The facility for rapeseed peeling in the ultrahigh frequency electromagnetic field

BACKGROUND: Well-known plants can process 12 tons of unpeeled rapeseed per day, producing 40% of oil for diesel fuel and 60% of cake with the oil content up to 20% from each ton of seeds. To produce edible oil, peeled rapeseed seeds should be used. The problem of high-quality peeling of rapeseed with separation of the husk from the kernel and the preservation of the integrity of the kernel remains unresolved.

AIM: Development of the facility for rapeseed seeds peeling in the ultrahigh frequency electromagnetic field in the process of hydromechanical destruction and abrasion of husk.

METHODS: Peeling of rapeseed seeds occurs:

– due to hydromechanical destruction (moistening of the husk to preserve strength of the kernel, a single impact to destroy the strength of the bonds between the husk and the kernel);

– due to abrasion of the husk as a result of friction against the rotating cone of the condenser part of the quasi-toroidal resonator and mutual friction of the seeds in the ultrahigh frequency electromagnetic field.

RESULTS: The flow of the initial rapeseed seeds is transported with the airflow into the receiving container, where it is moistened. Then, the moistened seeds follow through the radio-transparent funnel located in the condenser part of the quasi-toroidal resonator, fall on the surface of the rotor, and are subjected to repeated impact, intense friction against the abrasive surface. As a result, the husk of rapeseed seeds is separated from the kernel. The kernels fall down and are discharged through the container. Light particles are removed with the airflow through a pneumatic separation channel. In the sedimentary chamber, heavy tins are separated from light impurities. Microcracks appear in the husk of rapeseed seeds, which facilitates separation from the kernel. The amount and rate of moisture absorption depends on the temperature of endogenous heating of rapeseed seeds. As the temperature rises, the kinetic energy of the water molecules increases and, consequently, the intensity of moisture transfer in the husk increases as well.

CONCLUSION: Calculations show that the electric field strength in the resonator reaches up to 15 kV/cm, which makes it possible to increase the temperature of dielectric heating of rapeseed seeds by 15-20 °C at a circumferential rotor speed of 18–20 m/s and promotes the separation of the moistened husk from the seed kernel. With an electric rotor drive power of 4.2 kW, a rotation speed of 750 rpm, and a magnetron power of 3.3 kW, the facility capacity is 150 kg/h. Energy costs are 0.05 kWh/kg. Advantages of the microwave-powered husker with a quasi-toroidal resonator are high technological efficiency and relatively low power consumption. Endogenous heat enhances the process of husk swelling. The resulting internal shifts facilitate the process of separating the husk from the rapeseed kernel, and the thermal factor makes it possible to shorten the duration of separation of the husk from the kernel.