You need one mass energy balance. Very important information is RH of air at dryer outlet. Then your dryer inputs are;
Fuel flow (Btu/hr)
Sand flow+sand water flow (he, Ce, Te)
Air flow , he funcion of (T & RH)
Your dryer outputs are.
Sand flow+sand water flow (he, Ce, Te)
Air flow , he funcion...
In a old Combustion Engineering book, they show a small calorimeter. If you like I see in my books for these reference.
TSD in condensate is a good "rough" reference too.
The steam carry same chemical products for water "ever". More or minus. If you require clean steam, you require an aditional evaporator or boil your water without chemicals.
Alfredo
Dear Tequilalloy-15, I suggest the following.
Check flow of thermal oil. (Jonkatz)
Send one liter (or two) to thermal oil manufacturer for test and recomendations. Urgent!
Check for soot in radiation and convection section of thermal heater.
Check short-circuit of combustion gases through...