In case of liquid petrofuels, momentary combustion is observed at its (A) Flash point (B) Preheating temperature corresponding to viscosity of 25 centistokes (C) Flame temperature (D) Fire point

In case of liquid petrofuels, momentary combustion is observed at its
(A) Flash point
(B) Preheating temperature corresponding to viscosity of 25 centistokes
(C) Flame temperature
(D) Fire point
by

1 Answer

Answer :

(A) Flash point
by

Related questions

Preheating of combustion air is done to (A) Increase the adiabatic flame temperature (B) Increase the calorific value of the fuel (C) Complete the combustion of fuel (D) Reduce its requirement for effecting the complete combustion

Description : Preheating of combustion air is done to (A) Increase the adiabatic flame temperature (B) Increase the calorific value of the fuel (C) Complete the combustion of fuel (D) Reduce its requirement for effecting the complete combustion

Last Answer : (A) Increase the adiabatic flame temperature

Preheating of __________ the flame temperature. (A) The gaseous fuel before combustion decreases (B) Combustion air decreases (C) Either the fuel or the air or both, increases (D) Either the fuel or the air does not affect

Description : Preheating of __________ the flame temperature. (A) The gaseous fuel before combustion decreases (B) Combustion air decreases (C) Either the fuel or the air or both, increases (D) Either the fuel or the air does not affect

Last Answer : (C) Either the fuel or the air or both, increases

Maximum viscosity of tar/PCM/fuel oil for easy and efficient atomisation in conventional burner is __________ centistokes (or 100 Redwood I seconds). (A) 5 (B) 25 (C) 50 (D) 100

Description : Maximum viscosity of tar/PCM/fuel oil for easy and efficient atomisation in conventional burner is __________ centistokes (or 100 Redwood I seconds). (A) 5 (B) 25 (C) 50 (D) 100

Last Answer : (B) 25

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

The temperature at which flame persists for approximately five seconds is called..... (a) Fire point (b) Flash point (c) Pour point (d) cloud point

Description : The temperature at which flame persists for approximately five seconds is called..... (a) Fire point (b) Flash point (c) Pour point (d) cloud point

Last Answer : (a) Fire point

In case of pulverised coal fired steam boiler, the secondary air serves the main purpose of (A) Transportation of coal (B) Drying of coal (C) Combustion of coal by supplying it around the burner (D) Preheating the primary air

Description : In case of pulverised coal fired steam boiler, the secondary air serves the main purpose of (A) Transportation of coal (B) Drying of coal (C) Combustion of coal by supplying it around the burner (D) Preheating the primary air

Last Answer : (C) Combustion of coal by supplying it around the burner

In case of pulverised coal fired steam boiler, the secondary air serves the main purpose of (A) Transportation of coal (B) Drying of coal (C) Combustion of coal by supplying it around the burner (D) Preheating the primary air

Description : In case of pulverised coal fired steam boiler, the secondary air serves the main purpose of (A) Transportation of coal (B) Drying of coal (C) Combustion of coal by supplying it around the burner (D) Preheating the primary air

Last Answer : (C) Combustion of coal by supplying it around the burner

Preheating of a gaseous fuel results in increased (A) Flame length (B) Flame temperature (C) Quantity of flue gas

Description : Preheating of a gaseous fuel results in increased (A) Flame length (B) Flame temperature (C) Quantity of flue gas

Last Answer : (B) Flame temperature

In case of staged packed bed reactors carrying out exothermic reaction, use (A) High recycle for pure gas (B) Plug flow for dilute liquid requiring no large preheating of feed (C) Cold shot operations for a dilute solution requiring large preheating to bring the stream upto the reaction temperature (D) All (A), (B) and (C)

Description : In case of staged packed bed reactors carrying out exothermic reaction, use (A) High recycle for pure gas (B) Plug flow for dilute liquid requiring no large preheating of feed (C) Cold shot operations for a ... preheating to bring the stream upto the reaction temperature (D) All (A), (B) and (C)

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

Higher furnace temperature cannot be achieved by use of a lean fuel gas in the furnace by (A) Increasing the draft in the furnace (B) Preheating the fuel gas (C) Oxygen enrichment of combustion air (D) Preheating the combustion air

Description : Higher furnace temperature cannot be achieved by use of a lean fuel gas in the furnace by (A) Increasing the draft in the furnace (B) Preheating the fuel gas (C) Oxygen enrichment of combustion air (D) Preheating the combustion air

Last Answer : (A) Increasing the draft in the furnace

Temperature of a furnace fired with low calorific value fuel gas (i.e. lean gas) can be increased by (A) Preheating the combustion air (B) Oxygen enrichment of combustion air (C) Preheating the fuel gas (D) All (A), (B) & (C)

