chemical engineering furnace technology MCQs – Page 6

Practise multiple-choice questions from chemical engineering furnace technology for competitive examinations and subject revision. Review each marked answer and report any item that may be outdated or unclear.

chemical engineering furnace technology Mcqs
101. Which of the following accentuates clinkering troubles on furnace grate burning coal ?
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A. All A., B. and C.

B. Thick firebed and preheated primary air

C. Low reactivity of carbonised residue containing high proportion of iron & sulphur

D. Low forced draft & fuel bed temperature

102. Thermal efficiency of a limestone calcination rotary kiln may be around ______________ percent?
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A. 80

B. 65

C. 40

D. 20

103. Hearth furnaces are not used for____________________?
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A. None of these

B. Melting

C. Reheating

D. Roasting

104. In reverberatory furnace, charge is heated mainly by__________________?
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A. None of these

B. Natural convection

C. Conduction

D. Radiation of heat from the roof of the combustion chamber
105. _____________ furnace is not an electric furnace?
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A. Resistance

B. Arc

C. Induction

D. Pot
106. Forced recirculation of furnace gases is practised_______________?
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A. To increase heat transfer by convection

B. All A., B. and C.

C. To ensure uniform temperature

D. In furnaces, operating below 750C

107. The function of an economiser in a boiler is to preheat the _____________________?
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A. Feedwater

B. Furnace oil

C. Combustion air

D. Pulverised coal

108. Use of pulverised coal in boilers provides____________________?
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A. Less erosion on furnace wall

B. Better combustion

C. Smokeless burning

D. Higher calorific value

109. Combustion of furnace oil in a furnace (soaking pit) with preheated combustion air at 400C results in saving of about __________ percent furnace oil as compared to its combustion with atmospheric air, if the flue gas outlet temperature from the soaking pit is 1200C ?
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A. 60

B. 5

C. 40

D. 20
110. Waste heat from the outgoing flue gases in a thermal power plant is recovered by a/an_________________?
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A. Steam superheater

B. Air preheater

C. All A., B. and C.

D. Economiser

111. Maximum heat transfer in high temperature furnaces is by____________________?
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A. Either A., B. or C.; depends on the type of furnace

B. Radiation

C. Conduction

D. Convection

112. In a heating process, a heat flow diagram in which the quantities of heat in the various items of a heat balance are represented by the width of a band is called the__________________?
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A. Sankey diagram

B. Ostwald chart

C. Cox chart

D. None of these

113. Which of the following is not an additive for flue gases from furnace to reduce its dewpoint ?
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A. Ammonia

B. Fine dolomite

C. None of these

D. Alkaline powders

114. An electric furnace producing heat by means of an electric arc struck between each of three electrodes and the charge is called ____________ furnace?
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A. Low frequency induction

B. None of these

C. Resistance

D. Arc
115. ______________ is an indirectly heated furnace?
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A. Open hearth furnace

B. Soaking pit

C. Muffle furnace

D. Reheating furnace

116. The advantages of firing pulverised coal in the furnace lies in the fact that, it_____________________?
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A. Permits the use of high ash content coal

B. Accelerates the burning rate and economises on fuel consumption

C. All A., B. and C.

D. Permits the use of low fusion point ash coal

117. Scaling of furnace stock is reduced by _______________ in flue gas?
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A. CO

B. H2

C. All A., B. & C.

D. High CO/CO2

118. Thermal efficiency of furnaces can be improved by____________________?
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A. Minimising heat losses from furnace walls

B. Maintaining proper draught

C. All A., B. and C.

D. Waste heat recovery from flue gas

119. Which is a regenerative furnace ?
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A. Coke oven heating chamber

B. Open hearth furnace

C. Both A. and B.

D. Neither A. nor B.

120. Turn down ratio of a burner____________________?
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A. Should be 1:1 for a batch type furnace

B. Is the ratio of maximum to minimum permissible heat input rates

C. Is normally much more for a continuous furnace as compared to a batch furnace

D. Should be as low as possible i.e., 1 : 2