Calculating Freezing Times in Blast and Plate Freezers

摘要

Recent experiences using carbon dioxide have shown remarkable improvements in freezing times. Close analysis of the freezing process has shown that this improvement is a result of the elimination of hindrances which handicap traditional freezer designs such as high suction line pressure drops, intolerance of off-design operation and internal fouling. The paper presents several methods of modeling the freezing process which can be used in a simple spreadsheet, and which help to explain the benefits which can be gained by using a correctly designed system with carbon dioxide as the refrigerant The paper will provide an explanation of the theory behind the freezing process and will convert this into a methodology which can be implemented in a standard spreadsheet. For more advanced users the option of automating the spreadsheet by using macro programs will be explained.