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
Correct Answer :
A. Prevent flat surfaces under pressure from tearing apart
Related Questions
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 water tubes in a simple vertical boiler are
Horizontal
Vertical
Inclined
None of these
The state of vapour under saturation condition is described by
Pressure alone
Temperature alone
Pressure and temperature
Pressure and dryness fraction
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
In forced 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 impulse turbine rotor efficiency will have a maximum value of 0.5 cos 2α, where α is the nozzle exit flow angle, if the
Blades are equiangular
Blade velocity coefficient is unity
Blades are equiangular and frictionless
Blade solidity is 0.65
Sulphur content of fuels is very important to the plant operators because it
Has high heating value
Retards electric precipitation
Promotes complete combustion
Has highly corrosive effect
Expanding steam to a very low pressure (high vacuum) in steam engines is
Desirable
Economical
Essential
Uneconomical
The high pressure and low pressure cylinders in a receiver type compound engine are regarded as having cranks
180° to each other
90° to each other
0° to each other
None of these
The specific heat of superheated steam in kcal/kg is generally of the order of
0.1
0.3
0.5
0.8
The amount of water evaporated from feed water at _________ into dry and saturated steam at 100° C at normal atmospheric pressure is called equivalent evaporation from and at 100° C.
0°C
40°C
60°C
100°C
The performance of a boiler is measured by the
Amount of water evaporated per hour
Steam produced in kg/h
Steam produced in kg/kg of fuel burnt
All of these
For burning 1 kg of carbon to CO as per chemically correct combustion, amount of air required is
1 kg
4/3 kg
8/3 kg
2 kg
In designing air preheaters, the important design consideration is that
Approach temperature should be as low as possible
Handling and maintenance should be easier
Heat transfer area should be optimum
Stack gases should not be cooled to the dew point
The high pressure and low pressure cylinders in a Woolf type compound engine are regarded as having cranks
180° to each other
90° to each other
0° to each other
None of these
The factor of evaporation for all boilers is always
Equal to unity
Less than unity
Greater than unity
None of these
Heating wet steam at constant temperature is heating it at constant
Volume
Pressure
Entropy
Enthalpy
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
Lancashire boiler is used where working pressure and power required are
Low
Moderate
High
None of these
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
A wet vapour can be completely specified by
Pressure only
Temperature only
Dryness fraction only
Pressure and dryness fraction
The number of drums in Benson steam generator is
One
Two
One steam drum and one water drum
No drum
The diameter of tubes for natural circulation boiler as compared to controlled circulation boilers is
More
Less
Same
Could be more or less depending on other factors
The critical pressure gives the velocity of steam at the throat
Equal to the velocity of sound
Less than the velocity of sound
More than the velocity of sound
None of these
The ratio of heat equivalent to brake power to the energy supplied in steam is known as
Mechanical efficiency
Overall efficiency
Indicated thermal efficiency
Brake thermal efficiency
Gusset stays in a boiler are provided to
Prevent the bulging of flat surfaces
Avoid explosion in furnace
Prevent leakage of hot flue gases
Support furnace freely from top
In a throttling process
Steam temperature remains constant
Steam pressure remains constant
Steam enthalpy remains constant
Steam entropy remains constant
Which of the following boiler works on a forced circulation of water?
Lamont boiler
Benson boiler
Loeffler boiler
All of these
The purpose of governing in steam turbines is to
Maintain the speed of the turbine
Reduce the effective heat drop
Reheat the steam and improve its quality
Completely balance against end thrust
Over fire burning is the phenomenon of
Supply of excess, air
Supply of excess coal
Burning CO and unburnts in upper zone of furnace by supplying more air
Fuel bed firing