[Stoves] radiant heat capture, total heat measurement

[Richard Stanley]

Paul it looks like Alex is onto something.
 
Clearly  infra red has a substantial added effect even at the expense as Alex suggested, of "dumming down" (my interpretation)  those blue flames to the seemingly less (conductively) efficient but far more Ir efficient  red yellow flame or at least red glowing dome.

The added benefit of using the dome, may be that by using such a dome one is able to stabilise the optimum distance between pot and heat source. Otherwise, one has to deal first with convective heat, with the pot at a relative greater distance, then, as the flames recede to glowing embers, one has to either add more fuel to maintain the convective heat mode, or sink the pot into the embers  to maintian the same heat input to the pot. But then again you are gassifying your fuel. My supposition would more likely only apply with a natural convection stove  eh? 

Richard Stanley
www.legacyfound.org

 
On Mar 13, 2012, at 9:38 PM, Paul Olivier wrote:

Alex,

I took three sets of temperature readings with and without the dome.

                  With     Without
Reading 1 -  500 C    563 C
Reading 2  - 473 C    578 C
Reading 3 -  470 C    571 C

All measurements were taken at the same height above the burner.
With the dome, the probe remained its normal color.
Without the dome, the probe got red hot.

The burner that I am using is a Belonio burner.
In a first step I added a burner housing to the Belonio burner.
In a second step I added the dome.
I can't imagine that the burner housing alone accounts
 for the much better boiling time that I get in comparison to Belonio.
I am totally at loss in explaining these temperature readings.

Paul


On Wed, Mar 14, 2012 at 9:41 AM, Alex English <english at kingston.net> wrote:
Paul,
If your thermocouple is small enough you might try mounting it suspended inside a short piece of tubing. Copper or thin steel would equalize quickly.  You could even crimp the open ends a bit. The idea is to allow some through flow of hot gases while reducing the radiant losses and gains to and from the surrounding sphere of influence. It would give a second set of numbers for people to comment on.

Alex


Yesterday I bought a thermocouple that can measure up to 1,000 C.
This morning I will use it to measure temperature with and without the dome.
Both measurements will be taken at the same height above the burner (the height of the pot).

Any suggestions?

Paul



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-- 
Paul A. Olivier PhD
27C Pham Hong Thai Street
Dalat
Vietnam

Louisiana telephone: 1-337-447-4124 (rings Vietnam)
Mobile: 090-694-1573 (in Vietnam)
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