摘要 |
A process for the gas-phase polymerization of one or more alpha-olefins in the presence of a polymerization catalyst, the process comprising: at least a polymerization step wherein the polymer particles flow downward in densified form under the action of gravity so as to form a densified polymer bed; metering an anti-fouling agent in said polymerization step by means of at least N feeding lines placed at different heights of said densified polymer bed, N being the integer number satisfying the equation N≧(1+0.08·H), where H is the height (expressed in meters) of the polymer bed. |