Display of drops on surface at high temperature

Abstract

Heat extraction due to the use of water is the main cooling method used in various metallurgical processes, being the secondary cooling in continuous casting one of them, where through jets of water generated by nozzles, the most heat is removed. There are adaptations in this cooling method that allow to accelerate heat transfer, such as: water flow variation, water spray speed and water spray. However, there are few works that focus on the basic knowledge of heat transfer between the surface at high temperature and water droplets that spray out (Celata et al., 2006). Therefore, in this work by means of imaging techniques with high-speed cameras, an investigation is made of how the drop unfolds after it impacts a surface that is maintained at different temperature values. With the use of a microdropper and normogotero, two drop sizes 3.5 mm and 5 mm in diameter are guaranteed, respectively. The drops are dropped by gravity on the surface from a height of 80 cm, and with the help of images obtained from the high-speed camera, the deployment of the drop is analyzed for temperatures ranging from ambient temperature, to 800 °C. As a result, depending on the surface temperature of the metal plate, the behavior of the drop deployment at the time of contact varies. It is also observed how the roughness interferes in the deployment of the drop of water when making contact with the plate.