热泵-低温再生转轮除湿联合干燥对白萝卜片干燥特性的影响

Effect of heat pump-low temperature regeneration desiccant wheel dehumidification combined drying on drying characteristics of white radish slices

为探索新型转轮除湿干燥技术在白萝卜片干制领域的应用,通过实验研究了不同温度(35、40、45℃)、不同风速(1、2、3 m/s)和不同切片厚度(3、5、7 mm)下白萝卜片的干燥特性。结果表明,白萝卜片在切片厚度为5 mm和干燥风速为1 m/s的工况下,干燥温度为35℃时其干燥时间为5.5 h,随着干燥温度升高干燥时间显著缩短,45℃对应的干燥时间为4.0 h。另外随着切片厚度的减小干燥时间明显缩短,7、5、3 mm切片厚度下的干燥时间分别为6.5、4.0、2.5 h。同时提高干燥风速也可以提高萝卜片的干燥速率,风速为3 m/s的干燥速率与1 m/s的干燥速率相比可提高14%。热泵-低温再生转轮除湿联合干燥与单热泵干燥相比干燥时间缩短1.0 h,复水能力提高了6%,具有更高的干燥速率及干燥品质。另外该文通过对干燥数学模型分析得出Page模型能较好描述白萝卜片干燥过程中水分变化规律。

To explore the application of new desiccant wheel dehumidification drying technology in the field of white radish slices drying,the drying characteristics of white radish slices under different temperatures(35,40,45℃),different air speeds(1,2,3 m/s)and different slice thicknesses(3,5,7 mm)were experimentally studied.Results showed that the drying time of white radish slices under the conditions of 5 mm slice thickness and 1 m/s drying wind speed was 5.5 h at 35℃,and the drying time decreased significantly with the increase of the drying temperature,and the corresponding drying time at 45℃was 4.0 h.In addition,the drying time decreased significantly with the decrease of the slice thickness,and the drying times under the thicknesses of 7 mm,5 mm,and 3 mm were 6.5 h,4.0 h,and 2.5 h,respectively.Meanwhile,increasing the drying air speed can also improve the drying rate of radish slices,and the drying rate of 3 m/s can be increased by 14%compared with that of 1 m/s.Heat pump-low temperature regeneration desiccant wheel dehumidification combined drying and single heat pump drying compared with the drying time reduced by 1.0 h,rehydration capacity increased by 6%,with higher drying rate and drying quality.In addition,through the analysis of the drying mathematical model Page model,this paper can better describe the water change law in the drying process of white radish slices.