Method and Apparatus for Dispensing Cold Beverages

The present invention relates to liquid cooling systems, and more particularly to an improved method and apparatus for use in post-mix cold beverage dispensers in which measured quantities of fluids such as carbonated water and flavored syrups are selectively mixed and discharged through manually actuated dispensing heads.

Commercial installations of post-mix beverage dispensers typically include a "tower" with dispensing heads conveniently positioned on a foodservice counter for selectively mixing and discharging a variety of flavored syrups with plain or carbonated water. Due to the narrow front-to-back depth of the counter, severe design and space limitations are placed on the tower configuration which often preclude installation of a conventional refrigerating unit or cooler in the immediate vicinity of the dispensing heads. Consequently, the tower is installed on the counter with chilled water delivered through a long conduit from a remotely located cooler.

It is important for consistent performance of a cold beverage dispenser to deliver beverages at the same chill temperature each time. Under frequent usage, the temperature of the ingredients at the dispensing heads can be maintained fairly constant thus assuring a pleasing chilled beverage each time without excessive foaming. However, for so-called "casual" drinks where the dispenser may be idle for a prolonged period of time, usually 15 minutes or more, heat gain from the surroundings tends to increase the temperature of the stagnant ingredient near the dispensing heads. The temperature increase in the resulting beverage will vary depending on the quantity of quiescent water and syrup in the conduit and on the duration of exposure.

Several approaches for alleviating this problem are in use. One, such as disclosed in U.S. Pat. No. 4,969,576 to Merrill et al, periodically draws off an amount of warmed-up water near the dispensing heads allowing it to be replaced with chilled water from an ice-chilled cast aluminum plate. Another approach, disclosed in U.S. Pat. No. 4,781,309 to Vogel, recirculates the chilled water at a regulated temperature between a remote cooler and the dispensing heads in the tower. Both of these approaches provide an immediate discharge on demand of chilled water regardless of the length of conduit or the time elapsed since the dispenser was last used, but it does not compensate for increases in syrup temperature due to heat gain from external sources. Some installations, therefore, also chill the various flavored syrups by passing them through a cast aluminum heat exchanger with the chilled water, such as disclosed in U.S. Pat. No. 4,781,309 supra, or by running the syrup in lines along side the chilled water line within the insulated conduit.

After the syrup lines reach the beverage tower, however, they separate from the water line and continue to their respective dispensing heads for mixing and discharging with the water. When there is no demand, the quiescent syrup will warm up where the lines are separated resulting in a higher beverage temperature depending on the quantity of quiescent ingredients and the time lapse between usages.

Accordingly, it is an object of the present invention to provide a novel and improved post-mix chilled beverage dispensing system for delivering beverages at a consistent temperature regardless of the frequency of usage, in which syrups delivered to a remote beverage tower are chilled to the desired temperature in close proximity to the dispensing heads, in which temperature elevation of casual drinks due to quiescent syrup in the tower is minimized, and in which drawing off of one syrup does not adversely influence the temperature of adjacent syrups.

Another object of the invention is to provide a device for chilling liquid ingredients in a post-mixing beverage dispensing tower remotely located from a cooler, and which can be installed in a relatively shallow front-to-back housing of a beverage tower suitable for mounting on a foodservice counter or the like.

Still another object is to provide a method for dispensing a beverage at a consistent temperature regardless of usage frequency, and for chilling ingredients of a beverage in close proximity to the dispensing head.

Briefly, these and other objects and aspects of the invention are accomplished by a relatively simple and compact chilling device disposed within a beverage dispensing tower remotely located relative to a water and syrup cooler and recirculation unit. Chilled plain or carbonated water is circulated in a line within an insulated conduit between the unit and the tower with a portion of the water drawn off at selectively operated dispensing heads. Flavored syrups supplied through separate lines along side the water line and within the same insulated conduit, are selected for mixing in controlled amounts with the water at the dispensing heads. A thermal mass in close proximity to the dispensing heads is contiguous with the water and syrup lines for chilling the syrups immediately before being dispensed.

In one embodiment, the chilling device includes thermally conductive mass or bar, generally of rectangular cross section, disposed in the tower in close proximity to the dispensing heads. The chilled water line includes a U-shaped header intimately interfacing opposite sides of the bar fluid communication at spaced intervals with each immediately disposed dispensing head. The syrup lines separate from the insulated conduit and continue as a vertical stack intimately interfacing at least one of the other sides of the bar. The header and bar thereby act as a heat sink for the syrup lines in the immediate region of the dispensing heads. Thermally conductive tape wrapped around the outer surfaces of the syrup tubes, header and bar further assist in heat transfer from the syrup lines. Thermal insulators placed between individual syrup lines at the bar prevent each line from significantly influencing the temperature of the others as syrup is dispensed.

In another embodiment, the chilled water and syrups pass through conduits within a readily thermal conductive cast metal manifold located in the tower with pairs of water and syrup outlets from respective conduits immediately connected to the dispenser heads. In either embodiment any heat flowing into the thermal mass of the bars or manifold through the insulation or from the syrup is transferred to the chilled water. Temperature changes are minimized due to the thermal mass, relatively small amount of fluid is dispensed with each usage, and cooling is provided by the chilled water.

Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.

