I need to put energy balance for a Rotary dryer . the input feed contains the mixture of mono & di sodium phosphate and H20 (Mass flow rate and Temperature are known). Hot air is used to dry and calcinate the feed (400Deg C& mass flow rate known) to form STPP (mass flow rate & T is known). The hot air outlet temperature is unknown (Mass flow rate is known). I need to know the specific heat value to find the temperature of the outlet hot air stream and to put energy balance