JSSC- JE Mechanical Engg. Question Bank 3 (Chapter – 9) Boilers Classification #4
Mechanical
A closed vessel made of steel and used for the generation of steam is called a
steam boiler
steam turbine
steam condenser
steam injector
A good steam boiler is one which produces maximum quantity of steam with the given fuel.
Agree
Disagree
The selection of type and size of a steam boiler depends upon
the power required and working pressure
the geographical position of the power house
the fuel and water available
all of the above
In a fire tube boiler, the water is contained inside the tubes which are surrounded by flames and hot gases from outside.
True
False
In water tube boilers, the water passes through the tubes which are surrounded by flames and hot gases.
Yes
No
Which of the following is a fire tube boiler?
Lancashire boiler
Babcock and Wilcox boiler
Yarrow boiler
none of these
Fire tube boilers are limited to a maximum working pressure of
0.17 MN/m²
1.7 MN/m²
17 MN/m²
170 MN/m²
Which of the following is a water tube boiler?
Lancashire boiler
Babcock and Wilcox boiler
Locomotive boiler
Cochran boiler
In fire tube boilers
water passes through the tubes which are surrounded by flames and hot gases
the flames and hot gases pass through the tubes which are surrounded by water
forced circulation takes place
none of these
In water tube boilers
water passes through the tubes which are surrounded by flames and hot gases
the flames and hot gases pass through the tubes which are surrounded by water
forced circulation takes place
none 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
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
Fire tube boilers are
internally fired
externally fired
internally as well as externally fired
none of these
Water tube boilers are
internally fired
externally fired
internally as well as externally fired
none of these
Cornish boilers are multi-tubular boilers.
True
False
In natural circulation steam boilers, the circulation of water is by convection currents which are set up during the heating of water.
Right
Wrong
In forced circulation steam boilers, the force is applied
to draw water
to circulate water
to drain off the water
all of these
In a La-mont boiler, there is a …………… circulation of water and steam.
forced
natural
Lancashire boiler is a stationary fire tube boiler.
Agree
Disagree
Water tube boilers produce steam at a …………… pressure than that of fire tube boilers.
lower
higher
The rate of flow of steam is …………… in case of fire tube boilers.
less
more
Which of the following statement is correct?
A fire tube boiler occupies less space than a water tube boiler, for a given power.
Steam at a high pressure and in large quantities can be produced with a simple vertical boiler.
A simple vertical boiler has one fire tube.
all of the above
The water tubes in a simple vertical boiler are
horizontal
vertical
inclined
A Cochran boiler is a horizontal multi-tubular boiler.
Yes
No
The fire tubes in a Cochran boiler usually have …………… diameter.
6.25 mm
62.5 mm
72.5 mm
92.5 mm
The number of fire tubes in a Cochran boiler are
73
115
105
225
A grate, in a boiler, is a place in the combustion chamber upon which fuel (wood or coal) is burnt.
True
False
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
The crown of the fire box is made hemispherical in order to resist intense heat in the fire box.
True
False
The fire tubes in a Cochran boiler are
horizontal
vertical
inclined
A single ended Scotch marine steam boiler may have one to four furnaces which enter from front end of the boiler.
Right
Wrong
The fire tubes in a Scotch marine boiler are
horizontal
vertical
inclined
The diameter of a cylindrical shell of a Scotch marine boiler varies from
1.5 to 2 m
2.5 to 3.5 m
3.5 to 4.5 m
none of these
Lancashire boiler is
stationary fire tube boiler
internally fired boiler
horizontal boiler
all of these
For the same diameter and thickness of tube, a water tube boiler has …………… heating surface as compared to fire tube boiler.
more
less
equal
Lancashire boiler is used where working pressure and power required are
low
moderate
high
none of these
The cylindrical shell of a Lancashire boiler has diameter from
1 to 2 m
1.25 to 2.25 m
1.5 to 2.5 m
1.75 to 2.75 m
The length of Lancashire boiler varies from
5 to 6 m
6 to 7 m
7.25 to 9 m
9 to 10 m
Lancashire boiler has …………… internal flue tubes.
one
two
three
four
The diameter of internal flue tubes of a Lancashire boiler is about …………… that of its shell.
one-fourth
one-third
two-fifth
one-half
The internal flue tubes of a Lancashire boiler are reduced in diameter at the back to provide access to the lower part of the boiler.
