[Stoves] Pot shells / Fin shells

[Lanny Henson]

Well I had 186 LB of water and rice, the rice was 50 lb. 

Rice has a specific heat capacity of about .33 which is about the same as 16.5 of water so deduct 33.5 from 186 for a mass of about 152.5 lb water equivalent.

I started with 15 LB. of wood and had 2.95 LB. left over = 12.05 LB. of wood used, and there was 1.5 LB. of charcoal left.

The simmer time was about 30 min.

The wrapper is 60" x and the vat is 48" long . I estimate the water was contacting about 36" of the 60" wrapper so the contact area was about 12 sq. ft.

Does that give you the numbers you need?

Lanny

  ----- Original Message ----- 
  From: Crispin Pemberton-Pigott 
  To: 'Discussion of biomass cooking stoves' 
  Sent: Sunday, July 28, 2013 1:39 PM
  Subject: Re: [Stoves] Pot shells / Fin shells


  Dear Lanny

   

  I wonder if you can help me out with more numbers. The comparison between a trough with ends and a pot is interesting. 

   

  Can you provide some water boiling volumes (initial) and mass of fuel burned? To check heat transfer efficiency the char mass will be needed. To check the system efficiency (fuel efficiency) the char should be ignored in most cases. What I would like to do is calculate the two and see if the surface area of the pot and vat are important considerations. They should be, but as I often say, never assume anything.

   

  Best to check.

   

  The effective heating area of the vat might be the sheet length x Sin(45) x Sheet width, or it may be sheet length x width. If the heat transfer efficiency per sq cm is the same, then the matter will soon be settled with a calculator.

   

  Thanks
  Crispin

   

   

  From: Stoves [mailto:stoves-bounces at lists.bioenergylists.org] On Behalf Of Lanny Henson
  Sent: Monday, July 29, 2013 12:13 AM
  To: Discussion of biomass cooking stoves
  Subject: [Stoves] Pot shells / Fin shells

   

  Fins/ pegs/ pot shells/ rocket pots.

  If you are going to use fins they should be attached to a pot skirt that fits snug and stays on the pot until it needs to be cleaned. This keeps the soot if any contained and away from the cook.

  Instead of a fin shell I am now using a "pot shell" that totally encloses the pot. The pot shell has a top tray that can be easily slid back for easy access to the pot. This is actually easier that removing a lid and another benefit with total enclosure is the pot is heated from the top as well as the sides and bottom.

  The top tray can also dry wood and warm food items. 

  Another benefit of the pot shell is that it makes cooking in the rain possible.

  The construction is very simple and it can be built from most any material that is non combustible.

  A section of drum fits over a 40 qt sauce pot or a 60 qt stock pot. The pot handles may have to be bent in a little or the pot shell can be slightly oval to fit over the handles.

  A pot shell requires a flat top stove body or a burner under a flat surface.

  I believe the pot shell is the biggest bang for the buck to improve a stoves performance. They are cheep and easy to build. They add draft without allowing too much, they capture the heat, and allow cooking outdoor in the rain.

  If the pot shell design helps your stove, run with it, and that goes for everyone.

  I will have a video later today showing its use

  Lanny

   



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


  _______________________________________________
  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/20130728/13b812ab/attachment.html>