Patent ID: 9618204
Date: 2017-04-11
CPC Classifications: F23N,F27D

Claim:
1. A method for controlling the air flow to one or more burners in a balanced forced air draft ethylene cracking furnace comprising one or more coils receiving a feed of ethylene, said coils passing through a convection section in a furnace arch or exhaust and then through a radiant section having one or more radiant walls at a temperature from 800° C. to 1200° C., one or more fans, feeding air to one or more common air ducts leading to an array of two or more burners for burning a gaseous fuel, each said one or more burners drawing combustion air only from said one or more common air ducts and being associated with a variable forced air aperture and a flow controller there for having a control fidelity of 1% of said air flow at its maximum flow rate, and a probe to measure the air pressure drop across the flow controller so that the oxygen content in the exhaust gas at the furnace arch is from 0.5 to 1% dry oxygen and the distribution of said air flow to each said one or more burners is at a target value, the method comprising: i) measuring one or more of: ii) comparing said measurement to target value(s); iii) making an adjustment, to one or more of: