Geldart B类颗粒气固流化床内的压力波动特性(英文)

Pressure fluctuation in a gas-solid fluidized bed of Geldart B classification particle

采用多通道压力采集系统测量了GeldartB类颗粒(树脂)矩形流化床(2.000m×0.300m×0.025m)内的压力波动,探索了流化床内的压力波动特征;同时采用标准方差、自相关和互相关函数分析了表观气速和静床高度对压力波动、压力波速度和压力波主频的影响。结果表明,气泡行为(如:气泡的形成、发展、聚并和破碎)是影响流化床内压力波动的主要因素;密相和稀相界面处的压力波动幅值主要由气泡崩塌决定;压力波在流化床内进行传播,并且具有明显的周期性特征;此外,压力波动、压力波速度和压力波主频均与表观气速和静床高度密切相关。

A better insight into pressure signals could be helpful for the understanding of bubble behaviour as well as for the designing and manipulating of the gas-solid fluidized beds.Pressure fluctuations were measured in a rectangular fluidized bed with a height of 2.0m and a width of 0.3m by using a multi-channel pressure data acquisition system.Resin,belonging to Geldart B Group,was selected as experimental solid material.The characteristics of the pressure fluctuation were explored,and influences of superficial gas velocity and static bed height on the pressure fluctuation,pressure wave velocity and pressure fluctuation major frequency were investigated by using the standard deviation and the auto-and cross-correlation functions.The results show that the bubble behaviours such as formation,development,coalescence and break-up are major influence factors for the pressure fluctuation in the fluidized bed.The amplitude of pressure fluctuation near the interface between the dense phase and freeboard is governed by the bubble eruption.Pressure wave propagates within the bed and the pressure fluctuation signals along the bed height have obvious periodic characteristics in nature.Moreover,the pressure fluctuation,pressure wave velocity and main frequency are greatly dependent on the superficial gas velocity and the static bed height.