Help with creating superheated steam

[MelloTango]

Hi,

I'm working on gasifier project and I am looking for help to create superheated steam to use as gasifying agent in order to increase the calorific value of the syngas. We intend to use a waste heat economizer generated by a diesel generator to turn water into saturated steam. And from there we need to superheat the steam up to 800 degrees celcius and fed to the gasifier at a flow rate of 40 kg/hr. Can anyone provide recommendations as to how to design a superheater element? Amd also, whats the best way to power the superheater element, by electricity or oil/gas?

 

[katmar]

I have done this using an electrical heater. The heater element rods were installed in a shell to give something that looked very much like a shell and tube heat exchanger. You can use the normal shell side correlations to calculate the heat transfer coefficient on the gas (superheated steam) side.

I am sure you could use oil or gas, but I have not done that.

Katmar Software
Engineering & Risk Analysis Software

http://katmarsoftware.com

 

[steamdog]

Katmar,
These electric steam superheaters are commercially available, although the one shown does not go up to 800C, some fancy materials will be needed for that temperature.....

 

[MelloTango]

Thx for the suggestions. I'll def take the time to look into the electric superheater. I'm also wondering if it's possible to feed saturated steam into a small-sized conventional oil fired boilers, and having the oil burner inside the boiler heat up the steam temperature? I understand that flame temperature can be above 1000C. Would that help to raise the steam temperature to superheated, or are other factors like boiler pressure, etc involved? Sorry, I'm not from an engineering background

 

[ash9144]

Yes you can feed sat steam into a direct fired oil burner to create superheated steam. Normally this is just a certain number of tubes with steam on the inside bent around a combustion chamber. You should probably contact a company that can help with the design rather than try and do it yourself.

 

[KiwiMace]

Typically in boiler design, a superheater passes the dry saturated steam from the steam drum through another tube set in the stack discharge, making use of the hot flue gases.

A good reference is Steam: It's Generation and Use, by Babcock and Wilcox.

 

[MelloTango]

Thx for the replies. And how about boiler pressure or boiler capacity? How do they affect the properties of superheated steam?

 

[ctcs117]

supercritical boiler is untility boiler, the pressure and temp are very high over steam critical point(14.7Mpa, 560 C), and the capacity at least 1000t/h.

For your case, my idea is : first get saturated steam, after seperator, precede superheating upto 800 degree.

The key is control pressure and right steel tube.

Normally you need T91.