Preheater Exchangers Design Considerations
Materials in contact with flue gas must be selected to minimize corrosion due to sulfur in the fuel and low flue gas exit temperature.
When the heater is fired on oil, soot blowers or water washing devices must be provided for the preheater. If water washing is to be done, drains must be provided in the preheater and in the adjacent ductwork. An occasional washing may be necessary even with gas firing.