Reyer Sebastian, Awiszus Sebastian, Meissner Klaus, Müller Joachim
Institute of Agricultural Engineering, Tropics and Subtropics Group, University of Hohenheim, Garbenstraße 9, 70599 Stuttgart, Germany.
HardwareX. 2020 Aug 18;8:e00133. doi: 10.1016/j.ohx.2020.e00133. eCollection 2020 Oct.
Convective hot air drying is one of the most common post-harvest processes within the agricultural sector and a standard process in the food industry. The technique is used on fruits and vegetables in order to increase their added value or to extend their shelf life. Drying is highly dependent on the condition of the drying air in terms of temperature, relative humidity and velocity and on the thickness of the product layer. The influence of these drying parameters on the drying behavior and quality is product-specific and has to be investigated in laboratory experiments due to the high costs for full-scale evaluation. For this purpose, a high precision laboratory dryer was developed in order to achieve controlled and stable climate conditions during the drying of light bulk material. To avoid temperature drift of the load cell during drying, a temperature-controlled sensor housing was applied. To further stabilize the signal, it was corrected with the instantaneous temperature. The high precision laboratory dryer HPD TF1 could be potentially useful to establish drying curves for defined temperature, relative humidity and velocity of the drying air. Further potential applications are the establishment of sorption isotherms or the determination of diffusion coefficients of various materials.
对流热风干燥是农业部门最常见的收获后处理工艺之一，也是食品工业中的标准工艺。该技术用于水果和蔬菜，以增加其附加值或延长其保质期。干燥高度依赖于干燥空气的温度、相对湿度和速度条件以及产品层的厚度。这些干燥参数对干燥行为和质量的影响因产品而异，由于全面评估成本高昂，必须在实验室实验中进行研究。为此，开发了一种高精度实验室干燥机，以便在轻质散装物料干燥过程中实现可控且稳定的气候条件。为避免干燥过程中称重传感器的温度漂移，采用了温度控制的传感器外壳。为进一步稳定信号，用瞬时温度进行了校正。高精度实验室干燥机HPD TF1可能有助于建立特定温度、相对湿度和干燥空气速度下的干燥曲线。进一步的潜在应用包括建立吸附等温线或测定各种材料的扩散系数。
