Patent ID: 7465772

Claim:
An apparatus for continuous polymerization of olefin(s), comprising a plurality of serially-disposed gas-phase polymerization reactors which include a combination of an upstream reactor and a downstream reactor, the upstream and downstream reactors being adjacent to each other via a gas exchange vessel and the upstream reactor being disposed upstream of the downstream reactor, the gas exchange vessel being connected to the upstream reactor by a first transfer conduit and to the downstream reactor by a second transfer conduit, wherein the gas exchange vessel has a gas distributor plate therein, which partitions the inside of the gas exchange vessel into an upper section and a lower section, the upper section comprising: an inlet, which is an opening of the first transfer conduit and through which a polymer powder produced in the upstream reactor is transferred to the gas exchange vessel while being accompanied by a first gas from the upstream reactor; a gas exchange chamber, in which a polymer powder transferred from the upstream reactor is accumulated temporarily and the first gas which has been introduced from the upstream reactor together with the polymer powder and which exists in the polymer powder is exchanged at least partly with a second gas which is fed into the gas exchange vessel, and an outlet, which is an opening of the second transfer conduit and through which the polymer powder is discharged from the gas exchange chamber toward the downstream reactor; and the lower section of the gas exchange vessel comprising a gas introduction port, through which the second gas is introduced into the gas exchange vessel; the upstream reactor has a vertical side wall through which the first transfer conduit opens, wherein the first transfer conduit leaves the vertical side wall of the upstream reactor horizontally or downward and the first transfer conduit has an inner bottom bending anglewise or roundly at its intermediate portion, wherein the following expressions (1) and (2) are satisfied: 0°≦S 1 ≦90° (1) Ar≦S 2 ≦90° (2) where S 1 is the magnitude (°) of an angle formed by a horizontal line and the inner bottom of the first transfer conduit at bottom of a joint of the first transfer conduit and the vertical side wall of the upstream reactor, S 2 is the magnitude (°) of an angle formed by a horizontal line and a straight line which passes the top of the joint of the first transfer conduit and the vertical side wall of the upstream reactor and is tangent to the inner bottom of the first transfer conduit within the portion where the inner bottom bends anglewise or roundly, and Ar is an angle of repose of the polymer powder produced in the upstream reactor.