Control of a cracking furnace
AssigneePhillips Petroleum Company
InventorsGary L. Funk, Warren H. Huang, William S. Stewart
Life of this patent
Estimating the term…
Abstract
Measurements of process variables associated with a cracking furnace are utilized to calculate the actual maximum tube skin temperature for the cracking furnace. The thus calculated actual maximum tube skin temperature is then utilized to derive a control signal which may be utilized to manipulate the rate at which heat is supplied to the cracking furnace. The accurate prediction of the actual tube skin temperature based on actual process measurements enables the conversion rate for the cracking furnace to be substantially maximized while preventing damage to the cracking tubes.
Claims8
Apparatus comprising:
- a cracking furnace means;
- means for supplying a feed stream to said cracking furnace means;
- means for supplying a diluent fluid to said cracking furnace means, said diluent fluid being combined with said feed stream;
- means for supplying a fuel to said cracking furnace means, the combustion of said fuel supplying heat to said cracking furnace means;
- means for removing a gaseous mixture, containing the cracked components of said feed stream and containing said diluent fluid, from said cracking furnace means;
- means for establishing a first signal representative of a calculated actual maximum tube skin temperature based on the measurements of process variables associated with said cracking furnace means;
- means for establishing a second signal representative of a desired maximum tube skin temperature for said cracking furnace means;
- means for comparing said first signal and said second signal and for establishing a third signal responsive to the difference between said first signal and said second signal;
- and
- means for manipulating the heat supplied to said cracking furnace means in response to said third signal to thereby maintain the calculated actual maximum tube skin temperature substantially equal to the desired maximum tube skin temperature.
A method for maintaining a desired maximum tube skin temperature for a cracking furnace in which a mixture of a feed stream and a diluent fluid are cracked to produce a gaseous mixture which contains cracked and uncracked components of said feed stream and contains said diluent fluid, said method comprising the steps of:
- establishing a first signal representative of a calculated actual maximum tube skin temperature based on the measurements of process variables associated with said cracking furnace means;
- establishing a second signal representative of a desired maximum tube skin temperature for said cracking furnace means;
- comparing said first signal and said second signal and establishing a third signal responsive to the difference between said first signal and said second signal;
- and
- manipulating the heat supplied to said cracking furnace means in response to said third signal to thereby maintain the calculated actual maximum tube skin temperature substantially equal to the desired maximum tube skin temperature.
Dependencies are inferred from the claim text.