The theoretical substantiation for choosing a rational geometry parameter of “irradiator – object” system is presented. Selecting it is crucial for designing infrared drying machines for solid bodies, in the form of two concentric infinitely long bodies, when one body covers the other. Also, the effectiveness validation of this system is presented in practice using a laboratory stand in the form of two cylinders. An infrared flexible membranous electric heater is sprayed and fixed on the walls of cylinders, an optical sensor was installed between them in order to determine the reflection of the radiation flux. Positive results make it possible to obtain recommendations for designing infrared installations to dry solid bodies.