High pressure boiler

UNIT 2
HIGH
PRESSURE
BOILERS
CO - Select High Pressure Boiler for
Power Generation capacity of Plants.

SYLLABUS
2.1 High Pressure Boilers - Classification.
2.2 Construction and principle of working of Lamont boiler, Benson boiler, Loeffler boiler，
Velox boiler, Schmidt Hartman boiler, Ramsin boiler
2.3 Fluidized bed combustion boilers (FBC): principle, need, types, various arrangement,
control system and advantages over other boiler systems.
2.4 Comparison of various types of boilers
2.5 Indian Boiler Regulation Act
2.6 Maintenance procedure of major components of high pressure and FBC Boiler

• What is Boiler :- A boiler is a closed vessel in which water or other fluid is
heated. The heated or vaporized fluid exist the boiler for use in various Process
or Heating applications or for Power generation.
• According to Boiler Regulation Act 2007, “Boiler is a closed pressure vessel in
which steam is generated with capacity exceeding 25 liters, gauge pressure
greater than or equal to 1kg/cm2.
Application Of Boilers
1. Power Generation
2. Heating
3. Industrial Processes
Boiler

Classification of Boiler
1. Relative position of hot gases and water
• Fire tube boilers • Water tube boilers
2. Geometric orientation of boiler
• Vertical boilers • Horizontal boilers
3. Method of firing
• Internally fired boilers • Externally fired boilers
4. Pressure of steam
• Low pressure boilers (<= 80) • High pressure boilers (>80)
5. Method of circulation of water
• Natural circulation boilers • Forced circulation boilers
6. Nature of service to be performed
• Land boilers • Mobile boilers (or) Portable boilers
7. Number of tubes in boiler
• Single tube boilers • Multi tube boilers

Vertical boilers
Horizontal boilers

Mobile boilers (or) Portable boilers

Single tube boilers
Multi tube boilers

High PressureBoiler
High Pressure Boiler:- A boiler is called a high-pressure boiler when it
operates with a steam pressure above 80 bars and maximum steam temperature
of 540 °C and able to deliver steam at rate of 650 tons/Hr
The modern high pressure boiler:
• Steam capacities – 30 to 650 tons/hour and above
• Pressure – up to 160 bar
• Maximum steam temperature – 540 °
Features of high pressure boiler:
1. Force circulation of water 2. Larger Number of small dia. Tubes
3. Higher steam temp. and Pressure 4. High Efficiency
5. Improved mode of heat transfer and heating

Type of High PressureBoiler
• La-Mont boiler
• Loeffler boiler
• Benson boiler
• Schmidt-Hartman boiler
• Velox boiler
• Ramsin boiler

La Mont Boiler
• It is high pressure. water type
boiler
• The water circulation is
maintained by centrifugal pump.
• La Mont boiler generates
approximately 45 to 50 tonnes of
steam per hour at a pressure of
170 bar and a temperature of
500°C.
Advantages of a La Mont Boiler:
• Small diameter tubes are used, so
that high heat transfer rate is
maintained.
• The multiple tubes circuit gives
flexibility for suitable location of
heat transfer equipment's.

Principle of La Mont Boiler
• This boiler works on basic principal of forced circulation maintained by steam driven
Centrifugal pump.
• Various part of boiler
1) Economizer
2) Centrifugal pump
3) Evaporator tube
4) Grate
5) Furnace
6) Super heater
7) Water steam separator drum
• Types of boiler:
1) Water tube
2) Forced circulation,
3) High Pressure boiler
• Steam Generating Capacity:
1) 45 to 50 tones/hour
• Pressure: 170 bar.
• Temperature : 500 °C

La Mont Boiler Working
• A feed pump forces the water into the economizer where the temperature of water is
increases.
• This water forced into the evaporator tube by using centrifugal pump driven by steam
turbine.
• Water passes into the evaporator tube. The mixture of saturated steam and water is
formed inside the tube. This mixture sends to the steam separator drumwhichis outside
the boiler.
• Steam formed in separator drum is sent to the economizer, where the saturated steam
gets converted into superheatedsteam.
• The water againsends to the economizerwhere it again passed to the evaporatortubes.
• The air from the air preheater enter into the furnace where fuel is burnt. The flue gases
first heat the evaporator& then passes to super heater.
• These gases from the super heater again used to preheat the air into air preheater
before they exhaust into atmosphere.

