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This section includes 336 Mcqs, each offering curated multiple-choice questions to sharpen your Chemical Engineering knowledge and support exam preparation. Choose a topic below to get started.
1. |
Which of the following is the most suitable for preheating combustion air above 650°C ? |
A. | Regenerator |
B. | Metallic recuperator |
C. | Ceramic recuperator |
D. | None of these |
Answer» D. None of these | |
2. |
Acid dew point temperature (ADT) of a flue gas produced by the combustion of a fuel containing 1% sulphur may be about __________ °C. |
A. | 80 |
B. | 130 |
C. | 180 |
D. | 250 |
Answer» C. 180 | |
3. |
Ceramic recuperators (made of SiC) is economical, only when used for preheating combustion air above __________ °C. |
A. | 250 |
B. | 650 |
C. | 850 |
D. | 1000 |
Answer» C. 850 | |
4. |
In practical operation of any furnace, zero oxygen percentage or theoretical CO percentage in flue gas is rarely achieved, because of |
A. | use of non-preheated combustion air. |
B. | use of pulverised solid fuels. |
C. | imperfect mixing of fuel & air and infiltration of air. |
D. | use of excessive positive draft in the furnace. |
Answer» D. use of excessive positive draft in the furnace. | |
5. |
Combustion of furnace oil in a furnace (soaking pit) with preheated combustion air at 400°C 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 1200°C. |
A. | 5 |
B. | 60 |
C. | 20 |
D. | 40 |
Answer» D. 40 | |
6. |
While the fuel fired furnace can be used upto a maximum temperature of about 1700°C, the electric furnace can be used upto a temperature of about __________ °C. |
A. | 2000 |
B. | 3000 |
C. | 4500 |
D. | 6000 |
Answer» D. 6000 | |
7. |
Presence of SO in furnace gases attacks the ferrous metal by way of |
A. | accelerating the rate of scaling. |
B. | causing metal embrittlement. |
C. | attacking the grain boundaries; particularly severe on low carbon and nickel bearing steels at high temperature. |
D. | all (a), (b) and (c). |
Answer» E. | |
8. |
Which of the following advantages is not associated with the use of preheated air for combustion of a fuel in the furnace? |
A. | ncrease in calorific value of the fuel |
B. | ncrease in flame temperature |
C. | eduction in scale losses |
D. | aving in fuel consumption |
Answer» B. ncrease in flame temperature | |
9. |
In which of the waste heat recovery equipment, the flow of flue gas and air is alternately reversed after a fixed interval of time? |
A. | ecuperator |
B. | egenerator |
C. | aste heat boiler |
D. | one of these |
Answer» C. aste heat boiler | |
10. |
Which of the following is the most important deterrants to an extended use of pulverised coal in boiler firing? |
A. | sh disposal problem |
B. | xcessive fly ash discharge from the stack |
C. | igher power consumption in its transportation |
D. | rosion of induced draft fan blades |
Answer» B. xcessive fly ash discharge from the stack | |
11. |
Which of the following is not a continuous waste heat recovery equipment from the flue gases going out of furnace? |
A. | conomiser |
B. | egenerator |
C. | eramic recuperator |
D. | aste heat boiler |
Answer» C. eramic recuperator | |
12. |
Which is a regenerative furnace? |
A. | Coke oven heating chamber |
B. | Open hearth furnace |
C. | Both A and B |
D. | Neither A nor B |
Answer» D. Neither A nor B | |
13. |
Out of the following fuels used in a furnace exhausting flue gas at a temperature of 600°C, the percentage stack loss will be maximum in case of complete combustion of |
A. | Furnace oil with air |
B. | Furnace oil with oxygen |
C. | Blast furnace gas with air |
D. | Blast furnace gas with oxygen |
Answer» D. Blast furnace gas with oxygen | |
14. |
Which is the most thermally efficient furnace? |
A. | Reheating furnace |
B. | Reverberatory furnace |
C. | Rotary kilns |
D. | Boiler furnace |
Answer» E. | |
15. |
