Forney SCR Reheating User Manual

SCR Reheaters

Ensure Maximum SCR efficiency on low load swings with Forney’s SCR Reheaters.

Power plants must meet both stringent NOx reduction regulation and their customers'
needs of varying electricity demands by reducing their boiler's steam production.
Reducing boiler load causes lower flue gas temperatures reducing the operating abilities
of NOx control equipment such as selective catalytic reduction (SCR) reactors.
Forney Corporation utilized its vast combustion experience to develop a line of SCR
reheaters to supplement flue gas temperatures. When firing conditions dictate the
need for this additional heat, Forney's SCR reheaters pump heat into the flue gas
stream, thereby maintaining a flue gas temperature that ensures maximum SCR
efficiency. Forney can design a system for any configuration using one of three
solutions, sure to satisfy your installation requirements.

Forney was the first to introduce an external firing solution. This remedy
is ideal for high ash environments because it eliminates the problems of slag­ging, ash build-up, and burner fouling by designing the combustion equipment
to operate outside the boiler flue gas duct. Also, the external burners do not
increase system pressure drop, making them ideal for retrofit applications.

When boiler arrangement or customer preference does not permit an
external SCR reheater system, particularly in low dust flue gas streams,
Forney's reliable duct burner provides a compact in-duct burner system for
flue gas temperature control. The duct burner solution minimizes heat input
requirements and ongoing operating costs by providing reliable and even heat
distribution for effective SCR operation.

Forney's Perimeter-firing system combines the benefits of both in-duct and
external duct firing solutions. Strategically mounted directly on the flue gas
duct work, perimeter burners inject a high velocity, high temperature stream
directly into the flue gas creating excellent heat distribution to the SCR, in either
low or high dust applications.

··

CUSTOMIZED SOLUTION -

offering external, in-duct, or
perimeter fired SCR reheater
systems. Our engineers will
custom design and integrate the
system appropriate for your plant.

··

REDUCED INSTALLATION AND

CAPITAL EXPENDITURE COST -

Compared to installing an
economizer bypass system, a flue
gas reheat system can save expense
on installation and the loss of
efficiency experienced with an
economizer bypass system.

··

CFD MODELING - Forney

engineering can perform CFD
modeling of heat distribution to
assure efficient SCR operation.

··

EXPERIENCE - Forney

technologies are proven in SCR and
other firing applications around the
world.

··

SERVICE - Forney service

engineers provide start-up
expertise and periodic maintenance
capabilities to ensure your
equipment operates reliably.

BURNERS

Register Style Burner

Grid Style Burner

Perimeter Burner

External Induct Perimeter

Type: Grid Style or Grid Style Burner High Velocity Burner

Register Style Burner

Applications: High or low dust environments Low dust environments High or low dust environments

Space limited (register style) Augment air system Short mixing length

Fuel Consumption

Natural Gas Natural Gas Natural Gas

(per MMBTU): 17scfm 17scfm 17scfm

Air:

850 scfm @ 1psig 850 scfm @ 1psig 670 scfm @1psig

Location:

Modular Installation Installed innflue gas duct Installed directly

oonnttoo

flue

gas duct.

Accessories

Forney is a leading supplier of burner accessories for the utility burner market. Thousands of Forney

igniters, scanners, and oil guns are installed in utility boilers every year. These same components are

incorporated into Forney’s burners for utility burner performance and reliability. Available accessories

include:

·

IIggnniitteerrss

- Natural gas fired, No. 2 oil fired, or direct spark ignition

Class 1, 2 or Class 3 applications

High tension (6000 V) or High Energy ignition (12 joules per spark, 3 sparks per second)

·

SSccaannnneerrss

- Full line of flame scanners for every application.

·

OOiill GGuunnss

- Steam atomized, air atomized, and mechanical atomized to meet a wide range of needs.

·

FFuueell TTrraaiinnss

- Pneumatic or motorized valves, NEMA 12, NEMA 4, or explosion-proof enclosures.

·

BBuurrnneerr MMaannaaggeemmeenntt SSyysstteemmss --

Fireye E-110, Fireye Nexus, or PLC-based. Forney combustion con-

trol systems based on single-point positioning, parallel positioning, or fully metered control strategies.

·

DDiilluuttiioonn AAiirr HHeeaatteerr --

Grid style burner with duct work for ammonia vaporization in ammonia injec-

tion grid. Complete with fuel skid and Burner Management System (BMS).

·

FFaannss --

Skid mounted or ship loose fans to supply combustion air for grid register, high velocity,

and/or dilution air heater systems. Fans will be sized based upon required heat input.

·

DDiilluuttiioonn AAiirr BBlloowweerr SSkkiidd --

Forney also supplies skid mounted blower assemblies which supply air to

the dilution air burner system. Blowers are sized to ensure the air flow meets the requirements for

proper ammonia vaporization.

·

CCEEMMpplliicciittyy --

Low cost process control system for ammonia slip control.

Forney Corporation

3405 Wiley Post Road
Carrollton, TX 75006 USA
Tel: [phone]
Fax: [phone]
www.forneycorp.com

SCR Reheaters

BURNERS

TECHNICAL BULLETIN

PUBLICATION
#404002-13 REV 12/02