| 摘要 |
Solid, loose particulate materials are treated with vaporizable agent in a process chamber. The materials are combined with a mixture of hot gas and vapor in order to condense finely subdivided amounts of the treatment agent on the material. After a suitable time of reaction, the condensed material is partially removed from the treated material so that the pressure in the process chamber is reduced at least to the point at which the treatment agent partially evaporates, whereupon the portion which has revaporized is extracted from the process chamber. This cycle of introduction and removal of the treating agent is preferably repeated in a program-controlled operation until the desired result is achieved and a product which is suitably agglomerated is obtained. In the present process, particulate material in powder or granule form is agitated and heat-treated in a closed drum, by stirring agents and surface treated by a hot gas flow forced over or through the charge of the material and then extracted intermittently by a vacuum pump. The air is heated and vaporized so that the vapor does not condense on the charge material.
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