Temperature-dependent complex permittivity of several electromagnetic susceptors at 2.45 GHz

Electromagnetic susceptors, understood as trans-ductors of energy, from radiative to thermal, are of high interest when combined with materials that are non-efficient by themselves in a heating process using microwave technology. Susceptors can be either embedded into the material (as filaments, pow...

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Detalhes bibliográficos
Autores: Fayos Fernández, José, Pérez Conesa, Ithaisa, Monzó Cabrera, Juan, del Pino de León, Soledad, Albaladejo González, Juan Carlos
Tipo de documento: artigo
Estado:Versão publicada
Data de publicação:2018
País:España
Recursos:Universidad Politécnica de Cartagena(UPCT)
Repositório:Repositorio Digital UPCT
OAI Identifier:oai:repositorio.upct.es:10317/13294
Acesso em linha:http://hdl.handle.net/10317/13294
https://www.ampereeurope.org/issue-95/
Access Level:Acceso aberto
Palavra-chave:Electromagnetic susceptor
Dielectric properties
Loss factor
Ielectric constant
Permittivity
Temperature
Teoría de la Señal y las Comunicaciones
22 Física
33 Ciencias Tecnológicas
Descrição
Resumo:Electromagnetic susceptors, understood as trans-ductors of energy, from radiative to thermal, are of high interest when combined with materials that are non-efficient by themselves in a heating process using microwave technology. Susceptors can be either embedded into the material (as filaments, powders, etc.) or attached to them as a supplementary layer added on their interfaces. The loss factor modelled as the imaginary part of the complex permittivity of a material can predict the result of the pyroelectric effects that underlies during its microwave heating process. Such mechanisms have a dependence on temperature, hence the heating process rate may evolve with time as the temperature varies. Furthermore, the heat transfer coefficient can also vary with the temperature. Both, the loss factor and the heat transfer coefficient are involved in the heat transfer equation, and their dependence with the temperature can largely justify the thermal runaway effects. Such effects are noticeable when the heat generation and transfer rates overcome the period of time required by any artifacts introduced inside a microwave exposure chamber for leveling the volumetric heating uniformity. This study focuses on determining the complex permittivity of several susceptors at the 2.45-GHz frequency, in the temperature range 30-70 °C.