Authors

Abstract

In this study, a non-invasive experimental method based on the shell temperature field to invert the internal steam pressure is proposed for the distribution characteristics of saturated steam pressure in the mill chamber of the heat mill and its dynamic influence on the feed of fiber materials. The surface temperature field of the grinding chamber shell was measured by a high-precision infrared thermometer. Combined with the inverse heat conduction problem model and SteamTab software conversion, the cross-scale mapping relationship of ' shell temperature-internal pressure ' was constructed, and the pressure distribution cloud map was generated. The experimental materials were mixed wood chips with a moisture content of 45 ± 2 %. After preheating and cooking ( 160 ° C, 3 min ), they were put into the grinding chamber to analyze the coupling effect of the pressure field and the tooth shape parameters of the grinding disc. The results show that the saturated steam pressure in the grinding chamber is significantly non-uniformly distributed along the radial direction, and the pressure gradient is mainly driven by the gradient change of the tooth shape parameters of the grinding disc. A solution to the problem of blocking backflow and excessive feed caused by non-uniform distribution of steam pressure is proposed in combination with the tooth profile parameters of the grinding plate.

Abstract in Chinese

本研究针对热磨机磨室内饱和蒸汽压力分布特征及其对纤维物料进给的动态影响，提出一种基于外壳温度场反演内部蒸汽压力的非侵入式实验方法。通过高精度红外测温仪测量磨室外壳表面温度场，结合热传导反问题模型与SteamTab软件换算，构建了“外壳温度-内部压力”跨尺度映射关系，并生成压力分布云图。实验材料采用含水率45±2%的混合木片，经预热蒸煮（160℃, 3 min）后投入磨室，分析压力场与磨片齿形参数的耦合作用。结果表明：磨室内饱和蒸汽压力沿径向呈显著非均匀分布，压力梯度主要由磨片齿形参数梯度变化驱动；对蒸汽压力非均匀分布所导致的阻塞回流及进给过快问题结合磨片齿形参数提出了解决方案。