In regenerative air preheater (as practised in heating of coke ovens), the heat is transferred (A) Through a metallic wall (B) By direct contact of hot flue gas with air (C) By heating an intermediate material (like chequor bricks) and then heating the air from this hot material (D) None of these

In regenerative air preheater (as practised in heating of coke ovens),

the heat is transferred

(A) Through a metallic wall

(B) By direct contact of hot flue gas with air

(C) By heating an intermediate material (like chequor bricks) and then

heating the air from this hot material

(D) None of these

by

1 Answer

Answer :

(C) By heating an intermediate material (like chequor bricks) and then

heating the air from this hot material

by

Related questions

Flue gas from the heating chamber of byproduct coke ovens is removed by (A) Forced draft fan (B) Induced draft fan (C) Steam ejector (D) Natural draft

Description : Flue gas from the heating chamber of byproduct coke ovens is removed by (A) Forced draft fan (B) Induced draft fan (C) Steam ejector (D) Natural draft

Last Answer : (D) Natural draft

Waste heat from the outgoing flue gases in a thermal power plant is recovered by a/an (A) Economiser (B) Steam superheater (C) Air preheater (D) All (A), (B) and (C)

Description : Waste heat from the outgoing flue gases in a thermal power plant is recovered by a/an (A) Economiser (B) Steam superheater (C) Air preheater (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Beehive coke ovens are made of __________ bricks.(A) Silica (B) Fireclay (C) Silicon carbide (D) Corundum

Description : Beehive coke ovens are made of __________ bricks. (A) Silica (B) Fireclay (C) Silicon carbide (D) Corundum

Last Answer : (A) Silica

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

Description : 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

Last Answer : (B) 750

Which is a regenerative furnace? (A) Coke oven heating chamber (B) Open hearth furnace (C) Both (A) and (B) (D) Neither (A) nor (B)

Description : Which is a regenerative furnace? (A) Coke oven heating chamber (B) Open hearth furnace (C) Both (A) and (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) and (B)

Phenolic water generated in coke ovens & by-product plant of a steel plant are disposed off by (A) Quenching of hot coke (B) Discharging in the river stream (C) Filtration and recycling for cooling coke oven gas (D) None of these

Description : Phenolic water generated in coke ovens & by-product plant of a steel plant are disposed off by (A) Quenching of hot coke (B) Discharging in the river stream (C) Filtration and recycling for cooling coke oven gas (D) None of these

Last Answer : (A) Quenching of hot coke

Beehive coke oven (A) Facilitates by-products recovery (B) Takes 2-3 days for coking of coal but requires no external fuel for heating (C) Gives larger yield of coke (around 85%) as compared to by-product ovens (D) Produces coke with very poor strength

Description : Beehive coke oven (A) Facilitates by-products recovery (B) Takes 2-3 days for coking of coal but requires no external fuel for heating (C) Gives larger yield of coke (around 85%) as compared to by-product ovens (D) Produces coke with very poor strength

Last Answer : (B) Takes 2-3 days for coking of coal but requires no external fuel for heating

High rate of heating of coke ovens (A) May damage its walls due to abrupt excessive swelling of coal (B) Produces larger size coke (C) Increases the time of carbonisation (D) None of these

Description : High rate of heating of coke ovens (A) May damage its walls due to abrupt excessive swelling of coal (B) Produces larger size coke (C) Increases the time of carbonisation (D) None of these

Last Answer : (A) May damage its walls due to abrupt excessive swelling of coal

Height of coke oven is limited (say maximum upto 7 metres) mainly by the(A) Problem of uniform heating along its height(B) Structural strength of silica bricks(C) Problem in door cleaning(D) Buckling of ram of pusher car at the time of coke pushing

Description : Height of coke oven is limited (say maximum upto 7 metres) mainly by the (A) Problem of uniform heating along its height (B) Structural strength of silica bricks (C) Problem in door cleaning (D) Buckling of ram of pusher car at the time of coke pushing

Last Answer : (A) Problem of uniform heating along its height

Presence of free moisture in coal during its high temperature carbonisation (A) Reduces the coking time (B) Protects the volatile products from pyrolysis (cracking) in the presence of hot coke and hot oven walls (C) Increases the loss of fine coal dust from the ovens when charging (D) None of these

