IMPROVEMENTS RELATING TO COOLING DEVICES

Abstract: A cooling device for a potable, and in particular, a carbonated liquid, comprising a cooling chamber (6) and cooling means to retain a quantity of said liquid in the chamber in frozen condition. In particular, located within the chamber (6) is a cylindrical wall (8), providing an inner chamber (9). Extending adjacent to the outer wall is a cooling coil (12<u>a</u>), whilst a cooling coil (12<u>b</u>) extends adjacent to the cylindrical wall (8), through which coils refrigerant is pumped. The chamber (6) forms part of a circuit (40), by which liquid is drawn from the chamber through a dispensing head, the circuit returning to the chamber (6), the dispensing head providing means by which liquid may be drawn from the device. Part at least of the liquid returning to the chamber is delivered to the inner chamber (9), to ensure that the liquid is thoroughly cooled before returning to the main body of liquid within the chamber (6), to ensure that liquid exiting the chamber into the circuit is at a desired low temperature.

Description: Title: Improvements Relating To Cooling Devices Description of Invention This invention is concerned with improvements relating to cooling devices, in particular for the cooling of liquids. The invention has been devised particularly for the cooling of potable liquids, to be drawn off for consumption purposes, in which context the invention will hereinafter be described. It is however to be appreciated that the invention may be utilised in the cooling of liquids generally, where similar or analogous problems are encountered. A conventional cooling device for cooling a potable liquid comprises a cooling chamber in which a cooling liquid having a low freezing point is contained. Located in the chamber is a refrigeration coil, through which a refrigerant is pumped, to reduce the temperature of the cooling liquid. Potable liquid is in turn fed through a cooling coil in the cooling chamber, in contact with the cooling liquid, so that potable liquid flowing through the cooling coil is cooled by the cooling liquid. Conventionally to ensure a relatively constant temperature, mechanical impelling means is provided in the chamber, to cause the cooling liquid to flow across the refrigeration coils and the cooling coils. Conventionally to ensure that a potable liquid at an appropriate low temperature is available from a dispensing head, the liquid is continuously pumped around a circuit which contains the cooling coil, the dispensing head being operative to withdraw liquid from the circuit on demand. Fresh, uncooled liquid flows into the circuit upstream of the cooling coil, to replace that which is drawn off. In general such cooling devices are quite large, if they are to meet the requirements of providing cooled liquid at maximum demand, and it is one of the various objects of this invention to provide a cooling device which may cope with high demand without being unduly bulky. According to this invention there is provided a cooling device for cooling a potable liquid comprising a first chamber, a first cooling means adjacent to an outer wall of the first chamber, an inner wall defining an inner chamber located within the first chamber and which has an open top, second cooling means adjacent to the inner wall, and circulating means to pump liquid from the first chamber around a circuit and to return some at least of said circulating liquid to the inner chamber. Preferably the first cooling means is operative to retain a quantity of liquid in the first chamber in frozen condition, and preferably the second cooling means is also operative to retain a quantity of liquid in the inner chamber in frozen condition. By so retaining liquid in the chamber in frozen condition, a reservoir of "cold" is provided which is significantly larger than could conveniently otherwise be attained. As cooled liquid is withdrawn from the chamber inflowing liquid will be cooled by the frozen liquid, the frozen liquid being progressively melted. The rate at which said cooling means is capable of cooling the liquid may thereby be significantly less than the maximum demand, whilst maintaining a high rate of operational efficiency of the cooling device. Preferably the first and inner chambers are generally cylindrical, the inner chamber being located generally co-axially within the first chamber. Preferably the liquid is returned to the inner chamber at a lower region thereof and flows upwardly in the inner chamber to exit the inner chamber through the open top. Preferably additionally some at least of the circulating liquid is returned to the first chamber exteriorally of the inner chamber, conveniently so as to enter the chamber in a tangential direction. Thus the recirculation means is operative to cause liquid to flow into the container in such a way as to cause turbulent motion or other general flow of liquid within the chamber, and specifically to cause sufficient movement of liquid in the chamber to permit the conventionally utilised impelling means to be dispensed with. Preferably the circulating means is operative to draw liquid from the chamber at a location remote from the entrance of the circulating liquid into the chamber, conveniently being drawn from the chamber at a lower region, and being returned to the chamber at an upper region thereof. Preferably the circuit extends from the chamber, such as at a lower region thereof, and extends to a dispensing head, from which potable liquid may be withdrawn, the circuit extending from the dispensing head back to the chamber, preferably to an upper region thereof. Preferably means is provided to feed fresh liquid into the circuit, to replace liquid drawn from the circuit by the dispensing head. Preferably means is also provided to apply carbon dioxide to the liquid within the device. Preferably the device comprises a sensing means to sense the build up of ice within the chamber, conventionally around the refrigeration coil, and which is operative to supply refrigerant to the refrigeration coil on sensing a low level of ice, and to cease supply of refrigerant around the refrigeration coil on sensing a high level of ice. Preferably the device comprises sensing means to sense the level of liquid in the cooling chamber, and which is operative on sensing a reduction to cause or allow fresh liquid to flow into the chamber. In the accompanying drawings: FIGURE 1 is a schematic side elevational view of the device which is the preferred embodiment of the invention; FIGURE 2 is a schematic plan view of the device shown in FIGURE 1 ; and FIGURE 3 is a schematic view showing a flow circuit of the invention. The device which is the preferred embodiment of this invention is specifically for cooling potable liquid, and more particularly carbonated water. The cooling device comprises an enclosed, airtight cooling chamber 6 (hereinafter call the main chamber) within which an inner cylindrical wall 8 is provided, which terminates a short distance from the top of the chamber, said wall 8 defining an inner chamber 9. Extending annularly within the annular space between the outer wall 10 of the chamber and the inner wall 8 are twin cooling coils 12a, 12b through which refrigerant is fed as required by pump PI . In use the chamber 6 is filled to level 15 with potable liquid, specifically carbonated water. The main chamber 6 forms part of a circuit 40 comprising an outlet conduit 20 by which liquid is drawn from the chamber and pumped by pump 42 around the circuit to an inlet conduit 26, said circuit including a dispensing head 46 by which liquid may be drawn therefrom, as desired. As liquid is drawn from the dispensing head, the level 15 in the main chamber 6 falls, and this is detected by probe 24 to cause valve 25 to open, to admit fresh, uncarbonated water into the circuit. Downstream of valve 25 and prior to entry into the inner chamber 9, the circuit splits into two branches, providing inlet conduit 26 delivering liquid to the inner chamber 9, and inlet conduit 27 delivering liquid into the annular space between the two walls. A greater part of the water is however delivered into the inner chamber 9 via conduit 26, whilst water exiting conduit 27 flows generally tangentially, creating a vortex-like effect of the water in said annular space. In use, with a reduced level of withdrawing of cooled liquid from the chamber, ice will build up around the refrigeration coils, as is shown, until probe 22 detects a maximum desirable thickness of ice, and signals termination of feed of refrigerant by the pump PI. Liquid continues to be pumped around the circuit by pump 42. Carbon dioxide is fed into the chamber via gas inlet 29. By virtue of the location of the inlet conduit 26, recirculating liquid, which may contain a proportion of fresh liquid, initially flows downwardly within the inner chamber 9, and then upwardly in contact with the wall of ice located on the inside of inner wall 8, prior to entering the annular part of the chamber by flowing over the top+ of the ice wall. In this way, a "pre-chilling" may be effected, effectively ensuring that liquid flowing into the chamber will not immediately flow out from the chamber to the dispensing head. Thus during periods of maximum demand, when the rate of removal of cooled liquid from the circuit is greater than the rate at which the refrigeration unit can cool fresh liquid, the body of ice will melt to an extent sufficient to ensure, for some considerable time, that the liquid withdrawn from the circuit is at a desirable low temperature. It will be appreciated that the latent heat of freezing of water is such as to permit a relatively small quantity of ice to reduce in temperature a relatively large quantity of water. By directing the inlet conduit 27 into the outer annulus of the chamber, such that liquid flows back into the chamber in a generally tangential direction, a swirling motion is obtained within the chamber, to ensure maximum contact of the liquid within the chamber with the frozen liquid surrounding the walls, ensuring as far as possible an even, low, temperature, and effectively eliminating any tendency for the liquid to stagnate, without the use of mechanical impeller means. 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.

