苹果片热泵干燥工艺试验研究

Experimental Study on the Heatpump Drying Technology of Apple Slices

[目的]优化利用自制热泵干燥设备干燥苹果片的工艺参数。[方法]利用自制热泵干燥设备将苹果片脱水干燥,通过单因素试验和3因素3水平正交试验探讨了干燥介质温度、装料量和切片厚度对干燥速率及能耗的影响。[结果]在30～40℃下,在相同的干燥时间内,随着干燥介质温度的升高,干燥速率明显加快。装料量为1～2 kg/m2时,随着装料量的增加,干燥时间明显增加,干燥速率明显降低。在3～5 mm的厚度范围内,随着切片厚度的增加,干燥时间明显增加,干燥速率明显降低。方差分析表明,干燥介质温度和装料量是干燥速率的主要影响因素。多重比较结果表明,最优工艺组合为:干燥介质温度为30℃,装料量为15 kg,切片厚度为3、4或5 mm。[结论]热泵干燥工艺提高了干燥效率,减少了能耗。

[ Objective ] The purpose of the study was to optimize the technological parameters of drying apple slices with self-made heat-pump drying equipment. [ Method] The apple slices were dehydrated and dried with self-made heat-pump drying equipment, the influences of the temperature of drying medium, forced filling rate and slice thickness on drying rate and power consumption were discussed through single factor experiments and 3-factor and 3-level orthogonal test. [ Result ] Under 30 - 40 ℃, in the same drying time, as the temperature of drying medium was increased, the drying rate was accelerated obviously. When the forced filling rate was 1 -2 kg/m2, as the forced filling rate was increased, the drying time was increased and the drying rate was decreased obviously. In the thickness range of 3 - 5 mm, as the slice thickness was increased, the drying time was increased and the drying rate was decreased obviously. The variance analysis showed that the temperature of drying medium and forced filling rate were the main influencing factors of drying rate. The results of multiple comparison indicated that the optimum technological combination was as follows： the temperature of drying medium was 30℃, the forced filling rate was 15 kg and the slice thickness was 3, 4 or 5 mm. [ Conclusion ] The heat-pump drying technology enhanced drying efficiency and reduced power consumption.