Stovers:
This is a summary (reporter-type) note on the recently completed two-day
stove meeting – held at Seattle University. There were about 30 in attendance, with
the largest number associated with Aprovecho (Dean Still, Larry Winiarski, Peter
Scott, Mike Hatfield, et al). The next largest group were from three
Universities.
The presentations were well done and most will be available on
the web sites of one or more of the
three Universities that were involved::Iowa State (Prof. Mark Bryden – talking
about modeling and cookpot testing), Dayton (graduate student Chris Schmidt -
talking about student materials-testing of bricks), and Seattle (Prof.Ananda
Cousins).
Some new (to me and the “stoves” list) results:
- Mark Bryden gave some
early results from an experimental cook stove test apparatus, showing the ISU
capability to accurately measure and display temperatures and weights vs
energy consumption (using a liquid fuel as a surrogate) and other
variables..
- Chris showed rather complete physical
data (strengths, thermal qualities) comparing Ken Goyer’s insulative bricks
with hard brick and a Guatemalan tile.
- Ken’s formulation ,
(which had been given on “stoves” earlier (but I can’t find that message) by
Dean – I think by volume was - 2
parts local clay, 1 part fire clay, 1 part cement and 4 parts sawdust). These will float (for short time) –
and seem of high quality and probably low cost. Aprovecho seems to be going entirely
to these. Ken stated that his
“secret” ingredient was the cement – something “never” used by potters and
brick makers.
- Don
O’Neal talked about plancha stoves (built around rocket stove principles) he
designed, being installed in Guatemala – which are very attractive and are
made from concrete cast in fiberglass reproducible molds (with the Goyer
bricks for the firebox). His
planchas are locally produced for $19 (metal only) Traditional approach to cooking
the tortillas is a large ceramic platter – costing about $1.00 – but having
short expected life. Total stove cost about $65 – but not affordable to
the intended villagers.
- Tami Bond gave a
preliminary but detailed report on the efficiency and emissions testing of a
rocket stove and traditional three stone method – showing about a 50%
improvement. This was done using
expensive modern testing equipment, with especial attention to particulates
and their size distributions. The
Rockets are better by about 50% (both for CO and particulates). Efficiency up several points (mid-high
20’s versus low 20’s)
- Tami also gave a
detailed report on different possible future means of emissions testing in the
field and in laboratories. No
conclusions yet – but great start on options. Not clear that CO measurement alone is
sufficient – may also need particulates.
- Also considerable
discussion (no single talk) on the need for a lower cost locally produced
means of manufacturing
chimneys.
There was also a second-day period of group discussion
on previous day’s discussions; on funding, plans, then a period of stoves
demonstrations and a wrap-up self-selection into R&D team tasks led by Mark.
Bryden.
Summary – very useful meeting – especially for better
understanding the Rocket stove.
Good future R&D-result possibilities from University teaching
programs (and from Aprovecho).
Details will be available shortly on one or more web sites.
Ron