Disadvantages:
1) The deposition of salt and sediments
on the inner surfaces of the water
tubes, which reduces the heat
transfer rate.
2) There also formation of bubbling at
the inner surfaces of water tube. It
resist flow of heat
Advantages:
1) High Pressure Boiler
2) Flexible in design
3) Easily start

Benson Boiler/ Drum less Boiler
• To increase the pressure of water up to
super-critical value (225 bar) to convert
water into steam Without boiling"
• Difficulties of bubble formation is
eliminated.
• The transport of Benson boiler parts is
easy as no drums are required and
majority of the parts are carried to the
site without pre-assembly.
• Required smaller floor area.
• The superheater in the Benson boiler is
an integral part of forced circulation
system therefore no special starting
arrangement required.
• It has very little storage capacity
compared to drum type boiler.

Principle of Benson Boiler
• This boiler works on the basic principle of critical pressure of water .To increase
the pressure of water up to super-critical value (225 bar) to convert water into
steam Without boiling".
1) Economizer
2) Centrifugal pump
3) Evaporator tube
4) Grate
5) Furnace
6) Super heater
1) Water tube
2) Drum less
1) 150 tones/hour

Working of Benson Boiler
• In this boiler, the feed water enters at one end and discharges superheated steam at the
Otherend.
• The feed pump increases the pressure of water up to supercritical pressure thus the water
directlygetstransformedintosteamwithoutboiling.
• The water is passed through the economizer, where it gets heated. This hot water is sent to
radiantevaporator,wheremajorportionofwaterisconvertedintosteam.
• The remaining water is evaporated by absorbing the heat from hot gases passing over the
surfaceofconvectionsuperheaterTheheattransfermodeisconvection.
• The superheated steam at supercritical pressure of water sent to prime water mover to
produceusefulwork.

Advantages:
1) The benson boiler does not use water-steam separator, which reduce the total cost of
boiler.
2) This boiler can transport easily from one station to another.
3) It is economical and have higher efficiency.
4) The high pressure avoids bubble formation.
5) This can be start easily and can reach its maximum load capacity.
6) It is light weight boiler.
Disadvantages:
1) Danger of overheating
2) Salt deposition and sediment on the inner surface of water tube.

Loeffler Boiler
• Its working principal is to
evaporate the feed water by the
use of superheated steam from
the super heater.
• Difficulties of deposition of salt
and sediment is eliminated.
• Most of the steam is generated
outside from the feed water using
part of the superheated steam
coming out from the boiler.
• Loeffler boilers with generating
capacity of 100 tones/hr and
operating at 140 bar have already
been commissioned.

Principle of Loeffler Boiler
• Its principle of working is "To evaporate the feed water by means of superheated
steam from the superheater. The hot gases from the furnace are used for
superheating".
1) Evaporating drum
2) Steam circulating pump
3) Radiant super heater
4) Convection evaporator
5) Steam circulating pump and
feed water pump
1) Water tube
1) 100 tones/hour

• water is pumped to pass through economizer tube by a feed water pump. While
passing through economizer tube, feed water receives heat from the flue gases
and becomes hot.
• This feed water (hot) from the economizer tube is forced to mix with the
superheated steam in the evaporating drum. Due to absorption of heat from the
superheated steam, the feed water gets evaporated and converted into dry
saturated steam.
• This saturated steam is taken out from the evaporating drum with the help of
Steam-circulating pump. This steam passes through the tubes of radiant super
heater and then to the convection super heater, where it becomes superheated
steam and one cycle is completed.
• About one-third quantity of this superheated steam passes to the turbine to
produce useful Work (mechanical). And, the remaining two-third quantity is used
to evaporate the feed water present in the evaporating drum.
Construction & Working of Benson Boiler

