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
Correct Answer :
B. Non-coking or free burning coal
Related Questions
The power of a boiler may be defined as
The ratio of heat actually used in producing the steam to the heat liberated in the furnace
The amount of water evaporated or steam produced in kg per kg of fuel burnt
The amount of water evaporated from and at 100° C into dry and saturated steam
The evaporation of 15.653 kg of water per hour from and at 100° C
If partial pressure of air and steam be pa and ps respectively in a condenser, then according to Dalton's law, the pressure in condenser is equal to
ps - pa
pa - ps
pa + ps
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 value of the reheat factor varies from
1.02 to 1.06
1.08 to 1.10
1.2 to 1.6
1.6 to 2
Maximum energy loss in a boiler occurs due to
Unburnt carbon in ash
Incomplete combustion
Ash content
Flue gases
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 convection currents which are set up during the heating of water, then the boiler is known as
Internally fired boiler
Externally fired boiler
Natural circulation boiler
Forced circulation boiler
Water and sediment in fuel oil can be removed by
Heating the oil in the settling tanks
Cooling the oil in the settling tanks
Burning the oil
Suspension
The expansion of steam, as it flows over the blades in reaction turbine, represents
Isothermal process
Isentropic process
Throttling process
Free expansion process
The equivalent evaporation of a boiler is a measure to compare
The given boiler with the model
The two different boilers of the same make
Two different makes of boilers operating under the same operating conditions
Any type of boilers operating under any conditions
The efficiency of a boiler is defined as
Ratio of heat actually used in producing steam to the heat liberated in the furnace
Ratio of the mass of steam produced to the mass of total water supplied in a given time
Ratio of the heat liberated in the furnace to the heat actually used in producing steam
None of the above
Which of the following statement is correct?
A horizontal steam engine requires less floor area than a vertical steam engine
The steam pressure in the cylinder is not allowed to fall below the atmospheric pressure
The compound steam engines are generally non-condensing steam engines
All of the above
The draught (in mm of water), for maximum discharge of flue gases through the chimney, is given by (where H = Height of the chimney in metres, and T1 = Absolute temperature of air outside the chimney in K)
T1 /88.25H
88.25H/T1
T1 /176.5H
176.5H/T1
The bituminous coal is no caking if its carbon content is
78-81 %
81-85 %
85-90 %
90-95 %
The action of steam in a steam turbine is
Static
Dynamic
Static and dynamic
Neither static nor dynamic
The function of a piston in a steam engine is
To guide motion of the piston rod and to prevent it from bending
To transfer motion from the piston to the crosshead
To convert heat energy of the steam into mechanical work id) to exhaust steam from the cylinder at proper moment
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
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
The compounding of turbines is done in order to
Reduce speed of rotor
Improve efficiency
Reduce exit losses
All of these
Willians line follows the law (where b = A constant representing the shape of the Willians line, a = Another constant i.e. no load consumption per hour, I.P. = Indicated power, and m = Steam consumption per hour)
I.P. = a × m + b
m = a + b × I.P.
I.P. = b × m + a
m = (b/I.P.) - a
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 diameter of cylindrical shell of the Lancashire boiler is of the order of
1 to 1.25m
1 to 1.75 m
2 to 4 m
1.75 to 2.75 m.
A supercritical boiler is one that operates above the pressure and temperature of following values
100 kg/cm² and 540°C
1 kg/cm² and 100°C
218 kg/cm² abs and 373°C
218 kg/cm² abs and 540°C
1 kg.m is equal to
9.81 Joules
102 Joules
427 Joules
None of these
The process of maintaining the speed of the turbine constant for various load conditions, is known as
Bleeding
Reheating
Governing
None of these
By compounding the expansion of steam in two or more cylinders, the ratio of expansion
Does not change
Increases
Decreases
None of these
In a glass tube type water indicator for a boiler, one end of the tube is connected to water space and the other end is connected to
Water space also
Chimney
Steam space
Superheater
The draught produced by a steam jet issuing from a nozzle placed in the chimney is called
Induced steam jet draught
Chimney draught
Forced steam jet draught
None of these
The critical pressure ratio for gases is
0.528
0.546
0.577
0.582
Spontaneous combustion is a phenomenon in which
All the fuel burns instantaneously producing high energy release
Fuel burns with less air
Coal bursts into flame without any external ignition source but by itself due to gradual increase in temperature as a result of heat released by combination of oxygen with coal
Explosion in furnace