Furnace Technology MCQs

Option A: Addition of methane to the furnace atmosphere reduces decarburising by hydrogen

Option B: Nitrogen in presence of steam decor-burises high carbon steel, whereas hydrocarbon gases

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

Option D: None of these

Correct Answer: None of these ✔

Option A: Computing the excess/deficiency of combustion air

Option B: Calculation of flue gas temperature

Option C: Computation of flue gas analysis

Option D: None of these

Correct Answer: Computing the excess/deficiency of combustion air ✔

Option A: Soaking pits

Option B: Walking beam reheating furnace

Option C: Boiler furnace

Option D: Rotary kilns

Correct Answer: Boiler furnace ✔

Option A: Feedwater

Option B: Combustion air

Option C: Pulverised coal

Option D: Furnace oil

Correct Answer: Feedwater ✔

Option A: Ammonia

Option B: Fine dolomite

Option C: Alkaline powders

Option D: None of these

Correct Answer: None of these ✔

Option A: Furnace oil with air

Option B: Furnace oil with oxygen

Option C: Blast furnace gas with air

Option D: Blast furnace gas with oxygen

Correct Answer: Blast furnace gas with air ✔

Option A: Stoichiometric combustion air

Option B: Non-preheated combustion air

Option C: Combustion air not enriched with oxygen

Option D: Recuperators

Correct Answer: Stoichiometric combustion air ✔

Option A: Soaking pit

Option B: Reheating furnace

Option C: Open hearth furnace

Option D: Cupola

Correct Answer: Reheating furnace ✔

Option A: Glass melting furnace

Option B: Open hearth furnace

Option C: By product coke ovens

Option D: All A., B. and C.

Correct Answer: D. All A., B. and C. ✔

Option A: Supply of excess fuel

Option B: Supply of excess air

Option C: Burning carbon monoxide and other incombustible in upper zone of furnace by supplying

Option D: None of these

Correct Answer: C. Burning carbon monoxide and other incombustible in upper zone of furnace by supplying
more air ✔

Option A: Coke ovens

Option B: Annealing furnace

Option C: Glass tank furnace

Option D: None of these

Correct Answer: Glass tank furnace ✔

Option A: Range of fuel firing rates

Option B: Volume of the combustion chamber

Option C: Maximum heat input rate only

Option D: Minimum heat input rate only

Correct Answer: Range of fuel firing rates ✔

Option A: Updraft kiln

Option B: Muffle furnace

Option C: Continuous furnace

Option D: None of these

Correct Answer: Muffle furnace ✔

Option A: Shaft furnace

Option B: Rotary hearth furnace

Option C: Tunnel kiln

Option D: Muffle furnace

Correct Answer: Tunnel kiln ✔

Option A: Ash disposal problem

Option B: Excessive fly ash discharge from the stack

Option C: Higher power consumption in its transportation

Option D: Erosion of induced draft fan blades

Correct Answer: Ash disposal problem ✔

Option A: Sidefired

Option B: Underfired

Option C: Covered

Option D: Recirculating

Correct Answer: Underfired ✔

Option A: Oxidising

Option B: Reducing

Option C: Inert

Option D: Decarburising

Correct Answer: Reducing ✔

Option A: Sankey diagram

Option B: Cox chart

Option C: Ostwald chart

Option D: None of these

Correct Answer: Sankey diagram ✔

Option A: Conduction

Option B: Natural convection

Option C: Radiation of heat from the roof of the combustion chamber

Option D: None of these

Correct Answer: Radiation of heat from the roof of the combustion chamber ✔

Option A: 350

Option B: 750

Option C: 1050

Option D: 1250

Correct Answer: 750 ✔

Option A: Use of non-preheated combustion air

Option B: Use of pulverised solid fuels

Option C: Imperfect mixing of fuel & air and infiltration of air

Option D: Use of excessive positive draft in the furnace

Correct Answer: Imperfect mixing of fuel & air and infiltration of air ✔

Option A: Muffle furnace

Option B: Annealing furnace

Option C: Reheating furnace

Option D: Rotary kiln

Correct Answer: Annealing furnace ✔

Option A: Resistance

Option B: Arc

Option C: Low frequency induction

Option D: None of these

Correct Answer: Arc ✔

Option A: Heat release rate of the fuel

Option B: Preheat temperature of fuel & air

Option C: Method of mixing the fuel & air

Option D: All A., B. and C.

Correct Answer: D. All A., B. and C. ✔

Option A: Preheating of cold stock

Option B: Preheating of combustion air

Option C: Steam generation in waste heat boilers

Option D: All A., B. and C.