Advantages:
1) The evaporator tubes in this boiler carries superheated steam, therefore there is no salt
deposition on the surface of tubes.
2) Compact in design.
3) High steam generating capacity.
4) Suitable for marine application.
Disadvantages:
1)Bubbles are formed at inner surface of tube, which reduce the heat transfer rate.
2)Evaporating drum is used, which increase the cost of boiler

Schmidt-Hartmann Boiler
• Its principle of working is “Two
pressures can be used to effect an
interchange of heat energy.”
• The primary circuit, the steam at
100 bar is produced from distilled
water.
• The exchange of heat among high
pressure steam and impure water
to be changed into steam at a
pressure of 55-60 bar which is extra
passed into superheater for
superheating purpose. Superheated
stem is finally supplied to steam
turbine.

Principle of Schmidt-Hartmann Boiler
• Working operation is similar to an electric transformer, twopressures are used to effect
an interchangeof energy.
1) Evaporating drum
2) Air preheater
3) Supper heater
4) Primary evaporator
5) Feed water pump
1) Water tube
1) 40 to 50 tonnes
• Pressure:
1) 100 bar – Primary circuit
2) 60 bar – Secondary circuit

• The Schmidth-Hartmann boiler is different from other boiler because in this boiler distilled
water is used for generation of the high pressure steam which is recalculated without any
wastage in the circuit.
• This high pressure steam is utilized for generation of low pressure steam from impure water.
• Distilled water from water drum enters into the primary evaporating tubes by natural
circulation.
• Steam at 95-100 bar pressure is generated in the evaporating tubes with the help of hot flue
gases circulated over the tubes from combustion chamber.
• This steam enters via primary separator into the tubes submerged in impure water of the
evaporator or steam drum.
• The exchange of heat between high pressure steam and impure water allows the water to be
converted into steam at a pressure of 55-60 bar which is further passed into super heater for
superheating purposes.
• The superheated stem is finally supplied to the steam turbine.
• The condensate of high pressure steam collected from the drum passes through the feed
water preheater where it heat the low pressure feed water up to its saturation temperature.
• The low pressure (L.P.) feed water is pumped into preheater with the help of feed pump.
Construction & Working of Schmidth-Hartmann boiler

Advantages:
1) Any deposits in evaporator drum due to impure water can simply brushed off by remove
the submerged tube as of the drum or by blowing off water.
2) As it can use impure water there is no necessity of water softening plant eventually
reduces cost.
3) It can utilize impure water for creation of steam.
Disadvantages:
1)Evaporating drum is use which increase size of plant by cost.
2)Due to deposits in evaporator drum because of impure water plant has to stop
often for cleaning.

Velox Boiler
• When the velocity of the
gas is greater than the
speed of sound, its heat
transfer rate is also
increases. So more heat is
transfer from gas to water
as compare when the heat
transfer at the subsonic
speed.
• This boiler can increase the
heat transfer rate or can say
steam generation rate
without increasing boiler
size.
• This is why Velox boiler is
most successful boiler in
the gas turbine industries.

