[Stoves] Top lit updraft combustors

[Andrew Heggie]

On 16 December 2017 at 19:39, Nikhil Desai <pienergy2008 at gmail.com> wrote:
>
> What would PM per kg or MJ do? (It also has to have a time dimension and a
> location/spatial dimension). What would such PM per kg per minute do for
> whom and how? Under what theory of change in what else that may also change
> in mere cooking fuel PM emission rates?

Well as far as I can tell the PM I am interested in are formed during
secondary combustion so it should give some guidance on how to improve
that. To my mind the nearer we can get to the  cleanliness of the
other clean cooking sources the more likely they will be attractive to
those that aspire to these cleaner cooking methods but have no access
to them. Now I doubt I will ever be able to risk cooking indoors with
biomass as I do with an open natural gas flame but...

Lest you think I'm strangely obsessive let me reassure you I am [1]
>
> PM arises from different sources. PM emission rates from a cookstove (let's
> stick to primary solid fuels, not processed fuels or charcoal for cooking)
> vary according to combustion conditions, type and quality of fuel, location,
> air flow. Other PM sources are often right around - from mud floor and walls
> to animal husbandry sources, land, plants nearby.

Yes but as I said in a recent post as far as I can see the black
carbon particles from biomass fires are the ones that have been
implicated in lung problems and possibly once they get into the
bloodstream are DNA disruptors.
>
> The levels of concentrations "in" and "outside" - terms that do not have
> uniform meanings worldwide, compared to US or UK rural single family homes -
> homes vary, and so do exposures. There is no standard cook, standard home,
> standard neighborhood with standard transport network and standard land,
> trees, livestock, wind.

So what, I'm interested in reducing soot from stoves, removing other
sources of pollution in the local environment is beyond the scope of
this list.
>
> But let me stick to just fuel emission rates. Data on source, quality, and
> cost of fuel have to be collected and cooking behavior modeled according to
> not just the variables above but these economic signals. Which means a
> "service standard"- a multi-dimensional practice, not just changing the
> power level of a stove - has to be defined.

Not for my purposes.

< big snip>

>
> Even for poor people's fuelwood for cooking, something similar goes on, at
> least in the parts of India and Africa I am familiar with. Cutting and
> stacking wood is part of the work cycle across seasons. Some wood is
> obtained daily or weekly and some stored for winters and monsoons. They know
> their wood requirements from years of cooking and heating practice. Like
> you, they too think fuel economy is but one part of choosing a stove.
>
> In short, the IWA is a top-down lie.

Yes you have got across that particular rant and I have posted today about it.

It does not affect my wish to reduce particulate emissions from
stoves, in the early days of this list we were introduced to the
Reed-Larson cookstove with its good emissions, I played with the
technique a lot nearly 20 years ago, used my eyes and nose to detect
acridity of emissions but have never been able to see particulates
other than looking at the bottom of a pot.

[1] As I mentioned fuel consumption I'll carry on: in my last paid
work I had responsibility for the firm's vehicles and I monitored fuel
consumption, two other people drove the same type of vehicle with a
1.4 litre diesel engine. I consistently managed to achieve mileage
figures of 60-70mpg and handed my vehicle back with 305k miles on the
odometer. The other two  never managed to get better than 50mpg
although one did get to 300k miles in 3 years less before he blew the
engine.

Andrew