ABSTRACT

Roller screen is a key device in pelletizing plants employed to size classification of green pellets. Realistic observations showed that some pellets with size slightly larger than the gap were trapped between the rollers and caused blockage and decreasing the device efficiency consequently. Here, a speed regime for the rollers is proposed and its effects on the device efficiency were studied numerically. To perform the simulations, discrete element method was used and to ensure the results accuracy, surface meshing and the time step sensitivity analysis were performed. Using the numerical results, impact of each of the variables independently and also their cross effects were studied and discussed. The results proved that the proposed gradient speed regime improves the efficiency considerably. However, both the speed regime and the deck angle should be adjusted in optimum values to achieve maximum efficiency.

摘要

辊筛是造粒厂中用于生粒料粒度分级的关键设备。实际观察表明，一些尺寸略大于间隙的颗粒被困在辊子之间，导致堵塞，从而降低设备效率。在这里，提出了滚子的速度方案，并对其对设备效率的影响进行了数值研究。为了进行模拟，使用离散元方法并确保结果的准确性，进行了表面网格划分和时间步长灵敏度分析。使用数值结果，研究和讨论了每个变量独立的影响以及它们的交叉影响。结果证明，所提出的梯度速度方案大大提高了效率。然而，