Principle of Operation Gas Turbine Flow Meter
The operation of the International Gas Turbine Meter is based on the measurement of the velocity of gas. The flowing gas is accelerated and conditioned by the meter´s straightening section. The straightening vanes prepare the gas flow profile by removing undesired swirl, turbulence and asymmetry before the gas flows to the turbine wheel.
The dynamic forces of the flowing fluid cause the rotor to rotate. The turbine wheel is mounted on the main shaft, with special high precision, low friction ball bearings. The turbine wheel has helical blades that have a known angle relative to the gas flow. The conditioned and accelerated gas drives the turbine wheel with an angular velocity that is proportional with the gas velocity.
The rotating turbine wheel drives the index head with the eight digit mechanical counter via shafts and gears.
The volume and flow rate can also be indicated electronically. A proximity probe generates a signal at each passing blade of the turbine wheel. With the device-specific K-factor and the number of pulses the passed volume can be calculated. With the measured frequency the flow rate can be determined.
The rotating turbine wheel can also generate pulses directly by proximity sensors that create a pulse for each passing turbine blade. By accumulating the pulses the total passed volume and gas flow rate can be calculated.
