TUBE FURNACE (VERSIONS) Russian patent published in 2016 - IPC C10G9/20 

FIELD: metallurgy.

SUBSTANCE: invention relates to the tube furnace, comprising box casing with convection and radiation chambers, in which the convection and radiant coils and burners are installed in the furnace hearth, wherein the radiant coil is made out vertical pipes. Wherein the downward vertical pipes of the radiant coil are made having spiral shape, length of the furnace coil section comprising helical vertical downward pipes is 30-50% of total length of the coil, screw pitch is 3-11 pipe diameters, and screw diameter is maximum two pipe diameters. The invention also relates to the tube furnace, in which the vertical pipes of the radiant coil are made with variable cross-section on downward pipes out of cone adapters.

EFFECT: reduced time of presence of boundary film in zone of high temperatures, this ensures reduced rate of carburising internal surface of the radiant pipes.

10 cl, 22 dwg