| 摘要 |
A fluidized bed jet mill has been provided for grinding particles of material. The fluidized bed jet mill includes plural nozzle devices mounted through side walls into a grinding chamber for discharging a composite stream of high velocity fluid that receives and delivers, for particle to particle collision, entrained particles of material to be ground within the grinding chamber. Each of the nozzle device includes a plural odd number of bell-like nozzle openings for each discharging an individual stream of high velocity fluid that together form the composite stream of high velocity fluid. Each bell-like nozzle opening comprises (i) a converging region for converging and accelerating a volume of high pressure fluid being moved from a first end to a second end thereof; (ii) a throat region defining a narrowest diameter region of the bell-like nozzle opening; (iii) a first expansion region for producing a linear expansion of the volume of high pressure fluid passing through the throat region, and (iv) a second expansion region for producing a turning expansion as well as a parallel flow of the volume of high pressure fluid coming from the first expansion region. The first expansion region has a radius "r1" and a length "s1" running from the throat region towards the second end, and the radius r1 and length s1 are determined such that (dr1/ds1) is a constant. The second expansion region has a radius "r2" and a length "s2" running from the first expansion region towards the second end, and the radius r2 and length s2 are determined such that (dr2/ds2) is non-linear and is equal to a function of s2.
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