UDS Diffuser-Revision #1

SmokerKing

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Been working on a UDS diffuser, first prototype worked ok, hoping this one will work better;

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What problem are you trying to solve with this diffuser? i dont follow many threads so you may have answered this before.
 
Why a diffuser in your drum? I like the drippins falling on the coals and steaming back up on the meat much better!! IMHO.
 
I have a fairly large fire basket in mu UDS, the heat seems to go directly through the center of the barrel. On my drum, the center heat typically runs about 30 degrees hotter than the sides of the drum.

I want to alleviate the direct heat and balance the temps throughout the drum during a smoke.

I've used foil, water pans etc. Decided to design and experiment with a steel diffuser.

Why a diffuser in your drum? I like the drippins falling on the coals and steaming back up on the meat much better!! IMHO.

So, what happens when the fat hits a hot steel diffuser? Still vaporizes doesn't it? I think it would work better since the diffuser is closer to the meat than the fire.
 
I understand where you're comin from. I've never checked center temp. compared to side temp. on mine. I use a 12" stem Tru Tel therm. so it will reach to the center of the drum and hopefully that is giving me a truer reading across to the middle. I have a 2" stem and I may try to see how much diff. I may be missing. Good point! And nice work on the diffuser!
 
I have a fairly large fire basket in mu UDS, the heat seems to go directly through the center of the barrel. On my drum, the center heat typically runs about 30 degrees hotter than the sides of the drum.

I want to alleviate the direct heat and balance the temps throughout the drum during a smoke.

I've used foil, water pans etc. Decided to design and experiment with a steel diffuser.

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Keep us posted on your progress. I bought a long thermometer this summer and installed it below my upper grate (and above the lower grate). I had over 40° difference between that one and the pit therm mounted on the side (it has a 3" stem). The temps between the two did get closer several hours intot the cook as meats began to heat up. I'm starting to understand the faster cook times of a drum, as the actual temps are higher than the side thermometer says they are. In other words if my side thermometer says 250° early on in the cook, I'm cooking at 280°-290°.

So, like you, my first heat shield test was a 16" round baking sheet that I set on my lower grate. This evened the pit temps right out and both thermometers agreed to within 10 degrees. BUT, I like the open pit flavor, so a solid shield won't allow that. Your shield might...

Another theory I'm pondering would be to do a slight design change on the basket. Take a look at my mini basket sitting inside my regular basket. What if I made a smaller diameter core (say 3") and put the charcoal between the core and the edge of the regular basket? A ring of charcoal, with an empty center.


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I use digital therms when I smoke and I always suspend one probe just below the top grate and meat to monitor the center heat. Throughout the smoke I monitor the analog side mounted gauges and compare to the center suspended digital. As I stated earlier, I always saw a 30-40 difference without a diffuser or water pan.

With my first diffuser, and a few hours into the cook, I did see only a 15 degree difference between the digital and analog side thermos. I expect this one to work better.

Modifying the fire basket with an outside ring of charcoal is a good idea.

I also think the top vent location makes a difference on how the heat flows through the drum.
 
I use digital therms when I smoke and I always suspend one probe just below the top grate and meat to monitor the center heat. Throughout the smoke I monitor the analog side mounted gauges and compare to the center suspended digital. As I stated earlier, I always saw a 30-40 difference without a diffuser or water pan.

With my first diffuser, and a few hours into the cook, I did see only a 15 degree difference between the digital and analog side thermos. I expect this one to work better.

Modifying the fire basket with an outside ring of charcoal is a good idea.

I also think the top vent location makes a difference on how the heat flows through the drum.


Well, whatever you do, keep the pattern to that gadget.
 
[QUOTE I'm starting to understand the faster cook times of a drum, as the actual temps are higher than the side thermometer says they are. In other words if my side thermometer says 250° early on in the cook, I'm cooking at 280°-290°.[/QUOTE]

So THAT's it?! I always wondered how 250 degrees DIRECT could cook any faster than 250 degrees INDIRECT. Wonder what the BDS dude would say, but no wonder he suggests flipping meat.
 
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