Numerical investigations of a pseudo-2D spout fluidized bed with draft plates using a scaled discrete particle model
Numerical investigations of a pseudo-2D spout fluidized bed with draft plates using a scaled discrete particle model
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DOI：
10.1016/j.ces.2013.10.005
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发表时间：
2013-12
影响因子：
4.7
通讯作者：
Vinayak S. Sutkar;Ng Niels Deen;Bhageshvar Mohan;V. Salikov;S. Antonyuk;S. Heinrich;J. Kuipers
中科院分区：
文献类型：
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作者：
Vinayak S. Sutkar;Ng Niels Deen;Bhageshvar Mohan;V. Salikov;S. Antonyuk;S. Heinrich;J. Kuipers
喷口流化床通常用于涉及物理和/或化学转化的气固操作，如干燥、涂覆、造粒、燃烧、气化等。这是因为这些床结合了喷淋床和流化床的优点。随着喷淋流化床的发展，提出了几种几何形状的改进以优化床层的性能。其中一项改进包括在床层内插入导流管，通过限制颗粒交叉流动来提高性能。此外，由于减少了进口气体旁路（从喷口到环空），插入尾水管可以在较低流速下实现稳定的喷口。在这项工作中，采用离散颗粒模型（DPM）和亚网格尺度（SGS）湍流模型来模拟床层动力学，并考虑两种机制，即曝气喷淋和流化床喷淋（分散喷淋），从工业的角度来看，这是很有意义的。将得到的结果与我们的实验数据（Sutkar et al., 2013）进行比较，实验数据来自粒子图像测速（PIV）和数字图像分析（DIA）。此外，还采用了另一种模拟方法来模拟工业规模气固接触器的动力学，通过改变颗粒的物理性质来保持恒定的阿基米德数和雷诺数，从而减少了总计算时间。将所得结果与实验数据进行了比较，并与具有原始物理性质的模拟数据进行了比较。
Spout fluidized beds are often utilized for the gas–solid operations involving physical and/or chemical transformations such as drying, coating, granulation, combustion, gasification, etc. This is because these beds combine advantages of both spouted and fluidized beds. Following the spout fluidized bed development, several geometrical modifications have been proposed to optimize the bed performance. One of the modifications includes a draft tube insertion inside the bed, which results in improved performance by providing a restriction on particle cross flow. Moreover, the draft tube insertion leads to a stable spouting at lower flow rates, due to the reduced inlet gas bypassing (from spout to the annulus).In this work, a discrete particle model (DPM) with a sub-grid scale (SGS) turbulence model was used to simulate the bed dynamics and analyze the effects of the draft plates and particles physical properties by considering two regimes namely, the spouting-with-aeration and fluidized bed-spouting-with-aeration (dispersed spout), which are of interest from an industrial point of view. The obtained results were compared with our experimental data (Sutkar et al., 2013b) from particle image velocimetry (PIV) and digital image analysis (DIA). Furthermore, an alternative simulation approach has been used to simulate dynamics of the industrial scale gas–solid contactors consisting very large particles with reduced total computational time by changing the physical properties of the particles to maintain constant Archimedes and Reynolds numbers. The obtained results were compared with the experimental data, as well as with simulation data obtained with the original physical properties.