Temperature profile prediction within selected materials heated by microwaves at 2.45GHz

A modified microwave thermo-gravimetric-analyzer for kinetic purposes

“…However, it only measures surface temperature and has a high sensitivity to ambient conditions and reactor material; it thus requires frequent recalibration [14,15,30,31]. In addition, Sherif Farag et al, 2012 have claimed that MWH leads to non-uniform distribution of temperature, which is strongly affected by penetration depth and surface heat loss [32]. Accordingly, the measured temperature using an infrared thermometer does not represent the bulk value.…”

“…Another verification was conducted by comparing the measured temperatures during the MWP of sawdust and the temperatures predicted by the mathematical model that was published by Sherif Farag et al, 2012 [32]. That model was developed to be suitable for the geometry of the heated material and the carrier reactor, as well as the power settings used in this work.…”

“…As shown, the air-thermometer follows each heating interval with a reasonable response time. The deviation between the measured and the reference temperatures was calculated as average percentage relative error (APRE), using the method reported by Sherif Farag et al, 2012 [32]. The APRE was ±5% of the reference value, which might be originated from the thermal resistance of the thermometer-probe, and/or the response of the pressure transducer.…”

“…Upon entering the system geometry in COMSOL-Multiphysics, the timedependent solver algorithm applied the Finite Element Method to solve the partial differential equation of the energy balance, with a time range from 0 to 320 s. Kindly refer to Sherif Farag et al, 2012 for the full details regarding this model [32]. The dielectric properties of sawdust were measured at a temperature range of 298e900 K, using a "microwave and millimeterwave vector network analyzer" (Anritsu 37369D Microwave, 2-Port Vector Network Analyzer, 40 MHz to 40 GHz), and a circular resonance cavity at 2.45 GHz.…”

Thermodynamics model based temperature tracking control in microwave heating

“…Lambert's law is the simplification of the Maxwell's equations to describe the electric field distribution. Thus, Farag et al (2012) predicted a temperature profile of a selected material heated by microwaves via the Lambert's law. Yang and Gunasekaran (2004) proved that the model based on the Lambert's law has the same accuracy as the Maxwell's equations.…”