Power required in case of forced draught as compared to induced draught (for the same draught produced) is (A) Same (B) Less (C) More (D) Either more or less; depends on the flue gas density

Power required in case of forced draught as compared to induced
draught (for the same draught produced) is
(A) Same
(B) Less
(C) More
(D) Either more or less; depends on the flue gas density
by

1 Answer

Answer :

(B) Less
by

Related questions

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

Ingress of cold air in the furnaces through cracks, charging doors, openings etc(A) Reduces the flue gas temperature and makes the furnace atmosphereoxidising(B) Increases the load on the induced draft fan(C) Reduces the furnace draught(D) All (A), (B) and (C)

Description : 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)

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

Why is induced draught considered better than the forced draught? a) Because power requirement is high for forced draught b) Maintenance of induced draught fan is costlier c) Forced draught is less efficient d) Forced draught produces less amount of speed of air

Description : Why is induced draught considered better than the forced draught? a) Because power requirement is high for forced draught b) Maintenance of induced draught fan is costlier c) Forced draught is less efficient d) Forced draught produces less amount of speed of air

Last Answer : Because power requirement is high for forced draught

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

Which of the following is used to produce draught in the locomotive boilers? (A) Chimney (B) Induced draught fan (C) Forced draught fan (D) Steam jet arrangement

Description : Which of the following is used to produce draught in the locomotive boilers? (A) Chimney (B) Induced draught fan (C) Forced draught fan (D) Steam jet arrangement

Last Answer : Option D

Natural draught produced by a chimney depends upon the (A) Density of the chimney gases (B) Height of the chimney (C) Both (A) and (B) (D) Neither (A) nor (B)

Description : Natural draught produced by a chimney depends upon the (A) Density of the chimney gases (B) Height of the chimney (C) Both (A) and (B) (D) Neither (A) nor (B)

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

Define natural, mechanical, forced and induced draught systems.

Description : Define natural, mechanical, forced and induced draught systems.

Last Answer : Natural draught system: - When the fuel is burnt (combustion) in the furnace due to natural circulation of air, the draught is called natural draught. Mechanical draught system: -  In a mechanical ... combustion. OR If fan/blower is placed after the furnace then it is called as induced draught

The equilibrium liquid composition compared to the vapor composition in case of Azeotropic mixture is (A) More (B) Less (C) Same (D) Either more or less; depends on the system

Description : The equilibrium liquid composition compared to the vapor composition in case of Azeotropic mixture is (A) More (B) Less (C) Same (D) Either more or less; depends on the system

Last Answer : (C) Same

In case of the irreversible unimolecular type, first order reaction, the fractional conversion at any time for constant volume system as compared to variable volume system is (A) More (B) Less (C) Same (D) Either (A) or (B), depends on other factors

Description : In case of the irreversible unimolecular type, first order reaction, the fractional conversion at any time for constant volume system as compared to variable volume system is (A) More (B) Less (C) Same (D) Either (A) or (B), depends on other factors

Last Answer : (C) Same

Thermal efficiency of furnaces can be improved by (A) Waste heat recovery from flue gas (B) Minimising heat losses from furnace walls(C) Maintaining proper draught(D) All (A), (B) and (C

Description : Thermal efficiency of furnaces can be improved by (A) Waste heat recovery from flue gas (B) Minimising heat losses from furnace walls (C) Maintaining proper draught (D) All (A), (B) and (C

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

Capacity & power requirement for an air compressor working at high altitude compared to sea-level will be (A) More (B) Less (C) Same (D) Either more or less; depends on the climatic conditions

Description : Capacity & power requirement for an air compressor working at high altitude compared to sea-level will be (A) More (B) Less (C) Same (D) Either more or less; depends on the climatic conditions

Last Answer : (B) Less

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

Pressure drop through plate tower as compared to that through packed tower, for the same duty will be (A) Less (B) More (C) Equal (D) Either (A) or (B); depends on the packing height

Description : Pressure drop through plate tower as compared to that through packed tower, for the same duty will be (A) Less (B) More (C) Equal (D) Either (A) or (B); depends on the packing height

Last Answer : (B) More

For the same terminal conditions and valve size, the pressure drop in a fully opened globe valve as compared to that in a gate valve is (A) More (B) Less (C) Equal (D) Either (A) or (B); depends on the viscosity of the fluid

Description : For the same terminal conditions and valve size, the pressure drop in a fully opened globe valve as compared to that in a gate valve is (A) More (B) Less (C) Equal (D) Either (A) or (B); depends on the viscosity of the fluid

Last Answer : (A) More

In an exothermic reaction, the energy of the reacting substances as compared to that of products is (A) More (B) Less (C) Same (D) Either (A) or (B), depends on order of reaction

Description : In an exothermic reaction, the energy of the reacting substances as compared to that of products is (A) More (B) Less (C) Same (D) Either (A) or (B), depends on order of reaction

