Ultrasonic: The Ideal Solution For Gas Flow Measurement
Ultrasonic flow gas measurement is the best technology for flare gas applications as it does not interfere or intrude into the gas flows and measurement accuracy does not rely on gas properties. Ultrasonic measurement allows measurement over a wide range of flows with turndown ratios of 4000:1
Fluenta Ultrasonic Transducers
- Standard Transducer: With a temperature range of -70 to +140°C, this transducer is suitable for most standard flaring applications in both on-shore and off-shore installations.
- High Temperature Transducer: The high-temperature range transducer is capable of functioning at up to +180°C, allowing Fluenta’s ultrasonic technology to be deployed across a wider range of flare applications, particularly valuable in chemical processing and refining.
- High Methane and High CO2 Capability: High concentrations of methane and carbon dioxide have historically been challenging areas for ultrasonic gas sensors.
Fluenta’s specialists have developed new transducers and signal processing algorithms designed specifically to work with these difficult gas types.
The transducers are mounted in lateral flanges fitted with ball valves so that the transducers can be fitted or withdrawn whilst the flare line is in operation.
Accuracy and Flexibility
Fluenta installations are available with a range of accuracies as low as ±1% , depending on customer requirements. See technical data for more details.
With a turndown ratio of 4000:1 and range of pipe diameters from 6 inch to 72 inch, the Fluenta ultrasonic flare gas solution covers a wide range of applications.
Transducers which extend into the gas process are more likely to get damaged, increasing the need for repairs and replacement.
Other systems use a single frequency for sensing, which is normally selected by the customer on order. This is a basic setup, not able to adjust to changing gas compositions.
CONTINUOUS WAVE AND ‘CHIRP’
Fluenta transducers use two ultrasound modes. “Continuous wave” uses a constant beam of ultrasound projected through the gas, whilst “chirp” uses short pulses. The ability to have both modes in a single sensor increases range and accuracy.
Other systems require a ‘dual path’ setup (needing four sensors) to achieve the same combination of range and accuracy.
Variable Wave Chirp Ultrasound
Continuous Wave Ultrasound
Full Pipe Diameter Measurement
Examples Of Intrusive Sensors From Other Manufacturers
Whilst this has the advantage of making measurement easier for narrow band transducers, it comes with a number of disadvantages.
These sensors are vulnerable to damage from sand, water, oil and any other solid matter in the process. Given the high velocities associated with flare gas, impact damage can be severe and soon prevent the system from working.
These intrusive sensors also disrupt the flow of gas, causing turbulance in the region in which the sensors are measuring the flow. This turbulence can lead to inaccurate flow measurements.
Click here for current and historical Fluenta flare gas measurement product information, data sheets and more: