Up or down?

theyolksonyou

@henapple‌ I made it to the one minute mark. Now must jab out my ears and scrub my brain.

stemc33

This is quite the topic. How do I get my burgers to stop omitting VOC's? If I put some burgers on the BGE, white smoke starts pouring out the top. Also, how can I make them bastards that puff on electronic cigarettes keep from exhaling white smoke(VOC's)? Hmmm! Does white smoke equal VOC's? Am I going to die from white smoke?

@UncleFred‌, As far as up or down on the BGE, I dump hot lump on top. So top down for me on the egg. Starting from the bottom just doesn't seem all that convenient, plus lighting from top down works. I'm sure if I wanted to light an inferno in the egg, I would build from the bottom with a small fire adding fuel a little at a time to create the ultimate blaze(excellent for VOC burn off). I read somewhere that it's best to have all lump burning to eradicate the VOC's.

As far as the question about a house burning up or burning down, I have no clue. I'm not a fire man or a fire science guy. I will say that lighting my coal stove from the top down is a near impossible task. This is not some trumped up logic, but speaking from the stand point of experiencing severe difficulties trying to light top down and choking on coal smoke spewing out into the house. Actually been down this road a few times. I'm not the smartest tack in the barn. The whole lighting process goes much smoother lighting a small fire from underneath and adding coal as the fire allows.

I must apologize for being so facetious. I just couldn't help it after reading all the craziness. I wasnt following this thread until @Mikee‌ questioned my post on an OO thread. http://eggheadforum.com/discussion/1174188/another-ozark-oak-post#latest
when I clicked on his avatar to learn a bit more about his expertise, I found this thread. Great points of view from some of the forums more experienced members.

nolaegghead

Light from the top, light only enough fuel to have a hot fire sufficient to support the temperatures you desire.  As small and as hot and as on-the-top as you get get and you'll be karate chopping 2x4s and briskets like a pro.

Holepuncher

Did I hear that Mangrates eliminate VOC's?

nolaegghead

Holepuncher said:

Did I hear that Mangrates eliminate VOC's?

That and MIW - Money In Wallet.

Canugghead

Holepuncher said:

Did I hear that Mangrates eliminate VOC's?

I heard you must start an inferno to make sure 100% of the lump is lit, then choke down and wait four hours for temp to settle 

bigalsworth

I know this topic has been dead for a few days but I will dip my toe in.  I am trying to piece this together in my brain while I type so bear with me.  According to the EPA all of the nasty **** is burned off during the kiln process, also according to the Rockwood lump MSDS (material safety data sheet) it shows 100% carbon composition (they call it black carbon chunks).   It also states that the products of combustion are carbon compounds, which are CO2 and CO (CO only in incomplete combustion), and there will be H2O.  

the combustion process looks like this... CH4+O2 = C02 + H2O  there are some other numbers there but we won't worry about those. consider CH4 your lump charcoal (not likely its carbon compound but a similar chain with maybe a few more C's and H's), O2 is air of course and CO2 is carbon dioxide,  H2O you all should know.

when you start your lump you are likely getting incomplete combustion and producing CO which will account for the smoke, and maybe the smell.

My theory (I have not researched or done testing myself) on clean burning which I believe can happen from the top, or the bottom.  Basically after you light your charcoal and there are flames, you choke the air down and slow down the O2 getting to the heat/fuel causing the flame to go out and just have hot charcoal providing chemical reaction (for those not familiar you need 4 things for combustion: heat, fuel, O2, and chemical reaction).  When Choking the O2 down you are providing enough O2 to continue a SLOW and complete burn based on the fact that there is no flame to feed, just the chemical reaction.  So in essence you are just keeping the chemical reaction going and the chemical reaction creates heat continuing the process.

Now, there is a period of incomplete combustion causing smoke while getting this process going, depending on the moisture content, heat (initial and sustaining), and airflow depends on the time it takes to get to reach sustainable complete combustion.

Touching on putting wood chunks into the mix, we are not looking at piece of material that has been heated past all the flashpoints of all the constituents besides the carbon compound.  We are talking about unadulterated wood.  So there will be smoke, mostly in the form of water vapor.  VOC's generally are the first to go, but I do not know how much will get into your food.  And well F*ck it, it tastes good.  The carbonated (burnt) meat is probably worse for you.

Now to touch on how heat works.  Just because you light charcoal on the top does not mean there is no heat reaching the bottom charcoal.  When you start it with the flame we are talking about 1500 degrees, and the heated coal itself is not much less and the distance we are talking about is what 10".  Heat radiates in all directions, only heated AIR rises.  I have not stuck a probe in the bottom of my charcoal to see the temperature, but since we are creating an oven I'd say it is probably warmer than ambient. I will measure it next cook because I am curious.