Construction & Working of Velox boiler
• The Velox boiler works as a basic heat exchanger.
• The air is compressed by air compressor driven by gas a turbine driven. This compressed air
passes from the combustion chamber, where more heat release by the fuel which increase the
velocity of the flue gases up to sound velocity.
• From the bottom of combustion chamber, this flue gases pass from the fire tubes. These fire
tubes surrounded by the evaporator water tubes. The water from the economizer passes from
the evaporator tube force by a circulating pump.
• This water passes 15 - 20 time from the evaporator tube at very high speed. Due to this high
speed circulation, heat is transfer from the gases to the water at very high rate. The mixture of
water and steam is formed which further passes from the water and steam separator.
• The steam from the steam separator passes to the super heater and further for process work.
The remaining water in the steam separator again passes from the evaporator tube. The flue
gases from the fire tubes send to the super heater tubes, where it increases the steam
temperature. The gas from the super heater sends to the turbine where it rotates the gas
turbine and then passes from the economizer

Advantages:
1) This boiler has high heat transfer rate.
2) It has great flexibility.
3) It is compact in design.
4) It is easy to control. It is fully automatic.
5) It has thermal efficiency about 90-95%.
Disadvantages:
1) Need extra ground as of horizontal construction.
2) Fuel oil burning power station lies in the high cost of fuel.
3) It can only operate on liquid or gaseous fuels.

Ramsin Boiler
• Ramsin boiler is "one through"
type boiler.Here, no large drums
are needed. Small diameter
tubes are used.
• It consists of parallel tube
circuits connected by an inlet
header and an outlet header.
• The pressurized water enters
the tube inlets. And leaves the
outlets as superheated steam.
• There is no re-circulation of
water within the unit, which is
present in any conventional
steam boiler

• Feed water is supplied by feed water pump to the economizer, where it gets
preheated dire to heat received from flue gases leaving to atmosphere.
• This preheated water passes, through evaporator, tubes and then. convection super
heater' to become superheated steam
Advantages:
• This boiler has high heat transfer rate.
• It has great flexibility.
• It is compact in design
• It is easy to control.
• It is fully automatic.
Disadvantages:
• Fuel oil burning power station lies in the high cost of fuel

3.2 Fluidized Bed Combustion Boilers (FBC)
• Fluidized Bed Combustion
• Fluidization is a method
of mixing fuel and air in
a specific proportion, for
obtaining combustion.
• A fluidized bed may be
defined as the bed of
solid particles behaving
as a fluid.

Need of Fluidized Bed Combustion Boilers
• Burning of pulverized coal has some problems.
• Particle size of coal used in pulverized firing is limited 70-100 microns.
• The pulverized fuel fired furnaces designed to burn a particular coal cannot be used to
burn other type of. Coal with same efficiency,
• The generation of high temperature about 1650 °C in the. furnace creates number of
problems like slag formation on super heater, evaporation of alkali metals in ash and its
deposition on heat transfer surfaces,
• Formation of SO2 and NO in large amount.
• In order to overcome the above difficulties, fluidized bed combustion boilers are used.
By using fluidized bed combustion boilers
• We can burn any fuel including low grade coals (even containing 70% ash), oil, gas or
municipal waste.
• Desulphurization is improved.
• NOx emissions are reduced.

Working Principle of Fluidized Bed Combustion Boilers

• It operates on the principal that when an evenly distributed air is passed upward through a
finely divided bed of solid particles at low velocity, the particles remain undisturbed, but if the
velocity of air flow is steadily increased, a stage is reached when the individual particles are
suspended in the air stream.
• If the air velocity is further increased, the bed becomes highly turbulent and rapid mixing of
particles occur which appear like formation of bubbles in a boiling liquid and the process of
combustion as a result is known as fluidized bed combustion.
• The fuel and inert material like dolomite fed on a distribution plate and air is supplied from
the bottom of distribution plate.
• The air is supplied at high velocity, so that, solid feed material remains in suspension condition
during burning.
• SO2. formed during burning is absorbed by the dolomite and thus, prevents its escape with the
exhaust gases.
• The molten slag is tapped from the top surface of the bed.
• The bed temperature is nearly 800 to 900 °C which is ideal for sulphur retention. Addition of
Fuel and limestone or dolomite to the bed brings down SO2 emission level to about 15% of
that in conventional firing methods.

