Thermal flow meter optimises humidity control

30 July 2021

When it comes to industrial air blowers and heated dryers the ST50 series air/gas flow meter, from Fluid Components International (FCI), can provide precise measurement of both air flow and natural gas to operate batch systems more efficiently while improving end-product quality and reducing energy costs.

Engineers at a large vegetable drying plant processing onions requires accurate humidity control to avoid batch recycling due to the variable moisture content of the onions and other vegetables. The ST50 series thermal air/gas flow meters were placed in multiple locations allowing the engineering team to adjust air flow rates throughout the process, depending on onion humidity levels, which ensured drying of the onions by the end of the process, with minimal batch recycling.

Offering a wide flow range, the flow meter measures air, compressed air, natural gas or nitrogen from 0.23 to 122 MPS in line sizes from 51 to 610mm. Flow meter accuracy is up to +1% of reading, +0.5% of full scale, with repeatability of +0.5% of reading. The meter operates at temperatures from -18 to +121°C. Turndown ratio is up to 100: 1

The flow meter can be field-configured in either standard mass flow or volumetric engineering units. It features dual analogue outputs: two 4-20 mA outputs, which are field assignable to flow rate or temperature and an RS232C I/O port. A 0-500 Hz pulse output for totalised flow is also available as an option. All configurations are easily user set in the field with any standard laptop to the RS232C port and/or via the wireless IR link/PDA.