초록 ▼

There is provided a process and a device with a convection zone (A) and a radiation zone (B) in a furnace (10), whereby the process includes: a first stage of precracking a feedstock of light hydrocarbons (1) and a second stage of final co-cracking of the mixture that is composed of this precracked

There is provided a process and a device with a convection zone (A) and a radiation zone (B) in a furnace (10), whereby the process includes: a first stage of precracking a feedstock of light hydrocarbons (1) and a second stage of final co-cracking of the mixture that is composed of this precracked light feedstock (7) and a feedstock of heavy hydrocarbons (2). The process further includes: separate heating of the two feedstock streams (1 and 2) in the convection zone (A), in which the preheating temperature of each feedstock stream remains below the initial cracking temperature in each case; precracking (5) of the preheated light hydrocarbons; mixing of precracked light hydrocarbon stream (8) while a mixed stream (9) is formed; intense heating of mixed stream (9) to a temperature that is higher than the initial cracking temperature by virtue of the fact that the mixture is introduced into the radiation zone (B) of the furnace (10); and cooling (15) of cracked gases outside the furnace (10).

대표청구항 ▼

[ I claim:] [1.] A process for steam cracking of hydrocarbons in a cracking furnace (10) with a convection zone (A) and a radiation zone (B), in which the process comprises a first stage of precracking of a feedstock of light hydrocarbons (1), and a second stage of final co-cracking of a mixture com

[ I claim:] [1.] A process for steam cracking of hydrocarbons in a cracking furnace (10) with a convection zone (A) and a radiation zone (B), in which the process comprises a first stage of precracking of a feedstock of light hydrocarbons (1), and a second stage of final co-cracking of a mixture composed of resultant precracked feedstock of light hydrocarbons (7) and a feedstock of heavy hydrocarbons (2), wherein each feedstock has a initial cracking temperature, characterized in that the process comprises the following steps:a) in the convection zone (A) separately preheating each the feedstock of light hydrocarbons and the feedstock of heavy hydrocarbons, in which the preheating temperature of each feedstock stream remains below the initial cracking temperature of each feedstock,b) precracking the preheated light hydrocarbons,c) mixing the precracked light hydrocarbon stream (7) with preheated and unprecracked heavy hydrocarbon stream (8) while a mixed stream (9) is formed,d) heating of the mixed stream (9) to a temperature higher than the initial cracking temperature thereof, by introducing the mixture into radiation zone (B) of said furnace (10),e) proceeding with a final co-cracking step in radiation zone (B) of said furnace (10), andf) cooling the resultant cracked gases produced during co-cracking, said cooling being conducted outside of said furnace (10). [18.] A device for steam cracking hydrocarbons, comprising:a) a cracking furnace (10) with a convection zone (A) and a radiation zone (B),b) at least one preheating tube (3) for a feedstock of light hydrocarbons (1) in convection zone (A) for preheating feedstock, said preheating tube being connected downstream to at least one cracking tube (5) for the feedstock of light hydrocarbons (1) in order to precrack them in radiation zone (B), andc) at least one preheating tube (4) for a feedstock of heavy hydrocarbons (2) in convection zone (A) for preheating this feedstock,d) a mixing zone for forming a mixed stream (9) with at least one inlet line (7) for at least a portion of the precracked light hydrocarbon stream, which is connected to the upstream portion of cracking tube (5) for the feedstock of light hydrocarbons (1), and to at least one inlet line (8) for the preheated and unprecracked heavy hydrocarbon stream, which is connected to the upstream part of preheating tube (4) for a feedstock of heavy hydrocarbons (2),e) a separating zone (11) for dividing the mixed stream into a plurality of individual streams,f) a plurality of circulation tubes (13) that are arranged in parallel for the individual streams in radiation zone (B) in order to ensure a large increase in the temperature of the mixed stream, andg) at least one cracking tube (14) for the mixed stream, which is connected upstream to at least one of circulation tubes (13) for the individual streams and downstream to devices (15) for cooling cracked gases. Device according to claims 18, wherein two or more circulation tubes (13) are connected to at least one cracking tube (14) in radiation zone (B) of furnace (10).