IMS patented microwave technology involving Multi-stage Cylindrical Waveguide Applicator Systems for industrial fluids and liquids processing. A microwave applicator system exposing a material flowing through multiple applicator stages to a different radial heating pattern in each stage for uniform heating. A two-stage applicator system has a pair of back-to-back applicators, each having offset, outwardly jutting walls on opposite sides of a material flow path through a microwave exposure region. The offset, cylindrical juts formed in the wide walls of the generally rectangular waveguide cause hot spots to occur in material flowing through and between the narrow walls of the waveguide at opposite radial positions on a radial line oblique to the longitudinal direction of the waveguide.
Uniform product heating can be achieved by directing a material sequentially through these two applicators in opposite directions. A cascaded applicator in which each wide wall has a pair of outward juts offset from each other and from the pair of juts on the other side wall may be used. Other multi-stage applicator systems may be used to expose a flowing material to multiple heating patterns to achieve uniform heating.
IMS Technology: Cylindrical Waveguide Applicator Systems
The invention relates generally to microwave heating and, more particularly, to heating a material flowing through a waveguide applicator. Cylindrical waveguide applicators, such as the applicator in the Model CHS microwave heating system manufactured and sold by Industrial Microwave Systems, of North Carolina, USA are used to heat material flowing through the applicator in a flow tube. The tube is positioned in a focal region of the cylindrical applicator to subject the flowing material to a concentrated, but uniform heating pattern. The geometry of the applicator and the dielectric properties of the material to be heated largely determine the position and radial extent of the focal region.
For many applications, a tightly focused focal region works best. But that requires a small-diameter flow tube precisely positioned in the cylindrical applicator’s narrow focal region for efficient, uniform heating. And changing the position of the focal region and its concentration is difficult. Consequently, uniformly heating material flowing in a larger flow tube and adjusting the focus of the microwave energy is difficult without changing the geometry of the cylindrical applicator. Thus, there is a need for a microwave applicator that overcomes some of these shortcomings.