| 摘要 |
PURPOSE:To produce a polymer with the residence time distribution being narrow, by gas phase polymerization of an olefin in an apparatus wherein the shapes of a reaction tank and an agitating element, the locations of a catalyst inlet and an outlet for the polymer, and the condition of agitation are optimized, thereby preventing a catalyst from short-cutting. CONSTITUTION:An olefin-containing gas and a catalyst are introduced via a feed opening 11 and an inlet 12 respectively into a reaction tank 1 to conduct the gas phase polymerization of the olefin under such an agitating condition at a lower part 3 that the feed number Fr of the formula [wherein D1 is the diameter of the lower part 3; N is the number of revolutions (rps) of the agitating element; and g is the acceleration of gravity] is 0.5-5, and the polymer is removed from an outlet 13. The reaction tank 1 comprises a bottom part 2, the cylindrical lower part 3 having a height of 1/2 less of the diameter and separated by a dispersing plate 6 from the bottom part 2, an upper part 4 in the shape of an inverted conical trapezoid having a height 1-4 times as much as the lower end diameter and a conical angle of 1-10 deg., and a top part 5 having a space which prevents particles from being entrained, and is provided in the lower part 3 with a paddle type agitating element 8 having an angle of inclination of 30-60 deg. and a width 1/16.7-1/5 times as much as the diameter of the lower part 3 or a spiral type agitating element having an angle of inclination less than 30 deg. and a width at least 1/16.7 times as much as the diameter of the lower part 3, and in the upper part 4 with a spiral ribbon type agitating element 9 having an angle of inclination of 30-60 deg. and a width 1/16.7-1/5 times as much as the tank diameter at that level.
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