Furnace oil consumption in a furnace for a given duty employing preheated combination air (at 300°) may be reduced by about __________ percent as compared to the use of atmospheric combustion air. (A) 5 (B) 10 (C) 20 (D) 35

Furnace oil consumption in a furnace for a given duty employing
preheated combination air (at 300°) may be reduced by about __________
percent as compared to the use of atmospheric combustion air.
(A) 5
(B) 10
(C) 20
(D) 35
by

1 Answer

Answer :

(C) 20
by

Related questions

Combustion of furnace oil in a furnace (soaking pit) with preheated combustion air at 400°C results in saving of about __________ percentfurnace oil as compared to its combustion with atmospheric air, if the fluegas outlet temperature from the soaking pit is 1200°C.(A) 5(B) 60(C) 20(D) 40

Description : Combustion of furnace oil in a furnace (soaking pit) with preheated combustion air at 400°C results in saving of about __________ percentfurnace 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

Last Answer : (C) 20

Temperature of preheated air used for the transportation of pulverised coal through pipes to the burner of a boiler furnace is restricted to a maximum limit of about 300° C to avoid the (A) Requirement of large volume combustion chamber (B) Risk of explosion (C) Chances of clinker formation (D) Incomplete combustion of coal

Description : Temperature of preheated air used for the transportation of pulverised coal through pipes to the burner of a boiler furnace is restricted to a maximum limit of about 300° C to avoid the (A) ... chamber (B) Risk of explosion (C) Chances of clinker formation (D) Incomplete combustion of coal

Last Answer : (B) Risk of explosion

Which of the following advantages is not associated with the use of preheated air for combustion of a fuel in the furnace? (A) Increase in calorific value of the fuel (B) Increase in flame temperature (C) Reduction in scale losses (D) Saving in fuel consumption

Description : Which of the following advantages is not associated with the use of preheated air for combustion of a fuel in the furnace? (A) Increase in calorific value of the fuel (B) Increase in flame temperature (C) Reduction in scale losses (D) Saving in fuel consumption

Last Answer : (A) Increase in calorific value of the fuel

In a furnace employing forced draught as compared to induced draught, (A) Air is sucked in, so air leaks are more and hence the furnace efficiency is reduced (B) The fan operates hot and hence blades are liable to corrosion and erosion (C) Positive pressure exists in the furnace (D) None of these

Description : In a furnace employing forced draught as compared to induced draught, (A) Air is sucked in, so air leaks are more and hence the furnace efficiency is reduced (B) The fan operates hot and hence blades are liable to corrosion and erosion (C) Positive pressure exists in the furnace (D) None of these

Last Answer : (C) Positive pressure exists in the furnace

Fuel economy in an industrial furnace operation cannot be achieved by the use of (A) Stoichiometric combustion air (B) Non-preheated combustion air (C) Combustion air not enriched with oxygen (D) Recuperators

Description : Fuel economy in an industrial furnace operation cannot be achieved by the use of (A) Stoichiometric combustion air (B) Non-preheated combustion air (C) Combustion air not enriched with oxygen (D) Recuperators

Last Answer : (A) Stoichiometric combustion air

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

Description : 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 ... of fuel & air and infiltration of air (D) Use of excessive positive draft in the furnace

Last Answer : (C) Imperfect mixing of fuel & air and infiltration of air

Use of preheated air for combustion of fuel in the furnace, increases the (A) Scale losses of the furnace stock (B) Calorific value of the fuel (C) Flame temperature (D) None of these

Description : Use of preheated air for combustion of fuel in the furnace, increases the (A) Scale losses of the furnace stock (B) Calorific value of the fuel (C) Flame temperature (D) None of these

Last Answer : (C) Flame temperature

Which of the following is not increased by using preheated combustion air in place of ordinary air at room temperature? (A) Calorific value of the fuel (B) Flame temperature achieved (C) Speed of combustion of fuel (D) Heat transfer rate to the stock in the furnace

Description : Which of the following is not increased by using preheated combustion air in place of ordinary air at room temperature? (A) Calorific value of the fuel (B) Flame temperature achieved (C) Speed of combustion of fuel (D) Heat transfer rate to the stock in the furnace

