Carrier air heating system for SCR
AssigneeBabcock & Wilcox Power Generation Group, Inc.
InventorJohn Smith
Life of this patent
Estimating the term…
Abstract
A heat exchanger is provided in an air duct between an air heater and a windbox of a combustion means such as a boiler. Dilution air is carried to the heat exchanger from a dilution air fan in a separate duct. The heat in the air from the air heater is transferred to the dilution air via the heat exchanger and the heated dilution air is sent to vaporize ammonia before the ammonia is introduced into an exhaust duct with a selective catalytic reduction (SCR) chamber. A bypass valve is provided around the heat exchanger for blending heated and unheated air to control the temperature of the dilution air.
Claims9
An arrangement for heating dilution air to vaporize ammonia comprising:
- an air duct with a heat exchanger downstream from an air heater;
- a dilution air duct for carrying dilution air to said heat exchanger in said air duct;
- and
- a heated dilution air duct for carrying heated dilution air from said heat exchanger to a source of ammonia.
A method for supplying the heat necessary for ammonia vaporization in a selective catalytic reduction (SCR) system comprising the steps of:
- heating air in an air duct to provide heated air;
- carrying said heated air to a heat exchanger;
- carrying dilution air to said heat exchanger from a dilution air duct;
- transferring a portion of heat from said heated air to said dilution air via a heat exchanger;
- and
- carrying the heated dilution air to a source of ammonia.
A combustion system comprising:
- an air duct with a heat exchanger downstream from an air heater;
- a dilution air duct for carrying dilution air to said heat exchanger in said air duct;
- a heated dilution air duct for carrying heated dilution air from said heat exchanger to a source of ammonia;
- a combustion means downstream from said heat exchanger;
- an exhaust duct arranged at an exit for said combustion means;
- an ammonia injection grid in said exhaust duct and downstream from said combustion means, wherein said source of ammonia is connected to said ammonia injection grid for providing ammonia to said grid;
- and a selective catalytic reduction (SCR) chamber downstream from said ammonia injection grid.
Dependencies are inferred from the claim text.