Free Plant Design and Economics MCQs with Answers
803 Plant Design and Economics MCQs from Chemical Engineering, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
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- A. 10-100
- B. < 1
- C. 100-200
- D. 100-1000
Explanation: Phosgene is extremely toxic, with a permissible exposure limit well below 1 ppm, commonly quoted near 0.1 ppm.
Correct answer: < 1- A. 10000
- B. 5
- C. 500
- D. 1000
Explanation: Aquatic organisms generally require dissolved oxygen of about 5 mg/L or more for healthy survival.
Correct answer: 5- A. CO
- B. SO2
- C. NOx
- D. CFC (chloro fluoro carbons)
Explanation: Carbon monoxide is not normally identified as a major direct ozone-depleting pollutant, unlike stratospheric chlorine from CFCs and some…
Correct answer: CO- A. Potable water
- B. Industrial effluents
- C. Distilled water
- D. Cooling water
Explanation: BOD measures the oxygen microorganisms require to biologically decompose organic matter in wastewater, so it is important for assessing…
Correct answer: Industrial effluents- A. 102
- B. 105
- C. 109
- D. 1015
Explanation: Ultraviolet radiation releases chlorine radicals from CFCs, and the radicals repeatedly catalyse ozone destruction.
Correct answer: 105- A. 20
- B. 230
- C. 750
- D. 1500
Explanation: Atmospheric ozone is commonly reported in Dobson units, with a representative stratospheric value near 230 DU in many…
Correct answer: 230- A. Reheating furnace
- B. Soaking pit
- C. Open hearth furnace
- D. Cupola
Explanation: A reheating furnace commonly has separate preheating, heating and soaking zones.
Correct answer: Reheating furnace- A. Glass melting furnace
- B. All A., B. and C.
- C. By product coke ovens
- D. Open hearth furnace
Explanation: Regenerators recover heat from outgoing furnace gases and use it to preheat combustion air.
Correct answer: All A., B. and C.- A. Burning carbon monoxide and other incombustible in upper zone of furnace by supplying
- B. Supply of excess air
- C. Supply of excess fuel
- D. more air
- E. None of these
Explanation: Overfire burning occurs when carbon monoxide and other unburned combustibles burn in the upper furnace zone after additional air is…
Correct answer: Burning carbon monoxide and other incombustible in upper zone of furnace by supplying- A. Coke ovens
- B. Annealing furnace
- C. None of these
- D. Glass tank furnace
Explanation: A glass tank furnace operates continuously, with raw batch fed at one end and molten glass withdrawn at the other.
Correct answer: Glass tank furnace- A. Range of fuel firing rates
- B. Volume of the combustion chamber
- C. Maximum heat input rate only
- D. Minimum heat input rate only
Explanation: The turndown ratio is the ratio of a burner’s maximum to minimum stable firing rate.
Correct answer: Range of fuel firing rates32. A refractory wall separating the stock and the source of heat is provided in a__________________?
- A. Updraft kiln
- B. Muffle furnace
- C. Continuous furnace
- D. None of these
Explanation: In a muffle furnace, a refractory muffle wall lies between the stock and the combustion gases or heat source.
Correct answer: Muffle furnace- A. Reheating furnace
- B. Reverberatory furnace
- C. Boiler furnace
- D. Rotary kilns
Explanation: A boiler furnace is thermally efficient because heat released by combustion is transferred directly to boiler water, while the…
Correct answer: Boiler furnace34. Ingress of cold air in the furnaces through cracks, charging doors, openings etc ________________?
- A. Reduces the flue gas temperature and makes the furnace atmosphere oxidising
- B. Increases the load on the induced draft fan
- C. Reduces the furnace draught
- D. All A., B. and C.
Explanation: Leaking cold air dilutes and cools the flue gas, introduces excess oxygen that produces an oxidising atmosphere, and increases the gas…
Correct answer: All A., B. and C.- A. All A., B. and C.
- B. Preheating the combustion air
- C. Reducing the heat loss through furnace openings & doors
- D. Using oxygen enriched combustion air
Explanation: Oxygen enrichment and combustion-air preheating reduce the energy needed for combustion and lower flue-gas heat losses, while sealing…
Correct answer: All A., B. and C.- A. Open hearth furnace
- B. Muffle furnace
- C. Soaking pit
- D. Reheating furnace
Explanation: A muffle furnace heats the charge indirectly through a surrounding refractory chamber, so the material does not contact the flame or…
Correct answer: Muffle furnace- A. Air pressure
- B. Fuel gas pressure
- C. Speed of I.D. fan
- D. Damper
Explanation: Furnace pressure is commonly adjusted with the flue-gas damper, which changes the resistance to gas discharge and hence the pressure…
Correct answer: Damper- A. Blast furnace stove
- B. Sintering furnace
- C. High pressure boiler
- D. None of these
Explanation: A blast-furnace stove is normally operated with forced draught during combustion, rather than as an induced-draught furnace.
Correct answer: Blast furnace stove- A. Graphite powder
- B. Zircon powder
- C. Thoria
- D. Beryllium
Explanation: Zircon-based ceramic coatings provide a high-emissivity refractory surface, increasing radiative heat transfer to the charge.
Correct answer: Zircon powder- A. Calcination kiln
- B. Soaking pit
- C. Blast furnace
- D. L.D. converter
Explanation: A blast furnace contains carbon monoxide and hydrogen-rich gases produced from coke and injected fuel, which reduce iron oxides as the…
Correct answer: Blast furnace