Correct Answer: D. All A., B. and C. ✔

Option A: Arc

Option B: Induction

Option C: Pot

Option D: Resistance

Correct Answer: Pot ✔

Option A: Permits the use of high ash content coal

Option B: Permits the use of low fusion point ash coal

Option C: Accelerates the burning rate and economises on fuel consumption

Option D: All A., B. and C.

Correct Answer: Accelerates the burning rate and economises on fuel consumption ✔

Option A: Reheating furnace

Option B: Reverberatory furnace

Option C: Rotary kilns

Option D: Boiler furnace

Correct Answer: Boiler furnace ✔

Option A: Reduces the flue gas temperature and makes the furnace atmosphere oxidising

Option B: Increases the load on the induced draft fan

Option C: Reduces the furnace draught

Option D: All A., B. and C.

Correct Answer: D. All A., B. and C. ✔

Option A: Using oxygen enriched combustion air

Option B: Preheating the combustion air

Option C: Reducing the heat loss through furnace openings & doors

Option D: All A., B. and C.

Correct Answer: D. All A., B. and C. ✔

Option A: Open hearth furnace

Option B: Muffle furnace

Option C: Soaking pit

Option D: Reheating furnace

Correct Answer: Muffle furnace ✔

Option A: Air pressure

Option B: Fuel gas pressure

Option C: Speed of I.D. fan

Option D: Damper

Correct Answer: Damper ✔

Option A: Blast furnace stove

Option B: Sintering furnace

Option C: High pressure boiler

Option D: None of these

Correct Answer: Blast furnace stove ✔

Option A: Graphite powder

Option B: Thoria

Option C: Zircon powder

Option D: Beryllium

Correct Answer: Zircon powder ✔

Option A: Blast furnace

Option B: Steam boiler

Option C: Salt bath furnace

Option D: Annealing furnace

Correct Answer: Salt bath furnace ✔

Option A: Calcination kiln

Option B: Blast furnace

Option C: Soaking pit

Option D: L.D. converter

Correct Answer: Blast furnace ✔

Option A: Air supplied and furnace temperature

Option B: Burner design (thoroughness of mixing versus stratification)

Option C: Air preheat and the flow of gases in the furnace (mixing by induction, by acceleration or by

Option D: All A., B. and C.

Correct Answer: D. All A., B. and C. ✔

Option A: Type of fuels viz. solid, liquid or gaseous

Option B: Flue gas temperature

Option C: Emissivity of refractory walls

Option D: Initial temperature of the charged stock

Correct Answer: Type of fuels viz. solid, liquid or gaseous ✔

Option A: Increasing the draft in the furnace

Option B: Preheating the fuel gas

Option C: Oxygen enrichment of combustion air

Option D: Preheating the combustion air

Correct Answer: Increasing the draft in the furnace ✔

Option A: 10-15

Option B: 25-30

Option C: 45-50

Option D: 65-70

Correct Answer: 25-30 ✔

Option A: Soaking pit

Option B: Open hearth furnace

Option C: Coke ovens

Option D: None of these

Correct Answer: Soaking pit ✔

Option A: Air is sucked in, so air leaks are more and hence the furnace efficiency is reduced

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

Option C: Positive pressure exists in the furnace

Option D: None of these

Correct Answer: Positive pressure exists in the furnace ✔

Option A: Coke oven heating chamber

Option B: Open hearth furnace

Option C: Both A. and B.

Option D: Neither A. nor B.

Correct Answer: C. Both A. and B. ✔

Option A: More of excess air

Option B: Less of excess air

Option C: More of CO in flue gas

Option D: More of CO2 in flue gas

Correct Answer: More of excess air ✔

Option A: Emissivity of the refractory walls

Option B: Size of the furnace

Option C: Use of waste heat recovery equipments

Option D: Thickness of the stock

Correct Answer: Use of waste heat recovery equipments ✔

Option A: Protect the charge from the effects of the products of combustion

Option B: Smooth out temperature inequalities on the combustion side of the muffle wall

Option C: Both A. & B.

Option D: Neither A. nor B.

Correct Answer: C. Both A. & B. ✔

Option A: Solid fuels

Option B: Hydrocarbon containing fuel gases (e.g. coke oven gas, refinery gas etc.)

Option C: Both A. and B.

Option D: Neither A. nor B.

