RF energy can be added in the middle
of a process line to give an RF “boost” to the
conventional drying process. In this case, the RF heats the
inside of the product and drives the moisture to the surface
where conventional methods are effective. This option has
been used in a paperboard line and the RF made the downstream
steam cylinders more effective by moving the moisture to the
surface where the cylinders now contacted a wet product surface
rather than a dry, insulating product surface. As with the
other combinations of RF and conventional drying, the overall
drying time is reduced with the use of the RF boost.
