Rocket stove dryer oven

Hi all. We needed to dry faecal sludge prior to pyrolysis and have come up with a dryer prototype to dry out feedstock inside our ring kilns that make biochar. The objective is to decrease fuel consumption whilst driving out moisture. Believe it or not but our design is based on rocketmassheater design principles with the flue pipe creating the draft. Any thoughts are welcome.

Kobus

Is that an all-metal burn tunnel? The prevailing advice is: don't use metal in the burn tube and riser. It will function for a while, but eventually corrode.

Please read this thread - https://permies.com/t/40/52544/metal-burn-tunnel-heat-riser

He has no insulation and  a short riser, plus he seems to putting preheated air into the riser.
I doubt it will get hot enough to wreck the metal anytime soon.

Kobus. are you taking it from sludge to bio-char in one burn?

Hi Matt and William, new to this forum and still getting to grips with the layout. Matt thanks for the link it was useful, I am aware of metal corrosion inside a RMH but and as William also noted a lot of moisture will be present especially initially, and I really hope the central draft will cause enough "pull" on the exit gases to ensure a hot rocket burn, but not so hot as to warp the metal or cause it to burn through and deteriorate. It's all 5mm except the bottom which is 10mm through which the ash falls. No William this will be a dryer only. I am thinking of converting our current biochar kiln to using a rocket somewhere as it will save so much fuel. We use almost a ton of fuel to create the heat into the internal 55 gal drum retorts. The ring kilns are only 3mm and they don't last beyond 3 years, producing around 1 ton of biochar per month. Dr Hugh McLaughlin helped with the design. My main concern is if it will work - I guess time will tell. The sludge has over 60% moisture and we'll be putting it into 55 gal drums with perforated pipe spacing it out and hopefully allowing moisture to exit through it. The pilot project is externally funded and will start on the 7th of May. Will keep all here at permies in the loop with photos.