Identification of Rayleigh-Bénard Convection on Physical Model of Electric Furnace

Abstract

The released electric energy in the melting tank, the distribution of temperatures in the glass melt and by them generated the flow influences a quality of the manufactured glass melt especially their homogeneity. Between those places where the energy releases and where the energy consumes generates natural convection, called Rayleigh-Benard convection. This type of the convective flow is forming by the volumetric releasing of energy and this flow is also present in electric glass melting furnaces. In the melting tank of the furnace is released energy transported to colder areas for heating and melting of the batch. Experiments on the physical model were carried out with cooling the surface and heating the room below it. The temperature gradient area rises in the horizontal layer below the batch. From this layer the cooler blobs divide off and fall. Theirs velocities are depended on RaI 0,33 and it is less than the dependence of the flow velocity measured by Dubois and Berge with RaI 0,50. The results of the electric energy releasing in the physical model of the melting furnace showed that with decreasing depth of the tank is forming more smaller cells of Rayleigh-Benard convective flow and also by them is reducing ability of the blobs flow generating.