Description : Presence of free moisture in coal during its high temperature carbonisation (A) Reduces the coking time (B) Protects the volatile products from pyrolysis (cracking) in the presence of hot coke and hot oven walls (C) Increases the loss of fine coal dust from the ovens when charging (D) None of these

Last Answer : (B) Protects the volatile products from pyrolysis (cracking) in the presence of hot coke and hot oven walls

Ceramic recuperators compared to metallic recuperators for the same duty (A) Are lighter (B) Occupy more space (C) Are less costly (D) Have higher pressure differential between flue gas & air side

Description : Ceramic recuperators compared to metallic recuperators for the same duty (A) Are lighter (B) Occupy more space (C) Are less costly (D) Have higher pressure differential between flue gas & air side

Last Answer : (B) Occupy more space

Coke oven gas after passing through return electrostatic tar precipitator (RETP) is used for the (A) Hot scarfing of steel slabs (B) Mixing with blast furnace gas (C) Coke oven battery heating (D) Steel ladle drying

Description : Coke oven gas after passing through return electrostatic tar precipitator (RETP) is used for the (A) Hot scarfing of steel slabs (B) Mixing with blast furnace gas (C) Coke oven battery heating (D) Steel ladle drying

Last Answer : (C) Coke oven battery heating

Pot furnace which is either regenerative or recuperative, is used in the manufacture of (A) Glass (B) Stainless steel (C) Potteries (D) Refractory bricks

Description : Pot furnace which is either regenerative or recuperative, is used in the manufacture of (A) Glass (B) Stainless steel (C) Potteries (D) Refractory bricks

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Regenerators are used for waste heat recovery in (A) By-product coke ovens (B) Beehive coke oven (C) Blast furnace stoves (D) Soaking pits

Description : Regenerators are used for waste heat recovery in (A) By-product coke ovens (B) Beehive coke oven (C) Blast furnace stoves (D) Soaking pits

Last Answer : (A) By-product coke ovens

Heat penetration rate in narrow coke ovens in high temperature carbonisation of coal is around __________ cm/hr. (A) 2.5 (B) 0.5 (C) 10 (D) 20

Description : Heat penetration rate in narrow coke ovens in high temperature carbonisation of coal is around __________ cm/hr. (A) 2.5 (B) 0.5 (C) 10 (D) 20

Last Answer : (A) 2.5

Hydrogen is recovered from coke oven gas on commercial scale (as practised in fertiliser plant at Rourkela) by (A) Adsorption on palladium (B) Cryogenic operations (low temperature cooling) (C) Absorption (using ethanolamine or pyrogallol solution) (D) None of these

Description : Hydrogen is recovered from coke oven gas on commercial scale (as practised in fertiliser plant at Rourkela) by (A) Adsorption on palladium (B) Cryogenic operations (low temperature cooling) (C) Absorption (using ethanolamine or pyrogallol solution) (D) None of these

Last Answer : (B) Cryogenic operations (low temperature cooling)

In pipe flow, heat is transferred from hot wall to the liquid by(A) Conduction only (B) Forced convection only (C) Forced convection and conduction (D) Free and forced convection

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Last Answer : (C) Forced convection and conduction

Coke ovens in steel plant are heated by (A) Electricity (B) Blast furnace gas/mixed gas (C) Coke oven gas (D) Both (B) and (C)

Description : Coke ovens in steel plant are heated by (A) Electricity (B) Blast furnace gas/mixed gas (C) Coke oven gas (D) Both (B) and (C)

Last Answer : (D) Both (B) and (C)

Coke ovens in steel plant are heated by (A) Electricity (B) Coke oven gas (C) Mixed gas (D) Both (B) & (C)

Description : Coke ovens in steel plant are heated by (A) Electricity (B) Coke oven gas (C) Mixed gas (D) Both (B) & (C)

Last Answer : (D) Both (B) & (C)

Undercharging of coal in the by-product coke ovens results in (A) Decrease in the c.v. of coke oven gas (B) Increase in its throughput (C) Increase in the c.v. of coke oven gas

