远红外茶叶提香机设计与试验

Design and Test of Far-Infrared Tea Aroma Enhancement Machine

摘要:

针对传统热风式茶叶提香机控温精度低、茶叶受热不均、含水率偏高及香气品质不稳定等问题，本文设计了一种远红外茶叶提香机。阐述了远红外茶叶提香机整体结构和工作原理，进行了关键部件设计与试验;基于西门子S7-200 SMART PLC与昆仑通态触摸屏构建了PID闭环控制系统，实现温度精准调控与多段式提香工艺程序化运行。以黄山毛峰茶为原料，采用三因素三水平正交试验对增香阶段工艺参数进行优化，建立了含水率与碎茶率回归模型。结果表明，增香阶段最优参数组合为提香温度110℃、提香时间20 min、滚筒转速18 r/min。在此优化条件下结合预热与稳香阶段进行三段式工艺验证试验。试验结果表明，成品茶含水率为5.48%、碎茶率为1.81%、感官评审平均得分为95.12。整机生产率为50 kg/h，电耗率为0.68 kW·h/kg，较传统热风式滚筒提香机节能24.4%。该设备运行稳定可靠，提香品质均匀一致。研究结果可为茶叶提香装备技术升级提供参考。

Abstract:

Focusing on addressing the problems of low temperature control accuracy, uneven heating, high moisture content and unstable aroma quality commonly found in traditional hot-air tea aroma-enhancing equipment, a far-infrared tea aroma-enhancing machine was designed. The overall structure and working principle of the machine were elaborated, and its key components were designed and tested. A PID closed-loop control system was constructed based on a Siemens S7-200 SMART PLC and a Kunlun Tongtai touch screen, through which precise temperature regulation and programmed operation of a multi-stage aroma-enhancing process were achieved. With Huangshan Maofeng tea as the raw material, a three-factor and three-level orthogonal experiment was conducted to optimize the process parameters of the aroma-enhancing stage, and regression models for moisture content and broken tea rate were established. The results showed that the optimal parameter combination for the aroma-enhancing stage was a temperature of 110℃, a duration of 20 min and a drum rotation speed of 18 r/min. Under these optimized conditions, a three-stage process verification test combining the preheating and aroma-stabilizing stages was carried out. The experimental results indicated that the moisture content of the finished tea was 5.48%, the broken tea rate was 1.81%, and the average sensory evaluation score was 95.12. The machine productivity was 50 kg/h and the specific power consumption was 0.68 kW·h/kg, representing an energy saving of 24.4% compared with conventional hot-air drum aroma-enhancing machines. The equipment was proved to be stable and reliable in operation, with uniform aroma quality. The findings can provide a reference for the technological upgrading of tea aroma-enhancing equipment.