1. In a test on a coal-fired furnace, a representative sample of the coal as fired is found to contain 2.03% moisture, 14.47% volatile matter, 75.31% fixed carbon, 8.19% ash, and 2.26% S. The heating value of the coal as fired is 14,081 BTU/lb. The refuse contains 40.0% moisture, 15.3% fixed carbon, and 44.7% ash; and the fluegas analysis is 13.0% CO 2, 1.1% CO, 1.6% H 2, and 5.6% O 2. Calculate the following: (a) The percent of the heating value of the fuel fired that is lost as unburnt carbon in the refuse. (b) The ultimate analysis of the coal as fired. Neglect nitrogen in the coal. 2. The refuse from a coal-fired furnace is found to contain 36.0% moisture, 4.2% volatile matter, 13.6% fixed carbon, and 46.2% ash. The coal as fired contains 1.7% moisture, 29.2% volatile matter, 60.8% fixed carbon, and 8.3% ash, and has a heating value of 14,200 BTU/lb. Sulfur and nitrogen in the coal are negligible. 0 The flue-gas temperature is 430 F. A recording CO 2 meter indicates that the average percent CO 2 in the flue gas is 12.6 (dry basis). Under the firing conditions employed in this particular furnace, the CO and H 2 in the combustion gases are known to be very small in amount. The air used for combustion is 60% 0 saturated with water vapor at 70 F. The barometer is normal. Estimate the following quantities as accurately as possible: (a) Percent of the heating value of the coal fired that is lost as unburnt combustible in the refuse. (b) Complete Orsat analysis of the flue gas. (c) Moles of water vapor in the flue gas per 100 moles of dry gas.
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A furnace burns coal analyzing 78.35% C, 27% VCM, 1.3% N, 7.1% ash and 0.95% S. Analysis of the refuse shows 6% VCM, 32% FC and 62% ash. Air supplied is at 0 0 30 C, 735 torrs with 90% RH. The stack gases at 250 C and 745 torrs has a partial Orsat analysis of 9.79% CO 2 and 1.47% CO. Assuming that 5.19% of the C fired is lost in the refuse, calculate: a. Complete ultimate analysis of coal b. Type of combustible in the refuse c. Percentage Excess Air d. Complete Orsat Analysis of the stack gas e. Cubic meter stack gas per kg coal
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A furnace is fired with a bituminous coal having the following proximate analysis: Moisture 2.9% Volatile Matter 33.8 Fixed Carbon 53.1 Ash 10.2 100.00% The ultimate analysis is known only in part and includes (as-received basis) Sulfur 1.1% Carbon 73.8 The dry refuse from the furnace has the following composition: Volatile matter 3.1% Fixed carbon 18.0 Ash 78.9 The Orsat analysis of the flue gases is as follows: Carbon dioxide 12.1% Carbon monoxide 0.2 Oxygen 7.2 Nitrogen 80.5 100.0%
1. Examination of a Wyoming coal as received yields the following information: volatile matter, 31.4%; fixed carbon, 46.0%; ash, 3.1%; moisture, 19.5%; negligible sulfur; heating value, 10,100 BTU/lb, Estimate the per cent total carbon in the coal as received. 2. Study of a large number of samples of coal from the Connellsville, Pa., field indicates that the average analysis of the coal in this field is 27.5% volatile matter, 63.5% fixed carbon, 6.0% moisture, 3.0% ash, and negligible sulfur. The average heating value is 14,150 BTU/lb. A sample from a certain mine in the field found to contain 15% ash and 8% moisture. Estimate the percent total carbon and the heating value of the coal thus sampled. 3. A typical high-grade semibituminous coal found to contain 16.8% volatile matter and 83.2% fixed carbon on an ash- and moisture-free basis. On the same basis, the heating value is 15,880 BTU/lb, and the sulfur content is 0.79%. a. Estimate the weight ratio of net hydrogen to carbon in the coal. b. Estimate the ultimate analysis of this coal on an ash- and moisture-free basis, on the assumption that the nitrogen content is 1.2%.
