The best advice I can give is that you should probably avoid putting solids through the exchanger, as they could potentially lead to (and/or expediate the process of) fouling in the tubes, which would cause you to lose heat transfer. As far as what is practical for particle distributions for...
Steve -
In reference to your question of gkandy's surface area - he's actually referring to specific surface area. This means the surface area per unit volume. This property would be important if the concern is interaction between the soda and the plastic, as more soda would be in contact...
A note of warning about the Excel Add-in mentioned by Guidoo--
It works perfectly in earlier versions of excel, but Excel XP doesn't like it. You'll find that you'll be able to "install" it, but once you exit Excel and restart, the sheet is automatically hidden. I haven't found a...