On the 17th of June polynSPIRE project will take part at the “Iberian COMSOL Multiphysics Conference” in Malaga, Spain. Alberto Frisa Rubio (polynSPIRE coordinator) and Carlos González Niño, both from the CIRCE Foundation, will present a case study “Microwave Heating in the Presence of Fast Rotating Mode Stirrers: A Simulation Strategy”. The study, presented in a numerical form, is based on the research and development done in the polynSPIRE Work package 3 – “Chemical recycling using microwaves”.
Microwave heating technology is known for its multiple advantages such as its high efficiency, since the energy of the electromagnetic waves is directly transferred to the interior of the specimen being heated, and this can lead to dramatic energy savings. However, a critical drawback of this technology is the uneven heating produced as a result of the generation of standing waves in multimode cavities at a certain frequency. This problem has been addressed in two ways:
i) moving the sample inside the cavity (as in the case of conventional household appliances by means of a turntable)
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ii) introducing mode stirrers (moving parts made of microwave-reflective materials) to alter the standing wave pattern in the cavity over time
In the study, our researchers simulated the heating process of a stirred fluid placed in a vessel within a multimode cavity fitted with four fast rotative mode stirrers. In addition, an alternative strategy is proposed for situations where the movement of the mode stirrers can be considered very fast compared to the timescale of the heating process. Below are some details of the geometry and mesh employed in the simulations, where the position of the specimen in the cavity can be identified and results for the electromagnetic losses are shown.