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Air enters the furnace at a temperature of 65 F with a percentage humidity of 55%. The barometric pressure is 29.30 in Hg. The flue gases enter the stack at a pressure equivalent to 1.5 in. of water less than the 0 barometric pressure and at a temperature of 560 F. Compute the volume of air and flue gases per 100 lb of coal charged. 1.
A typical high-grade semi-bituminous coal has been found to 16.8% volatile matter and 83.2% fixed carbon on an ash- and moisture-free basis. On the same basis the heating value is 15,880 BTU/lb, and the sulfur content is 0.79%. a. Estimate the weight ratio of net hydrogen to carbon in the coal. b. Estimate the ultimate analysis of this coal on an ash- and moisture-free basis, on the assumption that the nitrogen content is 1.2%.
2.
A boiler is fired with a coal containing 76.0% C and 8.1% ash, burnt under conditions such that elimination of combustible matter from the refuse is complete. 0 The air enters the furnace at 90 F and is 80% saturated with water vapor at this temperature. The sulfur and nitrogen in the coal are negligible. The flue gases go to 0 the stack at 1 atm and 640 F. The average flue-gas
4. A billet-preheating furnace uses a coal containing 74.0% C, 4.8% H, 9.4% ash, and negligible S and N. This furnace fired with 50% excess air. a. Calculate the flue-gas analysis on the assumption of complete combustion. b. Repeat on the assumption that 10% of the carbon burns to CO only. 1. A furnace is fired with coal with the following proximate analysis: 5% M, 60% FC, 25% VCM and 10% ash. Its calorific value is 31.33 MJ/kg. Calculate the % VCM lost, %C lost in the refuse is the refuse analyzes: a. 25% FC, 4% VCM, 71% ash b. 14.4% FC, 6% VCM, 79.6% ash c. 19.6% C, 80.4% ash
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analysis shows 12.6% CO 2, 6.2% O2, and 1.0% CO. Calculate the following: a. Percent of net hydrogen in the coal. b. Percent excess air used in the furnace. c. Ultimate analysis of the coal. d. Cubic feet of wet flue gases going to the stack per pound of coal fired. e. Cubic feet of wet air entering the furnace per pound of coal fired.
8. Which of the following is the correct equation for % excess air: a. x’ss O2 x 100 c. ______ x’ss O2 ______ x 100 theo air supplied O 2 – theo O2 b. supplied O 2 – theo O2 x 100 d. Both a and b theo O2
A coal consisting of 72% C, 10% ash, negligible nitrogen and sulfur, and the remainder net hydrogen and water (combined and moisture) is burned completely with dry air. The Orsat analysis of the flue gas is 8.50% CO 2, 4.25% CO, 7.45% O2, and 79.8% N2. The flue gases leave at 750 mmHg. Calculate the following: a. The net hydrogen and water in the coal b. The partial pressure of water in the flue gases c. The percentage excess air.
10. The following are usually done in order to make the reaction of combustion faster. a. temperature is increased c. pulverizing the coal b. liquid spraying the fuel d. none of the above 11. Which of the following will not produce a diffusion flame? a. diesel engine c. gasoline engine b. gasoline engine d. gas turbines
The products and by products from coal combustion can create environmental problems if the combustion process is not carried out properly. A fuel analyzing 74% C, 14% H, and 12% ash is burned to yield a flue gas containing 12.4% CO 2, 1.2% CO, 5.7% O2, and 80.7% N2 on a dry basis. Your boss asks you to determine: a. The lb of coal fired per 100 lb mol of flue gas b. The percent excess air used c. The lb of air used per lb of coal d. Will the calculations be valid? Explain.
