Abstract

In the current global endeavor of energy conservation, waste heat recovery is a key contributor and deserves more focused attention. Process industries demand high energy inputs and often generate high-temperature exit gases, which can potentially be considered as secondary energy sources. If such waste heat is recovered, considerable savings in the net energy demand is possible. This report, based on this objective, details the outcome of an experimental study conducted in a vertical riser where solid particles, through a co-current contact with hot air, recover the energy content of the gas. Fabricated experimental setup is a prototype of suspension preheater (riser–cyclone combination) used in a modern-day cement industry. Data relevant to hydrodynamic and heat transfer patterns are collected as not much information is available in the literature on these aspects. Empirical correlations for acceleration length and heat transfer coefficient in dimensionless form, are reported and are recommended for not only cement but for diverse other industries, where waste heat recovery is possible.

摘要

在当前的全球节能行动中，余热回收是一个关键的贡献者，值得更多的关注。过程工业需要高能量输入，并经常产生高温出口气体，这可能被视为二次能源。如果回收这些废热，则可以显着节省净能源需求。本报告基于这一目标，详细介绍了在垂直立管中进行的一项实验研究的结果，其中固体颗粒通过与热空气的并流接触来恢复气体的能量含量。制造的实验装置是现代水泥工业中使用的悬浮预热器（立管-旋风组合）的原型。由于文献中关于这些方面的信息不多，因此收集了与流体动力学和传热模式相关的数据。报告了无量纲形式的加速长度和传热系数的经验相关性，并建议不仅用于水泥，而且推荐用于可以回收废热的其他各种行业。