Otto H. York Department of Chemical and Materials Engineering, New Jersey Institute of Technology, Newark, NJ 07102, USA.
Material & Analytical Sciences, Boehringer Ingelheim Pharmaceuticals Inc., Ridgefield, CT 06810, USA.
Eur J Pharm Biopharm. 2020 Jun;151:137-152. doi: 10.1016/j.ejpb.2020.03.014. Epub 2020 Apr 15.
Moisture plays a major role in determining the attributes of granules prepared by fluidized bed granulation (FBG). Here, a semi-theoretical droplet-based evaporation rate model was developed and incorporated into moisture mass-enthalpy balances to simulate the temporal evolution of bed moisture-temperature. Experimental data from a GPCG30 unit were used to fit the model parameters. With only two fitting parameters, the model demonstrated excellent capability to describe the moisture-temperature evolution for a wide range of operating conditions. Then, in a global process model (GPM) approach, the evaporation parameters were fitted to multi-linear functions of inlet air temperature, binder concentration, and spray rate. The GPM was validated successfully by simulating a different data set which was not used in its calibration. As the GPM demonstrated a good predictive capability, it was further used to investigate the impacts of process parameters. Numerical simulations suggest that the proposed GPM predicts the experimentally well-established trends of moisture-temperature profiles in previously published data, proving the applicability of the GPM approach. This study has demonstrated the capabilities of simple process models as a practical approach to predict time-wise evolution of bed moisture-temperature profiles in industrial FBG modeling, while also pointing out their limitations.
水分在决定流化床造粒（FBG）制备颗粒的性质方面起着重要作用。在这里，开发了一种半理论的基于液滴的蒸发速率模型，并将其纳入水分焓平衡中，以模拟床层水分-温度的时间演变。使用 GPCG30 单元的实验数据来拟合模型参数。该模型仅使用两个拟合参数，就能够出色地描述各种操作条件下的水分-温度演变。然后，在全局过程模型（GPM）方法中，将蒸发参数拟合为入口空气温度、粘结剂浓度和喷雾速率的多线性函数。该 GPM 通过模拟未用于其校准的不同数据集得到了成功验证。由于 GPM 具有良好的预测能力，因此进一步用于研究工艺参数的影响。数值模拟表明，所提出的 GPM 预测了先前发表的数据中水分-温度分布的实验确定趋势，证明了 GPM 方法的适用性。本研究展示了简单过程模型作为预测工业 FBG 建模中床层水分-温度分布随时间演变的实用方法的能力，同时也指出了它们的局限性。
