塔式鼓泡流化床内的涌渗流动特性

发布时间：2018-04-01 21:22

本文选题：鼓泡流化床　切入点：塔式反应器　出处：《化工学报》2017年11期

【摘要】：为强化气固接触,提出了一种新型塔式鼓泡循环床反应器,采用多个带有风帽的中间分布板、沿床层高度方向将反应器分隔成若干腔室,流化过程中形成一种特殊的涌渗(gushing)现象;依据连续拍照所得图像,基于快速傅里叶变换和小波包变换的方法,对床内压力脉动信号进行分析,研究涌渗产生和消亡条件,频率和能量大小,以期掌握涌渗的形成规律。结果表明,此反应器内流化数为3.47时涌渗产生明显,周期性寿命为1~2 s,频率分布于0.1~0.5 Hz区域;保持流化风速不变,改变反应器结构,加入一层中间分布板构成双腔室、调整下腔室高径比为3:1以及适当增大风帽开孔率时,涌渗主频明显,能量适中,涌渗效果得到优化。因此,塔式鼓泡流化床内的涌渗流动特性取决于流化风速以及塔式鼓泡床的几何结构。
[Abstract]:In order to enhance gas-solid contact, a new type of tower bubbling circulating bed reactor was proposed. The reactor was separated into several chambers along the height of the bed by using a number of intermediate distribution plates with a hood. In the fluidization process, there is a special phenomenon of gushing.According to the images taken continuously and based on the methods of fast Fourier transform and wavelet packet transform, the pressure pulsation signals in bed are analyzed, and the conditions for the formation and extinction of surge and seepage are studied. The results show that the fluidization number in the reactor is 3.47, the periodic life is 1 ~ 2 s, the frequency distribution is in the region of 0.1 ~ 0.5 Hz, and the fluidization velocity is not changed. When the reactor structure is changed, a layer of intermediate distribution plate is added to form a double chamber, the ratio of height to diameter of lower chamber is adjusted to 3:1 and the opening rate of air cap is increased appropriately, the main frequency of surge is obvious, the energy is moderate, and the seepage effect is optimized. The characteristics of surge and seepage flow in a tower bubbling fluidized bed depend on the fluidization velocity and the geometric structure of the tower bubbling bed.
【作者单位】：东南大学能源与环境学院能源热转换及其过程测控教育部重点实验室;
【基金】：国家自然科学基金项目(51561125001)~~
【分类号】：TQ051.13

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