TUBULAR RECUPERATOR Russian patent published in 1998 - IPC

FIELD: metallurgy, namely metallurgical furnaces for heating metallic products such as continuously cast ingots. SUBSTANCE: tubular recuperator includes inner tube having separate length portions. Each such portion is stationary mounted by means of lengthwise ribs of outer tube and separated from adjacent portion by cross gap. Lower and upper ends of each portion of inner tube are flared. Said flares are formed by concentrically arranged branch pipes. Width of annular slit between outer branch pipe and outer tube along height of recuperator is variable and it increases from minimum value equal to 0.08-0.12 of annular gap between said tubes until its maximum value equal to value of annular gap between tubes in upper end of said inner tube. Value of annular slit between branch pipes of said flared portion consists 0.1-0.5 of intertube gap value. Length of each portion of said inner tube is equal to 5-15 values of annular gaps between tubes. In slit between branch pipes of flared portion there are small tubes or lengthwise ribs. EFFECT: enhanced efficiency of air heating, lowered dimension and mass of recuperator. 4 cl, 5 dwg, 1 tbl, 6 ex