True
False
The damper in a steam boiler is provided to control the draught (i.e. rate of flow of air) and thus regulate the rate of generation of steam.
Correct
Incorrect
Which of the following statement indicates the difference between Cornish boiler and Lancashire boiler?
Cornish boiler is a water tube boiler whereas Lancashire boiler is a fire tube boiler.
Cornish boiler is a fire tube boiler whereas Lancashire boiler is a water tube boiler.
Cornish boiler has one flue tube whereas Lancashire boiler has two flue tubes.
Cornish boiler has two flue tubes whereas Lancashire boiler has one flue tube.
The diameter of Cornish boiler varies from
0.5 to 1 m
1 to 2 m
1.25 to 2.5 m
2 to 3 m
The capacity and working pressure of a Cornish boiler is …………… as compared to Lancashire boiler.
low
high
The length of Cornish boiler varies from
2 to 4.5 m
3 to 5 m
5 to 7.5 m
7 to 9 m
The diameter of flue tube in a Cornish boiler is …………… that of the shell.
one-fourth
one-third
two-fifth
three-fifth
Locomotive boiler is a
single tube, horizontal, internally fired and stationary boiler
single tube, vertical, externally fired and stationary boiler
multitubular, horizontal, internally fired and mobile boiler
multitubular, horizontal, externally fired and stationary boiler
Locomotive boiler produces steam at a very high rate.
Yes
No
The shell diameter of a Locomotive boiler is
1 m
1.5 m
2 m
2.5 m
The length of shell of a Locomotive boiler is
1 m
2 m
3 m
4 m
The Locomotive boiler has
137 fire tubes and 44 superheated tubes
147 fire tubes and 34 superheated tubes
157 fire tubes and 24 superheated tubes
167 fire tubes and 14 superheated tubes
The maximum steam pressure in a Locomotive boiler is limited to
0.18 MN/m²
1.8 MN/m²
18 MN/m²
180 MN/m²
The fire tubes in a Locomotive boiler has …………… diameter.
4.75 mm
5.47 mm
7.45 mm
47.5 mm
The diameter of superheated tubes in a locomotive boiler is
13 mm
31 mm
130 mm
230 mm
Locomotive boiler is a …………… boiler.
fire tube
water tube
Babcock and Wilcox boiler is a stationary type of water tube boiler.
Correct
Incorrect
The water tubes in a Babcock and Wilcox boiler are
vertical
horizontal
inclined
The water tube boilers produce steam at a …………… pressure than that of fire tube boilers.
lower
higher
La-mont boiler, is a high pressure water tube steam boiler working on forced circulation.
Agree
Disagree
Which of the following boiler works on a forced circulation of water?
La-mont boiler
Benson boiler
Loefller boiler
all of these
The forced circulation of water does not take place in
La-Mont boiler
Lancashire boiler
Velox boiler
Benson boiler
The working pressure range for a La-Mont boiler is
0.5 to 10 MN/m²
1 to 15 MN/m²
2.5 to 15 MN/m²
3.5 to 20 MN/m²
Loeffler boiler is a water tube boiler using a forced circulation of water.
True
False
Benson boiler requires
no drum
one drum
two drums
three drums
Benson boiler is a …………… water tube steam boiler using forced circulation of water.
low pressure
high pressure
The average operating pressure of Benson boiler is
100 bar
150 bar
200 bar
250 bar
The rate of steam produced in Benson boiler is
100 tonnes/h
135 tonnes/h
175 tonnes/h
250 tonnes/h
Which of the following boiler is best suited to meet the fluctuating demand of steam?
Locomotive boiler
Lancashire boiler
Cornish boiler
Babcock and Wilcox boiler
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
Which of the following statement is wrong?
Locomotive boiler is a water tube boiler.
Water tube boilers are internally fired.
La-mont boiler is a low pressure water tube boiler.
all of the above
The fittings mounted on the boiler for its proper and safe functioning is a
water level indication
pressure gauge
safety valve
all of these
Which of the following is not a boiler mounting?
