This video shows an ultra-low flow control closed-loop incorporating the Equilibar precision flow control valve with the Bronkhorst mini CORI-FLOW™ series and built-in PID software. The flow rate is adjustable from 0 to 1000 ml/hour, and the system controls flow at a rate of less than one cc per minute.
The mini CORI-FLOW™ sends a 0 to 5 VDC drive signal to an Equilibar QPV electronic pressure regulator, which converts the signal to a pilot pressure for the Equilibar FDO4 valve. The CORI-FLOW monitors the flow rate with its built-in Coriolis flow sensor. The internal PID loop adjusts the signal to the electronic pressure regulator, adjusting the pilot pressure to the FDO4 control valve and changing the flow rate.
The CORI-FLOW™ flowmeter integrates the control software, and a PC or PLC is not required (one shown in the video for demonstration purposes.) The CORI-FLOW™ connects via the Bronkhorst DDE and FlowPlot software (available as a download) to view the live data on the laptop screen. FlowPlot allows the user to adjust the PID control loop and modify various other loop parameters.
This demonstration uses a calibration of 0 to 1 liter per hour full scale. By leveraging the wide turndown ratio of the Equilibar FDO4 sanitary flow control valve, this setup allows for well over 100:1 flow turndown ratio. This control system is excellent for product blending or mixing applications or injection into bioreactors in biopharmaceutical process applications.
For more information about low flow and ultra-low flow control applications, contact Swanson Flo. Call 800-288-7926 or visit https://swansonflo.com.