[Stoves] Stove talk - Rocket mixing

Paul Anderson psanders at ilstu.edu
Fri Sep 23 10:50:52 CDT 2016


Kirk,

Your replies to Andrew and to me were very helpful.

Your new diagram (I hope everyone is selecting to see the drawings) 
prompts some comments:

1.  Under the lower plate that holds the fuel in the Rocket stove, there 
is also some air entering that will have a secondary function.   But the 
concept and intention is to minimize that secondary air, so showing it 
(maybe with a dashed blue arrow) is optional.

2.  What is informative in your diagram is the use of red arrows. As you 
wrote to Andrew, in the area of the red arrows you have several 
different gases competing for the space to get through the slots in the 
new mixer shelf.   As you wrote:
> The mixer reduces the quantity of primary air needed from under the 
> [Rocket] shelf.  Too much blows the flame out the mouth of the stove. 
In Rocket language, the exposed  ends of the stick fuel (over the Rocket 
grate) are getting primary air which you could want to restrict, that 
is, to have a deficiency of primary air, resulting in heat for pyrolysis 
but not much secondary air.   This MIGHT mean that the air entering 
under the "fuel shelf" (which has a grate at the interior end) MIGHT be 
progressively cut back by using a door or other controller.  Such 
control has not been done on Rocket stoves, as far as I know.  This 
action would be enhancing the pyrolytic activity, and is akin to (but 
not the same as) limiting the air in a TLUD.  (Remember that Rocket 
stoves require the advancement of the stick fuel into the area over the 
grate of the fuel shelf.)

3.  Continuing:  The red arrows involve the pyrolytic gases, any excess 
oxygen, N2, and the air that is entering alongside and above the stick 
fuel.  That new air is coming in from one side only (but that could be 
changed if merited).  Some of that is primary (reaching raw and 
torrified fuel).   And some is secondary (combusting some of the created 
gases).  **** Realization: Therefore it is of little consequence that 
some air UNDER the fuel shelf would "survive" to become secondary 
burning in the red zone, quite similar to the incoming (blue arrow) 
secondary air alongside the entering fuel.

NOTE:  In case it is not obvious, there is no structural 
(device-related) separation of the air as primary or secondary. Some of 
the O2 molecules end up with a primary function (supporting pyrolysis of 
the biomass) and others with a secondary function (supporting combustion 
of the gases).   And some of the O2 could be consumed in char-gasification.

4.  Continuing:  The slot restrictions of the mixer plate result in a 
large surface area of the rising (red arrow) "stuff" to come into 
contact with the air (O2) on the top side of the mixer.  GREAT!!!

5.  I suggest another color (orange??) for a spiral of lines through the 
stationary blades and upward a short distance, indicating the zone for 
the _time _of combustion to become more complete. And that transitions 
into some other color (or dashed lines??) to show the rise of the heat 
and emissions gases (to be quite clean mainly as CO2 and H2O and N2 ) 
that contact the cooking pot.

6.  I question one part of this generalized drawing, and it suggests an 
issue that could merit experimental research.  Above the green mixer 
plate, there are five each of red and blue arrows showing the flows 
through the slots.  The 4 arrows (2 red and 2 blue) on the right side 
are coming up under the stove body, not under the static blades in the 
vertical shaft (a pre-pot chimney or riser). Subject to experimental 
results, perhaps there should only be slits/slots under the blades.  
This also means that the diameter of the vertical shaft / riser could 
become more important relating to the thermal power of the stove.

7.  It is evident that the entry of the secondary air above the mixer 
plate could be controlled, such as by an entry door. Experiments could 
even use a small fan to force that air (checking on impact on emissions).

8.  But there remains the opening through which the fuel is being fed 
into the stove.  With a few exceptions, Rocket stoves do not attempt to 
restrict (or block) the entry of the air entering along-side the wood.   
And different amounts of fuel will impact the amounts of air that can 
enter.  The net result is less control over the processes.

