| 摘要 |
<p>1318970 Coating granular material STAMICARBON NV 28 Sept 1970 [3 Oct 1969] 46075/70 Headings B2E B2F and B2L Apparatus for coating granular material comprises a spray head 3 which forms a conical film 17 of oleaginous fluid which runs down obliquely disposed walls 4, 5 so that particles entering the coating chamber above the spray head pass through the film and then run down the walls 4, 5 to pick up more coating fluid. The particles then pass to a series of drums 22, 23, 24 with rotary vanes which mix the coated particles to produce an even coating thereon. The coating column has a water jacket 18 which can be filled with hot water to heat the granules and fluid during coating. The spray nozzle comprises a chamber in two parts 10, 11 a tangential inlet being provided to a supply pipe 13 and a tangential outlet to a return pipe 14. A valve is provided in the pipe 14 and when open allows coating medium to flow through from pipe 13 to 14 without being projected from the spray outlet 16. When the valve is closed or partially closed spray is emitted from the nozzle 16 in the form of a conical film due to the centrifugal force built up in the chambers 10, 11. The granules may be of urea and can be coated with a fluid comprising 75% mineral oil, 15% paraffin wax and 10% fat. Such a composition may be applied to the granules at a temperature in the range of 50‹ to 60‹C.</p> |
