In forced recirculation type boiler,
Heating takes place at bottom and the water supplied at bottom gets converted into the mixture of steam bubbles and hot water which rise to drum
Water is supplied in drum and through down comers located in atmospheric condition it passes to the water wall and rises to drum in the form of mixture of water and steam
Feed pump is employed to supplement natural circulation in water wall type furnace
Water is converted into steam in one pass without any recirculation
Correct Answer :
C. Feed pump is employed to supplement natural circulation in water wall type furnace
Related Questions
Boiler stays are used to
Prevent flat surfaces under pressure from tearing apart
Take care of failure in shear
Take care of failure in compression
Provide support for boiler
Heating wet steam at constant temperature is heating it at constant
Volume
Pressure
Entropy
Enthalpy
The difference of supersaturated temperature and saturation temperature at that pressure is called
Degree of super-saturation
Degree of superheat
Degree of under-cooling
None of these
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
The missing quantity per stroke is equal to
Cylinder feed indicated mass of steam
Cylinder feed + indicated mass of steam
Mass of cushion steam + indicated mass of steam
Mass of cushion steam + cylinder feed
The number of water level indicators in a boiler are generally _________ in number.
One
Two
Three
Four
Feed water conditioning in thermal power plants in done to
Reduce hardness and for removal of solids
Increase efficiency of thermal power plant
Increase heat transfer rate
Increase steam parameters
Tertiary air is the air used to
Provide air around burners for obtaining optimum combustion
Transport and dry the coal
Cool the scanners
Convert CO (formed in lower zone of furnace) into CO₂ at higher zone.
A regenerative steam cycle renders
Increased work output per unit mass of steam
Decreased work output per unit mass of steam
Increased thermal efficiency
Decreased work output per unit mass of steam as well as increased thermal efficiency
The object of producing draught in a boiler is
To provide an adequate supply of air for the fuel combustion
To exhaust the gases of combustion from the combustion chamber
To discharge the gases of combustion to the atmosphere through the chimney
All of the above
A device used in a boiler to control the flow of steam from the boiler to the main pipe and to shut off the steam completely when required, is known as
Blow off cock
Fusible plug
Superheater
Stop valve
In accelerated circulation type boiler
Heating takes place at bottom and the water supplied at bottom gets converted into the mixture of steam bubbles and hot water which rise to drum
Water is supplied in drum and through down comers located in atmospheric condition it passes to the water wall and rises to drum in the form of mixture of water and steam
Feed pump is employed to supplement natural circulation in water wall type furnace
Water is converted into steam in one pass without any recirculation
The increase in pressure
Lowers the boiling point of a liquid
Raises the boiling point of a liquid
Does not affects the boiling point of a liquid
Reduces its volume
An economiser is installed in a boiler primarily to
Superheat the steam
Reduce fuel consumption
Increase steam pressure
All of these
The change in internal energy in steam engines equals to
Work done during the Rankine cycle
Work done during compression
Work done during adiabatic expansion
Change in enthalpy
De-Laval turbine is a
Single rotor impulse turbine
Multi-rotor impulse turbine
Impulse reaction turbine
None of these
In forced circulation steam boilers, the force is applied
To draw water
To circulate water
To drain off the water
All of these
If a steam sample is nearly in dry condition, then its dryness fraction can be most accurately determined by
Throttling calorimeter
Separating calorimeter
Combined separating and throttling calorimeter
Bucket calorimeter
The reheat factor depends upon
Initial pressure and superheat
Exit pressure
Turbine stage efficiency
All of these
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
In a De-Laval nozzle expanding superheated steam from 10 bar to 0.1 bar, the pressure at the minimum cross-section (i. e. pressure at throat, p₂) will be
3.3 bar
5.46 bar
8.2 bar
9.9 bar
In an impulse reaction turbine, the pressure drops gradually and continuously over
Fixed blades
Moving blades
Both fixed and moving blades
None of these
Which is not correct statement about pulverised fuel firing?
High burning rate is possible
Heat release can be easily controlled
Fuel burns economically
It is the best technique for burning high ash content fuel having low fusion ash
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
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 ratio of the volume at cut-off to the swept volume is called
Cut-off ratio
Expansion ratio
Clearance ratio
None of these
The best suited coal for chain or travelling grate stoker boiler is
Coking coal
Non-coking or free burning coal
Pulverised coal
High sulphur coal
Fire tube boilers are those in which
Flue gases pass through tubes and water around it
Water passes through the tubes and flue gases around it
Forced circulation takes place
Tubes are laid vertically
Fire tube boilers are limited to a maximum design working pressure of
1 kg/cm
6 kg/cm
17 kg/cm²
100 kg/cm²
The rate of steam produced in Benson boiler is
100 tonnes/h
135 tonnes/h
175 tonnes/h
250 tonnes/h