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How long we can operate a Refinery Heater above its design duty keeping all other Heater parameters within design limits? How can a Refinery Heater design duty be reduced without reducing a Refinery Process Unit throughput?





 
Answers
13/07/2012 A: Ralph Ragsdale, Ragsdale Refining Courses, ralph.ragsdale@att.net
Some heaters have operated at rates above their design duty from day one. The important number is the skin temperature, not to be exceeded for long without expecting tube ruptures.
If there is a feed to effluent heat exchanger, add surface area. That is the most common way to debottleneck a hydroprocessing unit, for example.
12/07/2012 A: Mike Watson, Tube Tech International Ltd, mike.watson@tubetech.com
Refinery Heaters if operated above design duty naturally risk distortion and cracking of supports, not least refractory damage. Fouling has a big part to play in distortion due to hot spotting caused by imbalanced fouling between the finned convection zones.
The new Tube Tech designed "CleanFire" Heater will provide full accessibility for a cleaning and inspection robot.
Currently this is designed for thorough Offline cleaning however Tube Tech International are developing a self cleaning option which will allow a reduction in Heater design with increased throughput.