Description : Temperature of a furnace fired with low calorific value fuel gas (i.e. lean gas) can be increased by (A) Preheating the combustion air (B) Oxygen enrichment of combustion air (C) Preheating the fuel gas (D) All (A), (B) & (C)

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

In general, the limit of inflammability/explosion limit of fuel gases is widened by the (A) Increase in gas pressure (B) Increase in temperature (i.e. preheating) (C) Use of pure oxygen for combustion instead of air (D) All (A), (B) & (C)

Description : In general, the limit of inflammability/explosion limit of fuel gases is widened by the (A) Increase in gas pressure (B) Increase in temperature (i.e. preheating) (C) Use of pure oxygen for combustion instead of air (D) All (A), (B) & (C)

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

Preheating temperature of medium viscosity furnace oil for better atomisation through burner is about __________ °C. (A) 50 (B) 70 (C) 90 (D) 140

Description : Preheating temperature of medium viscosity furnace oil for better atomisation through burner is about __________ °C. (A) 50 (B) 70 (C) 90 (D) 140

Last Answer : (C) 90

Higher viscosity of lubricating oil usually signifies (A) Lower Reid vapour pressure (B) Higher acid number (C) Higher flash point and fire point (D) Lower flash point and fire point

Description : Higher viscosity of lubricating oil usually signifies (A) Lower Reid vapour pressure (B) Higher acid number (C) Higher flash point and fire point (D) Lower flash point and fire point

Last Answer : (C) Higher flash point and fire point

For the case of a fuel gas undergoing combustion with air, if the air/fuel ratio is increased, the adiabatic flame temperature will (A) Increase (B) Decrease (C) Increase or decrease depending on the fuel type (D) Not change

Description : For the case of a fuel gas undergoing combustion with air, if the air/fuel ratio is increased, the adiabatic flame temperature will (A) Increase (B) Decrease (C) Increase or decrease depending on the fuel type (D) Not change

Last Answer : (B) Decrease

What kind of combustion is observed in alkanes? Why do air holes of a gas burner have to be adjusted when vessel being heated gets blackened by the flame? -Science

Description : What kind of combustion is observed in alkanes? Why do air holes of a gas burner have to be adjusted when vessel being heated gets blackened by the flame? -Science

Last Answer : Alkanes are saturated hydrocarbons and generally burn in air with a blue, non-sooty flame. If the bottoms of the cooking vessels in our homes are getting blackened, it shows that the air holes of the gas stove are getting blocked and the fuel is not burning completely.

Absolute vapor pressure of petrofuels is found by Reid bomb which is heated in water bath to 100°F. In Reid apparatus, the ratio of the volume of air chamber to that of the liquid fuel chamber is (A) 4 (B) 3 (C) 2 (D) 1

Description : Absolute vapor pressure of petrofuels is found by Reid bomb which is heated in water bath to 100°F. In Reid apparatus, the ratio of the volume of air chamber to that of the liquid fuel chamber is (A) 4 (B) 3 (C) 2 (D) 1

Last Answer : (A) 4

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)

Fuel economy in furnaces can be achieved by (A) Using oxygen enriched combustion air (B) Preheating the combustion air (C) Reducing the heat loss through furnace openings & doors (D) All (A), (B) and (C

Description : Fuel economy in furnaces can be achieved by (A) Using oxygen enriched combustion air (B) Preheating the combustion air (C) Reducing the heat loss through furnace openings & doors (D) All (A), (B) and (C

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

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

Description : 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

Last Answer : (C) Ceramic recuperator

Ceramic recuperators (made of SiC) is economical, only when used for preheating combustion air above __________ °C. (A) 250 (B) 650 (C) 850 (D) 1000

Description : Ceramic recuperators (made of SiC) is economical, only when used for preheating combustion air above __________ °C. (A) 250 (B) 650 (C) 850 (D) 1000

Last Answer : (B) 650

Higher fuel combustion efficiency cannot be achieved by (A) Preheating of fuel gases & combustion air (B) Reducing sulphur content in the fuel (C) Adopting proper fuel firing technique & fuel preparation (D) Supplying correct amount of combustion air

Description : Higher fuel combustion efficiency cannot be achieved by (A) Preheating of fuel gases & combustion air (B) Reducing sulphur content in the fuel (C) Adopting proper fuel firing technique & fuel preparation (D) Supplying correct amount of combustion air

Last Answer : (B) Reducing sulphur content in the fuel

Which of the following does not require preheating during storage in the storage tank as well as during atomisation through burners? (A) PCM (B) Tar (C) Light diesel oil (D) Low viscosity furnace oil