Description : Undercharging of coal in the by-product coke ovens results in (A) Decrease in the c.v. of coke oven gas (B) Increase in its throughput (C) Increase in the c.v. of coke oven gas

Last Answer : (A) Decrease in the c.v. of coke oven gas

Compound coke ovens are those which can be heated by (A) Both steam and electrical power (B) Lean gas (e.g., B.F. gas) (C) Rich gas (e.g., coke oven gas) (D) Both (B) and (C)

Description : Compound coke ovens are those which can be heated by (A) Both steam and electrical power (B) Lean gas (e.g., B.F. gas) (C) Rich gas (e.g., coke oven gas) (D) Both (B) and (C)

Last Answer : (D) Both (B) and (C)

Preheating of coal charge for the coke ovens reduces the (A) Time of carbonisation (B) Yield of gas and tar(C) Fuel consumption in coking(D) All (A), (B) and (C)

Description : Preheating of coal charge for the coke ovens reduces the (A) Time of carbonisation (B) Yield of gas and tar (C) Fuel consumption in coking (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

A ______ is a specialized heat exchanger in which air and water are brought into direct contact with each otherin order to reduce the water's temperature. a. Cooling tower b. Heating tower c. Both d. All are wrong

Description : A ______ is a specialized heat exchanger in which air and water are brought into direct contact with each otherin order to reduce the water's temperature. a. Cooling tower b. Heating tower c. Both d. All are wrong

Last Answer : cooling tower

Nellore to medium temperature waste heat recovery system the most suitable device is ------ a) Economizer b) Heat wheels c) Air preheater d) Recuperate d) Carbonate

Description : Nellore to medium temperature waste heat recovery system the most suitable device is ------ a) Economizer b) Heat wheels c) Air preheater d) Recuperate d) Carbonate

Last Answer : Heat wheels

In a low to medium temperature waste heat recovery system which of the device is most suitable a) Economiser b) Heat wheels c) air preheater d) Recuperator

Description : In a low to medium temperature waste heat recovery system which of the device is most suitable a) Economiser b) Heat wheels c) air preheater d) Recuperator

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Air preheater is not used as a waste heat recovery system in a____. a) Boiler b) billet Reheating Furnace c) Heat treatment furnace d) compressor

Description : Air preheater is not used as a waste heat recovery system in a____. a) Boiler b) billet Reheating Furnace c) Heat treatment furnace d) compressor

Last Answer : compressor

A solid metallic block weighing 5 kg has an initial temperature of 500°C. 40 kg of water initially at 25°C is contained in a perfectly insulated tank. The metallic block is brought into contact with water. Both of them come to equilibrium. Specific heat of block material is 0.4 kJ.kg-1. K-1. Ignoring the effect of expansion and contraction and also the heat capacity to tank, the total entropy change in kJ.kg-1, K-1is (A) -1.87 (B) 0 (C) 1.26 (D) 3.91

Description : A solid metallic block weighing 5 kg has an initial temperature of 500°C. 40 kg of water initially at 25°C is contained in a perfectly insulated tank. The metallic block is brought into contact with water. Both of them come to equilibrium. ... .kg-1, K-1is (A) -1.87 (B) 0 (C) 1.26 (D) 3.91

Last Answer : (B) 0

White flue gas (resembling steam) coming out of the chimney of a thermal power plant indicates that the fuel used in the boiler furnace is (A) Tar (B) Coke oven gas (C) Pitch (D) Pulverised coke

Description : White flue gas (resembling steam) coming out of the chimney of a thermal power plant indicates that the fuel used in the boiler furnace is (A) Tar (B) Coke oven gas (C) Pitch (D) Pulverised coke

Last Answer : (B) Coke oven gas

Find false statement about effect of sulphur in fuel? (A) It has heating value (B) It helps in electrostatic precipitation of ash in flue gases (C) It leads to corrosion of air heaters, ducting, etc. if flue gas exit temperature is low (D) It erodes furnace walls

Description : Find false statement about effect of sulphur in fuel? (A) It has heating value (B) It helps in electrostatic precipitation of ash in flue gases (C) It leads to corrosion of air heaters, ducting, etc. if flue gas exit temperature is low (D) It erodes furnace walls

