A solid material shows case hardening properties while drying. Which of the following should be controlled to control the drying process ?

Question

Accepted Answer

Flow rate of inlet air. Controlling the flow rate of inlet air directly affects the drying rate and heat transfer to the solid. Relative humidity of outlet air is a result of the process, not the primary control variable for the process itself. The humidity of inlet air is an initial condition that might be set but controlling the flow rate offers more direct process control. Temperature of the solid is what is being dried and changes during the process.