Q.1

Heat transfer takes place through a liquid medium surrounding the submerged material under heating, in case of a/an

  • blast furnace.
  • steam boiler.
  • salt bath furnace.
  • annealing furnace.
Q.2

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

  • conduction
  • convection
  • radiation
  • can not be predicted.
Q.3

Which of the following is a directly fired intermittant furnace ?

  • Walking beam reheating furnace
  • Reverberatory furnace
  • Tower furnace
  • Tunnel kiln
Q.4

An example of indirectly heated furnace is the

  • soaking pit
  • muffle furnace
  • reheating furnace
  • none of these
Q.5

Turn down ratio of a burner

  • should be as low as possible i.e., 1 : 2.
  • should be 1:1 for a batch type furnace..
  • is the ratio of maximum to minimum permissible heat input rates.
  • is normally much more for a continuous furnace as compared to a batch furnace.
Q.6

Heat balance of furnace provides means of determining the

  • thermal efficiency of the process.
  • sources of heat losses.
  • scope of reduction of heat losses.
  • all (a), (b) and (c).
Q.7

Maximum thermal efficiency of boiler may be about __________ percent.

  • 10
  • 25
  • 65
  • 90
Q.8

Which of the following is a periodic furnace?

  • Tunnel kiln
  • Rotary kiln
  • Soaking pit
  • Reheating furnace.
Q.9

Specific heating capacity of a furnace is expressed as

  • weight heated/hr
  • weight heated/furnace volume
  • weight heated/hr/furnace volume
  • none of these
Q.10

Which of the following is not a continuous waste heat recovery equipment from the flue gases going out of furnace ?

  • Economiser.
  • Regenerator.
  • Ceramic recuperator.
  • Waste heat boiler.
Q.11

Rotary kilns are used in the

  • calcination of limestone & dolomite.
  • cement manufacture.
  • both (a) and (b).
  • neither (a) nor (6).
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