Apparatus for making glass and methods

A method of making glass comprising the steps of:

• providing a glass melt in a first melting furnace;
• flowing the glass melt through a connecting tube from the first melting furnace to a second melting furnace by initially flowing the glass melt through a first area defined by an interior surface of a first segment of the connecting tube located upstream from the second melting furnace with the glass melt contacting the interior surface of the first segment as the glass melt flows through the first area, and then subsequently flowing the glass melt through a second area defined by an interior surface of a second segment of the connecting tube located downstream from the first area with the glass melt contacting the interior surface of the second segment as the glass melt flows through the second area;
• providing an electrical discontinuity between the first segment and the second segment of the connecting tube;
• heating the glass melt within the first area by passing a first predetermined level of electrical current through the first segment of the connecting tube to directly heat the first segment with electrical resistance resulting from the first predetermined level of electrical current passing through the first segment, wherein heat is transferred from the first segment to the glass melt contacting the interior surface of the first segment;
• heating the glass melt within the second area by passing a second predetermined level of electrical current through the second segment of the connecting tube to directly heat the second segment with electrical resistance heating resulting from the electrical current passing through the second segment, wherein heat is transferred from the second segment to the glass melt contacting the interior surface of the second segment;
• and
• maintaining the temperature of the glass melt within a desired temperature range as the glass melt passes through the first area and the second area of the connecting tube by selecting the predetermined levels of current to provide corresponding levels of electrical resistance heating with the first and second segments of the connecting tube.