Benson boiler requires
No drum
One drum
Two drums
Three drums
Correct Answer :
A. No drum
Related Questions
In a nozzle, whole frictional loss is assumed to occur between
Inlet and throat
Inlet and outlet
Throat and exit
All of these
The dry saturated steam at very high pressure (150200 kg/cm²) when throttled to atmosphere will become
Wet
Superheated
Remain dry saturated
Dry
Bomb calorimeter is used to determine
Higher calorific value at constant volume
Lower calorific value at constant volume
Higher calorific value at constant pressure
Lower calorific value at constant pressure
The expansion of steam in a nozzle follows
Carnot cycle
Rankine cycle
Joule cycle
Stirling cycle
In a reaction turbine
The steam is allowed to expand in the nozzle, where it gives a high velocity before it enters the moving blades
The expansion of steam takes place partly in the fixed blades and partly in the moving blades
The steam is expanded from a high pressure to a condenser pressure in one or more nozzles
The pressure and temperature of steam remains constant
Reheating of steam in a turbine
Increases the workdone through the turbine
Increases the efficiency of the turbine
Reduces wear on the blades
All of these
The critical pressure ratio for initially superheated steam is __________ as compared to initially dry saturated steam.
More
Less
Same
None of these
The pressure of steam __________ while flowing through a nozzle.
Increases
Decreases
Remains constant
None of these
Carbonisation of coal is the process of
Pulverising coal in inert atmosphere
Heating wood in a limited supply of air at temperatures below 300°C
Strongly heating coal continuously for about 48 hours in the absence of air in a closed vessel
Binding the pulverised coal into briquettes
A device used to heat feed water by utilising the heat in me exhaust flue gases before leaving through the chimney, is known as
Economiser
Fusible plug
Superheater
Stop valve
The effect of friction in the nozzle __________ dryness fraction of steam.
Has no effect on
Decreases
Increases
None of these
The blade friction in the impulse turbine reduces the velocity of steam by __________ while it passes over the blades.
10 to 15 %
15 to 20 %
20 to 30 %
30 to 40 %
Which of the following is steam dial?
Non-coking bituminous coal
Brown coal
Pulverised coal
Coking bituminous coal
The crown of the fire box is made hemispherical in order to
Give maximum space
Give maximum strength
Withstand pressure inside boiler
Resist intense heat in fire box
The value of diagram factor depends upon
Initial conditions of steam
Back pressure
Initial pressure of steam
All of these
The length of Lancashire boiler varies from
5 to 6 m
6 to 7 m
7.25 to 9 m
9 to 10 m
The pressure velocity compounded impulse turbine allows a bigger pressure drop and hence __________ numbers of stages are required.
More
Less
Equal
None of these
1 kg.m is equal to
9.81 Joules
102 Joules
427 Joules
None of these
The efficiency of steam turbines may be improved by
Reheating of steam
Regenerative feed heating
Binary vapour plant
Any one of these
When the back pressure of a nozzle is below the designed value of pressure at exit of nozzle, the nozzle is said to be
Choked
Under-damping
Over-damping
None of these
Which of the following statement is correct?
The efficiency of steam turbines is greater than steam engines
A flywheel is a must for steam turbine
The turbine blades do not change the direction of steam issuing from the nozzle
The pressure of steam, in reaction turbines, is increased in fixed blades as well as in moving blades
100% efficiency of a thermal cycle cannot be achieved because of
Frictional losses
It is not possible to achieve 0°K temperature
Leakage
Non availability of ideal substance
The function of a valve rod is
To provide reciprocating motion to the slide valve
To convert reciprocating motion of the piston into rotary motion of the crank
To convert rotary motion of the crankshaft into to and fro motion of the valve rod
To provide simple harmonic motion to the D-slide valve
The critical pressure at which latent heat of vaporisation is zero is
225.65 kgf/ cm²
273 kgf/ cm²
100 kgf/ cm²
1 kgf/ cm²
Expanding steam to a very low pressure (high vacuum) in steam engines is
Desirable
Economical
Essential
Uneconomical
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)
The impulse reaction turbine has its driving force
As an impulsive force
As a reaction force
Partly as an impulsive force and partly as a reaction force
None of the above
A condenser where circulating water flows through tubes which are surrounded by steam, in known as
Surface condenser
Jet condenser
Barometric condenser
Evaporative condenser
The radius of a dished head is taken approximately as
One fourth
Half
One
Two
The overall efficiency of thermal power plant is
Boiler efficiency, turbine efficiency, generator efficiency
All the three above plus gas cycle efficiency
Carnot cycle efficiency
Regenerative cycle efficiency