POWER October 2010 - 32

TOP PLANTS
trostatic precipitator (ESP), first-generation
low-NOx
tive catalytic reduction for NOx
The original steam turbine was a General
Electric tandem compound, double-flow reheat
with two double-flow low-pressure turbines.
Steam conditions are a standard 2,400
psig at 1,000F/1,000F. Emerson Ovation
controls both units and the new air quality
control systems (AQCS).
AQCS Upgrades
On March 1, 2010, CE announced completion
of the Brandon Shores AQCS project,
which brings both units into MHAA compliance
well within the required deadlines
(Unit 1 was completed in December 2009).
Perhaps the most distinctive design requirement
was for the AQCS to treat flue gases
from coal that has a sulfur content ranging
from 0.4% to 4.0%.
The AQCS additions begin with injecting
hydrated lime for SO3
control at a nominal
rate of 0.022 lb/million Btu of fuel input
and powdered activated carbon (PAC) to remove
90% of the mercury. Pulsed jet fabric
filters (PJFFs) were included with each unit
to capture hydrated lime, PAC, and residual
ash from the ESP. To scrub the flue gases of
SO2
, a forced oxidation wet limestone dualflow
tray absorber wet flue gas desulfurization
(wFGD) system designed for up to 98%
SO2
removal efficiency was installed. The air
quality control systems are designed to meet
a filterable particulate matter permit limit of
0.015 lb/million Btu and a sulfuric acid mist
limit of 0.027 lb/million Btu.
Success on a project of this size and complexity
requires the specialized talents of a
solid team of professionals. The project team
employed intensive planning and developed
many innovation solutions to meet the aggressive
regulatory schedule-less than three
years from the notice to proceed until the first
unit was operational-for this complex AQCS
project. Leading the team was a group of CE
project management professionals. URS provided
engineering, procurement, construction,
and start-up services for installation of
the AQCS system in its entirety. Siemens
Environmental Systems & Services, formerly
Wheelabrator Air Pollution Control, provided
the AQCS process design, supply of major
process equipment, and erection services for
the absorber vessels. Siemens Water Treatment
designed, supplied, and erected the supply
water and wastewater treatment system.
Some additional statistics illustrate the
challenges for the project team when building
on this large, yet complex, project site:
■ Approximately 2.2 miles of conveyors
supplied by Roberts and Schaefer were
32
installed to unload, store, and convey
limestone delivered by barge and to store,
convey, and load gypsum for removal by
barge. Separate domed storage facilities
for limestone and gypsum storage were
also constructed.
■ The new 400-foot, two-flue stack was
designed, supplied, and erected by Karrena
International. The two existing
700-foot stacks are now capped and will
remain in place.
■ Flue gas from induced draft fan discharge
of each unit was routed to the new PJFFs
through a total of 2,000 feet of new 28foot
4-inch square duct.
■ Three 100%-sized vacuum filters dewater
the gypsum produced by the wFGD
to produce wallboard-quality gypsum as
a by-product. Also, about 80% of the ash
collected in the ESP is sold for processing
into products used in making concrete.
Water Supply Upgrades
The Siemens Water Technologies innovative
biological and chemical water treatment
system design reuses water from the nearby
Anne Arundel County's municipal wastewater
treatment facility for the wFGD makeup
water. A tertiary water treatment system was
constructed to treat the water so that it has the
level of constituents required for the wFGD
system. That tertiary system includes a chloride/fines
purge stream treatment system, including
state-of-the-art biological treatment
for nitrogen reduction.
As part of the project, approximately
4,000 feet of underground HDPE pipe to
transport the effluent from the neighboring
www.powermag.com
water reclamation facility to the plant's treatment
system was installed. Additionally, a
7.5 million-gallon above-ground oil storage
tank was converted to water storage.
Finally, another treatment system removes
heavy metals and nitrates from the wFGD
wastewater to produce treated effluent that
meets the requirements for discharge into
the Chesapeake Bay watershed. Although the
biological treatment technology itself is not
unique, this is the first time that a nitrogen
reduction system has been employed in a
wFGD wastewater treatment system.
Safety First
The plant staff consists of 160 employees
spread over five operating shifts. A separate
Fuel and Ash Operations group, consisting
of 48 employees, supports both the Brandon
Shores and Wagner plants with coal operations
and ash removal services.
Plant statistics reflect excellence in plant
operations: Industry benchmarking data
show BSGS in the middle of the top quartile
peer group in equivalent forced outage rate
and equivalent unplanned outage factor over
the past five years.
Safety at CE sites is always job one, and
excellent results reflect that priority. The
Brandon Shores plant staff and the Fuel and
Ash Operations staff worked from May 1997
through August 2010 (4.7 million man-hours)
without a lost workday case. In addition,
URS and its subcontractors worked more
than 3 million man-hours without a lost-time
accident on the AQCS project. ■
-Dr. Robert Peltier, PE is POWER's
editor-in-chief.
POWER | October 2010
burners with overfire air, and selecreduction.
1.
Built to last. Located on the shores of the Patapsco River on a 375-acre site 10 miles
south of Baltimore, the Brandon Shores Generating Station has two generating units with a net
capacity of 1,273 MW. A suite of new air quality control systems and 400-foot chimney (right)
were installed on Brandon Shores Units 1 and 2 (left). The gypsum stackout in the gypsum storage
dome is on the far right. The barge unloading station is about a mile to the right. Courtesy:
Constellation Energy and HDR/CB

http://www.powermag.com

POWER October 2010

Table of Contents for the Digital Edition of POWER October 2010