COOLflow™ Case Study 114
Smurfit-Stone Pulp and Linerboard Mill in New Richmond, Quebec
The Situation
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Smurfit-Stone Pulp and Linerboard Mill |
The Canadian Province of Quebec has implemented
legislation that will ensure improved air quality standards
within the region. To comply with the recent legislation, the
Smurfit-Stone Pulp and Linerboard Mill located in New
Richmond, Quebec, was required to lower particulate
emissions in Power Boiler No. 1 to 60 mg/GJ. After researching
the available low-emission technology, Smurfit-Stone
concluded the most cost-efficient and proven solution for
compliance was to perform combustion airflow modeling and
then install burner upgrade kits.
The Boiler
Smurfit-Stone's Power Boiler No. 1 is a Combustion
Engineering tangentially-fired boiler that fires bunker C heavy
fuel oil. The designed production rate is 375,000 lb/hr of
superheated steam at 625 psig and 750° F. The unit has eight
burners arranged one over one in each of the four corners. An
imbalance resulted in a deficient amount of combustion air
through one or more of the burners in the upper row.
Consequently, the flame geometry was uncontrolled,
combustion efficiency was poor and particulate discharge was
too high. To compensate, the boiler operated with only four
burners in service for an extended period of the total
operating time.
The TODD® Solution
In June 2000, John Zink Company's TODD Combustion
Group visited the Smurfit-Stone Mill to assess the situation
and advise of potential solutions. A site inspection of the
boiler in its operating mode confirmed that the poor
combustion performance was primarily due to the serious
airflow imbalance and outdated fuel-oil atomizing
techniques. A three-phase plan consisting of both
COOLflow™ and COOLkits™ technologies was recommended
to treat both conditions that were contributing to the higher
than normal opacity and flame instability.
First, COOLflow modeling techniques were used to
create a physical airflow model. The physical model was then
used to determine existing airflow patterns and design the
necessary solution. This consisted of air deflection baffles
and turning vanes that were installed in the wind boxes and
ductwork systems during the fall maintenance outage. After
the modifications were made, a stack emission test was
performed to verify that the airflow modifications were
successful. Phase three involved installation of COOLkits
with state-of-the-art, low-NOx oil atomizing equipment.
COOLkits, which entail installing custom-designed burner
components into existing air registers, are a low-cost
solution to reduce emissions.
The TODD Result
The COOLflow model and associated engineering
drawings were completed by October 2000. During the
November maintenance shutdown, the boiler's combustion
air system was modified according to the COOLflow results.
The installation went as planned, and the boiler started up
on schedule.
The phase-two, stack emission tests were completed in
early December. The Provincial Permit allowed a particulate
discharge of 60 mg/GJ fired, and the test results confirmed that
the COOLflow modifications alone had reduced particulate
emission below that level. Although the COOLkits
modifications were not required to comply with particulate
emission requirements, mill experts are still considering the
COOLkits modifications for increased emission reductions.
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| Particulate Discharge |
Emissions |
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| Pre-modification average |
80 to 85 mg/GJ |
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| Post-modification average |
35 to 40 mg/GJ |
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| Fig. 1 |
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| Fig. 2 |
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| Fig. 3 |
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| Fig. 4: |
COOLflow™ Physical Modeling |
The COOLflow solution delivered several additional benefits.
- Eliminated unwanted tramp air and air leakage
- Improved mass flow and air distribution from +32.8% to +3.8% between all eight burners
- Eliminated detrimental swirl of airflow entering each burner's register
- Improved and balanced the airflow velocity at the peripheral inlet of each register from +100% to +13.2% of mean
- Enabled lower excess O2 operation
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