Stirred Tank Heating Energy Balance

Question: A stirred tank is used to heat 100 kg of a solvent with a mass heat capacity of 2.5 J/g·°C. An electrical coil provides 2.0 kJ/s of power, and the stirrer’s shaft work adds 560 W. The solvent, initially at 25°C, loses heat through the tank walls at a constant rate of 200 J/s. a) Write a differential equation for the energy balance of the system. b) Solve the model equation analytically to obtain the solvent temperature as a function of time. c) Determine the time required for the solvent to reach a temperature of 70°C.

Subject: Chemical Engineering · Topic: Process Dynamics and Energy Balance