Figure 2 - uploaded by Francis Gagnon
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Piping and instrumentation diagram of the prototype. First instrument letters denote : flow (F), moisture content (M), temperature (T), rotational speed (S), and relative humidity analysis (A). Second ones stand for : controller (C), online sensor transmitter (T), and atline sensor element (E).
Source publication
Fully continuous drying can improve the production flexibility and throughput of tablets manufactured by wet granulation lines. A recently developed prototype incorporates a screw conveyor to a horizontal fluidized bed dryer for pharmaceutical particles. Research on advanced process control strategies led to the publication of a two-phase tanks-in-...
Contexts in source publication
Context 1
... process inputs are in gray, and outputs, in green (adapted from Zhang et al., 2021). Figure 2 presents the piping and instrumentation diagram (P&ID) of the prototype. The online sensors include a transmitter (second letter T in Figure 2). ...
Context 2
... 2 presents the piping and instrumentation diagram (P&ID) of the prototype. The online sensors include a transmitter (second letter T in Figure 2). Atline elements (second letter E in Figure 2) require manipulations and separate analysis to estimate the value. ...
Context 3
... online sensors include a transmitter (second letter T in Figure 2). Atline elements (second letter E in Figure 2) require manipulations and separate analysis to estimate the value. Two mass flow controllers modulate the air feed rate, and solid-state relays periodically switch two independent electrical heaters to reach temperatures at setpoint. ...
Citations
... Near Infrared (NIR) and Raman Spectroscopy, combined with chemometric analysis, have been used for monitoring the drying of pharmaceuticals (Nieuwmeyer et al., 2007;Kogermann et al., 2008;Märk et al., 2010;Peinado et al., 2011;Tewari et al., 2010;Hamilton et al., 2011;Maltesen et al., 2012;Kona et al., 2013;Fonteyne et al., 2014;Reddy et al., 2018;Peters et al., 2018;Gagnon et al., 2021). However, those studies use commercial probes that do not account for the nonuniformity of the monitored system in their signal collection geometry and signal extraction. ...
... Specifically in drying, beyond our recent publication presenting a simple model for a continuous dryer [23] , several other studies were published. These include detailed models of fluidized bed dryers [24,25] as well as a drying model being a part of a plant-wide model of an integrated manufacturing process. [26] Once a process model is validated (i.e., it can reproduce the experimental data with a quantified uncertainty within a validity region), it can be used for various purposes, from process analysis and design to control and optimization. ...
Drying is broadly used to enhance the stability of thermosensitive biologics (for example proteins, probiotics) despite the risk of inadequate product quality after the drying process. Continuous fluidized bed drying is an attractive technology for these active pharmaceutical ingredients owing to the short mean residence time at elevated temperatures, compared to batch-type drying technologies and the possibility to closely monitor and precisely control the process. In this work, an integrated continuous granulation – drying – milling line was used to manufacture granules ready for tableting from a suspension of probiotic bacteria. A mechanistic drying model suitable to predict the product temperature in the dryer and the moisture content of the granules was built. This allowed finding the optimal operating conditions for maximal bacteria load and low residual moisture content in the product, which has the potential to enable direct integration with the tableting unit. A continuous experiment was carried out with the in silico - optimized process parameters. The produced granules had high probiotic content and were suitable for tableting, which demonstrates the usefulness of the model-based process optimization in complex integrated pharmaceutical manufacturing processes.
... On this subject, Zhang et al. [2] designed a continuous horizontal fluidized bed dryer (CFBD) prototype to improve the production throughput and flexibility. Gagnon et al. developed [3] and validated [4] a phenomenological tanks-in-series (TIS) model to support the control system design and the instrumentation choice. The prototype simulator is able to systematically evaluate the potential gains of a more advanced control strategy. ...
... The manipulated variables are in red, measured outputs in green, measured disturbances in blue, and other variables in grey. Adapted from Gagnon et al. [4]. ...
... FF compensation for them would presumably not improve the closed-loop performances as the impact of T di on the drying is low, T a is approximately constant, and Φ a fluctuations are slow compared to the process dynamics [3]. This work keeps their value constant at Φ a = 10 %, T a = 25 • C and T di = 20 • C [4]. ...
Advanced process control can benefit to the operation efficiency and quality of tablets produced by wet granulation lines. Following the development of a new fully continuous fluidized bed reactor as a potential substitute for the current batch dryer design, this paper examines the energy and product quality performances of two predictive control strategies using an experimentally validated simulator. The first one proposes an economic model predictive controller explicitly minimizing the dryer energy consumption. The second one follows the same objective, but uses a simpler classical predictive control framework implementing targets on manipulated variables to drive them toward low energy consumption operating points. Both controllers lead to similar performances, and consume about 20 % less energy than a reference feedback scheme without manipulated variable setpoints. Results also show that tracking the product quality attribute significantly benefits from a feedforward action because of the long residence time. This article addresses a subject little explored by the literature, the control of continuous fluidized bed dryers, and clearly demonstrates that a standard linear strategy can reduce the operating costs with an appropriate design.