The burn propagates down because that is where the fuel and the oxygen is, simple as that.

Something that is worthy to note is that lighting from the bottom may in fact be less efficient (as in burns more fuel) because all of the lump is being heated to a higher degree and will more readily hit its flash point and combustion point, while lighting from the top means you have to take the time to heat the lump up to its flash/combustion point thus slowing the process down.  The time difference may be negligible.

It all boils down to the fact that I do not believe there are VOCs in the lump.  Even if there are some that aren't completely kiln dried I doubt there is because VOCs are basically the first to go, that is why they are call VOLITILE organic compounds, not hard to get rid of organic compounds.

This is all personal opinion that I have based on my my work and training, which is a Steam Engineer.  A lot of what we do is theory of combustion.  I have also been wrong before.

Scott

ps if anyone else has questions on what I put here fire me a message I can try to simplify it, or add to it if needed.

UncleFred

nolaegghead

@bigalsworth CH4 is methane gas

Legume

nolaegghead said:

@bigalsworth CH4 is methane gas

Wait, someone's been farting in the bags of lump?

stemc33

@bigalsworth‌, you lost me after the first paragraph. I light from the top because it's easier and it works. I try to make a small hot fire compared to a big smoldering fire. Seems to reduce smoke. Biggest rule, if I hold my hand over the top of the egg and it smells bad that means the foods gonna taste bad.

VOC's are all around us in everyday things like paint and cleaning stuff. I really could care less about the VOC's in the lump as long as they're not screwing with taste of my food.

bigalsworth

@nolaegghead‌ you must not have read further because I said that charcoal would not be the same carbon compound but that does not change the combustion process. I was just trying to keep it simple for people

Fred19Flintstone

Keeping it simple??? How about "If your smoke smells bad, your food will be bad. If your smoke smells good, your food will be good." It don't get no simpler than that. This ain't chemistry class, it's Barbeque. There's no need over complicate it, IMHO.

jtcBoynton

@bigalsworth‌, you make want to rethink the basic assumption that the lump we get for our eggs is 100% carbon composition. Everything I have seen, heard or experienced says that lump charcoal sold at retail is less than complete carbonization. It is the difference in the level of carbonization that contributes to the differences between the "good" and the "bad" perceptions we have of the different brands. 

Zmokin

bigalsworth said:

when you start your lump you are likely getting incomplete combustion and producing CO which will account for the smoke, and maybe the smell.

I don't know what science class you took, but last I heard, CO is both colorless and odorless.
Hence why it is such a deadly killer as the human eye and nose can not detect it.
CO is not the smoke you see nor the smoky smell you either enjoy or hate

Smoke is particulates, it is little teeny pieces of solid material, it is not a gas.

GATraveller

For a normal quick cook I use an electric element in the middle and stack around it.  For a low and slow I use starter cube cut in half and start on top thinking the "top down" will allow a longer burn time.  May not hold true but that's my train of thought.

bigalsworth

okay I have found an ultimate analysis of lump charcoal.  it can be found here https://books.google.ca/books?id=5Eb_sS0_G7QC&pg=PA105&lpg=PA105&dq=ultimate+analysis+of+lump+charcoal&source=bl&ots=fTaaAVo_q_&sig=ouCRGnSOuOdOkRoWv7UfJ1368m8&hl=en&sa=X&ei=uP-FVOPkJJGayATQpYGADw&ved=0CCkQ6AEwAg#v=onepage&q=ultimate analysis of lump charcoal&f=false

if you scroll down it shows that if the pyrolysis process goes to 600deg there will be 13.2%wt volatile carbon in oak charcoal.  I 

here is another good link about the pyrolysis process

http://www.biomassinnovation.ca/pdf/Factsheet_UofCaliforniaBerkeley_MayheadSnall&Shelly_PyrolysisofWoodyBiomass_2011.pdf

all of these companies likely have an ultimate analysis or even a proximate analysis of their charcoal, whether they hand that over to the public upon request is another matter

Legume

So, um, ah.  um.  crap.  I thought I had a question but I forgot.

Sardonicus

Legume said:

So, um, ah.  um.  crap.  I thought I had a question but I forgot.

)

Me too!

Little Steven

I just run my lump through the washing machine and then the dryer. Voila no VOC's

Canugghead

I suppose it's an electric, not gas, dryer?


(btw, did you get that Kijiji ad?)

Little Steven

Yeah thanks. Just about to call.