INDUCTION MELTING BOUNDARY LAYER OF ICE

In many technical applications, ice grows on metallic surfaces. In most applications this effect is unwanted like the icing on heat exchangers, on power lines or the ice building on the wings of airplanes. The ice influences the properties and the lifetime of some components. In other cases metallic surfaces are designed such that ice grows on them, e.g. in many types of ice slurry generators, ice grows on the surface of a heat exchanger. Whether the icing is a disadvantage or advantage, in a lot of cases deicing is necessary. Deicing purposes the knowledge of the adhesion force between ice and the surface. Typically, the ice is removed from the surface by some means of mechanical or thermal impact. With a scraper or some other tool the ice can be removed mechanically. The scraping force has to be higher than the adhesion force between the ice and the surface. In order to thermally remove the ice, the temperature of the metallic surface has to rise over the melting point of ice. In this research there is a combination of the mechanical and the thermal method. The thermal energy to heat up the surface is generated with an induction heater. The total heat energy of induction heating depends on the frequency and the amperage for the induction coil. With a high frequency only a thin skin layer of the metallic surface heats up. The surface temperature rises over the melting point of the ice and the ice at the boundary layer melts off. The adhesion force between ice and the metal decreases until there is a complete liquid layer. The correlation between adhesion force and an induction heating impulse will be shown.