Last Answer : (D) It erodes furnace walls

Regenerators are normally provided in the (A) Glass melting furnace (B) Open hearth furnace (C) By product coke ovens (D) All (A), (B) and (C)

Description : Regenerators are normally provided in the (A) Glass melting furnace (B) Open hearth furnace (C) By product coke ovens (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Regenerators are normally provided in the (A) Glass melting furnace (B) Open hearth furnace (C) By product coke ovens (D) All (A), (B) and (C)

Description : Regenerators are normally provided in the (A) Glass melting furnace (B) Open hearth furnace (C) By product coke ovens (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Which is a continuous furnace? (A) Coke ovens (B) Annealing furnace (C) Glass tank furnace

Description : Which is a continuous furnace? (A) Coke ovens (B) Annealing furnace (C) Glass tank furnace

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Regenerators are installed in (A) Coke ovens (B) Open hearth furnace (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : Regenerators are installed in (A) Coke ovens (B) Open hearth furnace (C) Both (A) & (B) (D) Neither (A) nor (B)

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An example of recuperative furnace is the (A) Soaking pit (B) Open hearth furnace (C) Coke ovens (D) None of these

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Narrow coke ovens as compared to wider coke ovens (A) Produce smaller coke (B) Produce stronger coke (C) Require less time of carbonisation (D) All (A), (B) and (C)

Description : Narrow coke ovens as compared to wider coke ovens (A) Produce smaller coke (B) Produce stronger coke (C) Require less time of carbonisation (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Coking time in narrow by-product coke ovens is around __________ hours. (A) 18 (B) 48 (C) 8 (D) 80

Description : Coking time in narrow by-product coke ovens is around __________ hours. (A) 18 (B) 48 (C) 8 (D) 80

Last Answer : (A) 18

Main use of hard coke produced by high temperature carbonisation is in the (A) Iron blast furnace (B) Cupola in foundries (C) Sinter making (D) Domestic ovens

Description : Main use of hard coke produced by high temperature carbonisation is in the (A) Iron blast furnace (B) Cupola in foundries (C) Sinter making (D) Domestic ovens

Last Answer : (A) Iron blast furnace

Coke made in narrower by-product coke ovens (as compared to wider ovens) is (A) Less reactive (B) Stronger (C) Smaller in size (D) All (A), (B) & (C)

Description : Coke made in narrower by-product coke ovens (as compared to wider ovens) is (A) Less reactive (B) Stronger (C) Smaller in size (D) All (A), (B) & (C)

Last Answer : (D) All (A), (B) & (C)

Pick out the wrong statement. (A) Nitrogen is normally supplied in fertiliser either in Ammoniacal or the nitrate form, from which the soil takes it up in the form of ammonium ions ornitrate ions and forms amino acids(B) Calcium present in the fertiliser helps in correcting the soil acidity(C) Particle size range of a good granular fertiliser is 10-15 mesh and itcontains less moisture as compared to finely divided powder form of fertiliser(D) Ammonium nitrate fertiliser is obtained as a by-product in an integratedsteel plant having by-product coke ovens

Description : Pick out the wrong statement. (A) Nitrogen is normally supplied in fertiliser either in Ammoniacal or the nitrate form, from which the soil takes it up in the form of ammonium ions ornitrate ... nitrate fertiliser is obtained as a by-product in an integrated steel plant having by-product coke ovens

Last Answer : (D) Ammonium nitrate fertiliser is obtained as a by-product in an integrated steel plant having by-product coke ovens

Phenolic water generated in coke ovens & by-product plant attached to an integrated steel plant containing phenol in concentration of less than 100 mg/litre can be removed by (A) Chlorination (B) Treating in biological oxygen pond (C) Chemical coagulation (D) None of these

Description : Phenolic water generated in coke ovens & by-product plant attached to an integrated steel plant containing phenol in concentration of less than 100 mg/litre can be removed by (A) Chlorination (B) Treating in biological oxygen pond (C) Chemical coagulation (D) None of these