Last Answer : (A) Calorific value of the fuel

Advantages of use of preheated combustion air are (A) Saving in fuel consumption (B) Reduction in scale losses (C) Increase in flame temperature (D) All (A), (B) and (C)

Description : Advantages of use of preheated combustion air are (A) Saving in fuel consumption (B) Reduction in scale losses (C) Increase in flame temperature (D) All (A), (B) and (C)

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

Correct viscosity of furnace oil at the burner tip for proper atomisation is about 25 centistokes. To reduce the viscosity of high viscosity furnace oil (250 centistokes) to the correct atomisation viscosity (i.e. 25 cst), it should be preheated to about ___________°C. (A) 70 (B) 85 (C) 105 (D) 145

Description : Correct viscosity of furnace oil at the burner tip for proper atomisation is about 25 centistokes. To reduce the viscosity of high viscosity furnace oil (250 centistokes) to the correct atomisation viscosity (i.e. 25 cst), it should be preheated to about ___________°C. (A) 70 (B) 85 (C) 105 (D) 145

Last Answer : (C) 105

Abrasion index of blast furnace coke should be around __________ percent. (A) 20 (B) 35 (C) 55 (D) 80

Description : Abrasion index of blast furnace coke should be around __________ percent. (A) 20 (B) 35 (C) 55 (D) 80

Last Answer : (D) 80

One kilogram of water at 0°C is changed to superheated steam of one atm pressure and 300° C. The major heat consumption in the process will be to (A) Heat the water from 0°C to 100°C (B) Evaporate the water (C) To superheat the steam (D) Data insufficient, can't be predicted

Description : One kilogram of water at 0°C is changed to superheated steam of one atm pressure and 300° C. The major heat consumption in the process will be to (A) Heat the water from 0°C to 100°C (B) Evaporate the water (C) To superheat the steam (D) Data insufficient, can't be predicted

Last Answer : (B) Evaporate the water

During combustion of coal on grate, clinker formation is increased by the (A) Use of thick fire bed (B) Low fusion point of ash (< 1100° C) (C) Use of preheated primary air (D) All (A), (B) & (C)

Description : During combustion of coal on grate, clinker formation is increased by the (A) Use of thick fire bed (B) Low fusion point of ash (< 1100° C) (C) Use of preheated primary air (D) All (A), (B) & (C)

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

Short/intense flame is produced during combustion of gaseous fuel by using (A) High amount/current of combustion air(B) Low amount/current of combustion air(C) Preheated secondary air(D) Very little excess air

Description : Short/intense flame is produced during combustion of gaseous fuel by using (A) High amount/current of combustion air (B) Low amount/current of combustion air (C) Preheated secondary air (D) Very little excess air

Last Answer : (A) High amount/current of combustion air

Which of the following accentuates clinkering troubles on furnace grate burning coal? (A) Low reactivity of carbonised residue containing high proportion of iron & sulphur (B) Low forced draft & fuel bed temperature (C) Thick firebed and preheated primary air (D) All (A), (B) and (C)

Description : Which of the following accentuates clinkering troubles on furnace grate burning coal? (A) Low reactivity of carbonised residue containing high proportion of iron & sulphur (B) Low forced draft & fuel bed temperature (C) Thick firebed and preheated primary air (D) All (A), (B) and (C)

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

Which of the following accentuates clinkering trouble on furnace grate burning coal? (A) Low reactivity of carbonised residue containing high proportions of iron & sulphur (B) Low forced draught and fuel bed temperature (C) Thick fire bed and preheated primary air (D) All (A), (B) and (C)

Description : Which of the following accentuates clinkering trouble on furnace grate burning coal? (A) Low reactivity of carbonised residue containing high proportions of iron & sulphur (B) Low forced draught and fuel bed temperature (C) Thick fire bed and preheated primary air (D) All (A), (B) and (C)

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

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

Description : 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

Last Answer : (B) Flame temperature

Thermal efficiency of blast furnace stoves used for heating blast (air) may be about __________ percent. (A) 20 (B) 40 (C) 60 (D) 80

Description : Thermal efficiency of blast furnace stoves used for heating blast (air) may be about __________ percent. (A) 20 (B) 40 (C) 60 (D) 80

