[Stoves] thoughts around ELFD Sampada / Venturi-burners / sooth

[Boll, Martin Dr.]

Dear Anand and stovers,

it is great and I am happy, that the  ELFD-Sampada stove, invented by your daughter, Dr. Priyadarshini Karve, works excellent.

 I want to invite the stovers, to see and get aware, a general system in this stove. 

All burners with forced draft are somehow "venturi-burners".
 Air-jets shooting into a gas-atmosphere suck gas into that air-jet.
In the TLUDs it is inverted to normal venturi gas-burners, and that is an excellent idea, because woodgas is not really pure gas.
It tends to clog nozzles by tars.

Now look to the ELFD-Sampada stove as a "double"-venturi burner-system.
1. vapor-jet drives air, in order to make
2. air-jets, which blow into woodgas, and each jet forms by that  a "somehow"-venturi-burner, as in a forced-draft TLUD.

Let me return to the simple gas-venturi-burners to guess about needed pressures:

LPG burners have a gas-pressure about 30 to 50 mbar; natural gas burners even lower ( 20 to 25 mbar?)
Rough assumed ( I am aware: big ratio-differences are possible): The streaming gas through the nozzle sucks about the same volume of air, to form together an excellent combustible mixture.
If so, that mixture could be made invers too: 30 to 50 mbar air-jet can suck the needed volume of woodgas.
And to get an  air-pressure about 30 to 50 millibar:
- A venturi-system driven by steam, -thumb-calculated-; has steam, pressurized to 100 mbar (or easily some lower or higher)

- Let us assume, that the steam condenses to water,
 naturally except the amount of water that is still in gas-form under that conditions (below 100°C).
 If the temperature in the system is above 100°C, there will be a lot of water(in gas-form) beside the air.
( same thumb "beginning" assume 50/50 above 100°C ??)
- The ELFD-Sampada shows in reality that the containing water does not disturb the combustion. In contrary it seems to help combustion in combination with forced draft. - I did not hear of speaking there would be water dripping out of the stove.

What about sooth and water?
 
The former discussion in the stoves-list about sooth, made me looking for sooth. I learned it is technically produced in different manners and in different qualities, for lots of purposes. - Yes they really want tons of sooth, we don't even want grams and want to avoid milligrams-
One solution to form sooth is to spray water into a flame.
Shouldn't we get to know, from industry by what amount  of water (and temperature) sooth starts to form, that we can avoid that?
And in contrary: what amount of water(in gas-form) makes burn better??

The lesson I learned:
As sooth is in parts like graphite, there are C's bound to C's, within a layer forming 6-rings, and that ring is so strong, that it needs more than 1000°C to burn/destroy the C-C-bondages. 
-That means, we have to avoid _from beginning!_ the forming of sooth so strictly as possible, because it is so difficult to get it burnt. 
- The simple truth I want to keep in my awareness: 
Sooth is no charcoal-C and needs roughly double the temperature of charcoal to burn! 

Just some of my ideas from before and after learning about the ELFD-Sampada-stove-

Kind Regards to all,
- and my compliments to Dr. Priyadarshini Karve.

Martin