Flow sensor: Self-cleaning mass flow meter great for dirty gas applications

By Control Engineering Staff January 18, 2007

The transmitter features a 4 line, 20 character, onboard LCD and full keypad for programming and display changes.

Measuring flow of a dirty gas stream can be problematic since debris left on the sensor invariably interferes with accurate measurements. If the sensor has to be dismounted for cleaning, maintenance costs pile up or the unit may not receive needed attention. FCI (Fluid Components International) has introduced its model GF90 thermal mass gas flowmeter which features purge ports for easy cleaning.

Depending on the application, the purge ports can be connected to compressed air, inert gas, or solvent supply lines for manual or automatic cleaning cycles. This happens while the unit is still mounted with no disassembly required. FCI says the unit operates with process gas temperatures from -100 to 850 °F (-73 to 454 °C) and pressures up to 1000 psi (69 bar). The sensor is inserted into the pipe or duct and creates minimal internal blockage. The gas stream velocity range is 0.25 to 1,600 sfps (0.08 to 488 nmps), which has to be translated to gas flow based on pipe diameter.

Output options include 4-20 mA, 0-10 V dc, 0-5 V dc, or 1-5 V dc. The transmitter housing is rated NEMA 4X (IP66) with hazardous enclosures available. Typical dirty-gas applications include chemical plants, power plants, stack gas monitoring, steel mills, and landfill gas.

Control Engineering Daily News Desk Peter Welander , process industries editor