Claims: CLAIMS 1 A cooling device for cooling a potable liquid comprising (a) a first chamber; (b) a first cooling means adjacent to an outer wall of the chamber; (c) an inner wall defining an inner chamber located within the first chamber and which has an open top; (d) second cooling means adjacent to the inner wall; and (e) circulating means to pump liquid from the first chamber around a circuit and to return some at least of said circulating liquid to the inner chamber. 2 A device according to claim 1 wherein the first cooling means is operative to retain a quantity of liquid in the first chamber in frozen condition. 3 A device according to one of claims 1 and 2 wherein the second cooling means is operative to retain a quantity of liquid in the inner chamber in frozen condition. 4 A device according to claim 1 wherein the first and inner chambers are generally cylindrical, the inner chamber being located generally co-axially within the first chamber. 5 A device according to claim 1 wherein the circulating liquid is returned to the inner chamber at a lower region thereof and flows upwardly in the inner chamber to exit the inner chamber through the open top. 6 A device according to claim 1 wherein some at least of the liquid flowing through the circuit is returned to the first chamber exteriorally of the inner chamber. 7 A device according to claim 6 wherein said liquid is returned so as to enter the chamber in a generally tangential direction. 8 A device according to claim 1 wherein the circulating means is operative to pump liquid from the chamber at a location remote from the entrance of the circulating liquid into the chamber. 9 A device according to claim 8 wherein the circuit extends from the chamber at a lower region thereof and extends into the chamber at an upper region thereof, a dispensing head being provided in the circuit, from which potable liquid may be withdrawn. 10 A device according to claim 1 comprising means to feed fresh liquid into the circuit, to replace liquid drawn from the circuit by the dispensing head. 11 A device according to claim 1 comprising means to carbonate liquid within the device. 12 Any novel feature or novel combination of features described herein and/or in the accompanying drawings.

Inventors: WYATT GARY DAVID, WYATT, GARY, DAVID
Applicants: WHITLENGE DRINK EQUIPMENT LTD, WYATT GARY DAVID, WHITLENGE DRINK EQUIPMENT LIMITED, WYATT, GARY, DAVID
Application year: 1999
Main classification: B67D1
IPC codes: B67D1