Which of the following statement is wrong?
The mechanical draught reduces the height of chimney.
The natural draught reduces the fuel consumption.
A balanced draught is a combination of induced and forced draught.
All of the above
Correct Answer :
B. The natural draught reduces the fuel consumption.
Related Questions
On Mollier chart, flow through turbine is represented by
Horizontal straight line
Vertical straight line
Straight inclined line
Curved line
The velocity of whirl at outlet for an axial discharge turbine is
Minimum
Maximum
Zero
None of these
Which of the following is a water tube boiler?
Locomotive boiler
Cochran boiler
Cornish boiler
Babcock and Wilcox boiler
The fire tubes in a Cochran boiler usually have _________ diameter.
6.25 mm
62.5 mm
72.5 mm
92.5 mm
Water tube boilers are
Internally fired
Externally fired
Internally as well as externally fired
None of these
In a steam condenser, the partial pressure of steam and air are 0.06 bar and 0.007 bar respectively. The condenser pressure is
0.007 bar
0.053 bar
0.06 bar
0.067 bar
With increase in load, convection superheater has
Drooping characteristic
Linear characteristic
Rising characteristic
Flat characteristic
In order to reduce the rotor speed of an impulse turbine, the method employed is
Velocity compounding
Pressure compounding
Pressure-velocity compounding
All of these
A steam nozzle converts
Heat energy of steam into kinetic energy
Kinetic energy into heat energy of steam
Heat energy of steam into potential energy
Potential energy into heat energy of steam
The value of diagram factor depends upon
Initial conditions of steam
Back pressure
Initial pressure of steam
All of these
When the circulation of water, in a boiler, is by a centrifugal pump, then the boiler is known as
Internally fired boiler
Externally fired boiler
Natural circulation boiler
Forced circulation boiler
Water boils when its vapour pressure
Equals that of the surroundings
Equals 760 mm of mercury
Equals to atmospheric pressure
Equals the pressure of water in the container
1 kg.m is equal to
9.81 Joules
102 Joules
427 Joules
None of these
The shell of the Cochran boiler is made hemispherical
To give maximum space and strength
To withstand the pressure of steam inside the boiler
Both (A) and (B)
None of the above
Willian's law states that the steam consumption per hour provided with a throttled governor is proportional to (where I.P. = Indicated power)
1/(I.P)
1/(I.P)²
I.P.
(I.P.)²
Maximum energy loss in a boiler occurs due to
Unburnt carbon in ash
Incomplete combustion
Ash content
Flue gases
The efficiency of steam turbines may be improved by
Reheating of steam
Regenerative feed heating
Binary vapour plant
Any one of these
The condition of steam in boiler drum is always
Dry
Wet
Saturated
Supersaturated
Parson's reaction turbine is a __________ reaction turbine.
40 percent
50 percent
60 percent
70 percent
The difference between Cornish boiler and Lancashire boiler is that
Former is fire tube type and latter is water tube type boiler
Former is water tube type and latter is fire tube type
Former contains one fire tube and latter contains two fire tubes
None/of the above
The effect of super-saturation is that the
Mass of the steam discharged increases
Entropy and specific volume of the steam increases
Exit velocity of steam reduces
All of these
Pick up wrong statement about desired properties of a good fuel
High calorific value
Produce minimum smoke and gases
Ease in storing
High ignition point
For the same diameter and thickness of tube, a water tube boiler compared to a fire tube boiler has
More heating surface
Less heating surface
Equal heating surface
Heating surface depends on other parameters
The effect of friction in the nozzle __________ dryness fraction of steam.
Has no effect on
Decreases
Increases
None of these
Which is not the correct statement about moisture in coal?
Inherent moisture and surface moisture are different things
In some coals moisture may be present up to 40%
Some moisture in coal helps in better burning which is not possible with completely dry coal
It increases thermal efficiency
Which of the following statement is correct?
Lancashire boiler is a fire tube boiler.
Fire tube boilers are internally fired.
Babcock and Wilcox boiler is a water tube boiler.
All of the above
Boiler H.P. is defined as the
Steam evaporation rate per kg of fuel fired
Work done in evaporating 1 kg of steam per hour from and at 100°C into dry saturated steam
The evaporation of 15.65 kg of water per hour from and at 100°C into dry saturated steam
Work done by 1 kg of steam at saturation condition
Alkaline pyrogallate is used in Orsat's apparatus for absorption of
CO₂
CO
O₂
N₂
The water tubes in a simple vertical boiler are
Horizontal
Vertical
Inclined
None of these
The critical pressure ratio (p₂/p₁) is given by
(p₂/p₁) = [2/(n - 1)] n/(n + 1)
(p₂/p₁) = [2/(n + 1)] n/(n-1)
(p₂/p₁) = [(n - 1)/2] n + (1/n)
(p₂/p₁) = [(n + 1)/2] n - (1/n)