| 摘要 |
<p>A pyrolysis furnace for the thermal cracking of hydrocarbons comprises a radiant zone within the walls of the furnace, which contains at least one reaction tube extending continuously through the radiant zone from its inlet end in a winding path. Furnaces contg. nonlinear reaction tubes can operate with lower mean tube-wall temps. than furnaces with straight tubes, and, for a given furnace height, a smaller no. of relatively large-bore tubes can be used, thus increasing the useful life of the tubes before removal of coke deposits becomes necessary. The tubes can be in the form of a helix, a double helix, a spiral, zigzag or a wave, and can be straight over part of their length. The radiant heat is pref. supplied by burners mounted on one end (pref. the top) of the furnace, or mounted on one side are pref. arranged vertically in the furnace. The pitch of the coil, etc., can be constant over the length of the tube or can be smaller at its inlet end than at its outlet end. The tubes are pref. circular in cross section.</p> |
