Benson Boiler: Working, Pros, Cons and Applications

Want to know about Benson Boiler?

Then you landed in the right place. Here you will know the perfect explanation of Benson Boiler, from scratch to end.

So, come with me and be comfortable while I start the engine of this knowledgeable journey.

Hence, without further delaying, Let’s dive in-

What is Benson Boiler?

Benson boiler is a high-pressure, drumless, supercritical, water tube steam boiler with forced circulation.

This boiler is a supercritical boiler in which the feedwater is compressed at a supercritical pressure and thus prevents the formation of bubbles in the water tube surface, unlike LaMont Boiler.

This boiler has a steam-generating capacity of 150 tones per hour approx.

This boiler was invented by Mark Bensen in 1927. Firstly. This boiler was kept in the West Germany power station.

Now, let’s move to the working principle of this boiler.

Working Principle of Benson Boiler-

It works on the principle of critical pressure of water where the pressure of the water is increased to the supercritical pressure.

This superheated water directly changes into steam without boiling the water and hence it prevents bubble formation.

Benson boiler diagram-

Benson boiler diagram

Parts and Construction of Benson Boiler-

Here are some parts or Boiler’s Mounting and Accessories of this boiler and its construction-

  • Chimney
  • Fan
  • Air Preheater
  • Economiser
  • Feed Pump
  • Throttle valve
  • Convective Evaporator
  • Super Heater
  • Radiant Evaporator
  • Combustion Chamber

1. Chimney-

The chimney is used to take out wasted gases from the chamber.

2. Fan-

The fan is used to pull the air from out and circulate the hot gases inside the chamber for further heating the water.

This hot air is sent to a hot well for further heating the water

3. Air Preheater-

Air preheater is used to preheat the air drawn by the fan and convert it into hot air to provide heat to the hot well water.

4. Economiser-

The function of the economizer is to preheat the water. It preheated the water which is coming from the feed pump to utilize the wasted heat and increase efficiency.

This preheated water is further sent to the combustion chamber situated bottom side of the boiler.

5. Feed Pump- 

A feed pump is used to draw the water from the hot well and send it to the economizer.

6. Throttled Valve-

Throttled valve is used to stop and release the steam as per need.

7. Convective Evaporator-

The function of the convective evaporator is used to raise the hot gases into the upward direction and settle down the cold gases.

8. Super Heater-

A superheater is used to further raise the temperature of steam at the maximum level.

9. Radiant Evaporator-

A radiant Evaporator is used to convert maximum water into steam using the heat radiation of the combustion chamber.

10. Combustion Chamber-

As you know, the Combustion chamber is the main part of the boiler where fuel and air are mixed to generate heat and provide the required heat to generate steam.

Working of Benson Boiler-

Here is the step-by-step working of Benson boiler-

  • The feed pump supplies the feed water to the chamber with high-velocity force
  • Now, this feed water is first going to the economiser, where water is preheated with the help of combustion gases.
  • Then this preheated water directly moves to the Radiant evaporator, where water gets converted into steam partially with the help of radiant heat coming from the furnace.
  • Here this partially converted steam goes to the convective evaporator where fully converted steam moves forward and liquid gets to settle down for further conversion.
  • Now, this fully converted steam moves to a superheater to further maximization of the temperature of the steam.
  • This high-pressure hot steam is now ready to supply to the turbine.
  • Here the key role of using multiple heat generation devices is to maximize the steam generation and thus increase the pressure of steam and raise it to supercritical pressure to maximize the overall efficiency of the boiler.
  •  The average Benson boiler pressure is 250 bar.
  • This is how Benson boiler works.

After construction and working of Benson boiler, I am heading you to the Benson boiler advantages and disadvantages and its applications.

Advantages of Benson Boiler-

Below are some major advantages of this boiler-

  • No Drum
  • Lightweight
  • Quick Starting time
  • Great thermal Efficiency
  • Quick achieving maximum load capacity(within 10min)
  • Easy transportation boiler
  • Economical


Below are some major disadvantages of this boiler-

  • Chances of the overheated tube due to absence of enough water
  • Controlling difficulties, if the load varies
  • Continues monitoring needed


Below are some critical applications of this boiler-



That’s it for now. Here I have covered multiple topics regarding Benson Boiler including definition, principle, working, advantages and disadvantages along with its applications in an easy and digestible manner, I guess.

I hope you loved spending time here and it added some value to you.

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Here are some suggested articles, If you want to read more

Velox Boiler

Lamont Boiler

What’s the Difference between condenser and Evaporator?

Thank you for being with me. I hope to see you in the next session.


Here is your gift, which I promise to give at the end of the article. So, here it is-

Benson boiler pdf benson boiler pdf
Benson Boiler ppt benson boiler ppt



Here are some MCQs of the boiler, you should consider having a look for while-


What is the capacity of the Benson boiler?

The capacity of this boiler is about 150tonnes/hr.

Amongst the following fittings, which is provided more than one in number for the boiler safety
A. Feed check valve
B. Steam stop valve
C. Fusible plug
D. Water level indicator

Answer- D. Water level indicator

Identify the valve that prevents any water from rushing back from the boiler-
A. Blow off cock
B. Steam stop valve
C. Feed check valve
D. Water gauge

Answer- C. Feed check valve

Economizer improves boiler efficiency by-
A. 1 to 5%
B. 4 to 10%
C. 10 to 12%
D. 15 to 20%

Answer- B. 4 to 10%

Economizers are usually used in boiler plants working above the pressure-
A. 30 bar
B. 50 bar
C. 70 bar
D. 100 bar

Answer- C. 70 bar

Which of the following devices is used to generate and supply steam at high pressure and temperature-
A. Steam boiler
B. Steam engine
C. Steam pump
D. Steam turbine

Answer- A. Steam boiler

When the pressure inside the boiler drum exceeds the desired level, then which of the following devices blows off the excess from the boiler-
A. Fusible plug
B. Blow-off cock
C. Safety valve
D. Stop valve

Answer- C. Safety valve

Which of the following device is used to preheat the feed water before being supplied to the boiler-
A. Superheater
B. Economizer
C. Air-preheater
D. Steam trap

Answer- B. Economizer

Which of the following device is not a type of boiler mountings-
A. Superheater
B. Feed check valve
C. Pressure Gauge
D. Water level indicator

Answer- A. Superheater

In a boiler, the device in which the waste heat of flue gases is utilized for heating feed water is called-
A. Superheater
B. Injector
C. Economizer
D. Air-preheater

Answer- C. Economizer

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