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JaWiB
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Homework Statement
The problem is fairly simple (hah): estimate the time it will take for a solar dryer (which I have to design) to dry 50 pounds of fruit from 80% water to 10% water.
Homework Equations
It seems there are at least a few equations that give an approximation for evaporation rates. THe first one that comes up is the penman equation:
[tex]\frac{mR_{n}+{\rho}_{a}c_{p}({\delta}e)g_{a}}{{\lambda}_{v}(m+\gamma)}[/tex]
Where, unfortunately, m, [tex]g_a[/tex], [tex]c_p[/tex], [tex]\rho[/tex], and [tex]{\delta}e[/tex] depend on temperature, wind speed, and relative humidity (Credit: wikipedia for all of the above)
The Attempt at a Solution
I could go on with all the other equations impacting those variables, but since I don't have a lot of data to work with (really we were just given solar radiation data for surrounding areas) I figure I must be able to make some approximations to boil this down to something more manageable.
Any idea where to start here?
I can probably fairly easily find an estimate for average temperature during the times/location that we're desiging this to be used. I can probably also estimate energy coming into the dryer and the energy leaving through the walls. But I don't know how that will affect the humidity, air flow, and temperature inside the dryer.