Patent ID: 7648626

Claim:
A process for reducing the rate of increase in pressure drop across a furnace convection section, the furnace convection section having a temperature profile, said process comprising the steps of: (a) establishing a ratio of total dilution H 2 O to feedstock for the system; (b) injecting a first portion of the total dilution H 2 O in the form of water into the convection section of the furnace; (c) injecting a second portion of the dilution H 2 O in the form of steam into the convection section of the furnace, wherein a ratio of dilution H 2 O in the form of water to dilution H 2 O in the form of steam is established; (d) monitoring the temperature profile across the convection section of the furnace; and (e) varying the temperature profile across the convection section of the furnace by adjusting the ratio of dilution H 2 O in the form of water to dilution H 2 O in the form of steam so as to spread coke build-up over additional rows of heat exchange tubes in the convection section, and reduce the rate of pressure drop across the convection section.