Intelligent electromagnetic flowmeter installation and maintenance
October 19 14:09:22, 2019
Intelligent electromagnetic flowmeter can measure the volumetric flow of general conductive liquid. It can also be used to measure the volumetric flow of strongly corrosive liquids such as strong acids and alkalis and even liquid-solid two-phase suspension liquids such as mud, pulp, and pulp. Smart electromagnetic flowmeters are widely used in petroleum, chemical, metallurgy, textile, paper, environmental protection, food and other industrial sectors as well as municipal management, water conservancy construction, river dredging and other areas of flow measurement. Because the electromagnetic flowmeter itself components damage caused by the failure, some because of improper use, improper installation, environmental conditions, fluid characteristics and other factors caused by the failure, such as showing fluctuations, decreased accuracy and even flowmeter damage. Intelligent electromagnetic flowmeters can be categorized into two types of faults: faults during installation and commissioning (failure during commissioning) and failures during normal operation (operational failures).
Intelligent electromagnetic flowmeter common faults:
1) Adhesion layer on the inner wall of the sensor Because the electromagnetic flowmeter is often used to measure the dirty fluid, after a certain period of operation, an adhesion layer may accumulate on the inner wall of the sensor and cause a failure. These failures are often caused by too much or too little conductivity in the adhesion layer. If the attachment is an insulating layer, the electrode circuit will be open circuit, the flowmeter will not work properly; if the adhesion layer conductivity is significantly higher than the conductivity of the fluid, the electrode circuit will be short circuit, the flowmeter can not work properly, It is necessary to remove the adhered scale layer in the measuring tube of the electromagnetic flowmeter in time.
2) Lightning strikes easily induces high voltage and inrush currents in the smart electromagnetic flowmeter circuit, causing damage to the flowmeter. It is mainly introduced through the power line is its excitation coil and the sensor and the converter between the flow signal line and other methods, especially from the control room power line to account for most of the area.
3) Changes in environmental conditions during the commissioning Because the smart electromagnetic flowmeter is working properly because the environmental conditions are good (for example, in the absence of interference sources), it tends to be easy to neglect installation conditions (such as grounding is not good) in this case, once the environmental conditions Changes, new sources of interference occur during operation (such as welding on pipelines near the flowmeter, large transformers installed nearby, etc.), will interfere with the normal operation of the instrument, the output signal of the flowmeter will fluctuate. Intelligent electromagnetic flowmeter debugging:
1) Installation: It is usually the fault caused by the improper installation position of the sensor of the electromagnetic electromagnetic flowmeter. Commonly, the sensors are installed on the highest point of the pipe system that easily accumulates gas, or are installed on the vertical pipe from top to bottom. Either emptying may occur or there is no back pressure behind the sensor, and the electromagnetic flowmeter fluid will be directly discharged into the atmosphere to form a non-full tube in the measuring tube.
2) Environmental aspects: There are mainly stray current disturbances in the pipeline, strong electromagnetic wave interference in space, and magnetic interference in large-scale motors. The stray current interference in the pipeline is usually a good result of good individual grounding protection. However, if a strong stray current is encountered in the pipeline of the electrolysis plant, the peak value of the AC potential sometimes induced at the two electrodes can be as high as needed. Take additional measures and insulate the flow sensor from the pipe.
3) Fluids: As long as the liquid to be measured contains evenly distributed microbubbles, it will not affect the normal operation of the smart electromagnetic flowmeter. However, as the air bubbles become larger, the output signal of the flowmeter will fluctuate. If the air bubbles are large, When the entire surface of the electrode can be covered, as the bubble flows through the electrode, the electrode circuit will momentarily open and the output signal will fluctuate more.