QB2 Air Volume Booster

Problem #1: Mark needs to pressurize this volume to 90 PSI in under 2 seconds!

This is where we implement a Proportion-Air air volume booster to increase the amount of flow into the process. By using our QBX to control the pressure on the dome side of the diaphragm in an air volume booster, we are able to control the process pressure through the volume booster as the forces on either side of the diaphragm naturally equal out. In other words, 90 psi on top of the diaphragm will naturally provide approximately 90 PSI on the bottom of the diaphragm, providing pressure control with higher flow.

Problem #2: Mark needs pressure accuracy of ±0.5% (in this case: ±0.45 PSI)An air volume booster is a mechanical pressure regulator that we control electronically. But if we are controlling pressure on the dome, we cannot measure the pressure in the process. This means the pressure accuracy in the process is affected by the mechanical hysteresis and inaccuracies of our volume booster. We call this single-loop control and (depending on the air volume booster) accuracy can range from 1% to >5%. Sometimes this accuracy is okay and can even be preferred in some applications. But for Mark, this is a problem.

The Solution: Proportion-Air Dual-Loop Pressure ControlAfter we size and select the optimal air volume booster for Mark’s application, we add a 2nd loop so we can achieve the accuracy that Mark needs. In this case, our 2nd loop is a Proportion-Air DSB pressure transducer that we install on the output of the air volume booster. This transducer measures process pressure and constantly provides direct feedback to the QBX (now a QB2X). Our electronic controller now puts whatever pressure is required on the dome of the air volume booster to achieve the commanded pressure in the process. The accuracy (±0.5%) of the DSB transducer now drives the accuracy of the dual-loop volume air booster assembly.