Simulation of energy absorption in a device for microwave heating of liquid

Microwave energy can be used for heating, drying, pasteurization and thawing of different foods, as this technology is suitable for processing various dielectric materials, efficient and environmentally friendly. This paper is devoted to simulation of energy absorption in a liquid pasteurizer. The device consists of a rectangular waveguide with hollow dielectric tubes passing through it. Flowing through the tubes, the liquid absorbs microwave energy and heats up. The electric field distribution in the waveguide and specific absorbed power are simulated for various parameters of the device using a specialized computer-aided design software. Based on performed calculations, the angle of inclination of the tubes equal to 43° is optimal. It is not possible to achive an even power distribution across all the tubes, and the power absorption in the first and last tubes differs by about 20 times. However, the liquid flows through all tubes consequentially, therefore, the resulting unevenness is acceptable. The evaluation of precision of the results is performed.