The flue gas recirculation (FGR) fan is an instrumental apparatus that facilitates the extraction of a portion of high temperature flue gas from boilers or incinerators, and subsequently recycles it back into the combustion chamber.

Operating Principle:

Flue Gas Extraction: The FGR fan interfaces with the stack of the boiler or incinerator to extract a fraction of the high-temperature flue gas from the system.

Cooling: The extracted flue gas travels through a cooler such as an air cooler or water cooler, thereby reducing its temperature.

Recycling: The cooled flue gas is recycled back into the combustion chamber, where it blends with fresh air.

Emission Reduction: The recycled flue gas aids in lowering the temperature within the combustion chamber, thereby curbing the production of nitrogen oxides (NOx) and other pollutants.

Role:

NOx Emissions Reduction: FGR suppresses the formation of NOx by diminishing the temperature of the combustion chamber.

Boiler Efficiency Enhancement: The recycled flue gas carries heat which can be reused, thereby augmenting the overall efficiency of the boiler.

Fuel Consumption Reduction: By reducing the temperature of the combustion chamber, FGR can lessen fuel consumption.

Equipment Life Extension: The recycled flue gas cools down components of the boiler or incinerator, extending their service life.

Design Considerations:

Flue Gas Volume: The volume of flue gas needing extraction and recycling.

Flue Gas Temperature: The temperature of the flue gas during extraction and recycling.

Cooler Type: The type of cooler used for cooling the flue gas (air cooler or water cooler).

Recycle Pipeline: The dimensions and design of the recycle pipeline connecting the fan and the combustion chamber.

The FGR fan serves as a crucial tool for mitigating emissions from boilers and incinerators, enhancing efficiency, and prolonging equipment lifespan.