Melting furnace

A melting furnace for melting raw material to produce a melt for mineral wool production, comprising:

• first peripheral sidewall means and bottom wall means defining a combustion chamber;
• second peripheral sidewall means supported on and extending upwardly from an upper end portion of said first peripheral sidewall means of said combustion chamber and defining a melting shaft for preheating and melting raw material for mineral wool production;
• a water-cooled grate provided between said combustion chamber and said melting shaft at a lower end of said melting shaft;
• a bed of ceramic filling bodies supported on said grate;
• said melting shaft being arranged to receive and peripherally enclose a charge of raw material supported on said bed of ceramic filling bodies on said grate;
• at least one main burner disposed under said grate in said combustion chamber for applying heat from below said grate to said charge of raw material, so that raw material near said bed of ceramic filling bodies melts, drips through said bed of ceramic filling bodies and grate and collects as a melt in a lower portion of said combustion chamber, at least partly on said bottom wall means;
• at least one outlet provided from said lower portion of said combustion chamber at a level which is above said bottom wall means, and through which said melt can be tapped from said lower portion of said combustion chamber;
• and
• a plurality of auxiliary burners disposed above said grate, in said melting shaft, adjacent to said bed of ceramic filling bodies, said auxiliary burners being arranged for applying heat to said charge of raw material, for preventing channels from forming in said raw material as said raw material melts.