high pressure boiler lamont boiler

1. HIGH PRESSURE BOILER
-: PREPARED BY:-
NAME ENROLLMENT NO.
HARSH PATEL 130450119094
HET PATEL 130450119096
KAUSHIK PATEL 130450119102
KEYUR PATEL 130450119103
GUIDED BY:
ASS. PROF. MAYUR MAKWANA
MECHANICAL DEPT.

2. CONTENT:
INTRODUCTION OF HIGH PRESSURE BOILER
TYPE OF H.P. BOILER
UNIQUE Features of High pressure Boilers
Advantages of High pressure Boilers
LAMONT BOILER
- CONTRUCTION
-WORKING
-ADVANTAGE & DISADVANTAGE

3. INTRODUCTION
• A boiler is called a high pressure boiler when it operates with a steam pressure above 80 bar.
The high-pressure boilers are widely used for power generation in thermal power plants.
• In high-pressure boiler if the feed-water pressure increases, the saturation temperature of water
rises and the latent heat of vaporization decreases.
• The feed water can be heated to saturation of temperature in the economizer with the help of
waste heat. Recovery from the exhaust gases escaping to chimney.
• Then the boiler supplies only latent heat of vaporization and superheat. Thus, a boiler operation
at high pressure will require less heat addition for steam generation.

4. INTRODUCTION
• According to Pressure of Steam
(a) Low pressure, boilers—pressure < 30 atm.
(b) Medium pressure boilers—pressure = 30 to 70 atm.
(c) High pressure boilers—pressure upto 150 atm.
(d) Super pressure boilers—150 to 190 atm.
(e) Super critical boiler—pressure > 225 atm.
• In applications where steam is needed at pressures, 30 bar, and individual boilers are required to
raise less than about 30000 kg of steam per hour, shell boilers are considerably cheaper than the
water tube boilers.
• Above these limits. shell boilers (generally factory built) are difficult to transport if not possible.
There are no such limits to water tube boilers.

5. INTRODUCTION
• The modern high pressure boilers employed for power generation are of steam capacity 30 to 650
tonnes/h and above with a pressure up to 160 bar and maximum steam temperature of about 540°C.

6. TYPE OF H.P. BOILER
1.Lamont boiler 2.Benson boiler

7. 3.VELOX BOILER 4. LOEFFLER BOILER

8. UNIQUE FEATURES OF HIGH
PRESSURE BOILERS
High-pressure boilers have the following unique features:
Forced circulation of water.
Large number of small diameter tubes.
Higher steam pressure and temperature.
Improved mode of heat transfer.

9. FEATURES
Improved mode of heating – the high-pressure boilers use the following methods for
improved heat transfer rate:
Evaporative of water above critical pressure of steam.
Heating of water by mixing superheated steam for high heat transfer rate.
Increasing the combustion air velocity over the tube.
Pressurized combustion – for increasing the combustion rate and thus heat-release
rate, pressurized air is used
Compactness – the high rate of heat transfer inside the boiler reduces the overall size of the
boiler and the boiler becomes compact.

10. FEATURES
High efficiency – High-pressure boilers have better firing methods,
monitoring, furnace conditions, control flue gases and water velocity.
Intensive heating – the furnace temperature in high-pressure boilers is
high enough and therefore, 70% of heat is transferred to water by radiation. This
is a faster way of heat transfer.
Once through construction – in high-pressure boiler operating at and
above the critical pressure, the water directly flashes into steam in the tube
itself. It eliminates the need of a boiler drum.

11. ADVANTAGES OF HIGH PRESSURE
BOILERS
 High-pressure boilers use the forced circulation of water which ensures the positive
circulation of water and increased evaporative capacity.
 They require less heat of vaporization.
 They are compact and thus require less floor space.
 Due to high velocity of water, the tendency of scale formation is minimized.
 All parts are uniformly heated and the danger of overheating is minimized.
 The steam can be raised quickly to meet the variable load requirements without use of
complicated control devices.
 The plant efficiency is increased.
 With the use of high-pressure boilers, the steam generation is economical.

12. LAMONT BOILER
La Mont boiler is the first forced convection boiler which is introduce in the
year 1925.
A water circulating pump is used in the boiler to circulate water inside the boiler
.this pump is driver by the steam turbine which uses steam of the boiler
It is used in power plant industries to generate electricity
This boiler works on basic principle of forced convection .the heat transfer rate
from gas to water is increases .

13. The boiler consist of various part which are as
follow:
 Economizer
 Centrifugal pump
 Evaporator tube
 Grate
 Furnace
 super heater
 Water steam separator drum
 Air preheater

14. WORKING
 In this type of the boiler ,the feed water coming from
hot well is pumped to boiler drum through economizer
as shown in fig.
This boiler drum is located in the boiler where hot
combustion gases pass.
In economizer ,the feed water absorbs the sensible
heat from flue gases passed over the economizer.
After then, the water from the drum is pumped to
radial and convection evaporator , and again to drum.

15. CONT..
The feed water in radial evaporator absorb radiant heat and in convective
evaporator absorb convective heat and it evaporator.
The evaporator water collected in the upper part of separating steam drum.
Then it passes through superheated where it become superheated, this
superheated steam is supplied to prime mover.
The atmospheric cold air is preheated in the air preheater by the fuel gases
before they are discharged through the chimney. The heated air from air
preheater is supplied to the combustion chamber .

16. ADVANTAGES
It can high pressure boiler .
It is flexible in design.
It can easy start.
It can high steam generation capacity of about 50 ton per Hr
This boiler has high heat transfer rate because of small diameter tube are used.

17. DISADVANTAGE
Bubble are produced at the inner face of heating tube .Because of which
it reduces heat transfer rate.
Required a small vertical external drum and power to drive a small
recirculating pump by high pressure seal pump.