Optimizing Control of Pump-Related Biopharma-Production Processes

In biopharma production, pumps are used in a variety of critical processing steps, most notably for liquid transfer that requires the creation and adherence to a required flow rate and pressure level. While this can be done manually through the reading of a pressure gauge and adjusting the motor speed if the pressure should venture outside of the acceptable range, this way is time-consuming and lacks the precision that an automated system can provide.

Automated pumps became viable after they were able to be outfitted with a programmable logic controller (PLC). In semi- or fully automated manufacturing processes, the PLC is connected to sensors to read process parameters like the pump’s flow rate and pressure levels during operation and then automatically adjusts those parameters through increases or decreases in the pump’s motor speed if they move out of the required range. However, adding a PLC increases the complexity and cost of the pump’s operation since it requires knowledge of software programming and setup, additional wiring and configuration expenses, and a human-machine interface (HMI).

The algorithm that processes the sensor readings and controls the output signal (e.g., for pump motor speeds) is the PID controller, where PID stands for a proportional-integral-derivative. The PID tracks, for instance, the pressure setpoint that is defined by the operator and as soon as the controller starts, the speed is adjusted until the target pressure is reached. Whenever process conditions change, the pump speed is automatically adjusted and monitored by the PID until the required pressure setpoint is reached again.

During operation, a pump outfitted with a PID controller continuously calculates a predetermined error value, which is the difference between the required operational setpoint and a process variable. If the error value is exceeded, the PID controller corrects it based on the pump’s proper operational proportional, integral, and derivative setpoints, which gives the controller its “PID” moniker. An everyday example of a PID controller is a motor vehicle’s cruise-control function. With cruise control in operation, as the vehicle ascends or descends a hill, the PID controller quickly adjusts the engine’s power output so that the vehicle can maintain the pre-set speed despite the change in driving angle.

The benefits that PID controllers can offer are widely used, with the developers of the pumps used in those applications addressing a new challenge – create a pump that can incorporate and take advantage of the ways that PID controllers can improve production systems.

This white paper will illustrate how a new technology – the integrated pump controller – can be used to optimize pump performance in biopharma production by giving the operator the ability to automatically control flow or pressure. This control will make it easier to run simple process steps in biopharma applications more effectively, resulting in better consistency and adherence to process conditions, which is imperative when manufacturing products that must adhere to strict process conditions to create a safe, useable end-product.

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