中文摘要：

研究以干燥银耳为主的食用菌热风换向干燥新技术取代传统的垂直气流热风干燥。采用垂直气流热风换向干燥与横向水平气流热风换向干燥的2个技术改造方案，分别进行试验。在恒定风速、干燥初始热风温度80℃条件下，分别测定各层物料含水率变化的分布曲线与平均含水率梯度Waj指标，得出较优干燥工艺为干燥温度70-80℃，换向时间间隔Ih，分别比传统垂直气流热风干燥速率提高30％与40％，后者还具有相同满负荷工作时间，节电50％，节省占地77．8％的优势。同时给出横向水平气流热风干燥自动化模拟。

英文摘要：

The technique of reversible hot air drying for tremella fuciformis replacing the traditional tech- nique of vertically hot air one - direction flow drying was studied, which is used to dry edible fungus mainly tremella fuciformis. Two modified schemes were adopted namely vertically reversible air flow technique and horizontally reversible air flow technique which were experimented on respectively. The profile of moisture content in each layer and the moisture gradient were measured under the condition of constant air speed and initiatory air temperature 80℃ , and the result showed that the optimal drying technology parameters were： drying termperature 70 -80℃, interval time for air direction change 1 h. The drying speed in the adopted new technique was improved by 30% and 40% respectively than that in the traditional vertical one - direction air flow. In the full load working condition, the new technique could save 50% electric energy and 77.8% equipment room compared to the traditional one. Finally, automatization simulation of horizontally hot air flow drying process is given in this paper.