5 gallon TLUD charcoal cooker

[Fulmen]

With pro's like Lloyd on their side I should be all over these, but I just don't see why this should be a good method. As far as I can tell the heat is simply radiated down from the top, so in order to cook the entire fuel load the fire needs to propagate through most of the cooked charcoal. Or am I missing something?

 

Also the wood is exposed to fresh oxygen during the entire process, this is about as far from the retort process you can get.

[starxplor]

With pro's like Lloyd on their side I should be all over these, but I just don't see why this should be a good method. As far as I can tell the heat is simply radiated down from the top, so in order to cook the entire fuel load the fire needs to propagate through most of the cooked charcoal. Or am I missing something?

 

Also the wood is exposed to fresh oxygen during the entire process, this is about as far from the retort process you can get.

 

I have used both retort and TLUD methods, and charcoal from both works well. Each has its own advantages and disadvantages, and a fireworker may decide to use only one, the other, or both.

 

With TLUD, it is not that 'heat' is radiated down, as you think of heat in the retort sense. It is literally a layer of fire in the container that moves from top to bottom. This fire has a couple of critical effects different from retort method: 1) some of the bio matter is actually burned and does not become charcoal, meaning a lower rate of uncooked to cooked (less efficient), and 2) no external heat source is need, so there is no constant refuelling like a retort and different types of wood are not needed (who burns willow to heat a retort?).

 

So, if someone already has a retort setup, already has a good supply of both fuel and charcoal wood, and has the time to wait for a retort to complete while potentially constantly refuelling it, a TLUD might not make sense to use. But for others, the speed (and it is really really fast) compared to a retort as well as the lack of need to build a full fire pit or containment system make a TLUD system super easy to setup, run, and store away.

 

EDIT: My anecdote: Setting up my paint can TLUD, running it to completion, and setting it aside to cool takes less time than it takes just go from zero to having a fire in my fire pit big enough to set my retort can in.

Edited May 18, 2019 by starxplor

[Fulmen]

I know I've sworn not to chase perfection for the sake of perfection, but the TLUD barely seems better than picking charcoal out of a fire pit. It wouldn't bee so bad if it at least tried to channel the heat back, but the charcoal seems more like a coincidental byproduct. I've been trying to redesign it to some sort of retort hybrid, but I haven't had much success yet.

 

 

Separate fire wood isn't a problem, I already have that for heating purposes. And to be honest, heating a retort using the good wood isn't any worse than what the TLUD is doing. In theory a well designed retort should waste less fuel than a TLUD.

[starxplor]

If it channelled the heat back, you would have wood and charcoal blowing all over the place. The thing really sounds like a jet engine because the 'exhaust' heat is moving so fast when it leaves the chimney.

 

Maybe separate firewood is fine for you, but there are others who do not heat their homes with wood and do not have a particularly heavy supply of cheap wood.

 

I do not know what you mean by 'isnt any worse than what the TLUD is doing'... the TLUD burns instead of converting a small percent of the input, running a hot enough external fire for long enough burns a lot more than the TLUD does.

 

I am still not sure why you are so concerned about convincing other people not to use a TLUD. Just because it is not the best option for you does not mean it is not the best option for everyone else. As I mentioned above, there are real reasons a person might choose either method over the other, you clearly fall in the retort camp. (for the record, I use both methods depending on the input material, time available, and if I am already having friends over for a bon fire).

[Fulmen]

I am still not sure why you are so concerned about convincing other people not to use a TLUD.

 

I'm not. I just don't "get" them. In fact they frustrate me a bit. They do seem very convenient in use, I just can't bring myself to trust the result. And I still think it should be possible to make a more efficient hybrid TLUD/retort cooker.

[starxplor]

There might be a more efficient hybrid, and if you come up with it, I am sure there are many here that would love to test it. If you want to create a hybrid, I suggest running a regular TLUD a few times to get a feel for how they actually work as just reading, seeing pics, and watching vids does not get across the power of the exhaust you want to capture.

 

As for the results, I have used both methods and the charcoal comes out just fine with both, including the TLUD.

[Mumbles]

I don't know if I've ever seen a good side by side test. I'd be interested in seeing some real results like that.

[Fulmen]

Me too. I'm just not sure if I want to make a TLUD for that purpose alone.

[starxplor]

If I get a chance this summer, I may try recording both and posting them.

[Boophoenix]

Some preliminary testing lead me to the conclusion that some if not many TLUDs run a little hot from recommended temperatures from research and literature on charcoal cooked for BP. Ive not followed up further yet as the plan at some point is also a comparison between processes. I dont think this is a big deal as I suspect many retorts are running a bit hot too.

