Convert propane to natural gas to fire burner 1

[ebt2011]

Hello. I'm a first timer here.
A client of mine has a 8.5 MMBTU/hr HTHW boiler with a burner that fires on Natural Gas. He has no NG on site, but runs his plant equipment on propane. There is an existing boiler, approx same size, that fires on propane and has a 10 psig supply line. I want to tie into this line, mix it with air to convert to NG and send to the NG fuel train.
I need some direction on equipment/valve/controls/components I need for this conversion.

Thanks.

 

[TD2K]

< mix it with air to convert to NG >

That isn't going to convert propane to NG but you'll make a nice explosive mixture. Don't do it. Don't even think of doing it.

Propane is C3H8. Natural gas is primarily CH4 with some C2H6 and other gases depending on the source and treatment.

If you are going to fire on propane, your burners and control valves need to be reviewed and modified as needed by a qualified professional. Volumetrically, you need a less propane compared to NG and that has to be taken into account.

Contact the boiler manufacturer, they are likely the best source of information as a starting point what needs to be looked at.

 

[chicopee]

Or contact a burner manufacturer.

 

[op9]

Hi there,
Firstly propane CAN BE AND IS mixed with air to reproduce natural gas. It is called SNG (S for synthetic, simulated, or substitute depending on the gas supplier's particular persuasion!!). I think the proportion is 55% propane, 45% air. The aim is, is to produce a gas with the same Wobbe index as nat gas.It is used in applications where stand-by supplies must be available or as an early intervention before nat gas becomes available at a site. Basically it "should" be quite safe (in the pipe) as it is well out of the explosive limits of propane. Obviously at the burner more air is added and it becomes flammable.

Having said that an SNG installation is quite involved with many safeguards and the mixer has to obviously produce a homogeneous mix. For your requirements it would be too expensive and impractical to feed just one burner.

I would almost definitely say that the boiler burner is capable of being converted to propane operation. Apart from supply componentry alterations already mentioned by others it is often necessary to modify the burner head. Yes speak with the boiler/burner manufacturer. However if you give me some details of the boiler make I may may be able to provide some prelim advice. If the burner is integral with the boiler then it is probably made by the boiler manufacturer. However it may be a bolt on burner in which case it will have its own ID and manufacturer. Send what you can.

Rod
Combustion and Engineering Diagnostics.

Rod Nissen.
Combustion & Engineering Diagnostics

 

[25362]

For a more general picture.see:

http://www.algas-sdi.com/propane-air.html

 

[ebt2011]

Thanks to all for your response.
After further research, comparing notes and options, management made the decision to replace the burner, which was best for a number of reasons.
I was on site for the replacement and all is working fine.......firing on plant supplied propane.

Thanks again.