A low-cost microwave heating system with coaxial applicator for experimental use

Abstract

Microwave heating has a long history since the technique was discovered in 1945. Yet this technology still find new applications in several areas including food manufacturing, acceleration of chemical reactions, agricultural post-harvesting processes, extraction and separation of chemical substances, disinfection, etc.. In order to design a microwave heating system for a specific industry, two important steps must be done. The first one is the investigation of the material to be heated referred to as load in terms of dielectric constant and loss tangent. The second step is the lab-scale microwave heating experiment. Mostly, microwave heating systems for experimental use in laboratories are bulky and expensive. As a consequence, numerous researchers in process engineering and food science use modified household microwave oven for doing microwave heating experiments. However, major drawbacks are limited experiment settings and safety of the personnel who are running the experiments due to possible leakage of microwave irradiation from the modified system. This work proposes a microwave heating system for experimental use with a coaxial applicator. As the microwave source, a standard magnetron of a household microwave oven was used.