Cylindrical Resonator-Type Microwave Heating Reactor with Real-Time Monitoring Function of Dielectric Property Applied to Drying Processes

Abstract

We developed a cylindrical resonator-type microwave (MW) heating reactor with the function of real-time monitoring of dielectric properties. Using automatic detection and tracking functions of the resonance frequency shift with a variable-frequency semiconductor generator, we estimated qualitative variations of the relative dielectric constant and dielectric loss factor for continuous heating of ethylene glycol without connecting a network analyzer. Additionally, we undertook resin-pellet drying using this reactor with a weight measurement function. The drying state of the resin pellets was estimated using resonance frequency variation. Moreover, differences of moisture reduction and resin-pellet melting were distinguished in situ from variation of the resonance curve corresponding to the S21 parameter.

Comparative Evaluation of Microwave Heating Performance across Structurally Diverse Tungsten Oxides

“…Figure 4a illustrates the process of determining the dielectric characteristics by measuring the resonance frequency and intensity of the quartz tubes, both with and without catalysts. 51 This method yielded precise values of f L , Δf L , f 0 , and Δf 0 . Subsequently, these values were systematically integrated into eqs 3 and 4, respectively,…”

Direct microwave energy input on a single cation for outstanding selective catalysis

“…1B, inset). A signal sensor for S parameter measurement (S 21 ) mounted on the semiconductor MW generator can simultaneously measure the dielectric properties of the catalysts (26)(27)(28). Typically, a temperature gradient from the core to the surface occurs in a cylindrical shape packed catalyst bed, that is, the core exhibits the highest temperature and then the temperature parabolically decreases toward the surface (29)(30)(31).…”

Semiflow Microwave Heating Reactor with Resonator Moving Mechanism Applied to Zeolite Synthesis

“…Figure presents a schematic drawing and the appearance of the semiflow MW reactor. This reactor consists mainly of a cylindrical resonator with a moving mechanism, a variable-frequency semiconductor generator (2.4–2.5 GHz, 0–100 W), and a liquid transfer unit. , The resonator’s inner diameter is designed so that the electromagnetic field distribution on the central axis of the resonator is maximized. The reaction tube is installed on the central axis.…”