 

Before the flaming starts I did go threw the trouble to mount thermo couples inside of the cooker in the upper and lower sections. The thermo couples were sleeved inside of small copper tubes to prevent possible damage to them, but waste case scenario theat slowed the reading down some in my perception.

 

I also found it difficult to regulate the temp of the cook by changing minor things in the upper section. This surprised me slightly. Ive started a larger cooker and plan further tests at a later date as this was just a proof of concept test stage. The new design is following Lloyds lead and will allow for bottom draft regulation as well.

 

As they say it didnt happen without video see below. I have some other materials for a TLUD this was my first TLUD I ever made shown in the below video. I used other materials for different configurations and little changed. It might be mentioned this burn was very docile which is how I started out cooking with the perception the jet engine cook would be hotter. I cant truely confirm that belief or state I was wrong yet though. Some of the tests in this round lead to the conclusion my belief was close, but further testing need to be done for sure.

 

I also believe the TLUD can be modified to be more efficient for out purposes. I just suspect that though and need to get around to some modifications and tests to find out. I have tinkered a little in the realm of screwing up the design purposefully and found the concept to be fairly forgiving if you want to deal with relighting.

 

 

Fulmen, not to be contradictory Im slightly fascinated by the processes. Ive always wondered about the quality of a retort as well? Dont get me wrong the retort seems a great method praised by many that I havent tried yet myself. Ive only ever seen one design posted publicly which was here by OldGuy that addressed a small concern of mine in the method. How do people deal with hot spots in retorts? The only viable ways Ive concluded to do so are a dual chamber ( bucket in a bucket with spacers ) or a heating chamber where the exhaust passes over to the cooking chamber as OldGuys did. It could be argued the temps equalize in a single cooking chamber which is fairly accurate, with the exception of close proximity to a hot spot. Ive rarely ever had a burn barrel in my life not glow in spots in the dark. Surely material in proximity of a hot spot like this is nearing these heats Id think?

 

https://en.m.wikipedia.org/wiki/Red_heat

 

Ive debated with a good friend about this many times. He argues a partial true statement. Once you process and blend the cooked materials they do average out, but is there not still the possibility of over cooked material in the mix meaning less efficient material being utilized?

 

How many people put the effort into trying to control the cooking temps of their retorts beyond build a fire and place it into it? Ive known one who cooked with gas and used thermo couples to monitor the cook. I didnt ask a lot of questions on their design or scope over it much as I have only seen it cook once.

 

With all that said is the temperature that important for our uses as most of the detailed research is from ballistics research usages of BP. I dont know, but hope to find out one day.

 

The simple answer at the moment is if someone is cooking by either method and it works for their uses. Keep it up. If it aint broke dont fix it. Run what ya brung.

[Fulmen]

How many people put the effort into trying to control the cooking temps of their retorts beyond build a fire and place it into it?

I did (ten - fifteen years ago). Basically a paint can in a large bucket so the can was heated by the hot gases. Temperature was measured inside the can with a BBQ thermometer.

 

I do agree that hot spots should avoided. You can't average away bad processing, just as you can't mix burned and raw meat to produce a perfect beef.

[Boophoenix]

Do you recall the temps you experianced? This is just a curious question. I’ve not been around much retort cooking. Did you do any testing to compare various temps material was cooked at?

 

The average practice I’ve seen is a barrel in a barrel to save on heating wood materials I would guess. Packing wood around a cooking drum is what I was mostly referencing above. I’m not sure how I would factor if a cooking drum was tossed into a pit fire. I have and know of two others that have considered or done a rotation of the cooking chamber if this cooking style is used. It would be a fair assumption in my mind that rotation and possibly adjustable height could be done to control the cooking temps and eliminate hot spots.

 

Now that I’ve come off as defending the TLUD I should share some other info from related sources. As I recall I think I found some tips in biochar research not charcoal for BP uses. In this research I found such things mentioned as mild pressure increasing yield along with a fairly rapid cooking cycle.

 

To be fair most of what I’ve learned has been threw research and small scale proof of concept testing. I’ve planned some researching for a while now, but have not started since I have some test method hurdles to over come. I’ve never wanted to back track in my testing so I don’t plan to start till I can preform all of the various tests I am interested in doing at the same time from the same materials.

[Fulmen]

From my notes I needed around 400°C to get complete charring. Never did any performance testing, I was aiming for the lowest temp.

[FlipperFuego]

solid, thanks for sharing! http://freeimagehost.info/i/md2jcCZMmF.png