Non-Clogging Supercritical Fluid Back Pressure Regulators
Equilibar is pleased to introduce the blockage resistant BR Series back pressure regulators. This series is ideal for specialty applications, particularly supercritical CO2 (SCO2) extraction applications, but is also useful for any process in which clogging, blocking, or freezing could be an issue.
This series integrates proprietary design features to help customers achieve precision control by reducing the Joule-Thomson effect of supercritical process fluids passing through the unit. A primary design feature in this regulator series is a downstream expansion cavity that provides a continuously increasing cross-sectional area to eliminate convergence points for ice buildup. Additionally, this large thermal mass provides increased heat transfer area to heat the outlet fluid through several different means. Lastly, this series has specially designed O-ring grooves to reduce stress during rapid decompression, increasing O-ring lifetimes. This series has several custom fitting options, including an outlet flange, tube stub, or NPT fittings.
Watch the BR regulate to a precise pressure while ice and oil flow through
Built to withstand the supercritical extraction environment
The BR Series is designed specifically to address the demands encountered when rapid cooling occurs as a supercritical gas expands during decompression.
- The shape of the internal passages prevents the accumulation of ice or viscous oils so the BR is free to regulate at the target setpoint.
- The body is CNC machined from premium stainless steel 316/316L dual cert alloy bar stock.
- The diaphragm material options include polyimide, PTFE, and PEEK depending on the co-solvents used and the maximum temperatures reached.
- O-ring cavities are designed to limit the explosive decompression that occurs when the SCO2 permeates the O-ring material.
- O-ring material options include Buna-N, Viton, PTFE, and DuPont Kalrez depending on the application.
Using supercritical fluid as a pilot fluid
Equilibar back pressure regulators are designed to be controlled by a pilot fluid adjusted to setpoint using a pilot pressure regulator. When using an Equilibar BR Series regulator to control SCO2 process pressure, it is possible to use the SCO2 fluid as the pilot fluid, eliminating the need for an extra gas canister for the pilot fluid. This technique, “process pilot”, is demonstrated in the video below.