Furnace Tube

Additional Details

Furnace tube are mainly used as process tubes in cracking furnaces for refineries and ethylene propylene plants.

In a typical ethylene furnace the pyrolysis reaction is endothermic. For this reason, furnace tube material must be suitable to accommodate the high process temperature. Continual improvement of furnace tube materials and furnace design has made it possible to accommodate 750 – 850oC and up to 900oC or even higher. The tubular coils within an industrial pyrolysis furnace are usually made of the base Cr/Ni alloys and grow in popularity. The coils are hung vertically in a firebox and vary in number according to design. Depending of furnace design, there may be between 16-128 coils per firebox. Burners are arranged on the walls and on the floor of the firebox for indirect firing. This section is called the radiant section because the radiant heat is recovered. Cr/Ni alloys for furnace tubes are selected for their better cocking erosion resistance, high creep strength, carburization resistance, ductility, and thermal shock resistance.

Furnace tube are usually produced of the following steel grades 304L, 316, 321, 304H, 347H (formally stabilized at 1650 °F for 4 hours - preferred if it can be done internally at the mill), 317L, 2205.