Precise control and documentation for validatable filtration processes in the cleanroom
Stable and safe process control under GMP conditions
As soon as processes have to run under defined conditions, reliable control technology is essential. Particularly in safety-critical or GMP-relevant applications, no exceeding of limit values can be left to chance. Thanks to the intelligent combination of sensors, actuators and automated control software, processes can not only be controlled in a stable manner, but also documented in a fully traceable manner. This creates the basis for validatable processes - regardless of operator influence or external interference.
A realized project in a cleanroom environment demonstrates how these requirements can be optimally implemented in practice.
Manual monitoring with limited traceability
In a qualified filtration process within a clean room, our customer was faced with the challenge of reliably monitoring the differential pressure across two filters connected in series and simultaneously controlling the flow rate of the process pump so that defined pressure limits were never exceeded. Although previous laboratory setups allowed manual monitoring of the pressure curve, they did not offer automatic control or seamless recording - an exclusion criterion for later use in a GMP environment.
Automated control concept with integrated sensors and control system
Delphin was responsible for the complete implementation of the control and measurement technology. The liquid is conveyed from tank A to tank B via two filter stages. The pressure upstream of the first filter is particularly critical here, as exceeding it would lead to damage or unacceptable stress on the filter material. To ensure that this limit value is reliably maintained, we implemented an automated control concept in which the PendoTECH pressure sensor upstream of filter 1 serves as a reference variable for the pump control.
Technical implementation in Reinraumdesign
Delphin integrated both the sensors and the power control of the pump into a standardized system. The constant voltage source (10 V) required for the pressure sensors was installed in the control cabinet, both pressure signals are permanently recorded, synchronously recorded and visualized in the software. The pump is controlled either via a 0-10 V or 0-20 mA signal and guided by a PID control algorithm so that the permissible pressure range is maintained at all times - regardless of filter loading or fluctuations in the viscosity of the liquid.
As the entire solution is operated in a clean room, Delphin designed the control cabinet in stainless steel with smooth, cleanable surfaces. The software also comes entirely from our company: it handles both the control and the process recording and provides the user with an intuitive user interface for starting, stopping and documentation.
The result: Validatable and reproducible filtration process
For the customer, this not only resulted in a safe and validatable filtration process, but also the ability to carry out automated and reproducible filtration tests - without manual intervention and with complete traceability of all critical process parameters.