Description : Which of the following does not require preheating during storage in the storage tank as well as during atomisation through burners? (A) PCM (B) Tar (C) Light diesel oil (D) Low viscosity furnace oil

Last Answer : (C) Light diesel oil

The temperature at which fuel flows to case is called.... (a) Fire point (b) Flash point (c) Pour point (d) Cloud point

Description : The temperature at which fuel flows to case is called.... (a) Fire point (b) Flash point (c) Pour point (d) Cloud point

Last Answer : c) Pour point

Pick out the wrong statement. (A) Strongly caking coal should not be used in the Lurgi gasifier (B) Acetylene gas cannot be used for illumination purpose (C) Water gas is called blue gas because of the color of the flame, when it is burnt (D) Gaseous fuels require less percentage of excess air for combustion as compared to liquid fuels

Description : Pick out the wrong statement. (A) Strongly caking coal should not be used in the Lurgi gasifier (B) Acetylene gas cannot be used for illumination purpose (C) Water gas is called blue gas ... is burnt (D) Gaseous fuels require less percentage of excess air for combustion as compared to liquid fuels

Last Answer : (B) Acetylene gas cannot be used for illumination purpose

Viscosity index of a lubricating oil (A) Is the measure of its flash point (B) Is the measure of variation of viscosity with temperature (C) Should be low (D) None of these

Description : Viscosity index of a lubricating oil (A) Is the measure of its flash point (B) Is the measure of variation of viscosity with temperature (C) Should be low (D) None of these

Last Answer : (B) Is the measure of variation of viscosity with temperature

Economizer is provided to utilize the flue gas heat for ___ a) preheating the boiler feed water b) preheating the stock c) preheating the combustion air d) preheating fuel

Description : Economizer is provided to utilize the flue gas heat for ___ a) preheating the boiler feed water b) preheating the stock c) preheating the combustion air d) preheating fuel

Last Answer : preheating the boiler feed water

Coke oven gas is a better fuel than blast furnace gas, because of its higher (A) Calorific value, cleanliness and relatively low distribution cost (due to its low specific gravity) (B) Adiabatic flame temperature (C) Heat release rate (thus requiring smaller combustion chamber) (D) All (A), (B) and (C)

Description : Coke oven gas is a better fuel than blast furnace gas, because of its higher (A) Calorific value, cleanliness and relatively low distribution cost (due to its low specific gravity) (B) Adiabatic flame temperature ... release rate (thus requiring smaller combustion chamber) (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

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)

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

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

Pick out the wrong statement. (A) Theoretical flame temperature is the temperature attained by the products of combustion, when the fuel is burned without loss or gain of heat (B) Burning the fuel with theoretically required amount of pure oxygen results in attainment of maximum adiabatic flame temperature (C) Burning the fuel with excess pure oxygen results in maximum theoretical flame temperature (D) Adiabatic flame temperatures of actual combustions are always less than the maximum values

Description : Pick out the wrong statement. (A) Theoretical flame temperature is the temperature attained by the products of combustion, when the fuel is burned without loss or gain of heat (B) ... flame temperature (D) Adiabatic flame temperatures of actual combustions are always less than the maximum values

Last Answer : (C) Burning the fuel with excess pure oxygen results in maximum theoretical flame temperature

During combustion of gaseous fuels, deficiency of air (A) Lengthens the flame (B) Tends to shorten the flame (C) Does not affect the flame length (D) Increases the flame temperature

Description : During combustion of gaseous fuels, deficiency of air (A) Lengthens the flame (B) Tends to shorten the flame (C) Does not affect the flame length (D) Increases the flame temperature

Last Answer : (A) Lengthens the flame

Actual flame temperature is always lower than the adiabatic flame temperature, because there is (A) No possibility of obtaining complete combustion at high temperature (B) Always loss of heat from the flame (C) Both (A) and (B) (D) Neither (A) nor (B)

Description : Actual flame temperature is always lower than the adiabatic flame temperature, because there is (A) No possibility of obtaining complete combustion at high temperature (B) Always loss of heat from the flame (C) Both (A) and (B) (D) Neither (A) nor (B)

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

Combustion of pulverised coal as compared to that of lump coal (A) Develops a non-luminous flame (B) Develops a low temperature flame (C) Can be done with less excess air (D) Provides a lower rate of heat release

Description : Combustion of pulverised coal as compared to that of lump coal (A) Develops a non-luminous flame (B) Develops a low temperature flame (C) Can be done with less excess air (D) Provides a lower rate of heat release

Last Answer : (C) Can be done with less excess ai

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

A fuel with high heat release rate will (A) Require smaller combustion chamber (B) Have high calorific value (C) Have high adiabatic flame temperature (D) None of these

