Hey, as part of a project we are designing a small boiler for a small water heater
I think the best material is going to be stainless steel, however is it better to cast the boiler or have it weild from two formed parts? or another way all together, baring in mind that the pressure in the boiler will be coming close to 20 Bar…any ideas? PLEASE!
Just to add this is the first time i have asked a question, so guys i am counting on you!
Just to add this is only a design project, the people arent mad enough to let us build one!
Also that the boiler is part of a larger system, which is why the water pressure needs to be so high! Also means we only need to pass a general design.
I am a qualified Marine Engineer with extension that allows me to work on and run all boiler / turbine plants. At land and sea.
No boiler is made from stainless steel. They are all made from black steel and/or cast iron. All pipes being seem less.
On the corrosion side, anti corrosion additives is fed to the water.
The reason for not using stainless steel, is that the price of the boiler would tenfold, thus not making the build economical feasible.
The Scottish Marine Boiler is a "fire pipe boiler". This is commonly used in the Merchant Navy around the world. This boiler is used where superheated steam is not needed, as it is not fitted with a super heater. It produces only saturated steam. There is of course exemptions.
The beauty here is that you can use any fuel imaginable.
Basically you have a combustion chamber surrounded by water. Vertically from this chamber you have a number of pipes going through the water up into the exhaust chamber. Simple as that.
This type of boiler is of course not very efficient, but it’s cheap to build.
for the 4th time in 3 years the boiler in my rented apartment has stopped working?
20 bar (300 psi) seems a rather high pressure. Given that, I would suggest that you are right – stainless steel would be the best material – but I would also suggest that you should not weld it together yourself. Get it done by a certified welder. At that pressure you will almost certainly need to get it tested by a boiler inspector. In that case, you will need to get the design approved by him before you start.
Don’t make the boiler as a casting.
At lower pressures (less than, say, 8 bar) you could make a small boiler out of copper, and silver solder it together. This is reasonably straightforward, but quite likely to be unsuccessful if it is your first attempt, unless you have expert help! Again, depending on the size, you may need to involve a boiler inspector.
References :
first if you plan to make a boiler to hold 300psi , HA NO WAY, i am a power engineer for the federal gov’t and specialize in HP boilers, you would have to go to school for about 3 years just to qualify to run something like this let alone design and build. unless this is just a design project, also if this is a water heater then i assume it is not making steam, thus it is a heating boiler meaning your pressure probably does not matter much, unless you are refering the pressure as being on the water side of a combustion chamber and heating it with flame, i need more info and exact questions to help with this one.
References :
I am a qualified Marine Engineer with extension that allows me to work on and run all boiler / turbine plants. At land and sea.
No boiler is made from stainless steel. They are all made from black steel and/or cast iron. All pipes being seem less.
On the corrosion side, anti corrosion additives is fed to the water.
The reason for not using stainless steel, is that the price of the boiler would tenfold, thus not making the build economical feasible.
The Scottish Marine Boiler is a "fire pipe boiler". This is commonly used in the Merchant Navy around the world. This boiler is used where superheated steam is not needed, as it is not fitted with a super heater. It produces only saturated steam. There is of course exemptions.
The beauty here is that you can use any fuel imaginable.
Basically you have a combustion chamber surrounded by water. Vertically from this chamber you have a number of pipes going through the water up into the exhaust chamber. Simple as that.
This type of boiler is of course not very efficient, but it’s cheap to build.
References :
Here’s a link that should be useful. They build boilers for any use you can imagine
http://www.aalborg-industries.com/
Search for "boiler types"