Ultrasonic Gas Flow Meter Helps Steel Mill Achieve Reliable Low-Pressure Flue Gas Measurement
Summary
A major steel mill in China, with a production capacity of tens of millions of tons per year, has a long and successful track record using ultrasonic flow meters. Already very familiar with Panametrics products, the customer has used many Panametrics liquid, gas, and flare flow meters with great success. However, it was also using a competing ultrasonic flow meter for flue gas measurement. The customer found it unreliable and wanted to replace it.
Application
Fig. 1: Welding the downstream transducer nozzle onto the flue gas duct.
| Fluid | Flue gas |
|---|---|
| Pipe Size and Material | 2410 × 4000 mm (7.9 × 13.1 ft), carbon steel |
| Process Temperature | 101 – 129 °C (214 – 264 °F) |
| Process Pressure | -11 Pa to 93 kPa (-0.0016 to 13.5 psig) |
| Fluid Sound Speed | ~390 m/s (~1,280 ft/s) |
Benefits:
- Measures down to very slight vacuum pressure
- No pressure drop
- Low maintenance
- Long-term stability
- Works on rectangular pipes
- Wide measuring range
Challenge
The flow meter had to be installed on a large 2.4 m × 4 m rectangular duct. The installation location offered only about 1.5 pipe diameters of straight run upstream, resulting in a non-fully-developed flow profile. With the two nozzles positioned far apart, achieving correct alignment was difficult — any offset risked losing signal capture and producing inaccurate, unreliable readings. There was no room for error: the measurement data feeds directly into the plant’s continuous emission monitoring system (CEMS).
Solution
Given the very long acoustic path, the Panametrics team recommended its DigitalFlow XGM868i gas ultrasonic flow transmitter with T5 transducers operating at 50 kHz. The wide beam angle of these transducers ensured an accurate measurement across the long path. In parallel, the Panametrics Services team used a laser alignment tool to achieve precise nozzle alignment. Following successful installation and commissioning, the flow meter delivered accurate and reliable data, and the customer was able to properly feed its CEMS with the required flow measurement data. Following this success, the Panametrics team is already discussing similar applications at other steel mills around the world.
Panametrics DigitalFlow XGM868i process gas ultrasonic flow meter
Datasheet (PDF) Panametrics DigitalFlow XGM868iSource: Panametrics Application Note PANA013AN (panametrics.com) — © Panametrics LLC. Localized and prepared by INTECH CONTROL, the official Panametrics representative for Slovakia and Hungary.