Many BioPharma processes require precise dosing and blending of Water-For-Injection (WFI), nutrients, and other buffer solutions as input to a reactor, fermenter, or chromatography column. These dosing or blending systems must often be able to control over a wide range of flow rate to hold the desired conditions in the downstream process.
Traditional dosing systems in BioPharma utilize flow control valves such as a diaphragm weir style or a globe or needle style body with sanitary fittings. These valves typically provide stable control through only a 15:1 flow rate range, and process engineers must often install multiple flow control valves in parallel to achieve the needed wide dosing range.
The Equilibar® Sanitary Back Pressure Regulator works across a very wide range of flow rate, and can be used to enhance dosing flow rate control in BioPharam processes in several ways:
Stabilize Downstream Pressure of Dosing Valve
Dosing valves often suffer from unexpected pressure changes downstream, which take time for the PID controller to adjust to. In other situations, dosing control valves are not able to function through the required flow rate range because of undesired pressure changes downstream. This application page explains how the Equilibar back pressure regulator has been used to address these problems to allow the flow metering valve to perform as required.
Function as 100:1 Flow Metering Valve
The Equilibar back pressure regulator can often function in place of a traditional flow control valve, and in many applications control flow rate through a 100:1 turndown range. While pressure changes downstream of the BPR are generally isolated and have no impact, it should be noted that this approach does require a stable upstream fluid pressure source. See video and application notes.
Precisely Control Pump Discharge Pressure
Regardless of the type of pump used, a precision back pressure regulator can be used to control its discharge pressure when a circulating loop in installed. A manually controlled back pressure regulator could be used to maintain the desired stable pressure to enhance the control valve performance. In addition, an electronic back pressure regulator can be used to actually control the flow rate of the dosing process (for example, across a fixed orifice or a spray nozzle). See application notes.
When a process calls for a WFI dose to rise the bioreactor out, the pharmaceutical engineer will set up the dosing system for that particular flow rate. When complete, the engineer will switch back over to a different setup to return to dosing low flow bioreactor components for production. Using the Equilibar in this setup will allow for dosing of a wide flow range (in the 1000:1 range for some applications), and thus prevent the unnecessary switching of equipment. Furthermore, this can be applied to other systems, such as upstream / downstream filtration, chromatography columns, and much more. The sanitary design of the Equilibar and high Cv window allow for the BPR to flow freely during CIP/SIP, preventing undesired restriction during these cleaning processes. Finally, the simple, elegant design provides chemical inertness, so this product can work for any phase of any process fluid.
Contact one of our Applications Engineers to help select the perfect back pressure regulator for your filtration application.