Water Environment Federation (WEF) Discussion Forums / WEF Discussion Forums / Operation & Maintenance / Pilot for gas flare / Latest Posts

RE: Pilot for gas flare

Rob Baur — Thu, 15 May 2008 14:08:26 GMT

The problem I see is if you get a brief interruption in gas, both the flare and the pilot go out. You need an independent source of ignition be it LPG, natural gas or a big spark plug.

RE: Pilot for gas flare

mjwboofer — Thu, 15 May 2008 11:31:23 GMT

Some companies are making flares with biogas pilots. It is well understood that the gas may be moist and unreliable...but you would only be flaring if you had TOO MUCH biogas. With some of the new ignition systems, it appears that they can ignite a biogas pilot and use that to ignite the full flare. If memory serves, Varec has a model that allows this. Another can be found here: http://www.paques.nl/?pid=59

Of course, this would be done on a case-by-case basis, however, it doesn't seem to make sense to pay for an additional LPG pilot source when biogas would be readily available. Perhaps a temporary source is used at startup to ensure the pilot burns. Once the digester gas gets "rich" enough with methane, the biogas could be used for pilot as well.

RE: Pilot for gas flare

Jerry — Tue, 06 May 2008 19:13:41 GMT

John/Victor

The person who spent a winter in a cabin with me would become a very religeous person. He/she would be using a lot of Rev Wright language at the end of the term.

Anyway that job doesn't start until August. I'm working on something in Missouri right now.

RE: Pilot for gas flare

g. — Tue, 06 May 2008 11:21:25 GMT

Sorry to rain on the parade, the alternative to propane would be Natural gas for pilot. Biogas may not be able to ignite or sustain a flame without a good quality gas source with it. An electrical heating element just isn't going to cut it under all operating conditions. From an environmental standpoint, unburned methane in the biogas has a 23 fold larger carbon footprint than the carbon dioxide by product.

RE: Pilot for gas flare

John Sansalone — Mon, 05 May 2008 13:18:43 GMT

Jerry -

So when are you likely to go there ? One of my coworkers recently spent a couple of months there (their summer / our winter), with the National Guard. I believe they said the temp. was a balmy 20 deg. or so.

So - would you be there just in time for winter ? (There's a thought - 5 months in a hut, in the dark, with Jerry. Can anyone say " cabin fever" ?).

RE: Pilot for gas flare

Jerry — Fri, 02 May 2008 20:04:45 GMT

"Dammit Jim"! I'm an operator, not a miracle worker.

RE: Pilot for gas flare

Victor — Fri, 02 May 2008 16:58:15 GMT

Dang it! That is all we need, Jerry melting the South Pole! By the way, you will still have to work for a private (contract) company down under--no different situation than what you were in the Isles.

RE: Pilot for gas flare

mjwboofer — Fri, 02 May 2008 16:41:21 GMT

Some of the newer flares have the option of using the digester gas as the pilot source and an electronic ignition (so you're not wasting your potentially valuable gas to run a pilot). I agree that the propane or natural gas pilot option was never a stellar idea since there's plenty of digester gas available...no sense in paying for and piping up something else...but I guess the thinking was that an external source would provide a consistent pilot because if it goes out, you're not flaring but rather venting.

I'd check with the manufacturer to see if they have any recommendations...perhaps a retrofit Digester Gas, electronic ignition pilot? As was suggested, hopefully the energy is being utilized for boilers at least...cogen is preferable these days. Energy is getting expensive enough to justify the added scrubbing, equipment, maintenance, etc. in most cases.

RE: Pilot for gas flare

Jerry — Fri, 02 May 2008 16:15:48 GMT

Sometimes Paradise can be Hades. Remember what Milton wrote. Looking at a job in the South Pole (not kidding). Anyway, I'm looking for work. "Have settleameter, will travel".

RE: Pilot for gas flare

Jeff Naumann — Thu, 01 May 2008 20:05:13 GMT

KABLOOM! Cough, cough,hak,hak.

Jerry .........

Are you choking on my math? Maybe I made a great arithmetic error. One of those embarassing ones, where I'm out by a factor of a thousand.

How's it feel to be out of the flip-flop belt?

RE: Pilot for gas flare

Jerry — Thu, 01 May 2008 17:18:08 GMT

KABLOOM! Cough, cough,hak,hak.

RE: Pilot for gas flare

Jeff Naumann — Thu, 01 May 2008 15:58:41 GMT

What do you use the gas for?

My rough calculations, assuming that the average gas production rate is 100 cfm, 600 btu/cf for the gas, and a natural gas cost of from $1.00 to $1.30 per therm (100,000 btu), shows that you have about $1000/day in heat value. I hope that gas is not all being just flared.

100 ft3/minute x 1440 min./day x 600 btu/ft3 = 86,400,000 btu/day

At a typical natural gas heat content of 1000 btu/ft3, this is the equivalent of:

86,400,000 btu/1000 btu = 86,400 ft3 equivalent per day

One therm = 100,000 btu; 1 therm is approximately 100 ft3 of gas. The typical natural gas cost per therm in Southern California is in the range of $0.90 to $1.30 for industrial customers. Your local cost will probably differ. Propane is probably more expensive.

86,400 ft3/day = 864 therms/day; 864 therms/day x say $1.10/therm = $950/day

RE: Pilot for gas flare

brich — Wed, 30 Apr 2008 13:18:24 GMT

That is what I would like to do but I do not get a high enough gas pressure. Our gas is only at a 3 Inches of water column.

I am going to try it after I get a flame arrestor ordered.

RE: Pilot for gas flare

Bill H — Tue, 29 Apr 2008 17:42:35 GMT

Where I used to work it was set up to ignite the gas by a spark plug. We used no pilot flame. Why couldn't you just hook up the line to the gas line from the digesters?

RE: Pilot for gas flare

brich — Tue, 29 Apr 2008 16:11:03 GMT

ttt

Pilot for gas flare

brich — Tue, 29 Jan 2008 16:09:03 GMT

I currenlty am running a Groth model 8391B Waste Gas Burner Automatic Ignition & Pilot Control system on my Anaerobic digester system with flows anywhere from 0 to 200 cfm depending upon the feed rate.

My question is what is the industry using instead of the propane pilot? There has to be a cheaper and better option to keep my flame lit?

This is my first post but I have been watching and learing from this board. There are some very intelligent individuals on here.

Thanks in advance for you help.

Ben