Last Answer : (D) 80

Fish contains about __________ percent oil. (A) 5 (B) 10 (C) 20 (D) 35

Description : Fish contains about __________ percent oil. (A) 5 (B) 10 (C) 20 (D) 35

Last Answer : (C) 20

Combustion of pulverised coal compared to the lumpy coal (A) Provides better control of furnace temperature (B) Facilitates combustion with lower excess air (C) Provides higher thermal efficiency & flame temperature (D) All (A), (B) & (C)

Description : Combustion of pulverised coal compared to the lumpy coal (A) Provides better control of furnace temperature (B) Facilitates combustion with lower excess air (C) Provides higher thermal efficiency & flame temperature (D) All (A), (B) & (C)

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

Major sources of noise in furnace operation arises from air inspirators, combustion, side wall vibrations and fluctuation in the process heat load. A 50% increase in fuel firing rate may increase the furnace noise level by about __________ decibels. (A) 3 (B) 30(C) 7 (D) 70

Description : Major sources of noise in furnace operation arises from air inspirators, combustion, side wall vibrations and fluctuation in the process heat load. A 50% increase in fuel firing rate may increase the furnace noise level by about __________ decibels. (A) 3 (B) 30 (C) 7 (D) 70

Last Answer : (A) 3

. Thermal efficiency of an internal combustion engine is around __________ percent. (A) 8 (B) 35 (C) 65 (D) 80

Description : . Thermal efficiency of an internal combustion engine is around __________ percent. (A) 8 (B) 35 (C) 65 (D) 80

Last Answer : Option B

Thermal efficiency of an internal combustion engine is around __________ percent. (A) 8 (B) 35 (C) 65

Description : Thermal efficiency of an internal combustion engine is around __________ percent. (A) 8 (B) 35 (C) 65

Last Answer : Option B

Thermal efficiency of an open hearth furnace may be about __________ percent. (A) 5 (B) 20 (C) 50 (D) 80

Description : Thermal efficiency of an open hearth furnace may be about __________ percent. (A) 5 (B) 20 (C) 50 (D) 80

Last Answer : (B) 20

'Utilities' in a chemical process plant includes compressed air, steam, water, electrical power, oxygen, acetylene, fuel gases etc. Utility costs for ordinary chemical process plants ranges roughly from __________ percent of the total product cost. (A) 1 to 5 (B) 10 to 20 (C) 25 to 35 (D) 35 to 45

Description : 'Utilities' in a chemical process plant includes compressed air, steam, water, electrical power, oxygen, acetylene, fuel gases etc. Utility costs for ordinary chemical process plants ranges roughly from __________ percent of the total product ... 1 to 5 (B) 10 to 20 (C) 25 to 35 (D) 35 to 45

Last Answer : (B) 10 to 20

In a furnace operation, which is not preheated? (A) Solid fuels (B) Hydrocarbon containing fuel gases (e.g. coke oven gas, refinery gas etc.) (C) Both (A) and (B) (D) Neither (A) nor (B)

Description : In a furnace operation, which is not preheated? (A) Solid fuels (B) Hydrocarbon containing fuel gases (e.g. coke oven gas, refinery gas etc.) (C) Both (A) and (B) (D) Neither (A) nor (B)

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

A typical yield of diesel in straight run distillation of crude oil may be about __________ percent. (A) 8 (B) 18 (C) 28 (D) 35

Description : A typical yield of diesel in straight run distillation of crude oil may be about __________ percent. (A) 8 (B) 18 (C) 28 (D) 35

Last Answer : (A) 8

Oxygen content in a flue gas was found to be 4%. It implies that excess air used for combustion was around __________ percent. (A) 4 (B) 96 (C) 20 (D) 40

Description : Oxygen content in a flue gas was found to be 4%. It implies that excess air used for combustion was around __________ percent. (A) 4 (B) 96 (C) 20 (D) 40

Last Answer : (C) 20

The function of an economiser in a boiler is to preheat the (A) Feedwater (B) Combustion air (C) Pulverised coal (D) Furnace oil

Description : The function of an economiser in a boiler is to preheat the (A) Feedwater (B) Combustion air (C) Pulverised coal (D) Furnace oil

