Abstract: The specification describes a method for producing a glass flow of high homogeneity in a tank furnace in which a selected layer of refined glass underneath the surface layers and above the bottom layers is drawn off at a point spaced from the end wall of the tank towards which the glass flows and is supplied to the processing station. The surface layers and the glass layers lying underneath the selected layer are returned into the refining section of the tank at a point upstream from the point of removal of the selected layer. Recirculation of the surface layer is encouraged by proper location of surface heating means and/or cooling means in the refining section in the tank.