tube for thermal cleavage of under normal conditions gaseous or liquid hydrocarbons to less saturated compounds and other products manufacturing

摘要

1,198,873. Tubular cracking furnace. PULLMAN Inc. 1 Nov., 1968 [16 Nov., 1967], No. 52009/68. Heading C5E. Normally gaseous or liquid hydrocarbons are cracked to produce olefins, e.g. ethylene, in a furnace comprising a refractory enclosure containing a plurality of essentially straight reaction tubes which make a single pass through the enclosure, and which communicate with a plurality of essentially straight quench tubes in a quench section. In Fig. 3, enclosure 10 contains vertical tubes 12 which extend below the enclosure as quench tubes 14 having cooling jackets 16. Burners 56 extend into enclosure 10 from the top. Feed enters at 40, and after preheating passes via lines 44A and 44B to feed header 46, and thence by flexible connectors 48 into lines 12. Product is collected, after quench, in header 52. Provision is made for on-stream decoking, e.g. by introducing steam from header 32, and also for high pressure steam or water lances for off-stream decoking. The reaction and quench tubes may be connected by U-bends, thus lowering the height of the overall structure (see Fig. 5, not shown). Fig. 4 shows the radiant section in two portions 104A and 104B, tubes 108 passing once through each section. Each portion is heated independently, by roof burners 114 and floor burners 106 respectively, thus providing close control of the overall time-temperature profile.