9.  However, imagine that the fuel entry was with a door to close, and 
that the fuel could be advanced horizontally inward via some mechanism 
(spring action, gravity on a slope, a horizontal "plunger with a rod or 
handle" to push the fuel manually, etc.).   In that case, the entire 
unit is essentially "sealed" except for the controllable air under the 
fuel shelf and above the mixer plate.  It is becoming closer and closer 
to being a gasifier with controlled creation of the gases and controlled 
combustion of the gases a (short) distance and time from where the gases 
are created.  In that case it would be sufficiently different from a 
Rocket stove so that it could merit a different name for the 
technology.  And I suspect that somewhere in the 150 years (or more) of 
gasifier development there might have been such a device made, but it 
certainly would not have been for a cookstove, but instead being much 
larger in both physical size and heat output.  [BTW, industrial large 
units are generally easier to make functional than units small enough 
for households.]

Kirk, I think you are on to something.  Please keep us informed of your 
progress, whichever directions you choose to take your actions.   We all 
hope that others will participate, also.

Paul

Doc  /  Dr TLUD  /  Prof. Paul S. Anderson, PhD
Email:  psanders at ilstu.edu
Skype:   paultlud    Phone: +1-309-452-7072
Website:  www.drtlud.com

On 9/23/2016 2:39 AM, kgharris wrote:
> Paul,
> Thank you for the response, suggestions and questions.
> 1.  The mixer is shaped to fit snugly into the stove.  Air also mixes 
> with any gas that leaks around the edges.  It is like having another 
> slot around the edge.
> The folks at Aprovecho did like the overall mixer idea.
> 2.  The sketch was very basic, just to show the mixer principle.  Yes 
> the shelf is still there.  The mixer reduces the quantity of primary 
> air needed from under the shelf.  To much blows the flame out the 
> mouth of the stove.  The reduced primary air is shown in the attached 
> updated drawing with a smaller arrow.  This may end up not being a 
> rocket stove, or being a distant variation of the rocket stove.
> 3.  I added split arrows to the drawing to show the primary and 
> secondary air coming from the same source as you describe.  The flame 
> is rich with wood gas, which is why the mixer could help.  Air control 
> is another challenge, perhaps less important if the mixing system can 
> handle large power variations.  This is true in the Wonderwerk TLUD, 
> the mixing system can handle both high and low power levels and no 
> secondary air control is needed.
> Kirk H.
>
>     ----- Original Message -----
>     *From:* Paul Anderson <mailto:psanders at ilstu.edu>
>     *To:* Discussion of biomass cooking stoves
>     <mailto:stoves at lists.bioenergylists.org>
>     *Sent:* Thursday, September 22, 2016 8:14 AM
>     *Subject:* Re: [Stoves] Stove talk - Rocket mixing
>
>     Kirk,
>
>     Nice!!!!   Very "Kirk-wellian" or "Harris-oniam".   (And those are
>     compliments!!!).
>
>     1,  You might want to try having more of the "nose" (innermost
>     part of the secondary air shelf) to be blocked off to force even
>     more of the flame nearer the center.  There are so many ways to
>     modify what you have caught as a concept.  And I know that you do
>     those modifications so well and with good observations of the
>     results.  I am sure that this is of GREAT interest to Aprovecho
>     and all who have worked so hard regarding Rocket stove technology
>     and dissemination.
>
>     2.  Your drawing does not show the standard shelf and grate of the
>     classic Rocket stove.  Please confirm it that shelf is still in
>     the design (I think that it probably should be.)  Removing that
>     shelf would remove the most fundamental characteristic of Rocket
>     technology.
>
>     3.  Your drawing does not acknowledge that the air entering under
>     your secondary air shelf has BOTH primary and secondary combustion
>     functions (because some of the created pyrolytic gases are being
>     burned with the surplus of air that is entering.  Very difficult
>     to gain additional control over the air flows, (and why Rocket
>     stoves are not gasifiers, which have gas production and gas
>     combustion sufficiently separate to have control over both.)  How
>     could you change your drawing to illustrate this?