Last Answer : (B) Treating in biological oxygen pond

Pick out the wrong statement. (A) The controlling resistance in case of heating of air by condensing steam is in the air film (B) The log mean temperature difference (LMTD) for counter flow and parallel flow can be theoretically same when any one of the fluids (hot or cold fluid) passes through the heat exchanger at constant temperature (C) In case of a 1 - 2 shell and tube heat exchanger, the LMTD correction factor value increases sharply, when a temperature cross occurs (D) Phase change in case of a pure fluid at a given pressure from liquid to vapor or vice-versa occurs at saturation temperature

Description : Pick out the wrong statement. (A) The controlling resistance in case of heating of air by condensing steam is in the air film (B) The log mean temperature difference (LMTD) for ... a pure fluid at a given pressure from liquid to vapor or vice-versa occurs at saturation temperature

Last Answer : (C) In case of a 1 - 2 shell and tube heat exchanger, the LMTD correction factor value increases sharply, when a temperature cross occurs

Which of the following variables affects the furnace capacity? (A) Temperature of flue gas (B) Thermal conductivity of stock (C) Thickness of heating stock(D) All (A), (B) and (C)

Description : Which of the following variables affects the furnace capacity? (A) Temperature of flue gas (B) Thermal conductivity of stock (C) Thickness of heating stock (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Oxygen enrichment of combustion air does not result in increase of the (A) Flame temperature (B) Oxygen in the flue gas (C) Stack loss (D) Heat transfer rate in the furnace

Description : Oxygen enrichment of combustion air does not result in increase of the (A) Flame temperature (B) Oxygen in the flue gas (C) Stack loss (D) Heat transfer rate in the furnace

Last Answer : (B) Oxygen in the flue gas

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) Recuperator (B) Regenerator (C) Waste heat boiler (D) None of these

Description : 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) Recuperator (B) Regenerator (C) Waste heat boiler (D) None of these

Last Answer : (B) Regenerator

To reduce the stack loss, heat recovery from flue gas can be done by (A) Preheating of cold stock (B) Preheating of combustion air (C) Steam generation in waste heat boilers (D) All (A), (B) and (C)

Description : To reduce the stack loss, heat recovery from flue gas can be done by (A) Preheating of cold stock (B) Preheating of combustion air (C) Steam generation in waste heat boilers (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Presence of nitrogen in combustion air does not reduce the (A) Amount of heat liberated (B) Flame temperature (C) Flue gas temperature (D) Any of the above

Description : Presence of nitrogen in combustion air does not reduce the (A) Amount of heat liberated (B) Flame temperature (C) Flue gas temperature (D) Any of the above

Last Answer : (A) Amount of heat liberated

Too much of excess air in combustion results in high (A) Fuel consumption for the same heat load (B) Stack gas temperature (C) Percentage of oxygen in flue gases (D) All (A), (B) and (C)

Description : Too much of excess air in combustion results in high (A) Fuel consumption for the same heat load (B) Stack gas temperature (C) Percentage of oxygen in flue gases (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

The main drawback of supplying more excess air in the combustion of fuel is the (A) Excessive power requirement of air blower (B) Enhanced sensible heat loss in the flue gas (C) Intermittent and uncontrolled combustion of the fuel (D) High exit flue gas temperature from the furnace

Description : The main drawback of supplying more excess air in the combustion of fuel is the (A) Excessive power requirement of air blower (B) Enhanced sensible heat loss in the flue gas (C) Intermittent and uncontrolled combustion of the fuel (D) High exit flue gas temperature from the furnace

Last Answer : (B) Enhanced sensible heat loss in the flue gas

Sensible heat of hot industrial flue gases cannot be recovered by a/an (A) Economiser (B) Regenerator (C) Ceramic recuperator (D) None of these

Description : Sensible heat of hot industrial flue gases cannot be recovered by a/an (A) Economiser (B) Regenerator (C) Ceramic recuperator (D) None of these

Last Answer : (D) None of these

Coke oven regenerators are made of __________ bricks. (A) Fire clay (B) Silica (C) Low thermal conductivity (D) High electrical conductivity

Description : Coke oven regenerators are made of __________ bricks. (A) Fire clay (B) Silica (C) Low thermal conductivity (D) High electrical conductivity

Last Answer : (A) Fire clay