[Stoves] Safety of stoves and conflicts of interests

[Crispin Pemberton-Pigott]

Dear Paul

I want to tell you as a member of committees that write standards (not that
it is a major part of anyone's life, let alone mine) that from such a
committee a principled abjection will arise to any safety system that
requires the presence of something to be safe, instead of its absence, where
there is a choice.

A good example of this is the FSP stove where the presence of the bluff body
(the central plate) is required to make the flame's continuance viable.  If
the plate is removed, rotated, swings away or falls off, the stove is
immediately rendered safe because the fuel jet speed is higher than the
flame speed.  It blows itself out.

There is an invention (patented) which works exactly as described below
which will retrofit into a Panda stove. However if the water evaporates, the
device no longer works as a safety mechanism.  It requires that someone
fetch water and put it into the device before the stove is safe.  In a place
where water has to be purchased by the bucket this is likely to be a flaw in
the system.  Thus the stove is 'not safe enough'.

That is how people think about the approach to safety.  For example you
couldn't hold that if enough cold paraffin floods the burner, it will
extinguish the flame.  While it could technically be true, it wouldn't be
allowed because there might not be enough fuel in the stove at the time it
fell over.

Regards
Crispin



-----Original Message-----
From: stoves-bounces at listserv.repp.org
[mailto:stoves-bounces at listserv.repp.org] On Behalf Of Paul S. Anderson
Sent: September 9, 2007 4:29 AM
To: Discussion of biomass cooking stoves; rnv impex
Subject: Re: [Stoves] Safety of stoves and conflicts of interests

Nickey made this suggestion for safety in the self-pressurized burners:

> Third Option :- have another  open tank surrounding the main tank -filled
> with water , to a much higher level , when tilted, this water spills first
> ,in the direction of the spill,could form the basis for extinguishing the
> fire to follow. Main Problem -Rusting

It is a good suggestion, and serves another purpose.  The self-pressurized
alcohol burners are "driven" by heat tranferred to the container.  If, when
tilted, some water at about 50 deg C would "internally spill" and contact
the
burner canister, that would cool the canister and the vaporization of
alcohol
would cease or diminish (diminished vapor = less fire = less heat to 
canister =
even less vapor making.)  I have done this as an attempt to control the 
size of
the flames (such as when wanting to have only a simmer heat).  To use the
cool
water bath as a safety feature is certainly a possibility.

Paul