The Exhibitor (1966)

DISPENSING EQUIPMENT senses this, and starts operation of a compressor which works to restore the ice bank. “Facts” advises that few systems of this type could cope with rush periods if they relied on their compressors alone to transport heat as rapidly as it comes in. Coke suggests that the capacities of such units be carefully evaluated, since restoration of a sufficient ice bank to insure a properly chilled beverage can require signifi¬ cant down time. Dry systems circulate a refrigerant through a block of conduc¬ tive metal, usually aluminum. This block also contains the coils for beverage ingredients. Heat is absorbed by the metal, which conveys it to the refrigerant. These systems have a smaller “reseiwe” than wet type units, but recover more rapidly. Supple¬ mentary refrigeration should be contemplated if such a system is desired for an operation where heavy rush periods are experi¬ enced. ICE AN EXCELLENT REFRIGERANT Units utilizing the ice bank principle should be periodically cleaned for removal of deposits which can interfere with efficient heat transfer through the coils. In mechanically refrigerated sys¬ tems, the heat absorbed by the refrigerant is carried to a con¬ denser where the heat is dissipated in the atmosphere. The condenser, acting as a radiator, cannot function efficiently if the flow of air from the fan is restricted by lint or other depos¬ its. It should be cleaned as frequently as necessary and should be Installed in a location that assures good circulation of air. The common soda fountain with its counter-mounted, icecooled dispenser is probably the most frequently seen example of a combination of mechanical and ice refrigeration. Ice is an excel¬ lent refrigerant, and Coke advises that the retailer who utilizes an ice-cooled system with sufficient capacity need not worry about capacity. To illustrate the efficiency of ice as a refrigerant. Coke cites the following example: If one pound of 32° water is mixed with four pounds of 72° water, the temperature of the five pounds of water will be about 64° — but if one pound of 32° ice is combined with the same amount of water, five pounds of water at a temperature of about 35° will result. There are many methods of chilling beverages with ice refrig¬ eration, with most systems utilizing cold plates, which are alu¬ minum slabs containing coils of tubing, usually of stainless steel. \ icM WdTA -WATCA .MOTOl^lZeU CVA90RATOR PRODUCT COJL5 coco 3 COHDEM^K T through which beverage products are forced. If caving or bridg¬ ing (a result of ice melting away from the surface of a cold plate) develops, the ice should be frequently tamped down to insure as much contact with the plate as possible. Operators finding they can dispense a great many drinks while using little ice on their cold plates should check the temperature of the finished drink to see if this condition exists. The refrigeration capacities of these plate units vary widely, and the operator must select a unit that will adequately meet his needs. A good point made in “Facts” is that, if ice refrigeration is intended to supplement mechanical refrigeration, it may be best to route the beverage products through the mechanical system first and then through the ice system. This will give maximum performance from the mechanical system and the lightest possible load will be placed on the ice-cooled system. This will conserve ice and can be most important if the ice supply is re¬ stricted. Conversely, if ice supplies are unlimited, the ice cooled component should precede the mechanically refrigerated unit for best performance. If the beverage products passing cold plates are adequately refrigerated, they will impart only so much heat to the plates. This means that a large plate will melt just a little more ice than a small one while it can respond much better when large demands are placed on the refrigeration system. Careful analysis of the ice requirements at a location should be made prior to selection of a unit. If many beverages are sold, and particularly if plain water is to be chilled by the cold plate, a great deal of ice may be melted. If ice is kept in a deep freeze, it may reach very low tempera¬ tures so that placing it on the cold plate may freeze the plain water or carbonated water in the cold plate, putting the system out of operation. Pouring a little warm water on the cold plate usually solves the problem. The capabilities of both ice-cooled and mechanically refriger¬ ated systems can be augmented by careful planning. As an exam¬ ple, Coke points out that a walk-in refrigerator might have suffi¬ cient space to provide for installation of an inexpensive metal water tank to chill incoming city water before it goes into the dispensing system. The performance of ice-makers can also be improved by use of pre-chilled water. AVOID OTHER HEAT SOURCES Accordingly, all tubing for carbonated water, plain water, and syrups should be routed so that it will not pass close to hot water lines, stoves, and other heat sources. Though variations in tem¬ perature have no effect on the way carbonated water or plain water flows through tubing, this is not true of most post-mix syrups. The viscosity of these syrups is directly related to their temperature. When CO2 gas is used to force syrup through the dispensing valves, warming, if left uncontrolled, can result in a greatly accelerated syrup flow which is wasteful, costly, and harmful to drink quality. SYRUP FLOW AND TEMPERATURE Syrups pre-chilled to a set temperature will also add to the refrigeration capacity of many dispensing systems. Where syrups are pushed by CO2 gas, it is of great advantage to store the pres¬ surized syrup container in a walk-in refrigerator. Pre-chilled syrup is also helpful for ice-cooled, gravity-fed units with syrup tanks located in the ice storage compartments of the dispenser. While a unit reduces the temperature of warm syrup over a period of hours, the viscosity of the syrup will also change, resulting in a wide variation of the amount of syrup dispensed into each drink from beginning to end of the temperature reduction cycle. Temperature affects many other aspects of drink preparation, some of which will be discussed in the next article in this series. Loss of carbonation, improper blending of syrup and water, and other factors can come into play that influence the quality of the drink served. EDITOR’S NOTE: Illustrations used in this article were pre¬ pared from original technical drawings in Coca-Cola’s “Facts For Quality Beverage Dispensing.” Parts of this article are taken di¬ rectly from “Facts,” while other material represents abstractions from Coke’s handbook and material included by the editor. In the June 15th issue of PHYSICAL THEATRE— EXTRA PROF¬ ITS we will make a timely analysis of warm weather handling of ice, syrup and water. “Taste Tests” for beverage quality will also be presented as June sales volumes and changing weather condi¬ tions begin to affect your drinks. PE-10 PHYSICAL THEATRE • EXTRA PROFITS DEPARTMENT of MOTION PICTURE EXHIBITOR May 18, 1966