Article Index

Evaporation- The change of state from a liquid to a vapor.

Evaporation rate- The number of pounds of water that is evaporated in a unit of time.

Evaporator- Pressure vessel used to evaporate raw water by means of a steam coil. The steam is condensed b means of cooling water coils, and this distilled water is used as make up for boiler feed.

Excess air- Air supplied in optimum amount will minimize heat loss up the stack and improve combustion efficiency. Some amount of excess air, depending on the available fuel/air mixing energy, is required to assure thorough mixing of the fuel and air for complete combustion.

Expansion joint- Permits movement without causing high stresses in penetration pipe and boiler wall.

Explosion door- A door in a boiler or furnace that is designed to function like a pressure relief valve calibrated by a predetermined gas pressure and protect the boiler against major damages caused by combustion gas explosions.

External treatment- Boiler feed water that is treated prior to its addition to the boiler.

Fan- A motor made up of a propeller and housing used to move air or gases at a considerable lower pressure.

Fan performance- Measuring fan performance in specifications of volume, total pressures, static pressures, speed, power input, mechanical and static efficiency, at a certain air density.

Fan performance curves– Representation in a graph for total pressure, static pressure, power input, mechanical and static efficiency and the range of amounts as abscissa, at constant speed and air density.

Feed pump- A pump that supplies water to a boiler.

Feedwater- Water introduced into a boiler during operation. It includes make-up and return condensate.

Feedwater regulator- A device for admitting feedwater to a boiler automatically on demand. Practically a constant water level should result

Feedwater treatment– Chemicals used in Boiler feedwater treatment is used to control alkalinity, prevent scaling, correct pH, and to control conductivity.

FGR- Flue Gas Recirculation is highly effective technique used for lowering Nitrogen Oxide (NOx) emissions from burners.

Filter- A porous device for removing impurities or solid particles from a liquid or gas passed through it.

Fired pressure vessel- Is a pressure vessel which is completely or partially exposed to fire from burners or combustion gases or otherwise heated from the combustion of fuel.

Firetube boiler- A type of boiler design in which combustion gases flow inside the tubes and water flows outside the tubes.

Firing rate control- Controls the firing rate of the burner according to fluctuations from pressure or temperature set points. This system can be set up to operate the burner on-off, high-low or in capacity to load demand.

Fixed carbon- Is the solid combustible residue that remains after a coal particle is heated and the volatile matter is expelled.

Flame- A hot glowing body of ignited gas that is generated by something on fire.

Flame detector- Is a sensor designed to detect and respond to the presence of a flame or fire and if it’s been lost, may send a signal to a control system.

Flame Propagation rate- The velocity of a flame spread in a combustible environment outward from the point at which the combustion started.

Flame safeguard- A control that completely runs a burner through many steps of operation to produce proper air purge, ignition, normal operation, and shutdown for operation safety.