The document discusses high-pressure boilers, focusing on the Benson and Lamont designs, highlighting their construction, working principles, and unique features. It explains how Benson boilers mitigate bubble formation at critical pressure to enhance efficiency through forced circulation and the absence of a steam separating drum. The advantages of the Benson boiler include its compact design, lightweight construction, quick start-up, and reduced explosion hazards.

1. High-Pressure Boilers: Benson Boiler
Visit Theory : Benson Boiler

2. High-Pressure Boilers: Benson Boiler, Lamont Boiler-Working, Adv&Disadv: In this article, we can
discuss Benson Boiler, Lamont boiler along with working, components and construction which comes
under High-Pressure boilers.
High-Pressure Boilers: The unique features of the high-pressure boiler are as follows.
1. Method of water circulation
2. Type of tubing and drums
3. An improved method of heating
The explanation of the above features is as follows.
1.An improved method of heating:
Above the critical pressure, Saving of heat takes place by the evaporation of water.

3. 2.Method of water circulation:
The circulation of water through a boiler may be natural or Forced type. In all modern high-pressure boiler
plants, water circulation is with the help of Pump i.e. by means of Forced Circulation.
3.Type of tubing and drums:
To avoid large resistance to the flow of water, these boilers have a parallel set of an arrangement of
tubes.
high-pressure boilers are characterized by the use of very small steam separating drum or by a complete
absence of any drum.

4. Benson Boiler: Explanation, Working, Advantages
In the Lamont boiler, the main difficulty experienced is the formation and attachment of bubbles on the
inner surface of the heating tubes. The attached Bubbles to the tube surfaces reduce the heat flow and
steam generation, as it offers high thermal resistance than Water film.
Benson in 1922, argued that, if the boiler pressure was raised to critical pressure, the steam and water
have the same density and therefore, the danger of bubble formation can be eliminated.
The Benson boiler also makes use of forced circulation but has a unique characteristic of the absence of
the steam separating drum. Its main principle is that, at the critical pressure, the steam and water coexist
at the same density and heat is zero.
The water thus transforms into steam, without boiling and passes quickly from liquid to Vapor, without
changing in volume.

5. Working of Benson Boiler:
The components of Benson boiler is as follows.
● Feed Pump
● Economizer
● Radiant Parallel tube section
● Transit section
● Convection Superheater
● Steam to the prime mover

6. The working of Benson boiler w.r.t. the above components are as follows.
Firstly, The feedwater passes through the economizer.The function of Economizer is to increases the
temperature of the feedwater(preheating) by absorbing the heat from the flue gases before they are sent
to the atmosphere.
The feed water after circulation through the economizer flows through the Radiant parallel tube section to
evaporate partly.
The steam-water mixture produced then moves to the transit section where this mixture is converted into
steam.
The steam is now passed through the Convection superheater and finally supplied to the prime mover in
order to drive the turbine.

7. Advantages of Benson Boiler:
● It can be erected in a comparatively small floor area.
● It is light in weight and hence the low cost of the boiler.
● It can be started very quickly due to welded joints
● Transfer of parts is easy as no drums are required.
● The explosion hazards are less as it has only tubes of small diameter and has less storage
capacity.
As superheater is an integral part of the process circulation system, no special starting arrangement for
superheating is required
depending on the size and pressure required the boiler can be put into service within 10 to 15 minute.

8. For more information, visit https://mechanicalstudents.com/high-pressure-boilers-benson-boiler-lamont-boiler/