INTENSIFICATION OF THE PROCESS OF EXTRACTING FAT FROM FAT-CONTAINING RAW MATERIALS BY DIELECTRIC HEATING

Abstract

The article substantiates the effective modes of heat treatment of fat-containing raw materials in a radiohermatic ultrahigh-frequency installation with a metal-dielectric resonator. The raw material for the study was the internal fat of cattle, sheep, chickens, their dielectric characteristics were systematized according to I.A. Rogov. The purpose of this work is to develop a continuous-flow microwave installation with air-cooled magnetrons and a resonator in the form of a truncated cone with an exponential generator, which contributes to increasing thermal efficiency and maintaining high electric field strength and radio tightness without a shielding housing when heating disinfected fat from fat-containing raw materials. The electrophysical parameters of the fat-containing raw material are analyzed, including the change in dielectric parameters from the frequency of the electromagnetic field (EMF), fat content, density. The intensity of the electric field is matched with the heating rate, the specific power of the generator. A continuous-flow microwave installation with a resonator in the form of a truncated cone with an exponential generator made of non-ferromagnetic material and a ceramic concave mirror base, inside of which a dielectric screw with a decreasing pitch and a diameter of a screw is located, has been developed. A concave ceramic mirror is installed coaxially on the large base of the resonator. A dielectric screw is inscribed along the resonator. Two sluice gates with non-magnetic bent blades are installed on the resonator. The melted fat flows down through the perforation on the surface of the resonator. Magnetrons with waveguides are installed with a shift of 120 degrees along the perimeter of the resonator base. The general properties of a resonator with dielectric inclusions (ceramic mirror, fluoro-formation auger) are analyzed. In such a metal-dielectric resonator, the reflection of the field from the non-magnetic walls of the resonator and critical sections can be combined with full internal reflection in the dielectric. The exponential generator of the resonator and the ceramic mirror contribute to an increase in the concentration of the electric field strength in it to 2 kV/cm when placing three magnetrons with a shift of 120 degrees along the perimeter of the large base. With a specific power of the generator of 2 W/g, the productivity of the microwave installation for heat treatment of fat-containing raw materials is 18-20 kg/h.; With a frequency of rotation of the electric screw drive of 1 rpm, 0.5-0.6 kg of raw materials is heated in 120 seconds. The specific energy costs compared to the prototype (0.2-0.25 kWh/kg) is reduced to 0.14-0.15 kWh/kg.