Equipment for measuring the liquid level of liquid ammonia storage tanks from the outside – Non invasive Ultrasonic Level Sensor
The measurement of liquid level in chemical Ammoniac liquide storage tanks mainly includes radar level gauges, magnetic flap level gauges, double flange differential pressure level gauges, and Non-invasive Ultrasonic Level Sensor. Due to the flammable, explosive, and toxic properties of Liquid Ammonia itself, the selection, installation, and commissioning of liquid level measuring instruments for liquid ammonia storage tanks are crucial.
Le Capteur de niveau à ultrasons non invasif adopts the principle of ultrasonic echo distance measurement, combined with multiple digital signal processing, pattern recognition, database processing and other technologies of the system, to overcome the influence of tank wall and external interference. At the same time, the externally mounted ultrasonic level gauge can also perform automatic parameter calibration, ensuring that the instrument is not affected by changes in medium temperature and composition, and ensuring high-precision non-contact measurement of the liquid level inside the tank. In addition, the use of ultrasonic processing technology has achieved ultra high speed digital signal processing function, realizing high-precision liquid level measurement. At the same time, it can output 4-20mA standard signals to output the measurement results to the DCS automation control system.
Le Capteur de niveau à ultrasons non invasif uses sensors (measuring probes, calibration probes) attached externally, and the sensors measure the liquid level in a non-contact manner with the measured medium, which can continuously measure the liquid level outside the tank. The renovation of the liquid ammonia level measurement system this time utilizes the power line and DCS signal channel of the original magnetic flip plate level measurement system, without the need for rewiring cables. The tank body is not perforated, no hot work is carried out, and non-stop installation is achieved, achieving true complete isolation measurement from the measured medium.
The Non-invasive Ultrasonic Level Sensor has been retrofitted and installed on Liquid Ammonia storage tanks A and B in the first phase Ammonia area of China Company, and has been in operation for 2 years. From the perspective of operating parameters and maintenance records, the externally mounted ultrasonic liquid level measurement system has the advantages of high measurement accuracy, strong signal anti-interference performance, stable and reliable operation, real-time automatic calibration, and long service life compared to the magnetic flip plate liquid level measurement system.
Through renovation, the environmental problems of inaccurate liquid level measurement in the first phase of the company’s Liquid Ammonia storage tank, device misoperation, and instantaneous nitrogen oxide exceeding standards caused by insufficient SCR ammonia supply have been fundamentally solved.