Classification of Fluidized bed combustion boilers
• Fluidized bed combustion boilers are classified as:
1. Circulating fluidized bed combustion boilers.(CFBCB)
operating on atmospheric pressure.
2. Pressurized fluidized bed combustion boilers (PFBCB).

Circulating Fluidized Bed Combustion (CFBC)

Construction & Working
• The combustion chamber of a circulating fluidized bed combustion boilers operates
under atmospheric pressure. Therefore, they are also called as atmospheric fluidized
bed combustion boilers (AFBCB).
• These boilers are further classified as underfeed and overfeed boilers.
• In case of underfeed boilers, loading of fuel and supply of air is from the bottom of
the bed, whereas, in case of overfeed boilers, loading of fuel and supply of air is on
the top of bed.
• The underfeed atmospheric fluidized bed combustion boilers (FBCB) are compact in
design. However, they have high operational, costs.
• The overfeed fluidized bed combustion boilers are simple in operation with less
operational cost.
• However, they give lower heat transfer rates per m2 area of the bed.
A Circulating Fluidized Bed Combustion

• A Circulating Fluidized Bed Combustion Boiler (CFBCB) is shown in Fig. It is also called
as bubbling fluidized bed combustion boileis.
• These boilers are called as circulating type FBCB, because a good portion of the
particles exit or leave the combustion chamber with' the flue gases. The particles are
then separated from the exhaust and reinjected into the fluidized bed system. .
• The fluidized air flows through the grid plate from the' air plenum chamber into the
bed, where the combustion of coal occurs. The coal is crushed between 6 mm to 22
mm size before supplied to the, combustion chamber with lime stone by the feed
hopper.
• The mixture of fuel and air becomes a swirling mixture in the combustion chamber
and rapid combustion takes place at a temperature of 800°C - 900°C. Heat is
transferred to the submerge tube tank. Lime stone allows the sulphur to remain in the
bed and formation of H2SO4 is prevented: The Lower combustion temperatures
prevent the formation of NOx. Thus, the coal having inferior quality can be burnt
without use of pulverize.

Advantages of Circulating Fluidized Bed Combustion :-
• Pulverized coal is not needed.
• NO formation does not take place.
• Desulphurization of coal takes place at the bed due to addition of lime stone and the
exhaust gases can be cooled to lower temperature before discharged through chimney.
• Slagging problem is reduced due to combustion at low temperature.
• Low grade coal can be used.
• Cheaper alloys can be used for its construction due to low combustion temperature by
fuel.
• Heat release rates are 10 to 15 times higher, compared to conventional boilers.
• Surface heat transfer rates are 2 to 3 times higher, compared to conventional boiler.
• Size of the plant is considerably reduced.

Pressurized Fluidized Bed Combustion (PFBC)

• Pressurized FBC boiler is the latest system used for generation of power, in which, air is
supplied under a pressure of 10 bar approximately with the help of an air compressor driven
by a gas turbine.
• The supply of air under pressure results into better rates of heat transfer as compared to
circulating type FBC boiler.
• The mixture of fuel and lime stone is supplied under pressure to the fluidized bed having a
part of evaporator tubes immersed in the bed and remainder tubes as free board tubes above
the bed. The ash is collected at the bottom.
• The flue gases along with unburnt carbon leaving the combustion chamber are passed
through a cyclone separator, where the unburnt carbon particles are separated from the gas
due to centrifugal action from the mixture. Separated carbon particles are returned to
fluidized bed to complete their combustion.
• The flue gases from separator are now passed through a dust separator.. The cleaned flue gas
is then. supplied to the gas turbine, where it expands up to the atmospheric pressure. The
power of the gas turbine is used to run an air compressor for supplying the compressed air to
the combustion chamber.

