Challenges and Opportunities for Innovation in the Public Works ...

New Burners Have Low Nitrous Oxide Emissions
by Sherri Senffner
B oilers serving Army buildings can burners offer an excellent turndown burners do comply with the U.S.
now be upgraded with burners that ratio of 5:1, allowing continuous Environmental Protection Agency
ensure lower nitrous oxide (NOx) operation for low demands without (USEPA) NOx emission limits for
emissions. wasting energy by frequently switch- boilers under 100 million BTU per
ing boilers on and off. Potts says most hour capacity.
CERL began testing these burners conventional burners can achieve up
in FY90 at a dormitory heating plant to a 4:1 ratio at best. "Both comply," Potts says, -but
at Fort Knox, KY. In early FY91 a low low NOx burners release less concen-
NOx burner also was installed at a trated pollutants into the environsmall
central heating plant at ment.-
Yakima Firing Center, WA, and
testing is scheduled to begin in CERL is still collecting longmid-FY92.
term test data. The first short-term
demonstration, con-ducted at Fort
Preliminary test results show Knox in April 1990, proved the inthe
burners emit approximately 35 stalled unit reduced NOx by 35
percent less NOx than conven- percent while burning natural gas
tional burners. It was also found - dropping from approximately
that the new burners are 1/2 99 to 64 ppm.
percent more efficient. This
relatively small increase offers a While the short-term data
10-year payback period. CERL shows only a small increase in efengineer
Noel Potts says the ficiency, the new burners still
burners may prove to be at least I offer an attractive option when
percent more efficient - which replacing old burners because of
would reduce the payback period their low NOx emissions. More
to less than 5 years. than 600 Army boilers serving
single buildings or small building
"I believe it will prove more clusters could be retrofitted with
efficient because of its sensors," these low NOx burners.
Fort Knox boiler mechanic Ruel
Allen agrees. "If it senses excess For more information, con-tact
oxygen, it decreases air intake, and Noel Potts at CERL, PO Box
if it reads less oxygen, it increases 9005, Champaign, IL 61826-9005,
air." 217-398-5545 or toll-free 800-
USA-CERL (outside IL) and 800-
Unlike the conventional 252-7122 (within IL); or Satish
burners, the low NOx burners Sharma, EHSC, Fort Belvoir,
have a system that compensates Boilers can be retrofitted with a new type of VA 22060-5516, 703-355-3577.
for changes in combustion air burner that can reduce nitrous oxide emistemperature
and pressure. This sions by up to 35 percent.
allows the burners to maintain an
optimum fuel-air mixture. Fuel is The test sites were chosen because
adjusted based on combustion air each had an identical pair of oil-/
pressure in the burner, according to natural gas-fired boilers allowing Coming Next Issue...
Potts. side-by-side comparisons of conven- FROM THE FIELD-tional
and low NOx burners.Exeornuatnad
Most Army bases have a demand Exterior Insulation and
for steam that fluctuates both season- Although the new burners emit Finish Systems
ally and during the day. Low NOx lower levels of NOx, conventional _1
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