[Stoves] slices

[Boll, Martin Dr.]

Dear Dr. Karve,
Still being some days within 2007 I wish you a happy New Year.

Many thanks for your detailed report about cooking habits in India in
combination with the *slices*-thread and Crispin's proposal for pressure
cookers. 
As I see from your description there is more need of quick speeding up fire,
controlling narrowly and turning down or extinguish quickly, as can be made
by a commercial gas-burner.
Some years ago I made an experiment with a wok and a commercial
card-board-burner which normally is used by roof-makers with propane-gas.
This burner worked fine for wok-cooking, with half-speed. 
That procedure seems to be more or less close to the needed
stove-characteristics in rural India.
Possibly the idea can be used in an altered form.

I want to add some other hint: In a workshop I saw a gas burner, which was
tuned up for higher temperature by blending the burning gas with pressurized
air in the way of a welding burner. For cooking, that is not necessary,
especially in that amount, but in a moderate way, I think, it could be of
advantage.

I hope, you can use this at least to smile.

Best regards

Martin Boll


> Message: 2
> Date: Wed, 10 Jan 2007 12:44:24 +0530
> From: adkarve <adkarve at pn2.vsnl.net.in>
> Subject: Re: [Stoves] slices
> To: Discussion of biomass cooking stoves <stoves at listserv.repp.org>
> Message-ID: <004401c7348a$0d1d3e60$4d69fea9 at adkarve>
> Content-Type: text/plain; charset=iso-8859-1
> 
> Dear stovers,
> pressure cookers are used in all the urban households in India. In rural
> regions of this particular region, they are not so common, because we do
> not
> grow rice. The main staple food is a type of tortilla made of sorghum
> flour,
> or millet flour. The flour is mixed with water to make dough. A dough ball
> is flattened into a tortilla. It is first roasted on a griddle and then
> the
> half-baked tortilla is roasted on a charcoal fire. The vegetable that is
> eaten with the tortilla is not cooked but also roasted in a shallow, round
> bottom pan, containing a tablespoonful of vegetable oil. It needs constant
> stirring during preparation, without which it gets charred near the
> bottom.
> I have not seen insulated pressure cookers anywhere in India.
> A.D.Karve
> ----- Original Message -----
> From: Boll, Martin Dr. <boll.bn at t-online.de>
> To: <stoves at listserv.repp.org>
> Cc: <crispin at newdawnengineering.com>
> Sent: Wednesday, January 10, 2007 2:03 AM
> Subject: Re: [Stoves] slices
> 
> 
> > Dear Crispin,
> >
> > I fully agree with your proposal for the pressure cooking pot.
> >
> > We do that regularly at home.
> >
> >
> >
> > Small practise-report: Some months ago I used an old cardigan to make a
> few
> > insolation on sides and top of our pressure-cooker (Valve protected
> against
> > not working by the cardigan). By the second run I burned a bit of the
> > cardigan on the foot of the pot near the electric-plate. After that I
> > stopped insolation, though I am thinking to use a more heat-resistant
> cloth
> > and retracting that by metal distance-ring from the plate.
> >
> >
> >
> > I would like poor people having a pressure cooker. I saw an old type of
> this
> > on a website-photo from India. And I asked myself weather the pot had
> still
> > its original full function (and by this enery-saving), because I did not
> see
> > the pressure-weight.
> >
> > Possibly Dr. Karve can tell us about spreading and common use of such
> > pressure cooker pots in India.
> >
> >
> >
> > I fear, it will be cheaper for poor people to grind and keep their
> knives
> > sharp, and shorten cooking-procedure at least a little bit, than to buy
> a
> > pressure-cooker with better effect; though both would be whishable.
> >
> >
> >
> > When I think of cutting food to small pieces, we must even think of
> changing
> > the cooking-procedure in direction of chineese wok-food, which needs big
> > heat, but short time to cook. A heat-calculation would be interesting in
> > that case.
> >
> > Is very hot in short time less energy use than normal hot in normal
> time?
> > (3-5KW for 3minutes? Against 1KW for ? minutes?)
> >
> > - Presumed the possible users like chineese food, are able to turn fire
> > immediately down (as possible by a roof-makers cardboard-burner) and
> they
> > have food, able to be cooked in that way. (I am sure millet gruel turns
> to
> > some coaly stuff by that! :-()- But on the other hand I like