Last Answer : (A) Feedwater

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 ofcomplete combustion of(A) Furnace oil with air(B) Furnace oil with oxygen(C) Blast furnace gas with air(D) Blast furnace gas with oxygen

Description : 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 ofcomplete combustion of (A) Furnace oil with air (B) Furnace oil with oxygen (C) Blast furnace gas with air (D) Blast furnace gas with oxygen

Last Answer : (C) Blast furnace gas with air

Which of the following would require maximum amount of % excess air for complete combustion? (A) Coke oven gas (B) Furnace oil (C) Pulverised coal (D) Lump coal (fixed on chain grate)

Description : Which of the following would require maximum amount of % excess air for complete combustion? (A) Coke oven gas (B) Furnace oil (C) Pulverised coal (D) Lump coal (fixed on chain grate)

Last Answer : (D) Lump coal (fixed on chain grate)

Advantages of fluidised bed combustion are (A) Reduced NOx formation in flue gas (B) Lower furnace operating temperature (C) High heat transfer rate (D) All (A), (B) & (C)

Description : Advantages of fluidised bed combustion are (A) Reduced NOx formation in flue gas (B) Lower furnace operating temperature (C) High heat transfer rate (D) All (A), (B) & (C)

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

Acute danger to human life (i.e. death) exists, if the concentration of CO2 in atmospheric air exceeds __________ percent (by volume). (A) 1(B) 3 (C) 7 (D) 20

Description : Acute danger to human life (i.e. death) exists, if the concentration of CO2 in atmospheric air exceeds __________ percent (by volume). (A) 1 (B) 3 (C) 7 (D) 20

Last Answer : (D) 20

Live storage of coal in a power plant means (A) Coal ready for combustion (B) Preheated coal (C) storage of coal sufficient to meet 24 hour demand of the plant (D) Coal in transit.

Description : Live storage of coal in a power plant means (A) Coal ready for combustion (B) Preheated coal (C) storage of coal sufficient to meet 24 hour demand of the plant (D) Coal in transit.

Last Answer : storage of coal sufficient to meet 24 hour demand of the plant

Black smoke coming out of the chimney of a furnace is an indication of the use of __________ in the furnace. (A) Low amount of excess combustion air (B) Large quantity of excess combustion air(C) Hydrocarbon fuel(D) Pulverised coal as fuel

Description : Black smoke coming out of the chimney of a furnace is an indication of the use of __________ in the furnace. (A) Low amount of excess combustion air (B) Large quantity of excess combustion air (C) Hydrocarbon fuel (D) Pulverised coal as fuel

Last Answer : (A) Low amount of excess combustion air

Overall thermal efficiency of a lumpy coal fired suitably designed heating furnace, if operated & maintained properly may be about __________ percent. (A) 10-15 (B) 25-30 (C) 45-50 (D) 65-70

Description : Overall thermal efficiency of a lumpy coal fired suitably designed heating furnace, if operated & maintained properly may be about __________ percent. (A) 10-15 (B) 25-30 (C) 45-50 (D) 65-70

Last Answer : (B) 25-30

The heat exhaust of an automobile with an internal combustion engine represents approximately what percent of the energy of the original fuel? w) 10 % x) 50 % y) 35 % z) 5 %

Description : The heat exhaust of an automobile with an internal combustion engine represents approximately what percent of the energy of the original fuel? w) 10 % x) 50 % y) 35 % z) 5 % 

Last Answer : ANSWER: Y -- 35 % 

Test specimen for determination of refractoriness under load (RUL) of a refractory is heated in a (A) Furnace employing neutral atmosphere (B) Carbon resistance furnace (C) Reducing atmosphere (D) Furnace employing negative pressure

Description : Test specimen for determination of refractoriness under load (RUL) of a refractory is heated in a (A) Furnace employing neutral atmosphere (B) Carbon resistance furnace (C) Reducing atmosphere (D) Furnace employing negative pressure

Last Answer : (B) Carbon resistance furnace

Pick out the wrong statement. (A) Dry process is used for the manufacture of cement, when the raw material is blast furnace slag (B) Portland cement is made employing wet process (C) Gypsum is added to Portland cement to lengthen its setting time (D) None of these

Description : Pick out the wrong statement. (A) Dry process is used for the manufacture of cement, when the raw material is blast furnace slag (B) Portland cement is made employing wet process (C) Gypsum is added to Portland cement to lengthen its setting time (D) None of these

