tailieunhanh - Ebook Refrigeration and Air-Conditioning (4th Edition): Part 2 - G. F. Hundy , A. R. Trott, T. C. Welch

Part 2 of ebook "Refrigeration and Air-Conditioning" provides to reader the following contents: Food refrigeration – product by product; refrigerated transport, handling and distribution; industrial uses of refrigeration; air and water vapour mixtures; practical air treatment cycles; air movement;. and other contents. Inviting you to refer. | Chapter Sixteen Food Refrigeration -Product by Product INTRODUCTION Almost all perishable foods are commercially prepared with the aid of cooling processes. These pages can do no more than give a very brief outline of some of the refrigeration techniques used in the food and drink industry today. MEAT INDUSTRY APPLICATIONS In the meat industry the main applications of mechanical refrigeration are Chilling of carcasses directly after slaughter and dressing Cooling of meat-handling rooms such as butcheries Chill storage of edible meats and offal Meat and poultry freezing Animals when slaughtered are at a body temperature of 39 C. The carcass cools slightly as it is being dressed but must be put into refrigerated chambers as soon as possible. The speed of cooling depends on the thickness of the joint so the larger carcasses are usually halved into sides. While there is a need to remove body heat to check deterioration if this process is too quick with beef or lamb the resulting meat may be tough cold shortening . A general rule for lean meat such as beef is that no part should be cooled below 10 C for at least 10 hours after slaughter although this limit may be varied by the local producer. The total time in this chiller stage will be at least 24 hours for a beef side. During the initial cooling stage the surface of the meat will be quite warm and careful design of the coolers and their operation is needed to reduce weight loss by evaporation from the surface and good air circulation is required at a humidity level of 90-94 . Meat-cooling curves which indicate weight loss 198 as found by Bailey and Cox 1976 are shown in Figure . At low air speeds Food Refrigeration - Product by Product 199 0 Air velocity m s Figure Effect of air velocity and temperature on the weight loss of beef carcasses the weight loss is high because the process takes a long time but higher air speeds .

• Cơ khí - Chế tạo máy
• Air Conditioning
• Ebook Refrigeration and Air Conditioning
• Food refrigeration
• Refrigerated transport
• Air and water vapour mixtures
• Practical air treatment cycles
• Electronic Engineering
• Ice storage
• Capillary radiation system
• Temperature and humidity independent control
• Cooling load estimation
• College reading hall
• Cooling load
• Heat transfer
• Heat ventilation airconditioning