> > low-temperature-cooking as well, which would be excellent for this.
> >
> > There is no (said in German:)"Eier legende Woll-Milch-Sau" (egg-
> producing
> > wool-milk-pig).
> >
> >
> >
> > By the way; some time ago I asked you for information about possible
> > dimensions of clay-rings, made by the machine you described. Certainly
> the
> > mail did not reach you, by what ever?
> >
> >
> >
> > Regards
> >
> > Martin
> >
> >
> >
> >
> >
> >
> >
> > >Message: 4
> >
> > >Date: Tue, 9 Jan 2007 11:53:45 -0500
> >
> > >From: "Crispin Pemberton-Pigott" <crispinpigott at gmail.com>
> >
> > >Subject: Re: [Stoves] slices
> >
> > >To: "Stoves" <stoves at listserv.repp.org>
> >
> > >Message-ID: <021401c7340e$bade0f10$6401a8c0 at Averatec>
> >
> > >Content-Type: text/plain;   charset="iso-8859-1"
> >
> >
> >
> > >Dear Martin
> >
> >
> >
> > >The BEST energy reducer for cooking is an insulated (on top and sides)
> >
> > >pressure cooking pot!
> >
> >
> >
> > >Regards
> >
> > >Crispin
> >
> >
> >
> >
> >
> > _______________________________________________
> > Stoves mailing list
> > Stoves at listserv.repp.org
> > http://listserv.repp.org/mailman/listinfo/stoves_listserv.repp.org
> > http://www.bioenergylists.org
> 
> 
> 
> 
> ------------------------------
> 
> Message: 3
> Date: Wed, 10 Jan 2007 12:36:06 -0500
> From: "Steve Redmond" <skiprock at earthlink.net>
> Subject: [Stoves]  Insulated pots
> To: <stoves at listserv.repp.org>
> Message-ID: <000301c734dd$d01c97a0$6701a8c0 at desktop1>
> Content-Type: text/plain;	charset="iso-8859-1"
> 
> Of course there is no one solution, they all contribute.
> 
> Pressure cookers can't be used for everything -- any cooking material that
> would tend to clog the rocker assembly is dangerous. They're fine for some
> foods, but not others
> 
> Pressure cookers require strong walls and a gasket or seal, flat matching
> surfaces, often requiring machining, as well as a reliable pressure valve,
> and therefore are expensive everywhere by comparison with open and covered
> containers. They often require a waiting time before opening, and
> additional
> amounts of water to cool the exterior if the waiting time is not
> acceptable.
> 
> They require operator training, and maintenance and should be discarded or
> repaired to avoid an explosion, when parts wear..
> 
> In other words they're great in some circumstances, if you can afford
> them,
> but not in others.
> 
> For boiling water the tea kettle has evolved for quite some period of
> time.
> I'm sure it could be improved further with a deeply corrugated thin
> bottom.
> But typically they have an extended skirt, tapered sides, a rounded top
> for
> reduced cooling surface area, a closely fitting lid, a spout to get the
> water out in any quantity desired without unduly cooling the rest of the
> contents, and a convenient handle for delivering various amounts of water.
> They and everyother kind of pot can be insulated, though they commonly
> aren't as a matter of convenience and cost.
> 
> They're obviously not meant to boil food in, but that's where the common
> cooking pot takes over. Some of the features of the teapot can be applied
> to
> the cooking pot, but at the expense of....well, greater expense.
> 
> Insulation is fine, but it does not have to be built in, or expensive in
> all
> circumstances -- to retain a slow cooking heat. Uh...there's this thing
> called a "tea cosy". Not expensive. Can be hand made. Washable.
> 
> Or of course built up solid versions of the same thing to set pots in. All
> kinds of insulating materials can be used for that since temps will be
> below
> 212 ....er 100, where anything with moisture in it is being cooked.
> 
> I'm sure that all this is boringly common knowledge to most cooks. It just
> seems like we shouldn't be arguing which is best, but simply accepting the
> need for diverse solutions matched to diverse needs. An improvement in one
> type of cooking utensil may borrow certain features of another, that's
> great. But I'm more interested in the specific detailed improvement
> actually
> built and tested than a general theoretical argument over whether pressure
> cookers are better than cooking pots. There's no answer, nor end to that.
> 
> Steve Redmond
> Vermont Heat Research
> 
> 
> 
> 
> 
> ------------------------------
> 
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> End of Stoves Digest, Vol 7, Issue 24
> *************************************