Patent ID: 7776278

Claim:
An apparatus for the polymerization of olefins comprising a gas-phase fluidized-bed reactor ( 1 ), a product offtake line ( 15 ) for taking polymer particles either continuously or discontinuously from the reactor ( 1 ), which line ( 15 ) is connected to a depressurization vessel ( 2 ) for separating polymer particles and gas, a recycle gas filter ( 3 ) for freeing the gas of entrained fine particles connected to the depressurization vessel ( 2 ), a compressor which compresses the gas which has been freed of fine particles and recirculates it into the reactor ( 1 ), with the recycle gas filter ( 3 ) having an inlet chamber ( 4 ) provided with a gas inlet ( 6 ), an outlet chamber ( 5 ) provided with a gas outlet ( 7 ), an essentially vertical sheet-like filter medium ( 9 ) for retaining the fine particles which separates the inlet chamber ( 4 ) from the outlet chamber ( 5 ) and a particle outlet ( 8 ), wherein the inlet chamber ( 4 ) has a dividing wall ( 10 ) which is arranged essentially parallel to the filter medium ( 9 ) and divides the inlet chamber ( 4 ) into an inflow region ( 4 a ), which is connected to the gas inlet ( 6 ), and a filter region ( 4 b ) in which the filter medium is located and has an upper opening and a lower opening which are dimensioned so that from 60 to 90% of the volume flow flows through the upper opening so that flow along the filter medium ( 9 ) from the top downward results.