Traditional "state-of-the-art" process modeling tools require steady-state operation before conducting process diagnostic and optimization tests. Process tests expose the cause-and-effect relationship between control infrastructure and a process' inherent characteristics. Failure to achieve or maintain steady-state operation during these tests impairs the efficacy of the model parameters produced by such tools. With LOOP-PRO's patent-pending technology, the requirement for steady state operation has been all but eliminated.
In the production of aluminum, maintaining effective control of the Calciner directly impacts product quality and a plant's overall profitability. An oscillating process wastes energy as the temperature heats up unnecessarily. If oscillation causes the process to cool too much, costly refractory material must be replaced. By correcting for variance within the process, improved temperature stability is achieved and energy consumption contained. Similarly, better distribution of particle size results and a higher quality product is ultimately produced.
Due to the complexity of a Calciner's process dynamics, maintaining steady-state operation is economically impractical. Below is a comparison of the modeling capability of traditional state-of-the-art tools and Control Station's LOOP-PRO NSS Modeling Technology.
State-of-the-Art Modeling Tools
In the absence of steady-state operation, traditional tuning tools are unable to accurately model process dynamics and to improve control. The slow responding characteristics of a Calciner along with frequent load upsets make it impractical to achieve and maintain steady-state within the process. Figure 1 shows a typical model fit produced by time-based tuning tools. Clearly the model fails to describe the Calciner's dynamics, resulting in unusable model and tuning parameters.
LOOP-PRO with NSS Modeling Technology
Control Station's revolutionary NSS Modeling Technology does not require steady-state operation in order to accurately model dynamic process data. Using the same Calciner data, LOOP-PRO produces a model that effectively describes critical dynamics within the process as shown in Figure 2. With a good model fit, LOOP-PRO produces tuning parameters that permit effective control over this vital production process. Excessive energy consumption and wasted production inputs are eliminated, enabling profitable operation of the process.
A typical production environment is inherently dynamic due to 100s or even 1,000s of interconnected and moving process variables. Assuring that all elements of a production process are "quiet" and stable prior to and during testing is often neither feasible nor possible. Coupled with other product enhancements, LOOP-PRO v5 has proven its worth to existing Control Station customers including those in the Metals, Oil & Gas, Pharmaceutical and Specialty Chemical industries.