Journal of Food Engineering, Vol.28, No.3, 271-282, 1996
Design and control of drum dryers for the food industry .1. Set-up of a moisture sensor and an inductive heater
The aim of this work is to analyse different ways for controlling the final moisture content of a product dried on a drum dryer and to reduce its unevenness in order to obtain a high-quality product and to increase dryer productivity A new way to determine product moisture content by means of product temperature measurement is presented, which is convenient for a moving and low thickness film. The product temperature is directly related to moisture content, because drying on a drum dryer takes place by boiling: this relation comes from the experimental desorption isobar, or boiling curve of the product. This measurement allows the detection of wet zones, and the correction of the moisture profile across the width by means of an additional inductive heater.