chemical engineering furnace technology MCQs – Page 7

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 Review each marked answer and report any item that may be outdated or unclear.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
121. If the flame is produced under the hearth and then sweeps up into the heating chamber, this is called a/an ______________ furnace?
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A. Underfired

B. Sidefired

C. Recirculating

D. Covered

122. Heat balance of furnace provides means of determining the_________________?
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A. All A., B. and C.

B. Scope of reduction of heat losses

C. Sources of heat losses

D. Thermal efficiency of the process

123. Which of the following is not a directly fired furnace ?
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A. Calcination kiln

B. By-product coke oven

C. Sintering furnace

D. Open hearth furnace

124. In a muffle furnace, the muffle_________________?
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A. Permits the use of controlled atmosphere for the protection of stock

B. Retards the heat transfer

C. All A., B. and C.

D. Assists in temperature equalisation in the charge

125. Heat transfer rate to the charge/stock in a furnace does not depend upon the________________?
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A. Flue gas temperature

B. Emissivity of refractory walls

C. Initial temperature of the charged stock

D. Type of fuels viz. solid, liquid or gaseous
126. Pick out the wrong statement ?
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A. Addition of methane to the furnace atmosphere reduces decarburising by hydrogen

B. None of these

C. Active nitrogen (formed by cracking ammonia at the metal surface) cause nitride formation

D. h increase in surface hardness

E. burise the surface of steel at annealing temperatures

F. Nitrogen in presence of steam decor-burises high carbon steel, whereas hydrocarbon gases

127. In a furnace employing forced draught as compared to induced draught______________________?
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A. Positive pressure exists in the furnace

B. The fan operates hot and hence blades are liable to corrosion and erosion

C. None of these

D. Air is sucked in, so air leaks are more and hence the furnace efficiency is reduced

128. Which is a continuous furnace ?
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A. Coke ovens

B. Glass tank furnace

C. Annealing furnace

D. None of these

129. Which one shows the diagrammatic heat balance in a furnace ?
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A. Ostwald chart

B. Sankey diagram

C. None of these

D. Cox chart

130. In producer gas making furnace, steam is added along with air to mainly control the____________________?
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A. Tar content in producer gas

B. Temperature of producer gas

C. Fusion of coal ash & clinker formation

D. C. V. of producer gas

131. The reason for excessive clinker formation in gas producers is the_____________________?
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A. Use of coal/coke containing a high % of fines and ash

B. All A., B. and C.

C. Development of hot spots in the fuel bed and an abnormally high rate of gasification

D. Use of fuel having too low an ash fusion temperature

132. Air filtration in a furnace___________________?
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A. Is indicated by flame sting out

B. None of these

C. Reduces its thermal efficiency

D. Increases the flue gas temperature

133. Artificial draught produced by a fan in the furnace can be controlled by the___________________?
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A. Variation in the pitch of fan blades

B. All A., B. and C.

C. Damper

D. Speed of the fan

134. Unit of furnace loading is____________________?
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A. Ton stock/hr/m2 hearth area

B. Ton stock/hr

C. Ton stock/m2 hearth area

D. Both B. and C.

135. Which of the following is a directly fired intermittent furnace ?
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A. Tunnel kiln

B. Walking beam reheating furnace

C. Reverberatory furnace

D. Tower furnace

136. Turndown ratio of a burner gives an idea of the ______________ in the furnace?
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A. Minimum heat input rate only

B. Range of fuel firing rates

C. Maximum heat input rate only

D. Volume of the combustion chamber

137. The purpose of controlling the furnace atmosphere is to prevent surface attack by__________________?
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A. Oxidation/scaling

B. Either of the above

C. Decarburising

D. Sulphur penetration

138. Dampers are located__________________?
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A. After the I.D. fan

B. Before the I.D fan

C. Near the top of the chimney

D. Anywhere after the I.D. fan

139. Oxygen percentage in the flue gas coming out of a gaseous fuel fired furnace should be ideally about _____________ percent?
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A. < 8

B. < 2

C. < 10

D. < 5

140. Thermal efficiency of an open hearth furnace may be about _____________ percent?
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A. 20

B. 80

C. 5

D. 50