Advantages :-
• High rate of coal loading with high rate of combustion of fuel is achieved.
• Load variation on plant can be met easily by varying the coal leading on plant.
• Considerable reduction in volume of furnace, hence size of plant is reduced drastically.
• High steam generation rates are achieved.
• Low NOx emissions.
• Reduced formation of S02.
• The cost of plant is reduced.
• Requires reduced air velocity compared to CFBCB.
Disadvantages:-
• Combustion rates cannot be controlled.
• Life of plant is low as compared to conventional laOilers.
• Erosion of walls of the furnace.
• Complexity of operation

Advantages of FBC boiler over Conventional boiler
1. Low combustion temperatures (820 to 950°C) prevents the formation of nitrogen oxides like
nitric oxide and nitrogen dioxide. Hence, NOx emissions are reduced.
2. Due to low combustion temperatures, fouling and corrosion of tubes is reduced considerably.
3. Due to better heat transfer, the unit size and hence, the capital cost is reduced.
4. The cost of coal crushing is reduced, since it is not necessary to grind the coal to very fine size.
5. This system can respond rapidly to changes in load demand, since, thermal equilibrium
between air and coal particles in the bed is quickly established.
6. There is rapid mixing of fuel particles in the bed, which ensures uniformity of temperature.
7. No moving parts, resulting in reduced maintenance cost.
8. Safe operation.
9. Fully automatic operation.
10. Efficient operations at temperatures down to 750°C, which is well below the ash fusion
temperature.
11. Easy ash removal system.
12. Shorter erection and commissioning period.
13. Higher thermal efficiency.
14. Combustion with lower excess air, which reduces the fan ratings and power cost.

Disadvantages of FBC boiler over Conventional boiler
1. Since the air had to be supplied at high pressure, so as to support the bed, the fan
power is increased sufficiently.
2. Problems associated with the distribution of coal and dolomite or limestone occur.
3. Erosion problems caused by the particles in the furnace, rubbing the evaporator
tubes.
4. Use of this system is limited to relatively low power applications. To obtain larger
power, many units need to be arranged in parallel.
5. The system requires about 50 % more dolomite and limestone than a flue gas
scrubber system for the sulphur-removal.

2.4 Comparison of various types of boilers
1. Water Tube boiler Vs Fire Tube boiler ( 10 Points )
2. Compare Lamont and Benson Boiler

• Boiler act contain the law related to registration and inspection of steam
boiler.
• This Act may be called the Indian Boilers Act, 1923.
• It extends to the whole of India except the State of Jammu and Kashmir.
• This act is applicable to all boiler (water tube and fire tube boilers).

• What is Boiler :- A boiler is a closed
vessel in which water or other fluid
is heated. The heated or vaporized
fluid exist the boiler for use in
various Process or Heating
applications or for Power
generation.
• According to Boiler Regulation Act
2007, “Boiler is a closed pressure
vessel in which steam is generated
with capacity exceeding 22.75 liters,
gauge pressure greater than or
equal to 1kg/cm2.

Accident
• "Accident" means an explosion of a boiler or steam-pipe or any damage to a boiler or
steam-pipe which is calculated to weaken the strength therefore so as to render it
liable to explode.

Neyveli, Tamil Nadu: Six men were killed and 16 others injured when a boiler exploded at
the NLC Ind...

• Simple control systems and high steam pressures were the causes of accidents during
operation.
• To prevent such hazards and explosions, some rules and regulations were introduced
as mandatory to follow by industrial sectors, In India, IBR Act was established, which
specified that, a Government Inspector would be responsible and would have to
certify all steam boilers as 'suitable' from the safety point of view.
• Every part of IBR approved steam system has to be manufactured, installed, tested,
operated and maintained under the watchful eye of local inspector.
• Every customer, who runs an IBR boiler, must carry out an annual IBR inspection in
presence of an IBR inspector.
• The local IBR office is a state, government department, and maintains satellite offices
close to each industrial zone, and they have to be invited to inspect the boiler and the
relevant system.

