The characteristics of microwave energy can be traced back to 1945, when Spansa, an American, discovered that sugar cubes in his pockets were melted when he was working on an experimental radar device. Microwave is an ultra high frequency electromagnetic wave with frequencies between 30 and 30000 MHz. Because microwave heating has the characteristics of heating in the heated object and producing uniform temperature rapidly, microwave drying machinery has been applied to industrial heating technology since 1959 to open up new thermal energy sources. Improve the utilization of heat energy and shorten heating time.
After several years of exploration, by 1968, the technology of using microwave to solve various heating problems in microwave heating of food industry had developed rapidly in Europe, America and Japan. In 1965, the U. S. S. S. E. F. T. F. O. D. first installed a 91.5 MHz 50 K W tunnel type microwave oven, in which microwave and hot air were mixed t o d r y fried potato chips. The potato chips can be baked 50-100 kilograms per hour, and can be eaten in the oven f o r only 2 minutes. The US O co m a f. D. Continuous microwave pre-cooking of chicken nuggets. The production line can process 1200 kg chicken nuggets per hour. The American Microwave Drying Company dries macaroni with microwave, and the temperature is 150, Z 0 000 F. Good bactericidal effect can be obtained. The United States Ray HT co n installation of microwave defrosting meat products into
It takes only 10 minutes to heat frozen meat from O O F to Z and 25"F. Each set of equipment can handle 1 500 and 4 500 pounds of frozen meat in an hour. In addition, the United States also uses microwave processing of bacon, fermentation and fried cookies to bake nuts and nuts. In 1966, the application of microwave energy in the food industry in the United States has been expanding, such as in meat processing. 19 for 3 years for 6 K W 10. In the past 19-6 years, more than 30 sets have been installed, and the use of microwave energy to process nuts and dry pulpy foods has increased. Also extended to onion drying.
Because microwave can be used in food industry, it not only increases the output and variety of food, but also improves the quality. After a period of research in Britain, microwave energy was applied to heating in 1959. Microwave drying of tobacco increases the puffiness, improves the quality and yield of cigarettes, and has significant effects on insecticide, sterilization, mildew control and improving the taste of tobacco.
Japan also uses microwave to process Rubber and plastics, tea drying, bread baking, wood drying and plywood production, extraction of cod liver oil, rapid curing adhesives, food insecticides, etc. The monthly output of household microwave ovens is about 13 in 1975. 0. It is the most common country in the world to adopt microwave oven.See the news list>>