30102SS wall heat conduction math

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• Jun 1, 2005
Hi all,

The internet has provided me with far too many conflicting rates and
formulae for calculating whether an external water bath for a stainless
steel boiler will or will not provide sufficient heat.

I'd very much appreciate it if an engineer on the list would give this a
once over:

T1 = 105 degC (water + table salt jacket)
T2 = 78 degC (mash)
Heat transfer coefficient = no idea... Ignoring it for the moment.
K = approx 14 W(m2 . K) (I have seen more figures for SS than I care to
poke sticks at. This is the most conservative, and is for 270K, so
anything better would be super).
Q = Watts
A = Area = .64m2
D = thickness of the SS wall = approx 2 mms

Q/A = (T1 - T2) / (D . 1/K)

Q/A = (27) / (.002 / 14)
= 27 . 7000
= 189,000

Q = 189,000 . 0.64
= 120.96 kW

So, what I'd like to know is -- will a 2mm stainless steel wall for an
area of .64m2 allow heat to pass through at a rate of up 120kW for that
temperature differential? Even approximately? As long as it's higher
than 3 or 4kW I'm happy. Unfortunately some formulae I've found
suggested the figure would be closer to 800W...

Cheers and thanks,
Andrew
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