Correct Answer: C. Both A. and B. ✔

Option A: Pulverised coal

Option B: Furnace oil

Option C: Blast furnace gas/mixed gas

Option D: Coke oven gas

Correct Answer: Blast furnace gas/mixed gas ✔

Option A: Roasting/reduction of ores

Option B: Annealing steel coil

Option C: Heating air

Option D: Steel melting

Correct Answer: Roasting/reduction of ores ✔

Option A: Coke oven

Option B: Blast furnace stoves

Option C: Beehive coke oven

Option D: High pressure boiler

Correct Answer: High pressure boiler ✔

Option A: Rotary Kiln

Option B: Tunnel Kiln

Option C: Natural draft furnace

Option D: Batch furnace

Correct Answer: Rotary Kiln ✔

Option A: Low reactivity of carbonised residue containing high proportion of iron & sulphur

Option B: Low forced draft & fuel bed temperature

Option C: Thick firebed and preheated primary air

Option D: All A., B. and C.

Correct Answer: D. All A., B. and C. ✔

Option A: < 2

Option B: < 5

Option C: < 8

Option D: < 10

Correct Answer: < 2 ✔

Option A: Fans

Option B: Arrangement of heating stock in the furnaces

Option C: Location of outlet ports and heating & combustion devices

Option D: All A., B. and C.

Correct Answer: D. All A., B. and C. ✔

Option A: Thermal efficiency of the process

Option B: Sources of heat losses

Option C: Scope of reduction of heat losses

Option D: All A., B. and C.

Correct Answer: D. All A., B. and C. ✔

Option A: Premix

Option B: Outside mixing type

Option C: Rotary

Option D: Diffusion

Correct Answer: Premix ✔

Option A: Preheating the combustion air

Option B: Oxygen enrichment of combustion air

Option C: Preheating the fuel gas

Option D: All A., B. & C.

Correct Answer: D. All A., B. & C. ✔

Option A: Walking beam reheating furnace

Option B: Reverberatory furnace

Option C: Tower furnace

Option D: Tunnel kiln

Correct Answer: Reverberatory furnace ✔

Option A: Transportation of coal

Option B: Drying of coal

Option C: Combustion of coal by supplying it around the burner

Option D: Preheating the primary air

Correct Answer: Combustion of coal by supplying it around the burner ✔

Option A: Hood annealing furnace

Option B: Muffle furnace

Option C: Both A. and B.

Option D: Neither A. nor B.

Correct Answer: C. Both A. and B. ✔

Option A: Higher calorific value

Option B: Better combustion

Option C: Smokeless burning

Option D: Less erosion on furnace wall

Correct Answer: Better combustion ✔

Option A: Economiser

Option B: Steam superheater

Option C: Air preheater

Option D: All A., B. and C.

Correct Answer: D. All A., B. and C. ✔

Option A: Economiser

Option B: Regenerator

Option C: Ceramic recuperator

Option D: Waste heat boiler

Correct Answer: Regenerator ✔

Option A: Increase in calorific value of the fuel

Option B: Increase in flame temperature

Option C: Reduction in scale losses

Option D: Saving in fuel consumption

Correct Answer: Increase in calorific value of the fuel ✔

Option A: Blast furnace stoves

Option B: Blast furnace

Option C: Coke oven heating chamber

Option D: Rotary kilns

Correct Answer: Blast furnace stoves ✔

Option A: Size of the furnace

Option B: Gas velocity in furnace

Option C: Ratio of wall surface to surface of stock

Option D: None of these

Correct Answer: None of these ✔

Option A: Change in volume during a change of temperature

Option B: Difference in density between hot and cold gases

Option C: Furnace pressure in conjunction with draft in flues

Option D: All A., B. and C.

Correct Answer: D. All A., B. and C. ✔

Option A: Increase in heating capacity/m2 of floor space

Option B: Elimination of cold spot at the bottom of the charge

Option C: Reduction in the temperature of furnace gases

Option D: Protection of the periphery of the charge from excessive radiation

Correct Answer: Increase in heating capacity/m2 of floor space ✔

Option A: Oxidation/scaling

Option B: Decarburising

Option C: Sulphur penetration

Option D: Either of the above

Correct Answer: Either of the above ✔

Option A: Store smaller quantity of waste heat

Option B: Are lighter & compact

Option C: Involve higher initial cost

Option D: All A., B. & C.

Correct Answer: Involve higher initial cost ✔

Option A: Before the I.D fan

Option B: After the I.D. fan

Option C: Near the top of the chimney

Option D: Anywhere after the I.D. fan

Correct Answer: Before the I.D fan ✔

Option A: Electric arc struck between electrodes and the charge

Option B: Flow of current through a heating element

Option C: Combination of induced current and skin effect

Option D: None of these

Correct Answer: Flow of current through a heating element ✔

Option A: Low emissivity

Option B: High thermal conductivity

Option C: Both A. and B.

