Fermentation Vessel Cooling Geometry (Engineer/Scientist Help!)

[Rosenhops]

I have been doing some modeling and simulation for my design project at school (food engineering, final semester), and I was modeling how geometry would effect the cooling of a fermentation vessel. By geometry I am referring to the cross sectional (parallel to the floor) shape. For example, when I model cooling and maintaining a lager at 10C taking into account heat produced by yeast, temperature of the room, etc. an ellipse greatly reduces the "hot spots" seen in circular tanks. Also, I am comparing how temperature would distribute in the Yorkshire square system (a square, and I know that lagers are never done in these, but that's not the point).

So my question is, does anyone have any knowledge of how this impacts fermentation? I can't find anything in the literature (I doubt I am the first to consider this), does anyone have any information that I can reference? Ultimately, any help would be appreciated.

Note: All I found was the patent in from Spokane Industries. I also posted this in the fermentation category of the forum, sorry for the spam.

 

[ajdelange]

For example, when I model cooling and maintaining a lager at 10C taking into account heat produced by yeast, temperature of the room, etc. an ellipse greatly reduces the "hot spots" seen in circular tanks.

Without having anything to base the comment on that seems quite counter intuitive. What mechanisms are responsible for increased hot spots in circular cross section relative to elliptic?

 

[Rosenhops]

According to Peter Mitham, a professional in wine production:
"The elliptical shape allows the jacket to better control tank temperature and reduce hot spots during fermentation, because a greater volume of wine is closer to the jacket thanks to the elliptical shape. Standard cylindrical tanks have a wider radius, and the center is further away from the jacket, creating the potential for hot spots in the middle of the tank."

Mostly though, I observe it in my model. Conductive heat transfer, in this case cooling capacity of the vessel, depends mostly on the distance from any point to the nearest wall. The maximum distance from a point to a wall is clearly dead center in both cases - whether a circle or an ellipse. In a circle, that distance is the radius. In an ellipse, that distance is the minor axis (not the major axis), which for the same tank volume, is always smaller than the radius. Thus, a smaller hot spot.