POWER March 2014 - 27

3. Completed conversion. A side view of a newly installed forced draft fan with stairs
and access platform (foreground) to the new fuel train and vertical, upward-mounted burner
(background). Courtesy: Lipten Co.
instead of wall-mounted burners for this
application to provide optimum flame
geometry for the furnace configuration,
improved water circulation patterns, improved
thermal efficiency, better overall
boiler performance, avoidance of flame
impingement, and simplified operation.
The existing ID fan curves were analyzed,
and it was determined that these
fans could be reused by replacing the
motors and installing VFDs. The FD fans
were replaced and also fitted with VFDs.
The project included new natural gas
supply systems, electrical modifications,
custom CombustionPac combustion control
systems utilizing programmable logic
controllers, and additional boiler system
modifications required to convert the coal
boilers to fire natural gas.
4. Side view of a newly installed fuel train and vertical-mounted burner.
Courtesy: Lipten Co.
To EPC or Not to EPC?
An engineering, procurement, and construction
(EPC) company with expertise in
the boiler conversion process can be invaluable
in optimizing installation costs,
efficiency, safety, and reliability. Make
sure that the firm providing EPC services
is not favoring a particular product or design
and is a truly unbiased boiler conversion
specialist that will select the proper
equipment and optimum design for your
application. An experienced EPC firm can
work from either an end user-provided
scope of work-allowing for a designbuild
application-or work from more detailed
specifications, if desired.
A boiler owner could enlist the assistance
of an engineering firm that specializes
in boiler coal-to-gas conversions to
work in unison with the owner to provide
site-specific drawings, design direction,
component requirements, and site work
details. The engineering firm's scope may
include a detailed set of plans and specifications
or a more simplified conceptual
design package to facilitate design-build
bidding. Detailed engineering packages
may then be used to solicit bids for individual
project aspects, such as skilled
trade work and equipment, or conceptual
design packages can be released to EPC
firms that may provide all-inclusive projboiler
while allowing for maintenance
access (Figure 3).
■ Is sufficient combustion air available in
the building to support the conversion?
A review of intake louvers and make-up
air units may be necessary.
A vertical-firing burner arrangement
(Figure 3) is almost always preferred, if
March 2014 | POWER
possible. That was the case when Lipten
provided the design-build conversion
of two 210,000 lb/hr steam boilers at
an automotive manufacturing facility in
Wentzville, Mo. The converted boilers were
commissioned in late 2013. The project involved
installation of a single 250-MMBtu/
hr vertical-mounted burner on each boiler.
A vertical burner design was chosen
www.powermag.com
ect implementation. ■
-John Ingraham is a proposal development
manager, Jim Marshall is president,
and Randy Flanagan, PE is a mechanical
engineer with Lipten Co. (sales@lipten.
com), a design-build firm specializing in
industrial central utility plant design and
construction with specialized expertise in
converting industrial coal-fired boilers to
natural gas firing.
27

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POWER March 2014

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