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21 Cards in this Set
- Front
- Back
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How does a fyrite flue gas analyzer work and what does it tell you? |
Reads co2 and o2 concentrations with co2 binding to a red dye ans o2 binding to blue. A provided scale reads out the percentage of each a gas Contains |
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What is the efficiency of an air preheater? |
1% efficiency gained for every 100degF rise in combustion air |
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How does sulfur in fuel affect the plant? |
Formation of Sulfuric Acid,which is a controlled pollutant and cause of cold end chorosion. Fuels with higher sulphur content also need additional chemical treatment and additives to help burn better |
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What determines the temp fuel can eb heated to for atomization? |
Flash point |
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What are the combustibles in fuel? |
Carbon, Hydrogen, and Sulfur |
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What are the impurities in coal? |
Ash and Sulfur. |
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How is the heating value of fuel determine? (2 methods) |
Bomb Calorimeter- a known volume of solid fuel is placed in a sealed vessel connected to an air line and igniter. The bomb is placed in an insulated water bath and the fuel burned. Based on the temperature rise in the water bath, btus can be calculated Dulong's formula - Heat Value= 14540x %Carbon +62,000x (%Hydrogen-(%Oxygen/8))+4050x%Sulphur |
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Which furnishes more air to a boiler, a forced draft or induced draft fan? |
Forced Draft |
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What is an appropriate percentage of excess air? |
20% |
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What are the constitutes of air by volume and weight? |
Volume 20.9% Oxygen, 79.1% Nitrogen Weight 23.15% Oxygen, 76.85% Nitrogen |
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What is furnace heat release? |
Btu's release per hour per cubic ft of furnace volume |
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What losses exist in a boiler? |
* Heat out the stack * water vapor (burning hydrogen) *unburned fuel in ash *incomplete combustion *moisture in fuel and combustion air *radiation |
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What is viscosity? |
Resistance of a fluid to flow |
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What is specific gravity? |
Ratio of a materials density when compared to the density of pure water |
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What is flash point? |
The lowest temp a material will produce enough flammable gas to be ignited by an outside source |
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What is pour point? |
The lowest temp an oil will flow at |
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What does low co2 in flue gas indicate? |
Excess o2 |
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What are the negative effects of sulfur in fuel? |
High sulfur content can result in cold end chorosion, requires more additives to burn cleanly, and is a controlled polutant |
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Stack temp has suddenly incresed, what could be the cause? |
Broken baffel |
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Stack temp has suddenly incresed, what could be the cause? |
Broken baffles can allow the exhaust gasses to short circuit the normal heating path |
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What is the difference between foced, natural, and induced draft? |
Forced Draft- push air in Induced Draft- suck air out Natural Draft- produced by convection due to difference in boiler and outside temps |