• The State Government may appoint
qualified persons as Chief Inspector,
Deputy Chief Inspectors etc. They may
define the local limits, within which, each
appointed Inspector shall exercise the
powers and perform the duties conferred
and imposed on Inspectors under this Act.

Meaning of IBR for a Manufacturer of Steam Equipment
• An IBR license is required to manufacture steam equipment.
• This is a factory approval, even before, the company starts manufacturing valve or pipe etc.
This licenses also given to workshops, where adequate infrastructure for pressurized joint
welding and testing is available.
• The product drawing is submitted for provisional IBR approval along with the necessary
fees paid.
• Once the approval is received, raw materials have to be purchased from IBR approved
vendors. Also, readily bought out parts must have an IBR approval certificate.
• The inspector has to be called to inspect and approve the material before manufacturing.
• The manufacturing can now be started. The manufacturer must use Welding methods and
fabrication procedures as specified by IBR.
• Before commencing manufacture of a boiler or boiler component, every manufacturer
shall engage an Inspecting Authority for carrying out inspection at various stages of
manufacture as per I.B.R. regulations.
• The Inspecting Authority shall follow necessary procedure for inspection and certification
of boiler or. boiler component.

Meaning of IBR for a Manufacturer of Steam Equipment

• If inspector finds the boiler or the boiler component conforming to the standards
prescribed by regulations, he/she shall issue a 'certificate of approval' and stamp the
boiler or boiler component. But if inspector finds the boiler or boiler component not
conforming to the standards prescribed by regulations, then 'certificate of refuse’ has to
be issued for non-conformance. Provided that no certificate shall be refused unless the
Inspecting Authority had informed the manufacturer to carry out necessary
modifications or rectifications.

• To check whether all boilers are
registered or not.
• To check all the boilers are according
to the provision of the act.
• To check boilers and its mounting and
accessories periodically.
• Advise the owner regarding the
maintenance and inspection of
boiler.
DUTIES OF PERSON IN-CHARGE

• Decide whether the certificate
is to be given or not.
• Maintain the record of all the
boiler.
• Supervise and control the
work of officer in-charge.
DUTIES OF CHIEF INSPECTION OFFICER

• Section 5 denotes the authority of state Government in order to installation and
inspection of boiler.
• Section 7 provides the rules regarding the registration of boiler for utilization Every
boiler must be resisted. If the boiler is not registered , than the owner has to apply for
the registration along with prescribed fees. After getting the application, the inspector
fix the date, within 30 days of receipt of the application. After that period, the
certificate of boiler is required to be renewed.
• Section 11 provides the rules regarding the revocation certificate of boiler: If the
person in charge of boiler, does not hold competent certificate, then the boiler cannot
be used.

• Accident in "Boiler Act" is defined as, "an explosion of a boiler or steam pipe or
any damage to a boiler or steam pipe"
• If any accident occurs due to a boiler or boiler component, the owner shall
report the same in writing to the Inspector within twenty- four hours.
• Every such report shall contain a true description regarding nature of accident,
damage to the boiler or to the boiler component or injury to any person.
• The report must specify all details, so that, inspector can judge the severity of
the accident.
• Every person shall be bound to answer truly to the best of his knowledge and
answer every question put to him in writing by the Inspector.
Report of Accidents

• The owner of any boiler, which is not registered under IBR, may submit application
to the Inspector along with documents as prescribed by regulations to obtain
certificate of registration.
• Every such application shall be accompanied by the prescribed fee paid.
• The Inspector shall fix a date (within thirty days or a specified period from the date
of receipt), for the examination of boiler.
• A certificate authorizing the use of a boiler is ceased after expiry of the granted
period or when any accident occurs to the boiler; or when the boiler is to be shifted
from one place to other.
Registration and Renewal of Certificate

• Any owner of a boiler, who uses the boiler
either without certificate of approval, shall
be punishable with fine up to one lakh
rupees, or in the case of a continuing
offence, along with fine, additional one
thousand rupees per day may be charged
after the first day of conviction.
• Also if any person, who has transferred
boiler from one state to another without
reporting to competent authority may
punished. The owner is liable to punish, if
he makes any structural changes, addition
or renewal in IBR system without obtaining
prior sanction of the Chief Inspector, or fails
to report about an accident.
Penalties for Illegal Use of Boiler

Provisions under Boiler Act for Remedial Measure
1. Prohibitions of use of unregistered or uncertified boiler
2. Renewal of certificate from time to time.
3. Modification and Renewal to boiler.
4. Modification or changes in steam pipes.

