| 摘要 |
<p>Granules(8) are deposited onto a surface(1) to a thickness of a single granule or just a few granules. A heat flow(3,4) or radiation is directed briefly at the granules and heating ceases when the granules start to melt on their surfaces, the other parts of the granules remaining solid. The granules are then collected before the heat at the surface penetrates to the core of each granule and molded into a product by compression(10). When heating with a radiant source only the granule surfaces facing the heater are heated until molten. Granulate layers(8) with a thickness of a few granules may be heated so that the uppermost and/or lowest layer melts and then the molten layers are mixed with the layers between them and compressed to form a product. Radiant heating is directed at granules running down a chute. For heating granules with a gas flow the latter flows through holes in a supporting surface(1). Holes have a smaller diameter than the granules. Heating may be effected by: i) moving a gas flow over a granule-supporting stationary surface; ii) keeping the supporting surface and the heating gas flow stationary. The supporting surface may be a conveyer belt on which granules are deposited. The belt passes through adjacent channels in which heating medium flows in opposite directions. Belt speed is controled(11) so that only the surfaces of granules are melted and the granules are then delivered to a press(10) for molding. Conveyer speed and heating medium temperature are set according to the surface melting conditions of granules. Granulate layer thickness on the belt is controled(9) at the feeding hopper(2). An additional granule feed hopper may be located between a group of heating medium channels. Granulate dwell time on the conveyer may be set so that the granules become fully molten before pressing. An independent claim is included for the process equipment which has: i) a granule feeding hopper with a doctor blade for limiting granule height on a conveyer; ii) a conveyer belt which moves past adjacent heating channels through which hot gas flows in opposing directions; iii) a conveyer speed which ensures granules are only molten on their surfaces at the end of the conveyer; iv) a press following the conveyer.</p> |
