[Syrupmakers] BTU requirement

[Bill Outlaw]

Tracey,

I'm just too lazy to do the math this morning, but I can point you in 
the right direction.   I just give the values in the units I think 
in, but of course there are converters on the www.

The starting point is to decide how many gallons of juice you will 
feed the evaporator per hour.  This amount of juice will need to be 
heated to the boiling point, say 225 F.  The sensible heat 
requirement is 1 cal/gm/degree K.

Then decide how much water you'll boil off per hour.  The latent heat 
requirement is 540 cal/g/degree K.

Throw in a 15% fudge factor to account for deviation from ideality 
(e.g. evaporation from a solution, not pure water)

Make a guess about efficiency (how much heat is going up the flue, 
how much heat is lost through the walls of the furnace, how complete 
is combustion, etc.).  As a perspective, my kettle furnace is lined 
with fire bricks that are wrapped in a ceramic blanket, which is 
surrounded by another layer of bricks.  My air flow is not 
ideal.  The efficiency is in the range of 50%.  Some searching on the 
www on boiler efficiencies will give you some more ideas.

Best wishes.

Bill
(sc, Tally, where light rain is keeping me inside on my off-day.  ugh.)


>-        How many propane 'finger-type' burners are required for 
>this size pan?  i.e., I currently cover the bottom of my SS pan with 
>burners, but I'm sure this could be made more efficiently by 
>channeling hot air across the bottom to a chimney.  My current 
>design is for two 'finger-type' burners per jet (29kBTU/jet w/ a #74 
>drill bit hole).
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