Maintenance Procedure for Major Components of
High Pressure And FBC Boilers
• Maintenance of high pressure and FBC boilers can be done in two stages:
(A) Boiler inspection:
• The boilers are required to be tested regularly as per Indian Boilers Act.
• Before inspection, boiler should be made empty and all manhole doors, caps,
mud drums, fire bars, front end bridge plates, oil burners etc. should be
removed and boiler should be cleaned. All tubes, smoke boxes and external
flues should be cleaned and checked. All the steam and water connections
should be disconnected and then, it should be made ready for conducting the
following tests:

• Hydraulic Test:
• leakages in steam boiler. For this test,
the mountings should be fitted tightly
except the safety valves. The openings
of the safety valves should be closed. All
the joints should be made tight and
leak-proof. Boiler should be filled with
water and inspector's gauges should be
fitted to the boiler. Generally, the boilers
are tested at a pressure equal to twice
the working pressure of the boiler.
During this test, no part of boiler should
deflect.

• Steam Test:
• This test is conducted to check
whether the safety valves
operate properly to relieve the
steam, when the steam pressure
inside the boiler exceeds the
rated pressure. This operation is
tested keeping the feed valve
and steam stop valve closed.

(B) Boiler Maintenance:
• Regular maintenance and careful supervision of working of various components
of boiler result in the efficient operation of the boiler.
• The various factors, which should be carefully observed for proper maintenance
of the boiler are as follow:
 The combustion equipment should be so adjusted that, the temperature in the
furnace does not exceed the designed value. The air supply to the furnace should be
in correct proportion.
 The water level in the boiler should not be allowed to fall beyond the minimum level.
 The temperature should change slowly and uniformly in the various parts of the
boiler. Rapid changes in temperature lead to unequal expansion.

 The water used for steam generation should be free from scale forming impurities,
because the scale deposited on tube and boiler shell does not allow the heat transfer
to take place effectively and sometimes causes over heating of tubes and boiler shell,
which may result in failure of tubes and boiler explosion.
 Soot and ash deposited in tubes on gas side should be removed regularly.
 Bearings of pumps, stokers, pulverizes and fans etc., should be lubricated regularly.
 Oil or scale in the tubes is undesirable. Hence, such tubes should be traced or located
to solve the problem.
 All stays should be in even tension and they should be properly adjusted.
 The tube leakage is caused due to extreme overheating of tubes as it is exposed to
high temperature. The boiler should be stopped, when such leakage is noted and it
must be immediately repaired.

• Questions for 2 Marks each
1. Define High pressure Boiler
2. Name any four components of La-Mont Boiler.
3. State any four advantages of Benson Boiler.
4. Name any four components of FBC Boiler.
5. State the need of IBR.
6. List Various types of High Pressure boiler.
• Questions for 4 Marks each
1. Explain with neat sketch construction and working of Lamont boiler.
2. State the two types of Fluidized Bed Combustion (FBC) boiler, Explain any one with neat sketch.
3. Explain the constructional feature of Schmidt Hartman boiler with neat sketch.
4. Explain the Indian Boiler Regulation (IBR) act.
5. Compare Lamont and Benson Boiler.(4 Points)
6. Water Tube boiler Vs Fire Tube boiler. ( 8 Points)
Assignment No. 2 : Unit 2 Power Plant Engineering

High pressure boiler

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