This invention relates to refrigeration systems and more particularly, to methods and apparatus for producing a soft, pliable CO.sub.2 snow and accurately delivering the same to a point of end use as an expendable refrigerant.
In order to economically transport refrigerated food products such as meat, it has been found necessary to cool such products to a temperature just above freezing upon completion of slaughtering and trimming operations. In-transport cooling requires bulky and expensive refrigeration equipment and consumes undue periods of time and power to adequately refrigerate food products. Such cooling delays have the deleterious effect of enabling the growth of bacteria which, of course, results in increased spoilage, and consequently complete reliance on intransport cooling of food products is clearly uneconomical. Accordingly, refrigerated transport systems are typically designed so as to maintain previously chilled food products at a desired temperature by merely compensating for heat leakage into the transport vehicle or container.
In the past, various techniques for chilling food products such as slaughtered and trimmed meat have been utilized. One such technique is commonly referred to as a "community bath" which is extensively utilized for chilling dressed fowl, such as chickens. Chilling is accomplished by immersing a dressed fowl in an ice water bath for a predetermined period of time. In recent years, however, it has become apparent that this chilling technique suffers from certain disadvantages. More specifically, the spread of bacteria from one contaminated fowl to other fowl being chilled in the bath has been found to occur through the medium of the chilled or ice water bath. Accordingly, the contamination of a plurality of fowl in a bath is deleterious and hence, a clear need for economical chilling of processed food products, while avoiding contamination of a multiplicity of such products, exists.