Adaptive Dryer Automation Program
GRAINTEC’s new ‘Adaptive Dryer Automation Program’ (ADAP) optimizes dryer settings to the most efficient operating point. When the most efficient operating point has been found, ADAP additionally facilitates online dryer control to maintain drying conditions that favor high energy efficiency, high accuracy on product moisture content (available 2018) and even high mechanical durability (available 2019). Hence, multi-objective and model-predictive control of energy, moisture and quality are made possible, as new add-on packages become available.
GRAINTEC is proud to announce that ‘ADAP-energy’ is now available as of January 2017. ADAP-energy will improve energy efficiency of your dryer now. It will also allow for smoother integration and transition to future add-on packages (ADAP-moisture, ADAP-quality), as many of the controls, sensors and actuators are already installed.
Airflow automation using ADAP-energy
ADAP-energy aims to increase the humidity level of the exhaust air out of the dryer, supply cooling and precooling demands as required, while maintaining dryer pressure specifications. The implementation of dryer airflow automation requisite installation of actuators on exhaust dampers, humidity, airflow, pressure and temperature sensors downstream the dryer, as well as a VFD or a control valve on the dryer fan. The implemented control logic is designed to allow actuators on exhaust dampers as well as the VFD/FCV on the dryer fan, to move to the most energy efficient operating point, while minimizing risk for process downtime and maintaining process safety.
ADAP-energy makes use of information retrieved from sensors placed in air ducts, to judiciously adjust air flow control measures (valves, dampers, etc.) to appropriate positions. This allows the dryer to react on relevant processing conditions. Studies have demonstrated that by implementing dryer automation in extruded pet food production, annual gas savings of 3 – 10 % can be realized, depending on processing conditions.
GRAINTEC and academia collaboration
GRAINTEC A/S have since 2012 collaborated with the University of Southern Denmark, Centre for Energy Informatics, on identifying optimal energy utilization in multi-zone hot air dryers, while securing – or even improving – obtained technical product quality. In June 2016 we finalized an Industrial PhD project on this topic; ‘Ensuring Technical Product Quality in the Energy Efficient Hot Air Drying of Extruded Fish Feed’. The project identifies connections between chosen drying parameters and obtained product quality of extruded feed. A dynamic simulation tool was additionally developed to describe the drying of each pellet in a deep bed, over time. This significantly aids the target of maximizing efficient utilization of energy in the drying process, while avoiding product quality deterioration.
The ADAP-moisture add-on package utilizes the afore mentioned dynamic deep-bed drying model to facilitate model-predictive control of product moisture content, together with an online moisture sensor out of the dryer. By using predictions by the dryer model, ADAP-moisture allows the dryer to react to changes in inlet conditions ~immediately, rather than 40+ minutes after the change can be found in the dryer outlet, by a manual sample or an external moisture sensor. The ADAP-quality add-on package will rely on the ‘glass transition temperature control’ methodology, developed through past years of research on mechanical durability and structural mechanics of extruded feed.