Boiler operation basics - 101


Old Time Steam Powered machine shop.


Eckrohr Marine Steam Boiler

The links on the left of this page offer alot of additional info in regards to steam powered ships. With multiple ships and steam plants and pictures. Take a look if interested. In addition there is a glossery of terms.

[B][U]There are several more examples of questions and answers at the source link provided above.[/U][/B]

Question: Boiler peak conditions
What will be the probable reasons, when the boiler load can not be increased to peak conditions?

Soot on the heating surfaces. Even a thin layer of soot will reduce the boiler efficiency. Not the right fuel for the burner. For instance, diesel oil to a rotary cup burner wouldn’t do. Too low feed water temperature.

Question: Boiler pressure
In tanker vessels we use boilers for cargo heating.
Lets say that steam pressure to deck line adjusted to 5 bar.
What will be most economical? Boiler pressure adjusted to 7 bar or to 16 bar ?

The higher pressure would be advantageous if the boiler is oil-fired,
but the difference is hardly measurable.
If you have a diesel engine exhaust gas economizer then 7 bar boiler pressure would gain more heat from the exhaust gases.

Question: Cavitation in a two flow line
We have a steam genereting facilty using process heat. The condenser is a vertical condenser with process vapours on tube side and boiler feed water on shell side. The outlet of the shell side is a two phase flow. Pipe thickness reduction of the shell side outlet pipe is observed for last couple of years. We replace the piece of pipe every one year. I want to know the probable reasons for this to happen.

I guess it might be a cavitation problem. Calculate the flow rate. Decreasing the speed of the flow might be a solution i.e., increase the pipe diameter