POWER October 2010 - 34

TOP PLANTS
1. Cool operator. Completed at the end of 2009, the cooling towers at PPL's Brunner Island
power plant are among the largest forced-draft cooling towers in the world and will help the
facility protect aquatic life by reducing the temperature of its water discharges to the Susquehanna
River. Courtesy: PPL
designed dollies. In addition, the existing
3A and 3B precipitators and associated
chevron were completely removed, and a
new air heater outlet duct was installed. At
the same time, most of the balance-of-plant
services that fed the demolished ESP were
also removed. During the outage, the new
ESP fields were tied to the inlet ductwork,
and the remaining ESP chambers and balance
of the utilities were reestablished,
completing the new installation within the
planned outage window.
In addition to executing its engineering,
procurement, and construction contract for
the FGD retrofit, Shaw provided engineering
services for the Unit 2 ESP retrofit.
" The Unit 2 ESP replacement project was
adverse impacts on aquatic life. In fact, discharge
of warm water into the river during
the winter creates a popular winter fishery at
Brunner Island.
The cooling towers have four large vertical
pumps operated by 3,500-horsepower motors.
The pumps deliver more than a half million
gallons of water through 34 cooling cells every
minute. Each cell has a fan that can be operated
from digital displays in the plant's control
room. Operators can adjust the speed and
number of fans running based on the amount
of water being discharged from the plant to
maintain a desired discharge temperature.
New Flue Gas Desulfurization
Systems
In addition to the cooling towers, PPL recently
installed wet limestone forced oxidation
flue gas desulfurization (FGD) systems to
treat flue gas from the plant's three generating
units. A single absorber system treats the
combined flue gas from Units 1 and 2 while
a dedicated absorber system treats flue gas
from Unit 3.
Installed by The Shaw Group (Shaw),
both absorbers are the dual-flow single-tray
design from Siemens Environmental Systems
and Services (formerly Wheelabrator).
Both absorbers consist of Stebbins Semplate
tile-lined concrete vessels, with C-276 metal
internals and fiberglass spray headers. Each
absorber has five spray levels. Both absorbers
discharge into a common 600-foot-tall
concrete chimney containing dedicated
fiberglass-reinforced plastic flues, each approximately
30 feet in diameter. The absorbers
themselves have an inside diameter of 66
34
feet and an 82-foot-diameter reaction tank at
the bottom.
The absorbers are designed for a maximum
chloride concentration of 30,000 ppm. Each
absorber is designed to remove up to 97% of
incoming sulfur dioxide, depending on the
number of spray levels in operation and the
coal's sulfur content. The forced oxidation-
along with some limitations on limestone
characteristics-allows the absorbers to produce
wallboard-grade gypsum.
" The installation of these systems was
very challenging due to the limited area available, "
said Marbaise. " Virtually all of the new
facilities were constructed on old, retired ash
basins. Of note, the storage area for limestone
and gypsum is outside the plant proper,
on top of a separate ash basin, on which the
rail yard and truck loading/unloading also are
located. Conveyors cross the public road to
carry the limestone and gypsum. "
Electrostatic Precipitator Retrofit
The Brunner Island Unit 3 electrostatic
precipitator (ESP) replacement project involved
the installation of new inlet fields by
Hamon-Research Cottrell on the existing
Lodge-Cottrell precipitators and demolition
of existing wire plate precipitators. The
work was accomplished by erecting the new
ESP inlet fields as a separate structure adjacent
to the existing C and D precipitators
on Unit 3 ESPs.
During the tie-in outage that was done
during a normal boiler overhaul, inlet nozzles
on the 3C and 3D ESPs were removed,
and the new fields were moved into place
using heavy lift equipment and specially
www.powermag.com
more complicated in scope and complexity
than the Unit 3 work, " said William Gibson,
project manager of Shaw's retrofit project at
the facility. " The area behind the Brunner Island
Unit 2 boiler had two existing weightedwire
ESPs in a piggy-back configuration and
is physically bounded by Units 1 and 3, the
existing boiler, other structures at grade, and
the new FGD ductwork. "
The need to maintain access to the other
boilers and access to open areas for outage
activities severely limited the available footprint
for a new ESP and for construction while
the unit was in operation. The project team
picked the only realistically available location:
a footprint 50 feet above grade, behind
the existing induced draft fans and elevated
above the building that supplies power to the
ESPs and baghouse on Units 1 and 3. Once
installed, the newly configured ESP was designed
to meet all applicable emissions limits
with multiple fields out of service.
Making Safety a Priority
PPL's Brunner Island power plant achieved
" Star " certification in the U.S. Occupational
Safety and Health Administration's Voluntary
Protection Program (VPP) in March 2003. The
plant was recertified in June 2006. The VPP
program recognizes companies that go beyond
compliance to protect worker health and safety.
The VPP Star certification is the highest safety
recognition given within the program.
" At Brunner Island, our commitment to
safety is evident not only in the VPP recognition
but in the everyday performance of our
employees, " Marbaise said.
The plant hosts a safety fair at the start of
each major outage to which all plant personnel
are invited, given lunch, and encouraged
to stop at the various stations that feature
games with safety themes or information
about new personal safety equipment or particular
safety themes. ■
-Angela Neville, JD, is POWER's
senior editor.
POWER | October 2010

http://www.powermag.com

POWER October 2010

Table of Contents for the Digital Edition of POWER October 2010