ARC E-Newsletter 12/19/25: Don't Let The Flame Touch The Pot

2 views

Skip to first unread message

Aprovecho Research Center

unread,

Dec 19, 2025, 5:21:19 PM12/19/25

to Aprovecho Research Center eNewsletter

Aprovecho E-Newsletter

Don't Let The Flame Touch The Pot

illustration of zones of a laminar diffusion flame

Zones of a Laminar Diffusion Flame www.chemistryviews.org/details/ezine/1393243/What_Makes_a_Candle_Flame/

As we iterate changes in natural draft TLUDs and Rocket stove prototypes, trying to reduce emissions while maintaining high thermal efficiencies, one design principle keeps on suggesting itself:

Don’t let the flame touch the pot.

The pot is ‘cold’ and if the flame has not burned itself out and contacts the surface, we instantly see CO and PM2.5 rise on the real time emissions screen. (See “Zone 3 and 4 boundary” comment in illustration above.)

Real time PM2.5 is not as accurate as the weight of particulates captured on a filter, but it can be useful. Changes can be done quickly in the prototype and resulting effects are seen right away on the computer screen. Fun!

When we get close to project goals, we switch to gravimetric PM2.5 and statistical confidence to make sure that measurements are accurate.

In both TLUDs and Rockets, changes in prototypes that make sure the flame doesn’t touch the pot seem to be quite effective.

Give it a try?

Find the new book "Improving Biomass Stoves 2025," resources, publications and information about our work at www.aprovecho.org

Find archived newsletters online at aprovecho.org/newsletters
© 2025 Aprovecho Research Center/Advanced Studies in Appropriate Technology
76132 Blue Mountain School Road, PO Box 1175, Cottage Grove, Oregon, 97424 - USA
(541) 767-0287 • www.aprovecho.org

Reply all

Reply to author

Forward

0 new messages