Fluid Components International ST51 Series Thermal Mass Flow Meter

The rugged ST51 Series Thermal Mass Flow Meter from Fluid Components International (FCI) provides continuously accurate measurement of syngas fuel flow to the combined heat and power (CHP) engine.

To ensure the biomass process is active and producing enough syngas to power the CHP engine (as well as to compute the correct energy value), the output flow of syngas needs to be measured accurately and with high repeatability. The flow meters are suitable because of their ability to be calibrated for mixed process gases, their all-welded closed sensor design ensuring no leak path for H₂ gas safety and their global Ex agency safety approvals for Zone 1/Division 1 hazardous areas with potentially explosive gases.

It is an insertion-style flow meter developed for use in pipe diameters from 63 to 610 mm. It is designed for the flow measurement of methane-based gases such as biogas, digester gas, landfill gas and natural gas, and for air, compressed air or nitrogen.

It can be easily installed into the pipe via a 0.5 or 0.75″ NPT compression fitting. It features a measurement range from 0.08 to 122 MPS with turndown ratio of 100:1 and with accuracy of ±1% reading, ±0.5% full scale. Depending on the chosen configuration, they are suitable for process temperatures from 121 to 177°C and pressures from 10 to 34 bar(g).

Designed with a no-moving-parts non-clogging thermal mass flow sensor, the meter features precision, lithography structured platinum RTD sensors embedded in FCI’s equal-mass, small-diameter, all-metal thermowells. Combined with microprocessor electronics and precision calibration, this meter achieves accuracy with a fast response. There is virtually no maintenance required over a long life for a low life-cycle cost.

The electronics are housed in a rugged IP67-rated enclosure with dual conduit ports in either NPT or M20 threading. The instrument comes standard with dual 4–20 mA outputs and a 500 Hz pulse output.