Biogas from organic waste such as food or meat processing plants, fermentation systems for dairy products, and wineries and breweries, as well as on-farm manure and sewage treatment plants, is often digested under anaerobic conditions in reactor tanks. The output is valuable biogas, which is measured with flowmeters to support green co-gen energy systems or for disposal by flaring.
This potent mixture of combustible methane (CH4), carbon dioxide (CO2), water and trace levels of corrosive hydrogen sulfide (H2S) gas is problematic for many flow-measuring technologies. The combustible properties of CH4 gas require HazEx safety approvals. In addition, the corrosive, sticky nature of the H2S particles affects the performance and can clog many flow sensors, leading to frequent labor-intensive cleanings.
FCI’s rugged thermal mass ST51A biogas flowmeter is designed specifically for dirty, potentially hazardous biogas processes. It provides system operators with highly accurate and repeatable mass flow measurement to facilitate system control, log gas production data and provide mandated safety and environmental reporting information.
To survive in biogas processes, the ST51 flowmeter comes standard with rugged 316 stainless steel body construction and Hastelloy-C22 thermal sensors. It features a no-moving-parts, non-clogging design, which eliminates the need for constant cleaning under wet, dirty biogas conditions. The ST51A meter comes with full global Division 1, Zone 1, Ex safety approvals.
The meter’s electronics are housed in a durable NEMA 4X, IP67 dust-and-water-ingress-protected and all-metal (aluminum or 316L stainless steel) enclosure with dual conduit ports in either NPT or M20 threading. The transmitter can be integrally mounted with the flow element (probe) or can be remote mounted for installation flexibility. The instrument comes standard with dual 4-20 mA, NAMUR NE43 compliant outputs and a 500-Hz pulse output.
