Title Assistant Director (Boiler) 2017.pdf ✅

AEF - A ] 10 [Contd. PROVISIONAL ANSWER KEY NAME OF THE POST : Assistant Director (Boilers) (AEF) (Advt. No. : 48/2016-17) Date of Preliminary Test : 01/01/2017 Subject : Concerned Subject (Que. 101 to 300) 101. In which the following regions of a boiler would you find the highest temperature of flue gas? (A) Economiser (B) Air PreheaterA (C) Boiler Drum (D) Superheater 102. The ratio of mass rate of water feeding to the steam-generating tubes to the mass flow rate of generated steam is defined as (A) Steam generation ratio (B) Circulation ratio (C) Turndown ratio (D) Evaporation ratio Upload Date : 03/01/2017 Objection shall be sent upto : 13/01/2017
AEF - A ] 11 P.T.O. 103. Which is the common coal firing system used in Indian thermal power plants? (A) Pulverized coal firing (B) Stoker firing (C) Fluidized bed (D) Pressurized bed 104. Which of the following is not true about Supercritical boilers? (A) Supercritical Boilers don’t have a steam drum (B) They operate above steam pressures of 22.064 MPa (C) There’s an increase in the thermodynamic efficiency of the Rankine cycle (D) The heat transfer area requirement is lower in comparison to subcritical boilers 105. What should be the silica percentage in superheated steam for efficient operation of steam turbines? (A) 0.2 ppm (B) 0.02 ppm (C) 2 ppb (D) 2 ppm 106. High pressure boilers are always (A) Bottom supported (B) Top supported (C) Can be supported from either (D) None of the above 107. Silica carryover in steam (A) Decreases when pH of boiler water is increased or Pressure of boiler is decreased (B) Decreases when pH of boiler water is decreased or pressure of boiler is increased (C) Is not dependent on pH of boiler water and only dependent on pressure of boiler (D) Is not dependent on pH of boiler water and only dependent on pressure of boiler 108. Which of the following is not a property of Boiler Quality plates? (A) Low carbon (B) Killed steel (C) Thin (D) High tensile strength 109. Which of the following can be used as a tube material (without hampering performance and efficiency) of boiler superheater exposed to a maximum flue gas temperature of 1025 degree Celsius (A) SA209 (B) SA516 (C) SA213T-11 (D) SA106 110. To drain condensate from main steam line, the following type of trap is a suitable trap. (A) Float (B) Bimetallic (C) Thermodynamic (D) None of the above 111. The Circulation ratio for once through steam boilers is (A) Greater than 1 (B) Less than one (C) Unity (D) Can take any value depending on type of circulation employed 112. The Atmospheric Fluidised bed Boilers have higher fluidising velocities in comparison to Pressurised Fluidised Bed Combustion units. For other conditions being constant, the heat transfer coefficient of Atmospheric Fluidised Bed Combustion units is: (A) Lower (B) Higher (C) Equal (D) Cannot be determined