>
>     Looking forward to your next report.
>
>     Paul
>
>     Doc  /  Dr TLUD  /  Prof. Paul S. Anderson, PhD
>     Email:psanders at ilstu.edu
>     Skype:   paultlud    Phone: +1-309-452-7072
>     Website:www.drtlud.com
>
>     On 9/22/2016 2:02 AM, kgharris wrote:
>>     All,
>>     There has been a lot of negativity on the list lately which Ron
>>     has been addressing.  I don't want to get caught up in this.  I
>>     would prefer to contribute stove talk to the list that suits my
>>     interests.
>>     To this end I have attached some photos of one of my current
>>     projects, using in a rocket stove the rapid mixing techniques
>>     which make the Wonderwerk TLUD-ND stove very clean burning.  This
>>     project is just getting started and so the technique is not yet
>>     developed.  It will hopefully be interesting for the members on
>>     the list.
>>     Kirk H.
>>     ----- Original Message -----
>>
>>         *From:* Ronal W. Larson <mailto:rongretlarson at comcast.net>
>>         *To:* miata98 at gmail.com <mailto:miata98 at gmail.com>
>>         *Cc:* Discussion of biomass
>>         <mailto:stoves at lists.bioenergylists.org>
>>         *Sent:* Wednesday, September 21, 2016 10:22 PM
>>         *Subject:* Re: [Stoves] WHO's for whom? For what?
>>
>>         Nikhil  cc List
>>
>>         You continue to miss the point.  At this site:
>>         http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org,
>>         the first line reads:
>>         /This discussion is provided to help people develop better
>>         stoves for _*cooking*_ with _*biomass*_ fuels in
>>         _*developing*_ regions. /
>>         The key words are cooking, biomass, developing.  Your message
>>         below addresses none of these.  Repeat NONE.  Your photograph
>>         proves the same - a waste of bandwidth.
>>
>>         If you wish to talk about /“fuel ideologies”/  (your last two
>>         words)- I think it best you find another list.
>>
>>         I find it insulting to many when you use terms like
>>         /“abuse of science”, “spurious theories”, “concocted data”,
>>         "volunteered blindness” and  “saviors…market ADALYs/” - none
>>         with any semblance of an example.  I cannot recall any such
>>         negative writing by anyone that is so devoid of proof.
>>
>>         The purpose of the ISO work (insulting to call it an
>>         exercise) is to get real numbers - the basis of science - to
>>         develop improved stoves.  I challenge you to say what you
>>         dislike about that ISO work - into which a lot of smart
>>         people have put a lot of effort.   My belief is that you know
>>         nothing about the ISO subject you are disparaging.
>>
>>         Please prove me wrong by being specific on your “positive”
>>         suggestion;  just one example of what the experts did wrong
>>         with the ISO work (what you termed “insane.”…)
>>
>>         Ron
>>
>>
>>>         On Sep 21, 2016, at 10:36 PM, Traveller <miata98 at gmail.com
>>>         <mailto:miata98 at gmail.com>> wrote:
>>>
>>>         Rnn:
>>>
>>>         Thank you. I have been busy looking for woodstove shops on
>>>         Cape Cod. None.
>>>
>>>         I was as disappointed as you are with me. I found some
>>>         kitchens with - egad, ventilator fans!!
>>>
>>>         What has come of EPA and MASSDEP?? Restaurants with foreign
>>>         food - Portuguese, Chinese (Trump alert!) - are polluting
>>>         the outside air, the pristine air of Provincetown! (Pictures
>>>         attached).
>>>
>>>         Where are WHO and EPA modeling emission rates and
>>>         concentrations over the Atlantic, the east coast of US and
>>>         Canada? At $9 million per saved statistical life, it's a
>>>         crime that our dear Global Alliance and Global modelers of
>>>         premature mortality are ignoring the lives of say, Nantucket
>>>         residents (median family income $90,000+)?
>>>
>>>         ****
>>>         What soured me on what is marketed as science? Well, the
>>>         marketing. Of spurious theories and concocted data.
>>>
>>>         But that is ok. Science evolves. New paradigms emerge.
>>>         Science struggles through.
>>>
>>>         What stinks to high heaven, however, is the abuse of science
>>>         by the advocates, the saviors of the poor ready to market