Last Answer : (A) More

In case of a super-cooled solution, which is on the verge of crystallisation, the free energy of the solution as compared to that of the solid is (A) More (B) Less (C) Same (D) More or less; depends on the nature of solution

Description : In case of a super-cooled solution, which is on the verge of crystallisation, the free energy of the solution as compared to that of the solid is (A) More (B) Less (C) Same (D) More or less; depends on the nature of solution

Last Answer : (A) More

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)

The film co-efficient is decreased due to the presence of non-condensing gases in the vapors. The film co-efficient of superheated vapor as compared to that of saturated vapor is (A) More (B) Less (C) Some (D) Either more or less; depends on the nature of vapor

Description : The film co-efficient is decreased due to the presence of non-condensing gases in the vapors. The film co-efficient of superheated vapor as compared to that of saturated vapor is (A) More (B) Less (C) Some (D) Either more or less; depends on the nature of vapor

Last Answer : (C) Some

Pick out the wrong statement pertaining to the cooling towers. (A) In case of induced draft cooling tower, the fan is placed at the top of the tower (B) Effectiveness of forced draft cooling tower is reduced by the recirculation of the humid and hot discharged air (C) A natural draft cooling tower is recommended to be used, when the air humidity is low and air temperature is also low (D) Effectiveness of a mechanical draft cooling tower is reduced with increase in air wet-bulb temperature

Description : Pick out the wrong statement pertaining to the cooling towers. (A) In case of induced draft cooling tower, the fan is placed at the top of the tower (B) Effectiveness of ... Effectiveness of a mechanical draft cooling tower is reduced with increase in air wet-bulb temperature

Last Answer : (D) Effectiveness of a mechanical draft cooling tower is reduced with increase in air wet-bulb temperature

Which one is not an induced draught furnace? (A) Blast furnace stove (B) Sintering furnace (C) High pressure boiler (D) None of these

Description : Which one is not an induced draught furnace? (A) Blast furnace stove (B) Sintering furnace (C) High pressure boiler (D) None of these

Last Answer : (A) Blast furnace stove

Pick out the wrong statement. (A) In case of heat transfer by purely forced convection, GR /Re 2 ≤ 1 (B) The equivalent diameter of heat transfer for a duct of square cross￾section (having each side as 'x') is equal to 4x (C) Distillation process is not the same as evaporation (D) The effectiveness of nucleate boiling depends basically on the ease with which the bubbles are formed and detached from the heating surface

Description : Pick out the wrong statement. (A) In case of heat transfer by purely forced convection, GR /Re 2 ≤ 1 (B) The equivalent diameter of heat transfer for a duct of ... nucleate boiling depends basically on the ease with which the bubbles are formed and detached from the heating surface

Last Answer : (B) The equivalent diameter of heat transfer for a duct of square cross￾section (having each side as 'x') is equal to 4x

What Are The Advantages Of Forced Draught System?

Description : What Are The Advantages Of Forced Draught System?

Last Answer :  Since the fan handles cold air, the fan size and the power required are less.  No need of water cooled bearings because the air being handled is cold air,  Pressure throughout the system is above atmospheric pressure so the air leakage into the furnace is reduced.

Write About Forced Draught System?

Description : Write About Forced Draught System?

Last Answer : In this system, the blower (forced draft fan) is located at the base of the boiler near the grate. Air is forced to the furnace by forced fan and the flue gases are forced to chimney through economizer and air preheater.

Differentiate between natural draught and forced draught cooling tower.

Description : Differentiate between natural draught and forced draught cooling tower.

Last Answer : Sr. No. Natural draught Forced draught 1 The air flows naturally without fan through tower and provides required cooling Fan is located at the top of the tower and enters the ... from tower cannot be controlled. The temp. of water coming out from tower can be controlled.

Write the elements of forced draught cooling tower.

Description : Write the elements of forced draught cooling tower.

Last Answer : Following are the elements of forced draught cooling tower; a) Forced draught fan b) Eliminator c) Spray header d) Spray nozzle e) Circulating pump

Pitch creosote mixture (PCM) as compared to furnace oil is a better fuel, because its (A) Emissivity factor is higher (B) Sulphur content is lower (C) Flue gas has lower dew point thereby facilitating more waste heat recovery (D) All (A), (B) and (C)

Description : Pitch creosote mixture (PCM) as compared to furnace oil is a better fuel, because its (A) Emissivity factor is higher (B) Sulphur content is lower (C) Flue gas has lower dew point thereby facilitating more waste heat recovery (D) All (A), (B) and (C)

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

The maximum adiabatic flame temperature in air as compared to that in pure oxygen is (A) Much lower (B) Much higher (C) Same (D) Either lower or higher, depends on the type of fuel

Description : The maximum adiabatic flame temperature in air as compared to that in pure oxygen is (A) Much lower (B) Much higher (C) Same (D) Either lower or higher, depends on the type of fuel

Last Answer : (A) Much lower

How The Induced Draught Is Working?

