. The principles of
 operation of such magnetic drives are well known.
 An agitator 30 for the second liquid, namely the coolant within reservoir
 15, is attached to the remote end of drive shaft 27 such that the agitator
 30 is below the level of the first magnetic drive component 28. Agitator
 30 serves to homogenise the coolant and avoid stratification of such
 coolant into zones of differing temperature. It also serves to move the
 coolant relative to the surface of an ice bank when such is present within
 the reservoir and also to ensure that syrup within tubes 22 is maintained
 at a substantially constant temperature.
 In operation, motor 26 operates to drive shaft 27 and to directly drive
 agitator blade 30 secured thereto. Rotation of shaft 27 also rotates
 magnetic drive component 28, which then imparts rotation to drive
 component 29. Drive component 29 then causes rotation of impeller 24 and
 agitator 25 attached thereto. The water in carbonator 10 is then
 carbonated by the mixing action of agitator 25 and is also pumped therein
 along line 17 and therefrom along line 18 by the action of impeller 24.
 Thus, those of skill will appreciate that carbonator 10 can provide for
 agitation of the heat exchange fluid there around and for the agitation of
 the water and therein as well as for the necessary pumping of water
 therein and carbonated water there from through the use of a single motor
 26.