I need to validate an opinion on combustion.....

[Joe Bob]

A commercial incinerator is going lean and/or rich during a vapor recovery cycle involving loading of tankers with Naphtha. Only a number of inputs are controlled. When the incinerator drops under the mandated 1400F destruction of vapor minimum it goes into shutdown.

The tankers are prior loaded with a divergent source of materials. The head space vapor content is all over the scope. The loaded material is not a final product but a contributor to a final product.

They are suggesting a flow shut down and a purge.

I suggested using an air fuel ration meter to determine what the optimal operating parameters would be. The people across the table got glassy eyed when I mentioned "stoichiometric".

This is old school tech on a 1937 vintage facility. Adjusting the a/f mix during loading is my idea.....

[John Rogers]

If this is in CA, I would doubt that any modifications could be done such as adding an A/F port even to just read data without a LOT of government agencies reviewing what will be done! By the time it got approved......

[Joe Bob]

Yes, this is in CA.....I have a permit to modify in hand......contaminants from the tanker ullage/head space from prior fuel loads make it run rich. I'd like to lean it out by adjusting fuel flow and/or air flow. Need an expert to confirm my shade tree mechanic opinions.

[lane912]

turn the brass screw in until it runs rough, then out two full turns

[red-beard]

Does the fuel source vary or is it always naphtha vapor? If it is always naphtha, a temp compensated flow meter (Vortex shedder, etc) should do the trick. You then control air flow to meet the mix range.

The problem with going stoichiometric is you will get a very large rise in temperature and large production of NOx (Nitrogen burning with the Oxygen). Also, is the burned fuel "doing" something? With the fuel here you could run a gas turbine and make electricity and it will control everything including emissions.

[red-beard]

BTW: NOT a combustion engineer, but I used to date a very crazy one...red head

[Joe Bob]

Incinerator that is running on PUC Natural Gas. The use is to destroy the vapor recovered from the tanker truck's head space during the loading of Naphtha. The vapor could and can be most any hydrocarbon based vapor. The Naphtha is feeder grade.

No NOX or SOX is emitted after the burn.

[asphaltgambler]

Originally Posted by lane912

turn the brass screw in until it runs rough, then out two full turns

^^^^^Clearly from someone who possesses a Masters degree in tuning^^^^^^^

[red-beard]

You need a Wobbe Meter on the recovered vapor. A Wobbe meter measures the btu per volume of the recovered vapor. This will allow you to control the Air Fuel mixture.

[Instrument 41]

Is there any value to those vapors? If so run it through a VRU instead of combusting it.

[pavulon]

you need Keith Stone.

[Joe Bob]

Originally Posted by pavulon

you need Keith Stone.

Another freaking comedian.....don't quit your day job.

As to using the vapors to run a generator.....the rules the facility is currently running under do not make it economically feasible to do so. This is a band aid 1937 facility. It's actually younger than a fewer refineries in So CA. Ask Sammy.....you will never open a new refinery here. So.....they fix the POS ones that are operating.....

Trust me, we ran the numbers......pay back is like 15 years.....IF you can get a permit.

[red-beard]

I guess I should ask how much vapor we're talking about. There are a lot of micro-turbines which might be perfect for this application. Capstone make California compliant micro-turbines. The ones designed for natural gas operate on Propane without any changes.

As long as the Naphtha gasses won't condense out in compression to 65-70 psig, they should run in the turbines no problem. Might need a little heating, but there is plenty of exhaust heat.

Capstone makes 30kW to 200kW turbines. But I think the only California compliant one is 65 kW.

[pavulon]

Oh...I see...your threads are intended to be strictly high-brow, engineering discussions only. I seemed to have missed that in one of your 30K other posts. My bad.

Originally Posted by Joe Bob

Another freaking comedian.....don't quit your day job.