A plant for drying and solid state polycondensing a granular moisture-containing polymeric material includes a conduit feeding material to be treated longitudinally, a treatment zone located along the conduit, a blower of an inert gas into the conduit, and a radiating device emitting an alternating electromagnetic field in the radio-frequency band to dry and upgrade the material. The radiating device includes applicators, located at the treatment zone and external to the conduit in longitudinally offset positions, which are connected to the terminals of an electromagnetic wave generator and include pairs of opposed radiating elements that generate an alternating electromagnetic field in the conduit, with field lines at least partially parallel to the direction of feed of the material, and that define magnetic dipoles with opposite polarities along the conduit. A method of drying and solid state polycondensing a polymeric material in granular form obtained by polycondensation using the plant.
B29B 13/08 - Conditioning or physical treatment of the material to be shaped by using wave energy or particle radiation
B01J 19/12 - Processes employing the direct application of electric or wave energy, or particle radiationApparatus therefor employing electromagnetic waves
F26B 3/347 - Electromagnetic heating, e.g. induction heating or heating using microwave energy
B01J 8/00 - Chemical or physical processes in general, conducted in the presence of fluids and solid particlesApparatus for such processes
F26B 17/00 - Machines or apparatus for drying materials in loose, plastic, or fluidised form, e.g. granules, staple fibres, with progressive movement
F26B 3/34 - Drying solid materials or objects by processes involving the application of heat by development of heat within the materials or objects to be dried by using electrical effects
B01J 8/12 - Chemical or physical processes in general, conducted in the presence of fluids and solid particlesApparatus for such processes with moving particles moved by gravity in a downward flow
A device for generating an alternating radio-frequency electromagnetic field in a working area includes an applicator emitting the electromagnetic field, an oscillator providing an alternate voltage and electric current having a predetermined value and a predetermined frequency to the applicator, a power supply supplying a substantially DC voltage to the oscillator, and a control system controlling the electrical parameters of the AC voltage, the AC current and/or the frequency provided to the applicator by the oscillator. The control system includes an input port connected to the electric power network, a first electronic control circuit connected to the input port and substantially instantaneously varying the electrical parameters and instantaneous control of the field emission power, and a second electronic control circuit regulating the operation of the oscillator. The first electronic circuit has an output connected to the power supply. A plant includes the device and a control method for the device.
A23L 3/01 - Preservation of foods or foodstuffs, in general, e.g. pasteurising, sterilising, specially adapted for foods or foodstuffs by heating using irradiation or electric treatment using microwaves or dielectric heating
Apparatus for applying oscillating electromagnetic fields, particularly for treating liquid, pasty, semi-solid or granular products, and method of use of such apparatus and system incorporating same
The invention relates to an apparatus for applying oscillating magnetic fields, particularly for treating liquid, pasty, semi-solid or granular products, to a method of use of such apparatus, and to a system incorporating it. The apparatus comprises at least one pipe of an electrically insulating material for conveying the products to be treated, at least one plurality of electrodes around the periphery of the pipe, and means for generating one high frequency oscillating electric voltage. Each of the electrodes has a substantially annular shape, with an inner surface having a minimum radial distance from the outer cylindrical surface of the at least one pipe, which is sufficient to prevent electric currents from passing to the product to be treated. The inner surface has at least one substantially conical edge with a predetermined conicity angle to allow use of relatively high voltages with no risk of discharges to air.
A23L 3/28 - Preservation of foods or foodstuffs, in general, e.g. pasteurising, sterilising, specially adapted for foods or foodstuffs by irradiation without heating with ultraviolet light
A23L 3/00 - Preservation of foods or foodstuffs, in general, e.g. pasteurising, sterilising, specially adapted for foods or foodstuffs
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