Application of external level gauges in petrochemical plants

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Level monitoring of liquefied gas spheres in petrochemical enterprises is quite complex. Radar level gauges or fiber optic level gauges are generally used, but in either case, holes must be made in the spherical tank. As pressure vessels, the more holes there are in such vessels, the lower their safety factor becomes. Sonar-based external level gauges allow it to avoid making holes in liquefied gas storage tanks. 　　　　A sonar-type external level gauge uses ultrasonic devices installed outside tanks and pipes to measure the liquid level in such equipment. Ultrasonic signals are continuously transmitted through the outer wall of the device into the liquid being measured, and then the echo signals are detected by sensing elements. The reflected echoes from transmission and reception are related to changes in the height and density of the liquid being measured, and the measurement results are obtained through calculations by electronic circuits. The calculated measurement values can be digital output, analog, or digital. 　　In the application of sonar-type external level gauges, it is required that the liquid being measured contain a small amount of gas or solid particles. There should be no sediment at the bottom of the tank, or only a small amount. The tank body can be made of the same material (such as plastic, glass, stainless steel, carbon steel, etc.). 　　A sonar-type external level gauge uses a transmitting unit to emit ultrasonic waves through the container wall; the speed of these ultrasonic waves as they propagate through the liquid is between the speed of the signals that are reflected off the inner wall of the container and the speed of the signals that are reflected back from the liquid surface. The time difference of the reflected signals received by the ultrasonic sensor is proportional to the liquid level height, with any other multiple reflections being compensated for in the calculations. 　　A sonar-type external level gauge is used to measure continuous liquid levels. The ultrasonic sensor is installed at the bottom of the tank or container; the time difference taken by the ultrasonic waves to pass through the liquid indicates the liquid level height, which is then converted into an analog output signal. It can also provide digital output signals for alarms indicating high or low liquid levels. 　　The installation of sonar-type external level gauges requires no welding or drilling; it is an external measurement method, and the gauges are attached using magnets, which makes installation and maintenance extremely convenient. They are widely used for measuring and controlling the liquid level in spherical and horizontal tanks in the petrochemical industry. 　　The sonar-type external level gauges produced by Dinghua Electronics utilize unique algorithms and cutting-edge technology to overcome the impact of liquid fluctuations caused by feed into storage tanks or temperature changes on level measurement, ensuring the stability of the readings. It facilitates operation by installers, saves time, and improves efficiency.