[Stoves] old patent-paper about a saw-dust stoves

Tue Jan 18 18:52:01 CST 2011

Dear Martin

Thanks very much for the time you have taken to translate the German patent. Comments are included below...
  ----- Original Message ----- 
  From: Boll, Martin Dr. 
  To: stoves at lists.bioenergylists.org 
  Cc: 'Frans Peeters' 
  Sent: Tuesday, January 18, 2011 6:46 PM
  Subject: Re: [Stoves] old patent-paper about a saw-dust stoves

  Dear Kevin, Marc, Crispin and all,

  I hope my rough and ready translation (link to the Original text below) will be exact enough.

  Those patent/law formulations are somehow twisted (the other possible translation of "verdreht" would be crazy J ) and difficult to understand even in the native language

  If there is some doubt to be right, or lack of understanding, use the very good dictionary 

  LEO Deutsch-Englisches Wörterbuch

  -Which I am often forced to use to understand English texts, even from the stoves-list; but worse the multiple-sensed abbreviations.

  Fritz Kaftanski Koeln am Rhein (Germany)

  Sawdust stove with insert-firing

  Patented in Germany beginning from November 28th 1922

  Object of the invention is a saw-dust stove with insert-firing in order to burn saw-dust an piece/lump (sized) fuel as Coal, wood and so on.

  It is possible to use the insert-firing in already existing saw-dust-stoves, without outer changing of the stove, as e.g.  mounting fire- or ash-doors and so on.

        Those stoves for burning saw-dust are composed mainly (as shown in Fig Abb3  ) out of a mantle, a cylindrical insert, which serves as fuel container, and the essential part (e),

        with its help the centre burning channel is created..

  # OK... it looks like the "essential part (e)" is the cylindrical stick used to form the hole up the middle of the packed sawdust.

   As there is lack of saw-dust or similar fuel, it is not possible to run such a stove with coal or other piece-shaped fuel, because there is no griddle, und especially, because saw-dust -stoves have neither  firing nor ash-doors. Following the invention there is the possibility to run the saw-dust-stove, as desired with flour-shaped and piece-shaped fuel and to run a saw-dust-stove by use of the insert-firing without essential change into a coal-stove..

  # I think what they are saying here is that the sawdust stove will not work on coal, because there are no entry points for air or ash removal. However, if no sawdust is available it can be run with "flour-shaped and piece-shaped fuel". I think what they mean here is "flour sized fuel", and "small pieces of fuel". 

  Fig 1 Saw-dust-stove with insert-firing, view from above

  Abb 2 insert-stove in vertical cut from the side Abb.3 saw-dust-stove with inbuilt insert-firing in cross-section

  The insert-firing consists mainly out of the housing d11 wit side hooking-edges. In the housing is the basket-griddle a . It is with sufficient distance from the wall of the housing d11 respectively d1 in that hooked, so that kindling can be brought in.  The housing d11 is at same time fire-starting-basket and ash-basket and it has a door for regulating the air-administration.

  # It appears to me that the assembly in Abb 2 (Figure 2) is a standard basket grate and ash collector system that someone could purchase to sit on a bucket, to make a coal burning system. "a" are grate bars, "b" is a sliding damper and "c" is a lever, or means to move teh slide damper to control primary air to coal in a basket grate. Does that make sense to you?

  In the bottom there is opening for ash removing containing an closing-clap c. This opening serves as well as duct for the heat-gas into the stove, when the basket is used as stove/burning-chamber. 

  # OK... what I think they mean here is that when the damper "b" is open and there is no coal in the basket grate, sawdust pyrolysis gases from below, are burned to completion in the basket grate, which now serves as a combustion volume.

  When used as saw-dust-stove it serves as centre-piece c as insert-opening.

  # I think what they are saying here is that when the basket grate "a" and cover "b" are removed, the hole helps to center the cylindricsl rod used to make a hole in the sawdust.

  By the position of the griddle-basket is it possible to start the fire from top, without a stove-starting-door at the side. By this manner of starting the fire, the fire burns from down (von unten) to top (nach oben). Before placing the inset-firing it is possible to place paper. To start the fire, it is sufficient to light the paper from above.

  # I do not understand this. It seems like they are suggesting to put paper (or kindling) on top of the sawdust bed and "Top Light" it. Could they mean that "... the fire from teh kildling burns downward to the top of the sawdust?" It appears in Figure 3 that there is another damper and ash pit at the bottom of the packed sawdustwith another sliding damper that could be opened to allow primary air up through the center hole formed by the cylinderical form. This being the case, they are describing a TLUD combustion configuration.

  The rest text is about rights for the patent. -I don't know if there are still rights on that, but now after 85 years I guess that is history.

  # Usually patents are good for 20 years.

  # OK... this looks like an interesting concept, even if 85 years old! Rather than a common "bottom lit packed sawdust" stove, that has a tendancy to increase its heat output as teh hole enlarges, with the "top lit packed sawdust" concept, the tendancy to overheat late in teh burn should be lessened. This system should work well with dry sawdust, that would ignite on teh top surface rather easily, but then, if dry, it might not pack well, and the hole may tend to close off prematurely. Or, the fire may tend to advance down the hole.

  # Does anyone on the List have a Sawdust Stove System where tehy could try to operate it in "top lit fashion?

  Best wishes,

  Kevin

  That's so far the translation.

  Marc, you can have a look to the DEOM-stove  (http://www.deomturbo.com/fonctionnement-poele-luxembourg.asp ) 

  made in Belgium and France, which can burn as well saw-dust. This type of stove is sold in Great Britain as well. Look at: http://www.relaxstoves.co.uk/

  The difference between both is the exit of the flue-pipe. The British has on top, the DEOM has rear.

  I know, there are different needs for the chimney-length between both and I think this is because of that different flue-gas-outlet.

  Possibly you are interested, to know that this type of stove is as well built as a cooking stove with baking-oven. Look at:

  http://www.deomturbo.com/cuisiniere-feu-bois-luxembourg.asp

  Crispin, thanks for your general comments about old stoves/inventions and their alterations. It is the same the line I am thinking, naturally without your profound knowledge.

  Regards

  Martin

  P.S. "Lonely logs don't like to burn" (MB)

     The links in original language:

    Cover-sheet with the description for the intention of the insert ("Einsatz") 

    http://www.collection-appareils.fr/brevet/Kaftanski/DE423728/page1.pdf

     Drawings with description:

    http://www.collection-appareils.fr/brevet/Kaftanski/DE423728/page2.pdf

    Sometimes progress can happen by altering old ideas.

    Let the stovers know if you would like to modernize it for whatever purpose.

    Best wishes for the New Year!

   Regards

   Martin

------------------------------------------------------------------------------

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.bioenergylists.org/pipermail/stoves_lists.bioenergylists.org/attachments/20110118/70db4be7/attachment.html>