The FLW-100 Emission Ultrasonic Flowmeter is applied for the Continuous Emission Monitoring System (CEMS) for real-time continuous measurement of emission flow rate. It is developed based on the ultrasonic time-difference priciple. It utilizes a pair of ultrasonic transducers to alternately (or simultaneously) transmit and receive ultrasonic waves in opposite directions. By observing the difference in propagation time of the ultrasonic waves traveling downstream and upstream in the emission stack, the flue emission velocity can be measured. It is the most reliable device for flue emission flow monitoring.
Working principle
The FLW-100 Ultrasonic flowmeter is designed based on the principle of the time difference of flight of ultrasonic waves. There is a pair of ultrasonic transducers installed inside the pipeline, facing each other and forming a certain angle with the direction of the flue emission flow. Under the influence of the flue emission flow, the flight time of the ultrasonic wave traveling downstream is shortened, while the flight time of the ultrasonic wave traveling upstream is extended. The higher the flue emission flow velocity, the bigger the difference in flight time.
Through measuring the flight time difference of the ultrasonic waves, the flue emission flow velocity can be calculated. This velocity is the average velocity along the path of the ultrasonic wave. Combined with the cross-sectional area of the pipeline at the measuring point, the instantaneous flow velocity can be calculated.
Application
Real-time measurement of temperature, pressure, velocity, and flow rate of flue gas in environments with large diameter, low velocity, high dust content, high temperature, and high humidity. eg. coal chemistry, petrochemical, steel plant, metallurgy, cement plant, waste incineration.
Features
• Time-difference measuring principle, high precision and reliability, quick response, support long-term continuous operation;
• Measurement results are not affected by fluctuations in gas composition, temperature, pressure, or humidity;
• Measurement of the average flow velocity along the line, the flow velocity is more representative & accurate;
• Suitable for different size of emission chimney installation, chimney dimension up to 13m;
• Integrated design for easy maintenance.
• Non-contact measurement, less risk of blockage & corrosion, high reliability and low maintenance work
• Explosive-proof available for Zone 1 and Zone 2 explosive gas environments.
