流化床干燥红茶的特性

Property of black teas during fluidized bed drying

阐述了流化床干燥CTC和Freedom红茶的干燥特性以及干燥温度对产品平均尺寸的影响.试验表明,干燥过程可以分为2个阶段,即第1干燥阶段和第2干燥阶段.在第1干燥阶段排气温度保持不变,而在第2干燥阶段排气温度逐渐升高.提高干燥温度有利于CTC红茶干燥强度以及排气相对湿度的提高;提高干燥温度难以使Freedom红茶的干燥强度大幅度提高,却使排气相对湿度降低.提高干燥温度可以增大CTC红茶产品的平均粒度,但不影响Freedom红茶产品的平均粒度.

The effects of drying temperature on drying characteristics and product shrinkage for CTC tea and Freedom tea during fluidized bed drying were investigated. Experiments showed two drying periods, the first drying period and the second drying period. The exit air temperature maintained constant in the first drying period and increased gradually during the second drying period. Increasing drying temperature could strengthen the drying intensity of CTC tea and increase its exit air relative humidity, but higher drying temperature improved drying intensity difficultly for Freedom tea and exit air relative humidity decreased with the increase of drying temperature. Increasing drying temperature could increase the average particle size of CTC tea, but did not influence the average particle size of Freedom tea.