Option D: Neither A. nor B.

Correct Answer: C. Both A. and B. ✔

Option A: Soaking pit

Option B: Muffle furnace

Option C: Reheating furnace

Option D: None of these

Correct Answer: Muffle furnace ✔

Option A: Cold rolled steel coil annealing

Option B: Open hearth

Option C: Soaking pit

Option D: Walking beam reheating

Correct Answer: Cold rolled steel coil annealing ✔

Option A: 15

Option B: 40

Option C: 70

Option D: 85

Correct Answer: 40 ✔

Option A: Combination of induced current and skin effect

Option B: Induction and resistance

Option C: Current flow through a heating element

Option D: None of these

Correct Answer: Induction and resistance ✔

Option A: Temperature

Option B: Time

Option C: Nature of atmosphere

Option D: All A., B. and C.

Correct Answer: D. All A., B. and C. ✔

Option A: Use of coal/coke containing a high % of fines and ash

Option B: Use of fuel having too low an ash fusion temperature

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

Option D: All A., B. and C.

Correct Answer: D. All A., B. and C. ✔

Option A: Conduction

Option B: Convection

Option C: Radiation

Option D: Cannot be predicted

Correct Answer: Radiation ✔

Option A: Physical nature, ash content and fineness of the coal

Option B: Amount of excess air supplied and load on the boiler

Option C: Type of burner and combustion chamber

Option D: All A., B. and C.

Correct Answer: D. All A., B. and C. ✔

Option A: Electricity

Option B: Blast furnace gas/mixed gas

Option C: Coke oven gas

Option D: Both B. and C.

Correct Answer: D. Both B. and C. ✔

Option A: Weight heated/hr

Option B: Weight heated/furnace volume

Option C: Weight heated/hr/furnace volume

Option D: None of these

Correct Answer: Weight heated/hr ✔

Option A: Ton stock/hr/m2 hearth area

Option B: Ton stock/hr

Option C: Ton stock/m2 hearth area

Option D: Both B. and C.

Correct Answer: Ton stock/hr/m2 hearth area ✔

Option A: 20

Option B: 40

Option C: 65

Option D: 80

Correct Answer: 40 ✔

Option A: 10

Option B: 25

Option C: 65

Option D: 90

Correct Answer: 90 ✔

Option A: Saving in fuel consumption

Option B: Reduction in scale losses

Option C: Increase in flame temperature

Option D: All A., B. and C.

Correct Answer: D. All A., B. and C. ✔

Option A: 20

Option B: 40

Option C: 60

Option D: 80

Correct Answer: 80 ✔

Option A: Fire tube

Option B: Water tube

Option C: Waste heat

Option D: Natural circulation

Correct Answer: Natural circulation ✔

Option A: Glass

Option B: Stainless steel

Option C: Potteries

Option D: Refractory bricks

Correct Answer: Glass ✔

Option A: Ingots

Option B: Coils

Option C: Sheets

Option D: Slabs

Correct Answer: Ingots ✔

Option A: Calcination of limestone & dolomite

Option B: Cement manufacture

Option C: Both A. and B.

Option D: Neither A. nor B.

Correct Answer: C. Both A. and B. ✔

Option A: 2000

Option B: 3000

Option C: 4500

Option D: 6000

Correct Answer: 4500 ✔

Option A: Same

Option B: Less

Option C: More

Option D: Either more or less; depends on the flue gas density

Correct Answer: Less ✔

Option A: Waste heat recovery from flue gas

Option B: Minimising heat losses from furnace walls

Option C: Maintaining proper draught

Option D: All A., B. and C.

Correct Answer: D. All A., B. and C. ✔

Option A: Fusion of coal ash & clinker formation

Option B: C. V. of producer gas

Option C: Temperature of producer gas

Option D: Tar content in producer gas

Correct Answer: Fusion of coal ash & clinker formation ✔

Option A: Ostwald chart

Option B: Cox chart

Option C: Sankey diagram

Option D: None of these

Correct Answer: Sankey diagram ✔

Option A: Accelerating the rate of scaling

Option B: Causing metal embrittlement

Option C: Attacking the grain boundaries; particularly severe on low carbon and nickel bearing steels at

Option D: All A., B. and C.

Correct Answer: D. All A., B. and C. ✔

Option A: Coke ovens

Option B: Open hearth furnace

Option C: Both A. & B.

Option D: Neither A. nor B.

Correct Answer: C. Both A. & B. ✔

Option A: Smelting

Option B: Calcining

Option C: Roasting

Option D: All A., B. and C.

Correct Answer: D. All A., B. and C. ✔