Electrode cleaning of electromagnetic flowmeter

Commonly used methods for electrode cleaning include the following:

1. Electrochemical method

Metal electrodes have electrochemical phenomena in the electrolyte fluid. According to the principle of electrochemistry, there is an interface electric field between the electrode and the fluid. The interface between the electrode and the fluid is caused by the electric double layer existing between the electrode/fluid phase. Research on the electric field at the interface between electrodes and fluids has found that molecules, atoms or ions of substances have enriched or depleted adsorption phenomena at the interface. It has also been found that most inorganic anions are surface active substances with typical ion adsorption rules, while the surface of inorganic cations Very little activity. Therefore, electrochemical cleaning of electrodes only considers the adsorption of anions. The adsorption of anions is closely related to the electrode potential. Adsorption mainly occurs in a potential range that is more positive than the zero charge potential, that is, on the electrode surface with a different charge. On the surface of electrodes with the same charge, when the remaining charge density is slightly larger, the electrostatic repulsion is greater than the adsorption force, and the anions are quickly desorbed. This is the principle of electrochemical cleaning.

2. Mechanical cleaning method

The mechanical cleaning method completes electrode cleaning by installing a special mechanical structure on the electrode. There are two forms:

One is to use a mechanical scraper, which is a scraper with a thin shaft made of stainless steel. The scraper is led out through the hollow electrode, and a scraper is used between the thin shaft and the hollow electrode. A mechanical seal is used to prevent the medium from flowing out, so a mechanical scraper is formed. When the thin shaft is rotated from the outside, the scraper rotates close to the electric surface to scrape away dirt. This kind of scraper can be manually scraped, or it can be scraped automatically by driving a thin shaft with a motor. Among the domestic electromagnetic flowmeters, Jiangsu Shengchuang's scraper-type electromagnetic flowmeter has such a function, and its performance is stable and easy to operate.

The other is to install a wire brush for removing dirt in the tubular electrode, and the shaft is wrapped in a sealed "O" ring to avoid fluid leakage. This kind of cleaning equipment requires someone to frequently pull the wire brush to clean the electrodes. It is not very convenient to operate and is not as convenient as the scraper-type electromagnetic flowmeter of Jiangsu Shengchuang Appearance.

3. Ultrasonic cleaning method

Apply the 45~65kHz ultrasonic voltage generated by the ultrasonic generator to the electrode, so that the ultrasonic energy is concentrated on the contact surface between the electrode and the medium, and then The power of ultrasonic waves is used to break up dirt and achieve the purpose of cleaning.

The above is the method for cleaning the electromagnetic flowmeter electrodes, which will not hinder the use and can also improve the efficiency of the electromagnetic flowmeter.