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what type of fuel?

Posted: Sun Oct 14, 2012 14:39
by orf
I know this is a loaded ? but ,what do you more experienced guys and gals, use for your heat/smoke source? I started with a brinkmann then modified it for more heat control until it became to small,I always had trouble with temp control. since then I've built a wooden smokehouse with a seperate fire pit. I like it , it has much more room and I can get the temp up to over 300 deg(for bbq and such) no problem or keep it low. once again I'm green and have much to learn. the temp control is o.k. but I've read to keep the temp increasing very slow for a long period of time and it seems to me using propane or electric would be easier than a wood fire. please throw so opinions out there for us greenies.thanks in advace orf...

Posted: Sun Oct 14, 2012 17:04
by ssorllih
Gas or electric heat can be controlled with a thermostat. The choice depends upon the available supply. Electric heat costs about 3 x as much as gas heat.

Posted: Sun Oct 14, 2012 17:19
by Gulyás
My fuel is electric. I have 2 Bradleys. Many years ago I got one with sliding heat control. First it was fun trying to get the right temperature. Then it was an art. Finely it became a pain in the I got the digital one. Now I'm happy.
Would you like me to catch a bird ? :mrgreen:

Posted: Sun Oct 14, 2012 21:14
by Big Guy
I have both gas and electric smokers, I use the gas in the North where outside temps are low, the electric just doesn't have enough power to smoke in the real cold, I use the electric smoker in FL and it works fine in the milder temps.

Posted: Sun Oct 14, 2012 22:01
by orf
i've also read that propane has more humidity,and if so is that any concern? by the sounds of things it isn't. I have a turkey deep fryer that I could probably rig up, huh? orf...

Posted: Sun Oct 14, 2012 22:22
by ssorllih
Time to do some engineering. First determine your insulation ratings. then determine your smoker's surface area and using those two factors determine the rate of heat loss. THEN you can determine the size of the heat source. You can not control the temperature in a drafty enclosure so you must be able to control the ventilation.

Posted: Mon Oct 15, 2012 23:50
by uwanna61
This may be over kill for what you are looking for, but this is a pretty sweet setup. Maybe you can get a few ideas from this read, I know I have! good luck..
Wally ... sc&start=0

Posted: Tue Oct 16, 2012 13:45
by orf
That is very nice but its a little too much for what I'm doing. Thanks for the read though,very cool and well done. orf...

Posted: Tue Oct 16, 2012 16:25
by ssorllih
In the years before central heating in homes we had solid fuel fired stoves . There were always cold spots in the rooms and places that were too warm. Considering that we need only heat the smoker to about 170°F perhaps we would do well with a remote heat source and a forced air circulating system for the heat. That would go a long way to avoiding hot spots in the smoker.

Posted: Tue Oct 16, 2012 17:18
by el Ducko
If you'll pardon a little engineering jargon, here's something that might help.

Chemical engineers use two types of reactor models. All practical cases can be reduced to a combination of the two, and practical cases always fall somewhere in between. It is our job to get them to fall close to one of the two models, usually for control reasons, but production rate (thruput) often challenges that. (Ever try to out-run an explosion? Combustion control is exactly that. Yikes!)
---Batch model, also plug flow model (reactor is a long, small-diameter pipe)- - Put everything together, then wait for a certain amount of time (or until it comes out the other end of the pipe).
---Stirred-Tank model, where stuff is added and product is removed but the reactor volume is so well mixed that composition and temperature are uniform throughout.

Our case, smoking meat, lies in between. The air/smoke/humidity are fed, circulated, then removed but the meat stays in the smoking chamber. Think of a combination: a continuous, stirred tank reactor as far as the vapors go, a batch reactor as far as the meat is concerned. (Great fun, huh? :roll: )

In a smoker, we'd like for the chamber to be well mixed (no hot spots, excess moisture, too much or not enough smoke, etc.). With the types of reactions and mass transfer that we're dealing with (relatively slow), composition and temperature uniformity can be approached by using an "adequate" circulation fan. We feed smoke and air mixture at a certain temperature, the chamber is reasonably well insulated, and if it's well mixed, the composition vented is about like that in the whole chamber.

But out here in the real world, it's never perfectly insulated, never well enough mixed... So you do what you can to lessen the problems. All sorts of tricks apply
- - adequate mixing (internal fan, etc.),
- - keeping the inlet smoke/air temperature relatively constant (separating the smoke pit/generator from the chamber is a good way to do this)
- - having a small flow in relation to the size of the chamber (think in terms of turnover time, or how many volumes of smoke/air are fed/vented per hour per unit of chamber volume).

That way, we approach the stirred tank model, where all the meat will see the same vapor temperature and composition for the longest time. At the other extreme, batch or plug flow model, vapor changes with time, which we don't want. Think temperature transients, hot spots, dead corners with no smoke and low temperature...

Sorry for the lecture. Believe it or not, that's what we use in the chemical industry. The thought process is simple, but not always obvious. (That way, we get paid more? "I wish." We get laid off a lot, too.)

To make a long story short: Ross sez (and I agree), "remote heat source and a forced air circulating system." The remote heat source helps avoid short-term transients, plus it gives you a shot at cooler smoke temperature. (You Ventura and Smoke Daddy guys have better control than an open fire, so you can close-couple to the smoke chamber and get away with it.) The forced-air recirculation system evens out temperature and concentration in the smoke chamber. I would add, an adequate (but not too big) vent (sometimes, leaks!), is necessary for control. This "wastes" heat, but gives you control.

...asleep yet? :mrgreen:

Posted: Tue Oct 16, 2012 17:52
by ssorllih
Thanks Ducky. I though that my crude model was close to what we seek. I think that I will pursue separate smoke source and heat source. The smoke being a component and the heat being,, well , the heat.

Posted: Tue Oct 16, 2012 18:48
by el Ducko
ssorllih wrote:Thanks Ducky. I though that my crude model was close to what we seek. I think that I will pursue separate smoke source and heat source. The smoke being a component and the heat being,, well , the heat.
"You da man," Ross! Thanks for all your help. Please keep us all updated on your efforts.

I'm struggling with the same problems (aren't we all?), namely, how to produce sufficient smoke and heat at a steady rate. I think you are on the right tack (sailing term! WooHoo!) with the separate smoke source, and have used a 10 foot section of gutter downspout to separate my smoke generator from the smoker cabinet. A consistent source of smoke is my current challenge.

I've tried imitating the Amaze-N approach, the Ventura approach, and the Smoke Daddy approach, besides just using a chip tray on a hot plate. I have a feeling that the consistency of the wood chips or sawdust is a big factor, but don't have a good way of controlling that part. It looks like the key to getting any of the above to work.

What thoughts, folks...? :mrgreen:

Posted: Tue Oct 30, 2012 15:48
by ssorllih
My smoker is also my grill but my smoke source is a fire box six fet below the grill. One of the secrets to making smoke is controlling the rate of combustion by controlling the air supply to the fire. With my fire box I can choke the air supply enough to snuff a full flame burn to a smoulder by closing the air inlet. I feed it small chunks of the wood species I want. The shoulder slabs were cold smoked with apple and when finished were well smoked and completely raw. I finished them in my oven. Image