Which of the following is a directly fired intermittant furnace? |
A. | Walking beam reheating furnace |
B. | Reverberatory furnace |
C. | Tower furnace |
D. | Tunnel kiln |
Answer» C. Tower furnace | |
16. |
Acid dew point temperature (ADT) of a flue gas produced by the combustion of a fuel containing 1% sulphur may be about __________ °C. |
A. | 80 |
B. | 130 |
C. | 180 |
D. | 250 |
Answer» C. 180 | |
17. |
Ceramic recuperators (made of SiC) is economical, only when used for preheating combustion air above __________ °C. |
A. | 250 |
B. | 650 |
C. | 850 |
D. | 1000 |
Answer» C. 850 | |
18. |
Combustion of furnace oil in a furnace (soaking pit) with preheated combustion air at 400°C 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 1200°C. |
A. | 5 |
B. | 60 |
C. | 20 |
D. | 40 |
Answer» D. 40 | |
19. |
While the fuel fired furnace can be used upto a maximum temperature of about 1700°C, the electric furnace can be used upto a temperature of about __________ °C. |
A. | 2000 |
B. | 3000 |
C. | 4500 |
D. | 6000 |
Answer» D. 6000 | |
20. |
Which furnace employs an I.D. fan for the removal of flue gases from the furnace? |
A. | Coke oven |
B. | Blast furnace stoves |
C. | Beehive coke oven |
D. | High pressure boiler |
Answer» E. | |
21. |
In furnaces operating at very high temperature (say) 1250°C, e.g. soaking pit), the maximum heat transfer takes place by |
A. | Conduction |
B. | Convection |
C. | Radiation |
D. | Can not be predicted |
Answer» D. Can not be predicted | |
22. |
Presence of SO₂ in furnace gases attacks the ferrous metal by way of |
A. | Accelerating the rate of scaling |
B. | Causing metal embrittlement |
C. | Attacking the grain boundaries; particularly severe on low carbon and nickel bearing steels at high temperature |
D. | All of the above |
Answer» E. | |
23. |
In practical operation of any furnace, zero oxygen percentage or theoretical CO₂ percentage in flue gas is rarely achieved, because of |
A. | Use of non-preheated combustion air |
B. | Use of pulverised solid fuels |
C. | Imperfect mixing of fuel & air and infiltration of air |
D. | Use of excessive positive draft in the furnace |
Answer» D. Use of excessive positive draft in the furnace | |
24. |
Which is not a hearth furnace? |
A. | Glass tank furnace |
B. | Open hearth furnace |
C. | Cupola |
D. | Reheating furnace |
Answer» D. Reheating furnace | |
25. |
Which is a continuous furnace? |
A. | Coke ovens |
B. | Annealing furnace |
C. | Glass tank furnace |
D. | None of these |
Answer» D. None of these | |
26. |
Which is not accomplished in an underfired furnace? |
A. | Increase in heating capacity/m² of floor space |
B. | Elimination of cold spot at the bottom of the charge |
C. | Reduction in the temperature of furnace gases |
D. | Portection of the periphery of the charge from excessive radiation |
Answer» B. Elimination of cold spot at the bottom of the charge | |
27. |
Which of the following is a natural draft furnace? |
A. | Blast furnace stoves |
B. | Power plant boilers |
C. | Sintering furnace |
D. | None of these |
Answer» B. Power plant boilers | |
28. |
Which of the following is the most suitable for preheating combustion air above 650°C ? |
A. | Regenerator |
B. | Metallic recuperator |
C. | Ceramic recuperator |
D. | None of these |
Answer» D. None of these | |
29. |
Which of the following is a batch furnace? |
A. | Cupola |
B. | Reheating furnace |
C. | Glass tank furnace |
D. | None of these |
Answer» B. Reheating furnace | |
30. |
Metallic recuperators are not used for waste heat recovery, if the hot flue gas temperature is above __________ °C, because corrosion prevails at higher temperatures. |
A. | 350 |
B. | 750 |
C. | 1050 |
D. | 1250 |
Answer» C. 1050 | |
31. |
Which of the following furnaces will have maximum thermal efficiency? |
A. | Soaking pits |
B. | Walking beam reheating furnace |
C. | Boiler furnace |
