Process and apparatus for cracking hydrocarbon; mixing device; apparatus and process for producing superheated steam; radiation block structure.

摘要

A process and apparatus capable of cracking hydrocarbon to produce a reaction product containing a high proportion of ethylene. A hydrocarbon such as naphtha (31) is vaporized and admixed with superheated steam (32) at high temperature in a mixing device (13). The resulting hydrocarbon/steam mixture is passed through a reaction zone (R) consisting of a reactor conduit (34) extending through a passageway defined in a radiation block structure (35). Heating gases (38) at extremely high temperatures are directed through the passageway co-currentiy with the hydrocarbon/steam mixture (39) to produce a desirable heat flux for the cracking reaction. A short residence time in the reactor conduit is maintained to prevent undesirable side reactions.

Superheated steam is produced by passing steam through a conduit (16) extending through a passageway defined in radiation block structures (22 and 25) and heated by hotgases (20 and 28).