Description : How The Induced Draught Is Working?

Last Answer : In an induced draught system, a blower (induced draft fan) is placed near (or) at the base of the chimney. The fan sucks the flue gas from the furnace creating a partial vacuum inside the ... aid the combustion of fuel. The flue gases drawn by the fan passes through chimney, to the atmosphere.

The heat recoverable from flue gases of furnaces depends on the (A) Thermal efficiency of furnace (B) Quantity of flue gases (C) Flue gas temperature drop through the furnace (D) All (A), (B) and (C)

Description : The heat recoverable from flue gases of furnaces depends on the (A) Thermal efficiency of furnace (B) Quantity of flue gases (C) Flue gas temperature drop through the furnace (D) All (A), (B) and (C)

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

Natural draft created by the chimney depends upon (A) Temperature of the flue gas (B) Its height (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : Natural draft created by the chimney depends upon (A) Temperature of the flue gas (B) Its height (C) Both (A) & (B) (D) Neither (A) nor (B)

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

With increase in C/H ratio of a fuel, the dew point of flue gases (A) Increases (B) Decreases (C) Remain same (D) May increase or decrease; depends on the type of fuel

Description : With increase in C/H ratio of a fuel, the dew point of flue gases (A) Increases (B) Decreases (C) Remain same (D) May increase or decrease; depends on the type of fuel

Last Answer : (B) Decreases

In case of an unsaturated mixture of gas and vapor, the percentage saturation is __________ its relative saturation. (A) Lower than (B) Higher than (C) Equal to (D) Either (A) or (B), depends on the mixture composition

Description : In case of an unsaturated mixture of gas and vapor, the percentage saturation is __________ its relative saturation. (A) Lower than (B) Higher than (C) Equal to (D) Either (A) or (B), depends on the mixture composition

Last Answer : (A) Lower than

In case of a Rotameter, the density of the float material is __________ that of the liquid it replaces. (A) More than (B) Less than (C) Equal to (D) Either (A) or (B)

Description : In case of a Rotameter, the density of the float material is __________ that of the liquid it replaces. (A) More than (B) Less than (C) Equal to (D) Either (A) or (B)

Last Answer : (A) More than

For a straight wire, induced current depends uponA. the speed of movement of wire B. the length of wire C. the magnitude of magnetic flux density D. all of above

Description : For a straight wire, induced current depends uponA. the speed of movement of wire B. the length of wire C. the magnitude of magnetic flux density D. all of above

Last Answer : all of above

Acid dew point temperature (ADT) of a flue gas produced by the combustion of a fuel containing 1% sulphur may be about __________ °C. (A) 80 (B) 130 (C) 180 (D) 250

Description : Acid dew point temperature (ADT) of a flue gas produced by the combustion of a fuel containing 1% sulphur may be about __________ °C. (A) 80 (B) 130 (C) 180 (D) 250

Last Answer : (B) 130

The amount of heat required to change a boiling liquid to a gas at the same temperature depends on one of the following properties of the liquid. Does it depend on the liquid's: w) heat of fusion x) heat of vaporization y) temperature z) density

Description : The amount of heat required to change a boiling liquid to a gas at the same temperature depends on one of the following properties of the liquid. Does it depend on the liquid's: w) heat of fusion x) heat of vaporization y) temperature z) density

Last Answer : ANSWER: X -- HEAT OF VAPORIZATION

A thermal nuclear reactor compared to a fast breeder reactor (A) Uses slower neutrons for fission (B) Uses faster neutrons for fission (C) Gives higher power density (D) Requires less fuel to run at the same power level

Description : A thermal nuclear reactor compared to a fast breeder reactor (A) Uses slower neutrons for fission (B) Uses faster neutrons for fission (C) Gives higher power density (D) Requires less fuel to run at the same power level

Last Answer : (A) Uses slower neutrons for fission

In reactions involving solids and liquids (where change in volume is negligible), the heat of reaction at constant pressure as compared to that at constant volume is (A) More (B) Less (C) Same (D) Unpredictable; depends on the particular reaction

Description : In reactions involving solids and liquids (where change in volume is negligible), the heat of reaction at constant pressure as compared to that at constant volume is (A) More (B) Less (C) Same (D) Unpredictable; depends on the particular reaction

Last Answer : (C) Same

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

Artificial draught produced by a fan in the furnace can be controlled by the (A) Speed of the fan (B) Damper (C) Variation in the pitch of fan blades (D) All (A), (B) and (C)

Description : Artificial draught produced by a fan in the furnace can be controlled by the (A) Speed of the fan (B) Damper (C) Variation in the pitch of fan blades (D) All (A), (B) and (C)