D. | Rotary kilns |
Answer» D. Rotary kilns | |
32. |
Flue gas outlet temperature from the chimney of any furnace should be ideally about __________ °C. |
A. | 50 |
B. | 100 |
C. | 150 |
D. | 250 |
Answer» D. 250 | |
33. |
In reverberatory furnace, charge is heated mainly by%! |
A. | Conduction |
B. | Natural convection |
C. | Radiation of heat from the roof of the combustion chamber |
D. | None of these |
Answer» D. None of these | |
34. |
Decarburisation of steel%! |
A. | Is the removal of carbon from iron carbide (Fe‚ÇÉC) |
B. | Affects its crystalline structure |
C. | Is favoured by CO‚ÇÇ |
D. | All of the above |
Answer» E. | |
35. |
If the flame is produced under the hearth and then sweeps up into the heating chamber, this is called a/an __________ furnace.%! |
A. | Sidefired |
B. | Underfired |
C. | Covered |
D. | Recirculating |
Answer» C. Covered | |
36. |
Means for giving direction to the circulation of gases in furnaces are%! |
A. | Fans |
B. | Arrangement of heating stock in the furnaces |
C. | Location of outlet ports and heating & combustion devices |
D. | All of the above |
Answer» E. | |
37. |
Pot furnace which is either regenerative or recupterative, is used in the manufacture of%! |
A. | Glass |
B. | Stainless steel |
C. | Potteries |
D. | Refractory bricks |
Answer» B. Stainless steel | |
38. |
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%! |
A. | Ostwald chart |
B. | Cox chart |
C. | Sankey diagram |
D. | None of these |
Answer» D. None of these | |
39. |
Size of the combustion chamber of a furnace depends upon the%! |
A. | Heat release rate of the fuel |
B. | Preheat temperature of fuel & air |
C. | Method of mixing the fuel & air |
D. | All of the above |
Answer» E. | |
40. |
In order to maintain a reducing atmosphere in a furnace, it should have%! |
A. | No O‚ÇÇ in flue gas |
B. | CO in flue gas |
C. | High excess air |
D. | None of these |
Answer» C. High excess air | |
41. |
__________ atmosphere is maintained inside an iron blast furnace.%! |
A. | Oxidising |
B. | Reducing |
C. | Inert |
D. | Decarburising |
Answer» C. Inert | |
42. |
Thermal efficiency of a limestone calcination rotary kiln may be around __________ percent.%! |
A. | 20 |
B. | 40 |
C. | 65 |
D. | 80 |
Answer» C. 65 | |
43. |
Which of the following is a natural draft furnace?%! |
A. | Blast furnace stoves |
B. | Power plant boilers |
C. | Sintering furnace |
D. | None of these |
Answer» B. Power plant boilers | |
44. |
In producer gas making furnace, steam is added along with air to mainly control the%! |
A. | Fusion of coal ash & clinker formation |
B. | C. V. of producer gas |
C. | Temperature of producer gas |
D. | Tar content in producer gas |
Answer» B. C. V. of producer gas | |
45. |
Blast furnace stoves are meant for heating%! |
A. | Air |
B. | Blast furnace gas |
C. | Steam |
D. | None of these |
Answer» B. Blast furnace gas | |
46. |
Rate of heat release in a furnace, which is the measure of heat intensity is defined as%! |
A. | Kcal/hr/m³ combustion space |
B. | Kcal/m³ combustion space |
C. | Kcal/hr |
D. | None of these |
Answer» B. Kcal/m¬¨‚â• combustion space | |
47. |
Combustion of fuel in a furnace with oxygen enriched air results in higher%! |
A. | Flue gas volume |
B. | Flame temperature |
C. | Fuel consumption |
D. | Stack loss |
Answer» C. Fuel consumption | |
48. |
Large tonnage of refractory bricks are dried in a%! |
A. | Shaft furnace |
B. | Rotary hearth furnace |
C. | Tunnel kiln |
D. | Muffle furnace |
Answer» D. Muffle furnace | |
49. |
*$_In order to maintain a reducing atmosphere in a furnace, it should have? |
A. | No O‚ÇÇ in flue gas |
B. | CO in flue gas |
C. | High excess air |
D. | None of these |
Answer» C. High excess air | |
50. |
*$_Blast furnace stoves are meant for heating? |
A. | Air |
B. | Blast furnace gas |
C. | Steam |
D. | None of these |
Answer» B. Blast furnace gas | |