Abstract: The flow pattern in the equipment can be the main performance index for its internal structure. Innovation of process equipment is to optimize its internal structure for desired flow pattern. Numerical simulation, as a primary research approach of fluid flow pattern, is not easy and economical to perform in large-scale or complex equipment, but the residence time distribution (RTD) experiment has the advantages of simplicity and convenience. In order to estimate the flow pattern with RTD experiments, taking the typical baffle structure as an example, several groups of structures were designed to compare and analyze the residence time distribution and the flow patterns corresponding to the structures, which can provide clues for short circuits judgement and determination of reasonable structures. The results showed that the short circuit and dead zone in the equipment were relativistic. The peak time and tailing of the RTD density function curve can be used to judge the short circuit and dead zone in the equipment. This conclusion can provide a theoretical basis for equipment design. The number of tanks in the multi-tank series model and the peak time and variance of the RTD curve were used to analyze the influence of flow rate, baffle gap area and plate spacing on the fluid flow pattern in the equipment. With the study of the pressure drop and the comprehensive consideration of the energy consumption and performance of the equipment, the most suitable tanks number, peak time and variance were put forward based on RTD experiments to determine the reasonable structure of the equipment, which provided a reference for the structural design of industrial baffle equipment.

Key words: residence time distribution, flow pattern, short circuit and dead zone, pressure drop, structural design

摘要： 折流板结构在大空间设备中形成折流通道，以防止短路，从而使流体与换热管和颗粒床等内构件充分接触。停留时间分布(RTD)实验具有简单便捷的优势，针对设备中的短路与如何确定设备合理结构的问题分别设计了几组结构来进行RTD实验与流场数值模拟研究。对比分析结果表明，设备中的短路和死区是相对存在的，通过RTD密度函数曲线的出峰时间及拖尾情况能判断设备中短路与死区的情况，该结论可以为设备设计提供理论依据。利用多釜串联模型的釜数及RTD曲线的出峰时间和方差分析了流量、折流板缺口面积及板距对设备中流体流动形态的影响；研究了设备中的压降，综合考虑设备的能耗和性能，提出了以RTD实验来确定折流板设备合理结构时最合适的釜数、出峰时间及方差。

关键词: 停留时间分布, 流动形态, 短路与死区, 压降, 结构设计