DEM modeling of fine powder convection in a continuous vibrating bed reactor
DEM modeling of fine powder convection in a continuous vibrating bed reactor
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DOI：
10.1016/j.powtec.2021.03.038
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发表时间：
2021-03
影响因子：
5.2
通讯作者：
J. Hartig;Hannah C. Howard;Tanner Stelmach;A. Weimer
中科院分区：
文献类型：
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作者：
J. Hartig;Hannah C. Howard;Tanner Stelmach;A. Weimer
开发了连续振动空间颗粒ALD反应器，以实现高粉末吞吐量，同时最小化反应器占地面积。与流化床反应器不同，连续振动空间颗粒ALD反应器在流态化以下运行，利用线性振动通过前驱体气体的交替区域传递颗粒。细粉在这些振动床反应器中的对流仍然不是很清楚，因此采用内聚离散元法（DEM）模拟来研究固体的流动行为。利用快速傅里叶变换（FFT）算法，建立了基于加速度计数据的反应堆运动学正弦和模型。加速度计的结果和DEM模拟揭示了高频激励的作用，以及在低加速度下水平输送机的反滑和粘滞避免的必要性。根据这些观察，我们提出了一种新的锯齿形激励，以实现低流速下粘性细粉末的对流。将模型结果与室内连续振动空间粒子ALD反应器的数据进行了比较。
Continuous vibrating spatial particle ALD reactors were developed to achieve high powder throughput while minimizing reactor footprint. Unlike fluidized bed reactors, continuous vibrating spatial particle ALD reactors operate below fluidization, using linear vibration to convey particles through alternating regions of precursor gas. Fine powder convection in these vibrating bed reactors is still not well understood, so cohesive discrete-element-method (DEM) simulations were performed to investigate the solids flow behavior. Using a Fast Fourier Transform (FFT) algorithm, we constructed a sum-of-sines model for the reactor kinematics based on accelerometer data. Accelerometer results and DEM simulations revealed the role of high-frequency excitations and need for backsliding and sticking avoidance in horizontal conveyors at low-g accelerations. From these observations, we propose a novel sawtooth excitation to enable convection of cohesive fine powders at low flow velocities. The model results were compared to data from an in-house continuous vibrating spatial particle ALD reactor.