Assignment -II Unit(III) Boilers.pdf

ASSIGNMENT-II 1. Derive and expression for the Draught of Boiler in terms of water column. 2. Calculate the mass of flue gases flowing through chimney when the draught produced is equal to 1.9 cm of water. Temperature of flue gases is 290°C. The flue gases forme...

ASSIGNMENT-II 1. Derive and expression for the Draught of Boiler in terms of water column. 2. Calculate the mass of flue gases flowing through chimney when the draught produced is equal to 1.9 cm of water. Temperature of flue gases is 290°C. The flue gases formed per kg of fuel burnt are 23 kg. Neglect the losses and take the diameter of the chimney as 1.8 m. 3. Calculate the height of chimney required to produce a draught equivalent to 1.7 cm of water if the flue gas temperature is 270°C and ambient temperature is 22°C and minimum amount of air per kg of fuel is 17 kg. 4. Find the minimum height of the chimney required to produce a draught of 16 mm of H2O, if 19 kg of air is required/kg of fuel burnt on the grate. The mean temperature of flue gases inside the chimney is 330°C and the atmospheric temperature is 30°C. 5. A thermal power plant has a chimney draught of 3.5 cm of H2O column. The flue- gas temperature flowing through the chimney is 280°C and the ambient temperature is 15°C. The amount of air supplied/kg of the fuel is 20 kg. Calculate the height of the chimney. 6. Why are superheaters used on boilers? Explain their working. 7. Discuss in brief with their function a) Fusible plug b) Man hole c) Blow-off cock d) Feed check value 8. Explain the working of Babcock and Wilcox boiler with the help of a neat sketch. 9. Explain the construction and working of a La Mont boiler with the help of a neat sketch. 10. Explain the working principle of a Velox boiler with the help of a neat sketch. 11. Explain the construction and working of a Loffler boiler with the help of a neat sketch. 12. Explain the working phenomenon of the Economiser in boiler. 13. Differentiate between fire tube and water tube boilers.