In the process of aquatic products drying, there are problems of dewatering too fast on the surface and water spread passage blocking, which cause high moisture unevenness and affect the product quality after drying. For solving the problems, authors designed a U-shaped tunnel-drying room for aquatic products. Some key techniques were analyzed and studied, which contains cross flow drying, switching forward and reverse airflow, on-line controlling of temperature and humidity of drying medium and circulating use of heat energy etc.. Compared with single as well as double passageway drying room,...