Furnace Technology

51.In furnaces operating at very high temperature (say) 1250°C, e.g. soaking pit), the maximum heat transfer takes place by

  1. Conduction
  2. Convection
  3. Radiation
  4. Cannot be predicted

Correct answer: (C)
Radiation

52.In low or standard frequency induction furnace, heat is produced by the

  1. Combination of induced current and skin effect
  2. Induction and resistance
  3. Current flow through a heating element
  4. None of these

Correct answer: (B)
Induction and resistance

53.In order to maintain an oxidising atmosphere in a furnace, it should have

  1. More of excess air
  2. Less of excess air
  3. More of CO in flue gas
  4. More of CO2 in flue gas

Correct answer: (A)
More of excess air

54.In practical operation of any furnace, zero oxygen percentage or theoretical CO2 percentage in flue gas is rarely achieved, because of

  1. Use of non-preheated combustion air
  2. Use of pulverised solid fuels
  3. Imperfect mixing of fuel & air and infiltration of air
  4. Use of excessive positive draft in the furnace

Correct answer: (C)
Imperfect mixing of fuel & air and infiltration of air

55.In producer gas making furnace, steam is added along with air to mainly control the

  1. Fusion of coal ash & clinker formation
  2. C. V. of producer gas
  3. Temperature of producer gas
  4. Tar content in producer gas

Correct answer: (A)
Fusion of coal ash & clinker formation

56.In reverberatory furnace, charge is heated mainly by

  1. Conduction
  2. Natural convection
  3. Radiation of heat from the roof of the combustion chamber
  4. None of these

Correct answer: (C)
Radiation of heat from the roof of the combustion chamber

57.In salt bath furnace, heat is transferred to the charge mainly by

  1. Conduction
  2. Convection
  3. Radiation
  4. None of these

Correct answer: (A)
Conduction

58.In which of the waste heat recovery equipment, the flow of flue gas and air is alternately reversed after a fixed interval of time?

  1. Recuperator
  2. Regenerator
  3. Waste heat boiler
  4. None of these

Correct answer: (B)
Regenerator

59.Ingress of cold air in the furnaces through cracks, charging doors, openings etc.

  1. Reduces the flue gas temperature and makes the furnace atmosphere oxidising
  2. Increases the load on the induced draft fan
  3. Reduces the furnace draught
  4. All (A), (B) and (C)

Correct answer: (D)
All (A), (B) and (C)

60.Large tonnage of refractory bricks are dried in a

  1. Shaft furnace
  2. Rotary hearth furnace
  3. Tunnel kiln
  4. Muffle furnace

Correct answer: (C)
Tunnel kiln

Previous
Page 6 of 15
Next
Copyright © EngineeringMCQ.com