Boilers, kilns and process furnaces send a large amount of heat up the stack. An air preheater recovers part of that heat and uses it to warm the combustion air entering the furnace, reducing fuel consumption and stack loss.
How it works
Hot flue gas passes over a finned tube bundle while combustion air flows through the tubes or across the other side of the surface. The air enters the combustion zone at a higher temperature, which improves ignition and combustion efficiency.
Where the value comes from
- Lower fuel consumption for the same heat output
- Lower stack temperature and reduced heat loss
- Stable operation with a low failure rate when the cold end is designed correctly
- Materials and fin spacing selected against the flue gas composition
The cold-end check
Sulphur-bearing flue gas can condense on the cold end and corrode the tube wall. The acid dew point and cold-end wall temperature must be checked before the surface area is fixed. ND steel, stainless steel or enamel-coated fins may be required.
Mazelu designs air preheaters for boilers, kilns and process furnaces. Send the flue gas and air conditions for a thermal check.