DETERMINATION OF EQUALLY IRRADIATED SPACE IN THE WORKING CHAMBER OF A CYCLIC ACTION MICROWAVE INSTALLATION

An important requirement for microwave treatment of agricultural products is the dosing accuracy of the energy supplied. The most successful dosing of microwave energy is achieved in installations of cyclic action. At the same time, the microwave field in the working chambers of such installations is distributed unevenly, which puts forward the task of finding a compromise between the degree of loading and the uniformity of impact. To search for equally irradiated space, the authors have conducted an experimental study of the distribution of the microwave field. Basing on the study results, they have designed a three-factor mathematical model in the form of a nonlinear polynomial. Stationary points of the process have
been determined by solving a system of linear algebraic equations obtained as a result of setting to zero partial derivatives of the mathematical model with respect to length, width, and height. The maximum value of the extremum has been established with Sylvester’s criterion by alternating the diagonal minor signs of the Hessian matrix. The theoretical part of the work consists in studying the distribution of the microwave field by interpolating a mathematical model in the space of the working chamber. To do this, a calculation has been made of the energy dose reported to the treated material at various points in the working chamber and the results have been compared with an acceptable value. If the dose divergence at any point is small, then
this point is recognized as part of the equally irradiated space. To provide for objective results in the process of searching for equally irradiated space and to achieve the uniformity of results, sequential studies have been performed on points located on the surface of a ball with an increasing radius. To implement the model of ballooning, use has been made of a computational algorithm consisting in a step-by-step search of points on the circles surrounding the ball. After the calculation of the impact dose on the points located on the ball surface, its radius increases and the research can be resumed.