>>>         ADALYs.
>>>
>>>         I don't celebrate my ignorance. I do object to volunteered
>>>         blindness.
>>>
>>>         I have a single positive suggestion -- dump the ISO
>>>         exercise. Get out of the box mentality, look at the cook and
>>>         food, not fuel ideologies.
>>>
>>>         Nikhil
>>>
>>>
>>>         On Thu, Sep 22, 2016 at 12:04 AM, Ronal W. Larson
>>>         <rongretlarson at comcast.net
>>>         <mailto:rongretlarson at comcast.net>> wrote:
>>>
>>>             Nikhil, cc list
>>>
>>>             I apologize for not responding sooner.  Been busy.
>>>
>>>             I find your response below to be most disappointing.  It
>>>             is clear that you have no use for WHO, EPA, GACC,
>>>             Michael Johnson - and essentially no-one on this list -
>>>             many/most of whom have put in many years in trying to
>>>             develop cleaner, fuel-saving stoves.  I have no idea on
>>>             what has soured you on science.
>>>
>>>             Dr. Michael Johnson, who was the key presenter in this
>>>             webinar had been asked to develop a methodology to help
>>>             countries solve indoor air pollution problems - that
>>>             included stoves but was for more than stoves.  I thought
>>>             his work was outstanding; he answered an important
>>>             question that many of are interested in.  It is clear
>>>             you had/have no idea of what either he nor WHO is trying
>>>             to do.
>>>
>>>             I have not seen you give one single positive idea from
>>>             you about helping the aim of this list.  Your satire
>>>             leaves me cold. Your humor leaves me cold.
>>>
>>>             I ask that you stick to the topic of this list - which
>>>             does not include supporting the use of coal or
>>>             ridiculing those who are concerned about global
>>>             warming.  It does not include giving advice such as your
>>>             last line:
>>>
>>>>             /The rest is blogal noise of vested interests who know
>>>>             nothing about the poor, nor care. /
>>>
>>>             I have read nothing by you that gives you the right to
>>>             be so insulting to very bright and highly motivated
>>>             scientists like Dr. Johnson - or most on this list. It
>>>             is clear too me that you know nothing about the poor
>>>             yourself, nor about stoves.
>>>
>>>
>>>             Ron
>>>
>>>
>>>>             On Sep 14, 2016, at 2:51 PM, Traveller
>>>>             <miata98 at gmail.com <mailto:miata98 at gmail.com>> wrote:
>>>>
>>>>             Ron had asked us all "I suggest waiting until after
>>>>             this webinar to answer your questions about WHO and
>>>>             stoves."
>>>>
>>>>             There was no mention of Daniel Wilson's ES&T paper.
>>>>
>>>>             I watched much of the Webinar. It was quite an
>>>>             entertainment. Comedy. Tragedy. Horror. Drama. Action.
>>>>
>>>>             I am not enlightened.  Can anybody tell me if s/he was
>>>>             able to find light - or heat?
>>>>
>>>>             Priesthood of any sect/cult narrates platitudes around
>>>>             which questions can or cannot be asked and answered.
>>>>
>>>>             I don't remember any mention of that four-letter word
>>>>             FOOD.
>>>>
>>>>             A stove can do many things - the glass top electric
>>>>             ranges are as good as a table top.
>>>>
>>>>             And a stove can get dirty in a myriad of ways. Cooking
>>>>             IS dirty; just ask anybody who has had to clean a stove
>>>>             or a kitchen.
>>>>
>>>>             But we have most Quixotic adventurers, tilting at the
>>>>             windmills, in search of "clean air". Via box models. 
>>>>             Clean kitchen or clean food - or the quality of food -
>>>>             are assumed to be irrelevant to the question of cooking
>>>>             and health.
>>>>
>>>>             Find your little sandbox and play. Let someone else
>>>>             bother about food and health.
>>>>
>>>>             -------------
>>>>
>>>>             WHO will save the people?
>>>>
>>>>             Not WHO.
>>>>
>>>>             My humble (!) suggestion to well-meaning stove
>>>>             designers: Avoid and ignore advocates' deceit and
