Chapter 6

  1. The gas pilot pressure regulator ____ the incoming header gas pressure to ensure a satisfactory pilot flame.



    A.   Reduces
  2. The main gas pressure regulator controls the gas pressure at a ____ setting than the pilot regulator.



    C.   Higher
  3. A ____ prevents the burner from operating when the gas pressure in the supply line drops below the pressure necessary to maintain a stable flame at the burners.



    (D) Low Gas Pressure Cut-off Switch
  4. A low gas pressure cutoff switch _______ the burner from operating when the gas pressure in the supply line drops below the pressure necessary to maintain a stable flame at the burner.



    D. prevents
  5. The high gas pressure switch contacts are normally _______ whenever the main gas line pressure is below a preset pressure.



    C. closed
  6. The main gas valves are ON/OFF, normally open, single-seated gas valves, when the electric motors on the valves are energized.
    (a) True
    (b) False
    (b) False
  7. There are several more common designs of gas burners used for steam generation.
    1. Multi-Spud Burner
    2. Low Flow Burner
    3. Turbulent Flow Burner
    4. Ring Type Burner
    5. High Efficiency Low NOx Burners



    (D) 1,4,5
  8. Each spud on a multi-spud burner is equipped with a ____ so that it may be removed for cleaning.



    (C) Shut Off valve
  9. Most burners have the fuel entering the combustion air stream at or near a ______ angle to promote good mixing.



    B. right
  10. The multi-spud burner has ______ spuds or jets connected to a circular manifold.



    B. eight
  11. In a multi-spud burner, each spud is equipped with a ______ valve so that it may be removed for cleaning.



    C. shutoff
  12. The nitrogen and oxygen in the combustion air ______ at high temperatures to form NOx.



    D. react
  13. The main function of a gas burner is to:




    A. Provide for intimate mixing of gas and combustion air
  14. The thermal NOx reaction occurs rapidly above _____ °C.



    A. 1535
  15. To achieve lower NOx the flame temperature must be kept as low as possible. This is achieved by:






    D. A & C
  16. The above ground storage must have an earth or concrete dyke around the tank of such a size as to contain the total volume of oil stored plus one _____.



    A. third
  17. An oil storage tank must not have galvanized pipe, as sulphur in the oil will react with the galvanizing zinc causing _______.



    D. sludge
  18. The tank steam smothering line is used in the event of ____.



    C. fire
  19. The heating of heavy fuel oil takes place in ___ stages.



    B. two
  20. The second stage of heating, to allow atomization of the oil, involves heating the oil to between _________ C.



    A. 70 and 100
  21. Failure to burn a fuel oil at the correct pressure and temperature and with the correct atomizer will result in:
    1. Flame sputtering
    2. Carbon formation
    3. Flash back
    4. Soot




    D. 1, 2, 3, 4
  22. The main function of an ____ is to change the liquid into a fine mist or vapor-like state and then thoroughly mix this “vapor” with air so that combustion can take place quickly and efficiently.



    (C) Oil Burner
  23. The atomizing steam for a steam atomizing burner must be dry because moisture causes ____.



    B) (f) Pulsations
  24. Which of the following burners supplies oil under high pressure:




    A. Mechanical atomizing
  25. The steam atomizer type burners operate on the principle of producing a steam-fuel emulsion that atomizes the oil through the rapid _______ of the steam when released into the furnace.



    C. expansion
  26. The advantages of steam atomizing is:
    1. A low turn down ratio is possible
    2. A high turn down ratio is possible
    3. Low pressure may be used
    4. A constant pressure may be maintained from low to high firing condition




    D. 2, 3
  27. Steam atomizing burners require cleaning:




    A. Less often than mechanical atomizers
  28. In an air atomizing oil burner the air is called:




    A. Primary air
  29. The cup of a rotary cup oil burner rotates at:




    B) 3 500 rpm
  30. Coal belt conveyors are built with a maximum incline of about ____ depending upon the coal built.



    (C) 18 Degrees
  31. The purpose served by the coal ______ is to receive the incoming coal supply, place it on stock, and then transport it from stock to boilers at the time and in the form required.



    A) Plant
  32. The coal is fed to the surge bin, where in-line ______ remove any metal.



    C. magnets
  33. A belt scale operates by measuring the speed of the belt and the weight on a suspended section of the carrying run. An ________ relates running weights to belt travel and records the tonnage of coal handled.



    (C) Integrator
  34. Screens are fitted in the coal route to the bunkers to remove timber, stone, and oversize coal so that the supply to the ________ mills is kept free.



    (C) Pulverizing
  35. Reserve Storage coal, stocked for extended periods in the open air it will __________ by weathering and also there is an ever present danger of spontaneous combustion.



    A. deteriorate
  36. The temperature of the stock should be monitored as temperatures of ___ C and above indicate the threat of fire.



    C. 70
  37. There are three general firing arrangements:






    F. A, B, C
  38. The secondary air is admitted to the burner housing surrounding the central nozzle through adjustable _____.



    C. vanes
  39. Horizontal firing pulverized coal burners the burner(s) are located in the front wall and the flame travels ____ across the furnace.



    B) f) Horizontally
  40. In a vertical firing arrangement the burners are located in the furnace arch (top) and fire vertically ________.



    C. downward
  41. The tangential firing arrangement has burners installed in each of the ______ of the furnace.



    C. corners
  42. The cyclone furnace burns crushed coal up to ____ size rather than pulverized coal.



    (C) 6mm
  43. In a tube or ball mill pulverization of coal is achieved through continual cascading of the mixture, results from:
    1. Impact
    2. Screens
    3. Attrition
    4. Crushing
    5. Heat



    (D) 1,3,4
  44. A tube (or ball) mill is a hollow cylindrical shell, filled, approximately half full, with forged steel or cast alloy balls, ranging in diameter from ___ mm to ___ mm.



    C. 25, 51
  45. Coal pulverizes are commonly called ____.



    A) k) Hammers
  46. High-speed impact pulverizes (turning at 1200 to 1800 r/min) consist of a series of hinged or fixed ____ revolving in a chamber.



    (B) Hammers
  47. The bowl mill has ______ to grind the coal between themselves and a slowly rotating horizontal table



    C. rollers
  48. Using preheated air with pulverized coal:





    E. Dries the coal
  49. In an underfeed stoker, air for combustion is supplied to a chamber below the grates, then it passes through the grates via:




    B. Tuyeres
  50. An overfeed stoker uses the _____________ flow of fuel and air, with fuel flowing downward and air flowing upward.



    A. countercurrent
  51. A spreader stoker distributes the coal onto the surface of a traveling grate with ash discharged at the ______ of the furnace.



    A. front
  52. In a ________ stoker, altering the position of the spill plate or the speed of the rotor changes the distance the coal is thrown.



    B. spreader
  53. In a ________ stoker, air for combustion is supplied by a forced draft fan and passes up through openings in the grate to the fuel.



    C. crossfeed
  54. The types of grates used on a crossfeed stoker are:
    1. Roller grate type
    2. Chain grate type
    3. Bar grate type
    4. Mesh




    C. 1, 3
Author
PowerPrep
ID
317555
Card Set
Chapter 6
Description
Chapter 6
Updated