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

Artificial draught produced by a fan can be controlled by the (A) Speed of the fan (B) Damper (C) Variation in the pitch of the fan blades (D) All (A), (B) and (C

Description : Artificial draught produced by a fan can be controlled by the (A) Speed of the fan (B) Damper (C) Variation in the pitch of the fan blades (D) All (A), (B) and (C

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

Equal volumes of aniline and diesel oil when mixed at room temperature (during summer) was found to be completely miscible. It means that the aniline point of the diesel is __________ the room temperature. (A) More than (B) Less than (C) Same as (D) Either more or less; depends on the room temperature

Description : Equal volumes of aniline and diesel oil when mixed at room temperature (during summer) was found to be completely miscible. It means that the aniline point of the diesel is __________ the room temperature. (A) ... (B) Less than (C) Same as (D) Either more or less; depends on the room temperature

Last Answer : (C) Same as

Select the wrong statement pertaining to flow of an incompressible fluid through a Venturimeter. (A) For frictionless flow, the fluid pressure entering the venturi meter will be exactly equal to that leaving the Venturimeter(B) Discharge of fluid through a Venturimeter depends upon the gagedifference irrespective of the orientation of Venturimeter(C) Venturimeter occupies less space than an orificemeter(D) Venturimeter incurs less power loss compared to an equivalentorificemeter

Description : Select the wrong statement pertaining to flow of an incompressible fluid through a Venturimeter. (A) For frictionless flow, the fluid pressure entering the venturi meter will be exactly equal ... than an orificemeter (D) Venturimeter incurs less power loss compared to an equivalent orificemeter

Last Answer : (C) Venturimeter occupies less space than an orificemeter

When the temperature and humidity of air is low, we usually use __________ draft cooling tower. (A) Natural (B) Forced (C) Induced (D) None of these

Description : When the temperature and humidity of air is low, we usually use __________ draft cooling tower. (A) Natural (B) Forced (C) Induced (D) None of these

Last Answer : (A) Natural

The most efficient cooling tower out of the following is (A) Induced draft (B) Forced draft (C) Natural draft (D) Atmospheric

Description : The most efficient cooling tower out of the following is (A) Induced draft (B) Forced draft (C) Natural draft (D) Atmospheric

Last Answer : (A) Induced draft

The noise produced by a ______ cooled machine is less as the rotor moves in a medium of smaller density. (a) air (b) hydrogen (c) either (a) or (b) (d) none of the above

Description : The noise produced by a ______ cooled machine is less as the rotor moves in a medium of smaller density. (a) air (b) hydrogen (c) either (a) or (b) (d) none of the above

Last Answer : (b) hydrogen

In a furnace, the heat taken by the charge/stock and the heat lost to the furnace structure & flue gases depends on the (A) Rate of firing and emissivity of flame (B) Thermal conductivity of the charge & structural materials of furnace (C) Nature of process; whether batch, continuous or intermittent (D) All (A), (B) and (C)

Description : In a furnace, the heat taken by the charge/stock and the heat lost to the furnace structure & flue gases depends on the (A) Rate of firing and emissivity of flame (B) Thermal conductivity of the charge & ... (C) Nature of process; whether batch, continuous or intermittent (D) All (A), (B) and (C)

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

Ringelmann chart is used for the measurement of the (A) Combustibles present in automobile exhaust (B) Smoke density from a chimney (C) Exhaust gas density (D) Flue gas temperature

Description : Ringelmann chart is used for the measurement of the (A) Combustibles present in automobile exhaust (B) Smoke density from a chimney (C) Exhaust gas density (D) Flue gas temperature

Last Answer : (B) Smoke density from a chimney

Calculate the recoverable waste heat (Q, in kCal/hour) from flue gases using the followingparameters: V (flow rate of the substance) 2000 m3/hr r (density of the flue gas): 0.9 kg/m3 Cp (specific heat of the substance): 0.20 kCal/kg oC DT (temperature difference): 120 oC h (recovery factor): 50% a. 21600 b. 43200 c. 25600 d. 34000

Description : Calculate the recoverable waste heat (Q, in kCal/hour) from flue gases using the followingparameters: V (flow rate of the substance) 2000 m3/hr r (density of the flue gas): 0.9 kg/m3 Cp (specific heat ... (temperature difference): 120 oC h (recovery factor): 50% a. 21600 b. 43200 c. 25600 d. 34000

Last Answer : 21600

In order to maintain an oxidising atmosphere in a furnace, it should have (A) More of excess air (B) Less of excess air (C) More of CO in flue gas (D) More of CO2 in flue gas

Description : In order to maintain an oxidising atmosphere in a furnace, it should have (A) More of excess air (B) Less of excess air (C) More of CO in flue gas (D) More of CO2 in flue gas

Last Answer : (A) More of excess air