Microwaves are a form of electromagnetic energy with frequencies between 300 MHz and 300 GHz, generated by the magnetron under the joint force of magnetic and electric fields perpendicular to each other. In the electromagnetic spectrum they are identified between radio waves and optical waves. The most common frequency used for industrial purposes is 2450 MHz, due to the advantages offered by this frequency. Microwave fields are reflected by metals, which do not heat up. For this reason, metals are used as conduits for microwaves, or wave guides and as walls for the microwave oven.
Since industrial equipment is made of stainless steel, the chamber acts as insulation for microwaves by reflecting them. Microwaves penetrate materials and release their energy in the form of heat as polar molecules (those with positive and negative ends – such as water) vibrate at a high frequency to align with the frequency of the microwave field (2.45 GHz).
This vibration generates heat. Many studies have now been published showing no difference in the stability and physicochemical properties of materials dried with microwave processing, when compared to other drying methods. Since microwaves are non-ionizing and do not have an amount of energy necessary for the formation of free radicals, there are no conditions created during microwave drying that generate product instability.
This characteristic can greatly accelerate the drying of the material, which is why our dryers are so efficient and advantageous in terms of low energy consumption.