1. A type of gaseous fuel which is said to be clean burning type of fuel and emits lower levels of potentially harmful by-products into the air. a. Producer Gas c. Natural Gas b. Lurgi Gas d. Wood Gas 2. It is made by letting coal partially burn to CO and then using CO as fuel. a. Wood Gas c. Oil Gas b. Natural Gas d. Fossil Fuel 3. A manufacture gas from coal by gasification in air and steam. a. Lurgi Gas c. Water Gas b. Blast Furnace Gas d. Producer Gas 4. A colorless, flammable gas with an odor similar to garlic. a. Ethylene c. Nitrogen b. Oxygen d. Acetylene 5. Otherwise known as Blue Gas. a. Lurgi Gas c. Water Gas b. Blast Furnace Gas d. Producer Gas 6. The following are the description of combustion except: a. oxidation takes place b. reactants are nitrogen and fuel c. accompanied by the evolution of light and heat d. none of the above 7. Oxygen required for complete combustion to take place. a. Theoretical Air c. Excess Air b. Theoretical Oxygen d. Excess Oxygen
9. Who proposed an equation relating the vapor pressure to the temperature condition of the system or the mixture? a. Antoine b. Amagat c. Dalton d. Raoult
12. He drove a rocket powered car which reached a speed of 125 mph in Germany of 1928. a. Osamu Nagano c. Tsiolkovsky b. Opel d. Goddard 13. Deflagration means a. combustion reaction b. sudden explosion
c. thin region of rapid exothermic rxn d. rate of reaction zone
14. A type of design of boiler where the flue gas flows inside the tubes. a. fire-tube boiler c. water tube boiler b. kettle boiler d. steam turbine 15. He pioneered the work of the first commercial steam turbine (5 hp). a. George Herman Babcock c. Gustaf de Laval b. Stephen Wilcox d. John Barber 16. In 1905 the Frenchmen Chrales Lemale and ____________ used a 25 stage Brwn Bovari centrifugal compressor (running at 4000 rpm, absorbing 325 hp, and giving a 3/1 pressure ratio. a. Rene Armengaud c. Gustaf de Laval b. Stephen Wilcox d. John Barber 17. Usually found compressed in porous rocks and shale formations sealed in rock strata below the ground. a. fossil fuel c. peat b. coal d. natural gas 18. It is largely produced in the environment which causes global warming a. carbon monoxide c. carbon dioxide b. oxygen d. sulfur dioxide 19. He begun the direct measurements of carbon dioxide at the Mauna Loa Observatory in 1958. a. Rene Armengaud c. Gustaf de Laval b. Stephen Wilcox d. Charles Keeling 20. This theory originates from the work on the structure of detonations. a. Zeldovich-Doring -von Neumann c. combustion b. Phlogiston d. Laminar flame model
21. All the energy from earth came from the. a. man c. star b. sun d. environment 22. Before 1850, this became the primary worldwide fuel a. natural gas c. wood b. oil d. coal 23. What does OPEC stands for? 24. The type of oil that is used as a lubricant prior to crude oil use. a. spermaceti b. tar oil c. stearin d. whale oil 25. Benjamin Thompson experimented with over ______ different lamp designs. a. 1 b. 10 c. 100 d. 1000 26. Oil obtained from the head of sperm whales. a. spermaceti b. tar oil c. stearin d. whale oil 27. This is a soft, white odorless solid found in many natural fats. a. spermaceti b. tar oil c. stearin d. whale oil 28. In 1930s, this was used in particulate control. a. electrostatic precipitator c. cyclone collectors b. fabric filters d. baghouse 29. He built the four stroke internal combustion engine a. Rudolf Diesel c. Niklaus August Otto b. Stephen Wilcox d. John Barber 30. The first diesel powered submarines were developed in ____ of German and British Companies. a. 1910 b. 1921 c. 1920 d. 1911 31. He wrote the Future Developments in Aircraft Design a. Hans von Ohain c. Tokiyashu Tanegashima b. Frank Whittle d. Ernst Heinkel 32. He pioneered the aircraft gas turbines in prewar Germany. a. Hans von Ohain c. Tokiyashu Tanegashima b. Frank Whittle d. Ernst Heinkel 33. One of those who developed the first gas turbine in Japan. a. Hans von Ohain c. Tokiyashu Tanegashima b. Frank Whittle d. Ernst Heinkel 34. In 1903, it is the first city to have a central power station designed exclusively for steam turbines. a. Ohio c. Chicago b. Oklahoma d. Rhode Island 35. He invented the electrostatic precipitator a. Lenoir c. Clark b. Cottrell d. Diesel
