boiler Air Heater fitted to: 1) To increase efficiency by recovery of heat from flue gases ( except where bled steam heaters are in use, these increase overall plant efficiency but by a different method); 2) Accelerate rate of combustion; 3)Avoid effect of cold air impinging on boiler surface. As a by product air heaters also form a convenient way to warm up a standby boiler before initial firing. However, the effects of dew point corrosion and fouling in smoke tube air heaters should be taken into account when designing the heat absorption limit. i.e. the amount of heat to be removed from the flue gas should have a limit. For water tube boilers gas air heaters are only considered where the temperature at inlet to economiser is greater than 200oC. Due to greater heat transfer efficiency between gas/water economisers are preferred to gas/air exchangers. At low loads all gas/air heaters should be bypassed to keep uptake temperatures as high as possible.
Related Terms |
ABMA
American Boiler Manufacturers Association.
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RETURN-STEAM CONDENSATE
That steam produced by a boiler which returns to the boiler after it has condensed.
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ASME SECTION VII SUBSECTION C6
Operation of boiler auxiliaries.
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ASME SECTION VII SUBSECTION C4
Prevention of direct causes of boiler failure.
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ASME SECTION VII SUBSECTION C2
Operating and maintaining boiler appliances.
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CONDENSATE POLISHER
A device used to clean the returning condensate to the boiler feedwater system.
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CALCIUM
A scale forming element found in boiler feed water.
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DE-CARBONATION
Refers to the removal of carbon dioxide from the boiler feedwater.
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DE-AERATING HEATERS
Mechanical device using steam to strip dissolve gases from the boiler feedwater and heating the feedwater.
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DE-MINERALIZER
A device which removes dissolved matter from boiler pretreated water by contacting the water with ion-exchange resins.
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