Fans and Air Pollution Control for Oil and Gas Fired Boilers

The process

Oil and gas fired boilers have clean flue gas and no dust collector, so the fan set reduces to an FD or combustion air fan and, on larger units, an ID fan. The duty is clean air or clean gas, selected for efficiency and quiet running, with a silencer on the FD inlet where the boiler house is near offices.

The gas

Clean air that has passed through an air heater or recuperator. Density is lower than ambient, so the fan is selected at the hot condition and checked for motor load at cold start.

Fans in this process

Duty	What it does here	Type usually selected
FD Fan	Supplies combustion air to a boiler or furnace, pushing ambient air through the air heater and into the windbox against the furnace draft.	Backward curved and backward inclined
ID Fan	Sits at the outlet of a boiler, kiln or furnace and draws the flue gas through the plant to the stack.	Backward curved, backward inclined and radial tipped
Combustion Air Blower	Feeds a burner with air at the pressure the burner register needs.	Backward curved and radial tipped
Fan Silencer	An absorptive silencer at the fan inlet, outlet or in the duct, cutting fan noise with minimum pressure loss..	Silencer
Vent Silencer	Cuts the noise from steam or gas expanding from high pressure to atmosphere at safety valve outlets, start-up vents and blow-down lines..	Silencer
Ventilation Fan	Moves air through a plant or building for fresh air supply, heat removal and fume dilution where the system is ducted.	Backward inclined and forward curved

Industries

Related processes