| 摘要 |
Apparatus for spray coating discrete particles while the particles are suspended in a gas flow, the apparatus including a vertically disposed coating chamber; a gas receiving, compressing and accelerating enclosure open at the top and bottom, such as a truncated hollow cone, within the chamber and including therewithin coating and drying zones and forming on the outside thereof therebetween it and the inside wall surface of the coating chamber an annular storage zone for a load of the discrete particles; one or more gas shaping or aerodynamic structures centrally disposed in spaced relation below the truncated hollow cone defining therebetween with the apparatus inside wall surface an annular nozzle for a Coanda flow of upwardly moving gases substantially into the truncated hollow cone; a particle supporting screen between the truncated hollow cone and the aerodynamic structure(s); at least one spray nozzle extending above the central aerodynamic structure and projecting through the particle supporting screen for providing an atomized spray of coating material within the truncated hollow cone; and a source of upwardly moving gases from below the aerodynamic structure(s). |
