Smoke from clogged biochar burning

I have noticed that the main time that my biochar oven creates smoke is when it is internally clogged.  This can happen from settling of the logs/branches/sticks, so that no air is flowing through. I run a TLUD (top lit, up draft), so flow of some limited air through the bottom of the barrel up and through is required.  I often find that if I remove the chimney and move the branches so that air once again can flow, when I put the chimney back on, it will start burning. This is true even if it wasn't burning when I stopped it.  The chimney seems to make it burn better and more efficiently.  I think it's something about the difference in air pressure, temperature, or flow from the bottom of the barrel to the top of the chimney. Anyone with a better understanding of the physics is welcome to explain how.  

Sorry, I know this observation might not be helpful to those burning biochar in an open container by limiting the airflow by adding more branches on top.  It also might not be helpful to those doing the same thing in a trench or in a barrel, or those with the tilted barrel. The mechanisms are different with the different types of biochar burners.   I just wanted those who are using the TLUD to be able to go beyond this frustration point if they experienced it.  

John S
PDX OR

Unlike wood pellets in a small burner, there are a lot of variables in a natural-wood-fired TLUD that you can't possibly fully control.

If you clamp on with a big vise-grip and shake the barrel hard, that may well re-establish the flow. The simplest solutions are often the best.

Inserting two chunks of rebar, bashed into a crude auger (helix) shape as you load would let you pull or twist the mass at will.

If you inserted a perforated full-length pipe down the middle, with a cap on top, as a precaution, you could quickly re-establish strong draft top-to-bottom to limit smoke.

Just some ideas.

These are great ideas! I have kicked it before, sometimes with success.  I'll have to look for a type of a metal tube somewhere, or some rebar.  Of course, I wouldn't want to grab the metal rebar or tube if it's been in the fire.  Gloves at least or a stick to move it.  I am going to have to try some of these ideas. Thanks,
John S
PDX OR

So I went down to the restore and found this object.  I think it's a grab bar for when you're in the shower.  It was $3.  I forgot to load it in at the beginning.   I put it in afterwards and it seemed to help.  It didn't really clog afterwards.  The main problem was that I had been adding pieces of wood in through the top of the chimney and down. It was ok before, but now they got stuck and were burning.  They burned through some of the rivets and now I"m going to rerivet the chimney.   I am excited to try using this bar at the beginning and try it WITHOUT adding wood in through the top of the chimney and down.
JohN S
PDX OR

OK, so I did my next biochar burn.  I reriveted the chimney and repaired the chimney lifting plate.   Fortunately, I placed that grab bar in before I started burning this time.  The second thing I did right was I did not place pieces of wood down from the top into the chimney, so I avoided the disaster of last time.  They got stuck, due to the bar being in there and burned up some rivets, which I had to replace.

It worked great! No clogging, very little smoke, lots of biochar and almost no ash.  Thanks to Douglas Alpenstock for the idea.

John S
PDX OR