FIG. 1 is a schematic representation of a post-mix cold beverage dispensing system utilizing a beverage chilling apparatus according to the invention;

FIG. 2 is a side elevation view of a portion of one embodiment of a chilling device installed in a dispensing tower of FIG. 1;

FIG. 3 is an isometric rear view of the chilling device of FIG. 2;

FIG. 4 is a cross sectional view of the chilling device of FIG. 3 taken in a plane along the line 4--4 thereof;

FIG. 5 illustrates an alternate embodiment of a beverage chilling device suitable for installing in the dispensing tower of FIG. 1;

FIG. 6 is a view partially in cross section of the chilling device of FIG. 5 taken in a plane along the line 6--6 thereof; and

FIG. 7 is a schematic representation of the fluid lines within the chilling device of FIG. 5.

Referring now to the drawings wherein like reference characters designate like or corresponding parts throughout the several views, FIG. 1 illustrates a typical arrangement for dispensing post-mixed, chilled carbonated beverages. Water is supplied under pressure to a carbonator tank 12 through a motor-driven pump 14, and pressurized carbon dioxide is delivered through a regulator 16 from a tank 18. The amount of water supplied to tank 12 is regulated according to the fluid level. Carbonated water from tank 12 passes through a cooler and recirculation unit 20 and an insulated conduit 22 to a horizontal row of dispensing heads 24 mounted in counter-top beverage tower 26 in a location convenient to the user, usually remotely from unit 20. Various flavored syrups, maintained under pressure in containers 28 by CO.sub.2 supplied from tank 18 through regulators 16 and 30, are also chilled in unit 20 and delivered to dispensing heads 24 through the same insulated conduit 22. By manually initiated actuators, not shown, carbonated water and syrup are mixed and discharged as a cold beverage at heads 24.

Referring to FIGS. 2, 3 and 4, the chilled carbonated water and syrup lines separate from insulated conduit 22 and continue as water tubes 32 and syrup tubes 34 to a chilling device 36 located in immediate proximity to dispensing heads 24. Device 36 includes a chill bar 38 having vertically disposed flat sides and of a material selected for its ability to absorb and transfer thermal energy with ease such as aluminum. Where space permits, another bar 40 may be arranged in an L-shape with bar 40 for supplemental chilling. Bar 38 is closely aligned lengthwise along the row of dispensing heads. Water tube 32 is generally U-shaped to define a header section 32a and a return section 32b, each respectively contiguous with top and bottom surfaces of bars 38 and 40. The section 32b returns through conduit 22 to unit 20 for recirculating carbonated water which has not been drawn off by dispensing heads 24. In a further embodiment, there is provided an apparatus for dispensing a fluid mixture at a substantially uniform temperature, comprising, in combination; a fluid mixture dispensing means; a first means for delivering a substantially uniform temperature fluid to said dispensing means; a second means for conducting a variable temperature fluid to said dispensing means; and a thermal mass mean disposed in immediate proximity to said dispensing means and secured in heat exchanged relation to said first and second means. Thermistors, not shown, are attached to header section 32a for regulating recirculation at unit 20. Short risers 42 respectively communicate at spaced intervals along the length of chill bar 40 between header section 32a and dispensing heads 24. The portions of syrup tubes 34 separated from conduit 22 divide in approximately equal numbers to contact opposite sides of bar 38 in heat exchange relationship, recombine to contact the rear side of bar 40, and fluidly connect to dispensing heads 24.

Adjacent syrup tubes 34 do not significantly influence one another as syrup is drawn off and warm syrup takes its place because chill bars 38 and 40 maintain interfacing contact with all syrup and water tubes 32 and 34 and immediately cool the warm syrup. In addition, thermal insulating spacers 44 inhibit heat transfer between adjacent syrup tubes 34. The vertical stacking arrangement of syrup tubes 34 along the surfaces of chill bars 38 and 40 allows the thermally conductive tape 46 to be wrapped around the assembly of chill bars 38 and 40 and water and syrup tubes 32 and 34 thereby providing another heat transfer path between adjacent components. Tape 46 may be wrapped in the same manner as tape on the grip of a baseball bat.

Thus, it is seen that a slim vertical stack-up of tubes yields a very shallow front-to-back depth behind the dispensing heads. This feature allows the tower depth to be minimized while improving the availability of a chilled casual drink. That is, by keeping the fluid lines short between header 32a and dispensing heads 24, the casual drink temperature very closely approximates a steady flow temperature.

The embodiment of FIGS. 5-7, the chilling device comprises a manifold 50 mounted within beverage tower 26 immediately behind dispensing heads 24 for chilling the syrup. It includes a cast aluminum plate 52 with cast-in-place header and return sections 32a' and 32b', and syrup tubes 34' which are connected respectively to the syrup and recirculating water lines in insulated conduit 22. Syrup tubes 34' are circuitously formed within plate 52 in a roundabout manner as illustrated in FIG. 7 to provide maximum surface exposure for heat transfer. Plate 52 is completely insulated by thermal jacket 54 to minimize the effects of ambient temperature. Thus, any heat flowing to manifold 50 from the syrup or water is absorbed by plate 52 and transferred to water line 32'. Syrup temperature changes are thereby minimized when the product is dispensed due to the relatively large thermal mass of plate 52 and the relatively small amount of unchilled fluid dispensed.

Many modifications and variations of the present invention are possible in view of the above disclosure. It is therefore to be understood, that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.