>>>>             pretense of knowledge. Don't insult the pursuit of
>>>>             knowledge - with all the qualifiers about assumptions
>>>>             and uncertainties that researchers do emphasize but the
>>>>             ritual of cite-o-logy ignores. It is unethical to be
>>>>             guided by unconvincing science just because it is done
>>>>             by scientists.
>>>>
>>>>             What is to be done? a) Keep on innovating for specific
>>>>             geographic markets, considering a variety of fuels and
>>>>             appliances, focusing first and foremost on "cook food";
>>>>             b) Formulate your ideas of market size and timing; c)
>>>>             Understand your customers' desires but also keep in
>>>>             mind that desires and needs are pliable and change in
>>>>             response to factors beyond your control; can you make
>>>>             just a fifth of the customers in a particular
>>>>             geographic market adapt your stove/fuel solution
>>>>             enthusiastically? If anybody comes to buy a second
>>>>             stove - even if the first one is virtually given away -
>>>>             that's the proof of your design. d) Yes, emissions,
>>>>             exposures, fuel consumption, time taken to cook, are
>>>>             all relevant to customers, but you really don't know
>>>>             who weighs what more than others, and what other things
>>>>             (fuel cycle management drudgery)
>>>>
>>>>             The rest is blogal noise of vested interests who know
>>>>             nothing about the poor, nor care.
>>>>
>>>>             Nikhil
>>>>
>>>
>>>
>>>         <photo 2.JPG><photo 1.JPG>
>>
>>         ------------------------------------------------------------------------
>>         _______________________________________________
>>         Stoves mailing list
>>
>>         to Send a Message to the list, use the email address
>>         stoves at lists.bioenergylists.org
>>
>>         to UNSUBSCRIBE or Change your List Settings use the web page
>>         http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org
>>
>>         for more Biomass Cooking Stoves,  News and Information see
>>         our web site:
>>         http://stoves.bioenergylists.org/
>>
>>         ------------------------------------------------------------------------
>>
>>         No virus found in this message.
>>         Checked by AVG - www.avg.com <http://www.avg.com>
>>         Version: 2016.0.7797 / Virus Database: 4656/13061 - Release
>>         Date: 09/22/16
>>
>>
>>
>>     _______________________________________________
>>     Stoves mailing list
>>
>>     to Send a Message to the list, use the email address
>>     stoves at lists.bioenergylists.org
>>
>>     to UNSUBSCRIBE or Change your List Settings use the web page
>>     http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org
>>
>>     for more Biomass Cooking Stoves,  News and Information see our web site:
>>     http://stoves.bioenergylists.org/
>>
>
>     ------------------------------------------------------------------------
>     _______________________________________________
>     Stoves mailing list
>
>     to Send a Message to the list, use the email address
>     stoves at lists.bioenergylists.org
>
>     to UNSUBSCRIBE or Change your List Settings use the web page
>     http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org
>
>     for more Biomass Cooking Stoves,  News and Information see our web
>     site:
>     http://stoves.bioenergylists.org/
>
>     ------------------------------------------------------------------------
>
>     No virus found in this message.
>     Checked by AVG - www.avg.com <http://www.avg.com>
>     Version: 2016.0.7797 / Virus Database: 4656/13061 - Release Date:
>     09/22/16
>
>
>
> _______________________________________________
> Stoves mailing list
>
> to Send a Message to the list, use the email address
> stoves at lists.bioenergylists.org
>
> to UNSUBSCRIBE or Change your List Settings use the web page
> http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org
>
> for more Biomass Cooking Stoves,  News and Information see our web site:
> http://stoves.bioenergylists.org/
>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.bioenergylists.org/pipermail/stoves_lists.bioenergylists.org/attachments/20160923/9775d925/attachment.html>


More information about the Stoves mailing list