Courtesy RMF Engineering Inc.
The new plant was built to house two storage silos
adjacent to the boilers.
Two live-bottom storage silos
are located adjacent to the boilers
at the new plant. Each silo can store
approximately 18,500 cu ft of wood
fuel – between two and three days’
worth, depending on system load.
The silo system operates through a
first-in-first-out method to minimize
fuel degradation. A Jeffersonian-style
architectural enclosure surrounds the
silos, helping the plant blend with other
campus buildings.
From the silos, fuel is delivered
to each boiler’s metering bin through
fully redundant conveyors. Each bin
provides about an hour’s worth of fuel
at 100 percent load. The live-bottom
bins discharge to a knife-edge feeder
and then into an air venturi, where the
fuel is picked up in the air stream of
the pneumatic, dilute-phase conveying
system. This system delivers the fuel
to the swept spout for distribution
on the grate. Furnace flue gases leave
the boiler through a combustion air
preheater and then through tandem
mechanical separators that remove
particulate matter.
Many Goals Met
The replacement plant has
already met many of the university’s
goals. According to Dick Bratcher,
Longwood’s vice president of facilities
management and real property, “The
new heating plant and our move away
from fossil fuels really fit in with a lot
of what we are doing as a university in
the area of sustainability.” Additionally,
the plant has reduced operational costs
through increased system reliability;
streamlined fuel unloading operations,
minimizing operator supervision; and
mitigated risks to students and other
pedestrians by improving the traffic
pattern around the plant.
Future system improvements
will include
• an off-site receiving, processing
and storage site to facilitate
management of a constantly
fluctuating fuel supply;
• more efficient unloading and
fuel management procedures to
accommodate the future doubling
of wood fuel use and increased truck
traffic through the facility;
• installation of the third wood-fired
boiler within the next five years; and
• possible conversion of the original
plant building into the campus’
first central chilled-water plant
or for other use by the physical
plant department.
With the new sawdust-fired steam
plant up and running, Longwood
continues its search for new fuels
that are available in the local supply
chain and offer cost savings. Recently,
the university began researching
the feasibility of burning ground
or pelletized warm-season grasses,
available from local growers. Should
that be feasible, Longwood will be
able to incorporate yet another
renewable fuel to its mix, furthering its
goals for a more sustainable campus.
And it will do so while supporting
the local economy – proving that
sometimes the most cost-effective
green energy solutions can be found
close to home.
Geoff Chenoweth, PE, is an
infrastructure and mechanical
systems project engineer with
RMF Engineering Inc. Over his
10-year tenure at RMF, he has
worked on all engineering and
planning aspects of energy production and
utility distribution designs related to steam,
high-temperature hot water and chilled water.
A registered professional engineer, he holds
a bachelor of science degree in mechanical
engineering from the University of Evansville.
He can be contacted at gchenowe@rmf.com.
Phil Jones is a project
coordinator with RMF
Engineering, Inc. and a member
of the Virginia Biomass Energy
Group. Throughout his 10 years
with RMF, he has contributed
to renewable fuel studies as well as condition
assessments of district energy plants and
distribution piping systems. He received
a bachelor of science degree in business
administration from Towson University and a
master of business administration degree from
the University of Baltimore. He can be reached
at pjones@rmf.com.
Toward a Sustainable Future
Longwood University has embraced a broad-reaching, long-term commitment to sustainability. Several years ago, it
adopted the definition of sustainability taken from the United
Nations-sponsored Brundtland Report of 1987: Sustainability is
“meeting the needs of the present without compromising the
ability of future generations to meet their own needs.” This
definition encompasses three components – economic security,
environmental protection and social responsibility.
The university’s commitment to creating a more sustainable campus can be seen in the sustainability goals of its 2020 Campus
Master Plan. They set the standard for the campus’s future physical needs by focusing on water, material flows, transportation and
energy. In 2008, Longwood received a $138,000 grant from the
Jessie Ball DuPont Fund to develop a comprehensive sustainability
program, including a full-time Office of Sustainability. The expanded sustainability program will support the implementation of the
master plan’s sustainability goals and will establish formal policies
for the construction and operation of future campus facilities.