Description : A fuel with high heat release rate will (A) Require smaller combustion chamber (B) Have high calorific value (C) Have high adiabatic flame temperature (D) None of these

Last Answer : (A) Require smaller combustion chamber

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

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)

If the specific heat of gaseous products of combustion of a fuel is high, the abiabatic flame temperature will be (A) Low (B) High (C) Very high, if the fuel is of low calorific value (D) None of these

Description : If the specific heat of gaseous products of combustion of a fuel is high, the abiabatic flame temperature will be (A) Low (B) High (C) Very high, if the fuel is of low calorific value (D) None of these

Last Answer : (A) Low(A) Low

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

__________ test is done to find out the softening point of bitumen. (A) Impact (B) Ball and ring (C) Flame (D) Viscosity

Description : __________ test is done to find out the softening point of bitumen. (A) Impact (B) Ball and ring (C) Flame (D) Viscosity

Last Answer : (B) Ball and ring

Pick out the wrong statement. (A) LPG is also used as fuel for automobiles & small furnaces and for cutting & welding of metals (B) The minimum temperature, at which a petroleum oil vapor catches fire and continues to burn, is called its flash point (C) Each ton of petroleum oil on distillation produces about 30-50 Nm3 of gas (D) Maximum yield of naphthalene is obtained on distillation of crude oil

Description : Pick out the wrong statement. (A) LPG is also used as fuel for automobiles & small furnaces and for cutting & welding of metals (B) The minimum temperature, at which a petroleum oil vapor catches ... about 30-50 Nm3 of gas (D) Maximum yield of naphthalene is obtained on distillation of crude oil

Last Answer : (B) The minimum temperature, at which a petroleum oil vapor catches fire and continues to burn, is called its flash point

Pick out the wrong statement. (A) Aromatics have higher specific gravity than paraffins (B) Gross calorific value (GCV) of petrofuels is equal to (12400 - 2100 ρ 2 ) where, ρ is the specific gravity of the fuel at 15.5°C (C) Heavier petrofuels have higher GCV on weight basis (i.e., Kcal/kg) but lower GCV on volume basis (i.e., Kcal/litre) (D) Higher specific gravity of petrofuels means higher C/H ratio

Description : Pick out the wrong statement. (A) Aromatics have higher specific gravity than paraffins (B) Gross calorific value (GCV) of petrofuels is equal to (12400 - 2100 ρ 2 ) where, ρ is the specific gravity ... volume basis (i.e., Kcal/litre) (D) Higher specific gravity of petrofuels means higher C/H ratio

Last Answer : (C) Heavier petrofuels have higher GCV on weight basis (i.e., Kcal/kg) but lower GCV on volume basis (i.e., Kcal/litre)

Testing of the knocking characteristics of petrofuels is done in a __________ engine. (A) Carnot (B) CFR (Co-operative fuel research) (C) Stirling (D) Diesel

Description : Testing of the knocking characteristics of petrofuels is done in a __________ engine. (A) Carnot (B) CFR (Co-operative fuel research) (C) Stirling (D) Diesel

Last Answer : (B) CFR (Co-operative fuel research)

The lowest temperature, at which a solid fuel produces enough vapors to support continuous combustion, is called (A) Fire point (B) Smoke point (C) Burning temperature (D) Kindling temperature

Description : The lowest temperature, at which a solid fuel produces enough vapors to support continuous combustion, is called (A) Fire point (B) Smoke point (C) Burning temperature (D) Kindling temperature

Last Answer : (C) Burning temperature

The most important property for a jet fuel is its (A) Viscosity (B) Freezing point (C) Calorific value (D) Flash poin

Description : The most important property for a jet fuel is its (A) Viscosity (B) Freezing point (C) Calorific value (D) Flash poin

Last Answer : (B) Freezing point

Pick out the wrong statement. (A) Pensky-Marten apparatus is used for determining flash points above 50°C (B) Characterisation factor of paraffinic crude oil is more than 12 (C) Abel apparatus is used for determining flash points below 50°C (D) An oil having high susceptibility to change in viscosity with temperature changes, has a high viscosity index

Description : Pick out the wrong statement. (A) Pensky-Marten apparatus is used for determining flash points above 50°C (B) Characterisation factor of paraffinic crude oil is more than 12 (C) Abel ... An oil having high susceptibility to change in viscosity with temperature changes, has a high viscosity index

Last Answer : (D) An oil having high susceptibility to change in viscosity with temperature changes, has a high viscosity index

A multigrade lubricating oil means an oil having high (A) Viscosity index (B) Viscosity (C) Aniline point (D) Flash point

Description : A multigrade lubricating oil means an oil having high (A) Viscosity index (B) Viscosity (C) Aniline point (D) Flash point

Last Answer : (A) Viscosity index