| 摘要 |
<p>Hollow pellets, with interior and exterios surfaces of different material, are formed by coating liquid drops with a powder which includes material for the exterior surface portions, while the liquid contains material for the interior surface. Either the liquid or the powder contains a binder for the powder material which is soluble in the liquid. The liquid is evaporated through the shell of powder to provide a hollow pellet. The method is used particularly for forming catalytic pellets, for use in a car exhaust emission converter in which the outer portion is an abrasion resistant material such as mullite or aluminium oxide base ceramic and the desired catalyst for the inner surface.</p> |
