Contrast between heated air drying of Chinese prickly ash under constant temperature and that under graded and controlled temperature

The Chinese prickly ash is mainly dried by heated air under constant temperature or graded and controlled temperature at present. In order to find the optimum technology of heated air drying of the Chinese prickly ash, tests were conducted to contrast the two drying methods. The test results show that the qualities of the Chinese prickly ash dried with the two methods do not present big difference. However, the latter consumes less energy and time than the former. The best technology is that the beginning temperature is 35℃, the lasting time under the temperature is 180 min, the final temperature is 50℃, the air flow rate is 1.4 m/s and the total drying time is 300 min.