Blow off cock
Feed check valve
Economiser
Fusible plug
The device attached to the steam chest for preventing explosions due to excessive internal pressure of steam is called
safety valve
water level indicator
pressure gauge
fusible plug
The number of water level indicators in a boiler are generally …………… in number.
one
two
three
four
A water level indicator is a device to indicate the exact water level in the boiler at any instant.
True
False
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 function of a safety valve is
to blow off steam when the pressure of steam inside the boiler exceeds the working pressure
to indicate the water level inside the boiler to an observer
to measure pressure of steam inside the steam boiler
none of the above
A safety valve usually employed with stationary boilers is
lever safety valve
dead weight safety valve
high steam and low water safety valve
all of these
A safety valve mainly used with locomotive and marine boilers is
lever safety valve
dead weight safety valve
high steam and low water safety valve
spring loaded safety valve
The high steam and low water safety valve is not used in
Cochran boiler
Cornish boiler
Lancashire boiler
Locomotive boiler
The high steam and low water safety valve is used to blow off steam when the
steam pressure exceeds the working pressure
water level in the boiler becomes too low
both (a) and (b)
none of the above
The principal function of a stop valve is to
control the flow of steam from the boiler to the main pipe and to shut off the steam completely when required
empty the boiler when required and to discharge the mud, scale or sediments which are accumulated at the bottom of the boiler
put off fire in the furnace of the boiler when the level of water in the boiler falls to an unsafe limit
increase the temperature of saturated steam without raising its pressure
Blow off cock in a boiler is used to
control the flow of steam from the boiler to the main pipe and to shut off the steam completely when required
empty the boiler when required and to discharge the mud, scale or sediments which are accumulated at the bottom of the boiler
put off fire in the furnace of the boiler when the level of water in the boiler falls to an unsafe limit
increase the temperature of saturated steam without raising its pressure
A …………… in a boiler is used to put off fire in the furnace of the boiler when the level of water in the boiler falls to an unsafe limit.
blow off cock
fusible plug
stop valve
safety valve
The function of a superheater is to heat the feed water by utilising the heat in the exhaust flue gases before leaving through the chimney.
Yes
No
An economiser is used to increase the temperature of saturated steam without raising its pressure.
Right
Wrong
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
A device used to empty the boiler whenever required and to discharge the mud, scale or sediments which are accumulated at the bottom of the boiler, is called blow off cock.
Yes
No
A valve installed between the boiler and the feed pump is
blow off cock
feed check valve
steam stop valve
none of these
A device used to put off fire in the furnace of the boiler when the level of water in the boiler falls to an unsafe limit, is called
blow off cock
stop valve
superheater
none of these
A device used to increase the temperature of saturated steam without raising its pressure, is called
blow off cock
fusible plug
superheater
stop valve
A device used to heat feed water by utilising the heat in the exhaust flue gases before leaving through the chimney, is known as
economiser
fusible plug
superheater
stop valve
Which of the following are boiler accessories?
economiser
superheater
both (a) and (b)
none of these
An economiser …………… the steam raising capacity of a boiler.
increases
decreases
has no effect on
The pressure of feed water has to be raised before its entry into the boiler. The pressure is raised by a device known as
feed pump
injector
feed check valve
pressure gauge
There is about 15 to 20% of coal saving when an economiser is used in a boiler.
True
False
An economiser is generally placed between
last superheater or reheater and air preheater
induced draft fan and forced draft fan
air preheater and chimney
none of the above
An air preheater
increases evaporative capacity of the boiler
increases the efficiency of the boiler
enables low grade fuel to be burnt
all of the above
An air preheater is installed
before the economiser
before the superheater
between the economiser and chimney
none of these
An economiser is installed in a boiler primarily to
superheat the steam
reduce fuel consumption
increase steam pressure
all of these
A device in which some portion of waste heat of flue gases is recovered to heat the air before it passes to the furnace for combustion purpose, is known as
superheater
air preheater
economiser
injector
JSSC- JE Mechanical Engg. Question Bank 3 (Chapter – 9) Boilers Classification #4
