How to manage excess air in process heaters and steam generation equipment

Sept. 27, 2016
Review the operations of your process heaters and steam generation equipment to justify upgrading excess air control mechanisms.

Over the past two year, my colleague, Subodh Chaudhari, and I have been doing BoilerMACT energy assessments. We assessed more than 100 process heaters and steam generation equipment along with their historical operating data (hourly averages for one year). These units varied significantly in design, heat duty and operational characteristics, but still had commonalities when it came to excess air control, heat recovery and operating efficiencies.

In a nutshell, our energy assessment results relating to improving excess air control showed that:

  • Steam systems are usually better set up and controlled than process heaters;
  • Process heaters can save ~2–5% of the energy, whereas steam systems can save ~1–3%;
  • Simple payback on these projects can be anywhere from a few months to 1.5 years; and,
  • Excess air control is dictated by environmental regulations and also sometimes by unique operating constraints determined by management through analysis (e.g., less frequent decoking required by using higher excess air).

Large deviations from the targeted, optimized excess air (and flue gas oxygen content) are possible over time and varying maintenance schedules. Additionally, changing production demands and fuel mix, heating value and firing rate will cause the optimized excess air percentage to fluctuate.

To learn more, read "Energy Efficiency: Better Manage Excess Air" from Chemical Processing.

Sponsored Recommendations

Arc Flash Prevention: What You Need to Know

March 28, 2024
Download to learn: how an arc flash forms and common causes, safety recommendations to help prevent arc flash exposure (including the use of lockout tagout and energy isolating...

Reduce engineering time by 50%

March 28, 2024
Learn how smart value chain applications are made possible by moving from manually-intensive CAD-based drafting packages to modern CAE software.

Filter Monitoring with Rittal's Blue e Air Conditioner

March 28, 2024
Steve Sullivan, Training Supervisor for Rittal North America, provides an overview of the filter monitoring capabilities of the Blue e line of industrial air conditioners.

Limitations of MERV Ratings for Dust Collector Filters

Feb. 23, 2024
It can be complicated and confusing to select the safest and most efficient dust collector filters for your facility. For the HVAC industry, MERV ratings are king. But MERV ratings...