FURNACE

A furnace provided with a wall and a refractory inner masonry structure, between which there is a space, there being compressible elements from a material of high heat conductivity arranged in contact with the walls of said space, for improving heat discharge from the interior of the furnace. The said space may be filled with a ramming mix or tamping mixture. The elements are preferably copper pipes. For many furnaces and applications said space will be annular around the furnace and the elements are provided at regular intervals and compressible in a radial direction with respect to the furnace.