摘要 |
<p>Manufacture of granules built up from a core and an envelope in a fluidized bed of nuclei. A stream of liquid containing the enveloping material is hydraulically sprayed within the bed from the bottom upwards by means of at least one hydraulic sprayer surrounded by a coaxial, annular, converging aperture through which auxiliary gas is discharged at such a vertical velocity that the conical stream of droplets is narrowed to a stream having an apex angle of less than 20 DEG , and in such a quantity that a cavity of dilute fluidized phase is formed above each sprayer, which cavity is located entirely within the bed.</p> |