Last Answer : (D) None of these

Equipment installation cost in a chemical process plant ranges from __________ percent of the purchased equipment cost. (A) 10 to 20 (B) 35 to 45 (C) 55 to 65 (D) 70 to 80

Description : Equipment installation cost in a chemical process plant ranges from __________ percent of the purchased equipment cost. (A) 10 to 20 (B) 35 to 45 (C) 55 to 65 (D) 70 to 80

Last Answer : (B) 35 to 45

Calorific value of furnace oil is about __________ Kcal/kg. (A) 10,000 (B) 15,000 (C) 5,000 (D) 20,000

Description : Calorific value of furnace oil is about __________ Kcal/kg. (A) 10,000 (B) 15,000 (C) 5,000 (D) 20,000

Last Answer : (A) 10,000

Aerosols present in atmospheric air may be (A) Positively charged (B) Negatively charged (C) Neutral (D) Combination of all (A), (B) & (C)

Description : Aerosols present in atmospheric air may be (A) Positively charged (B) Negatively charged (C) Neutral (D) Combination of all (A), (B) & (C)

Last Answer : (D) Combination of all (A), (B) & (C)

The excess air required for the combustion of pulverised coal is of the order of about __________ percent. (A) 5 (B) 15 (C) 30 (D) 45

Description : The excess air required for the combustion of pulverised coal is of the order of about __________ percent. (A) 5 (B) 15 (C) 30 (D) 45

Last Answer : (B) 15

The thermal efficiency of a steel slab reheating furnace (walking beam type) may be about __________ percent. (A) 15 (B) 40 (C) 70 (D) 85

Description : The thermal efficiency of a steel slab reheating furnace (walking beam type) may be about __________ percent. (A) 15 (B) 40 (C) 70 (D) 85

Last Answer : (B) 40

Explosion limit of blast furnace gas is 37 to 71% gas in gas-air mixture. It means that the blast furnace gas will explode when burnt in a confined space, if its concentration in the gas-air mixture is __________ percent. (A) < 37% (B) > 71% (C) In between 37 & 71% (D) None of these

Description : Explosion limit of blast furnace gas is 37 to 71% gas in gas-air mixture. It means that the blast furnace gas will explode when burnt in a confined space, if its concentration in the gas-air mixture is __________ percent. (A) < 37% (B) > 71% (C) In between 37 & 71% (D) None of these

Last Answer : (C) In between 37 & 71%

For every 10% increase in the excess air; the fuel consumption increases by __________ percent. (A) 0.1 (B) 0.2 (C) 0.5 (D) 1.0

Description : For every 10% increase in the excess air; the fuel consumption increases by __________ percent. (A) 0.1 (B) 0.2 (C) 0.5 (D) 1.0

Last Answer : (A) 0.1

Death may occur, when SO2 concentration in atmospheric air exceeds __________ ppm.(A) 20 (B) 100 (C) 400 (D) 200

Description : Death may occur, when SO2 concentration in atmospheric air exceeds __________ ppm. (A) 20 (B) 100 (C) 400 (D) 200

Last Answer : (C) 400

Oxygen percentage in the flue gas coming out of a gaseous fuel fired furnace should be ideally about __________ percent. (A) < 2 (B) < 5 (C) < 8 (D) < 10

Description : Oxygen percentage in the flue gas coming out of a gaseous fuel fired furnace should be ideally about __________ percent. (A) < 2 (B) < 5 (C) < 8 (D) < 10

Last Answer : (A) < 2

High speed cutting tool steels contain about __________ percent of tungsten. (A) 6-8 (B) 18-20 (C) 30-35 (D) 50-55

Description : High speed cutting tool steels contain about __________ percent of tungsten. (A) 6-8 (B) 18-20 (C) 30-35 (D) 50-55

Last Answer : (B) 18-20

P2O5 content in superphosphate is about __________ percent. (A) 30-35 (B) 15-20 (C) 65-70 (D) 85-90

Description : P2O5 content in superphosphate is about __________ percent. (A) 30-35 (B) 15-20 (C) 65-70 (D) 85-90

Last Answer : (B) 15-20