Tag Archive for: Iterative Development

Lowering Emissions in a Short, Natural Draft TLUD

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Lowering Emissions in a Short, Natural Draft TLUD

The great thing about 12” high tincanium natural draft TLUDs is that they are cheap, short and powerful. Dr. Tom Reed had a dream that a billion TLUDs would protect health, save wood, etc. We wondered if an all Tier 4, affordable, stainless steel ND-TLUD might help?

The first step was to test the baseline ND-TLUD. It’s great for camping outdoors but not close to Tier 4 for PM2.5, CO and Thermal Efficiency. We are now trying three ways to achieve all Tier 4:

  1. A nothing fancy prototype. Control primary and secondary air and don’t let flames touch the bottom of the pot.
  2. A static mixer prototype. 
  3. A better concentrator ring prototype.

Usually when we make one change a day in a prototype and test the effects under the emission hood it takes about a month to get close to an “optimal” solution. Doing one iteration a day leaves us time to do all the other work here at the lab. 

Looking forward to sharing test results! 

Iterative Development: Addressing Health & Climate Change

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Iterative Development: 

Addressing Health & Climate Change

http://plume.ams3.digitaloceanspaces.com/wp-content/uploads/2020/10/Iterative-design-1500x787.jpg

Thanks to the Osprey Foundation, ARC just finished building a new heating stove lab and we are experimenting with how to make very clean burning home heating stoves. The intended price points are considerably lower than higher emission stoves currently for sale. Zero Green Premium products cost less than the dirty technology products they replace. 

ARC uses the Iterative Development process (see above) to create market viable products. Dr. Sam Baldwin started us on this path in 1987. He described how to develop and disseminate improved cook stoves with simultaneous lab and field-testing in his important book: http://www.newdawnengineering.com/website/library/Papers+Articles/Biomass%20Stoves,%20Engineering%20Design,%20Development%20and%20Dissemination,%20Samuel%20Baldwin%201987.pdf

We change one variable at a time in a prototype and test the result under the emissions hood that collects and records the amounts of climate gases and Black Carbon. Usually ~50 iterations result in a closer to optimal stove. The new Osprey Health and Climate Heating Stove Lab is set up to do 3 to 6 iterations per week. Lab staff includes Travis Volpe who builds, tests and changes prototypes. The prototype is thoroughly field-tested, as well.

Clean burning for cooking and heating stoves!

Tuning up Health/Climate Heating Stoves and Cook Stoves

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Travis Volpe and Kim Still in the Osprey Lab at Aprovecho

“ARC is trying to figure out how to burn wood without making smoke.” 

That’s how we sometimes explain our work to visitors. 

Folks often say, “That’s not possible!” “How could you do that?”

We respond: “It doesn’t seem to be too hard.”

“Force the right amount of smoke into the fire for long enough, making sure that it’s well mixed and there’s enough air.”

“Oh, OK! That makes sense!”

Working with US Stove Company (USSC) and Shengzhou Stove Manufacturer (SSM), ARC is developing three kinds of clean burning heating stoves and six cook stoves:

  1. A bestselling, forced draft pellet stove needed a tune up under the emissions hood to achieve closer to complete combustion. We adjusted the inputs and decreased PM2.5 by 84%, winning 2nd place in a 2023 DOE wood stove national competition. Development continues!
  2. Controlling primary air achieved a 2 to 1 Turndown Ratio in a natural draft pellet stove and a tune up resulted in much better emissions and dramatically lowered the Black Carbon ratio. Mr. Shen, owner of SSM, built a beautiful prototype and we are testing it now. 
  3. Log burning heating stoves are really interesting! The box in which the wood burns allows controlled, small changes that have big effects! Osprey Foundation has funded us to tune up an affordable, log burning heating stove (using big fuel loads as suggested by NESCAUM)  Six manufactured cook stoves will be tuned up in the same way with local advice.

So much fun! Come on by for a visit! We make good coffee!