Improved fluid bed reactor system for the catalytic polymerization of olefins composed of cylindrical reaction vessel equipped with distribution plate and agitator

Claim 1

A fluid bed reactor system in which an olefin monomer or monomers can be catalytically polymerized in a fluid bed under fluidized conditions and comprising a cylindrical reaction vessel, a distribution plate provided in the lower section of the vessel, an agitator disposed in a fluidized bed above the plate and adapted to cause a rotational flow in the fluidized bed, a fluidizing gas medium supply line means provided below the plate and adapted to cause said fluidized conditions, a catalyst introducing line means adapted to supply a catalyst to the fluidized bed, a fluidizing gas medium recycle line means provided above the fluidized bed in the reaction vessel and adapted to recycle the gas medium to the gas medium supply line means, and a polymer product recovering line means adapted to recover the polymer product from the fluidized bed; characterized in that the distribution plate satisfies the following conditions, (i) each of many passage holes provided in the distribution plate for passage of the fluidizing gas medium is covered with a cap having an opening, (ii) the opening in said cap is provided only on one side of the cap, and the direction (A) of the opening is not opposite to the direction (B) of the rotational flow, (iii) the direction (A) of the opening varies with the distance (d) from the center (X) of the plate to the center (Y) of the hole, (iv) the opening direction (A) of a cap or caps at a hole or holes whose distance (d) is minimum is directed nearer to the center (X) than is the tangential direction of a circle having the center (X) as a center and the distance (d min. ) to the hole or holes as a radius, (v) the opening direction (A) of a cap or caps at a hole or holes whose distance (d) is maximum is directed farther from the center (X) than is the tangential direction of a circle having the center (X) as a center and the distance (d max . ) to the hole or holes as a radius, and (vi) the opening directions (A) of caps at holes other than the hole or holes specified in (iv) and (v) are displaced from the direction specified in (iv) to the direction specified in (v) according to the distance (d) to these holes.