Apparatus and process for the polymerisation of olefins

An apparatus for the gas phase polymerisation of olefins, said apparatus comprising:

• a) a reaction zone comprising a grid at its base,
• b) an inlet located in the lower half of the reaction zone for introduction of a reaction gas to the reaction zone,
• c) an outlet located in the upper half of the reaction zone for removal of the reaction gas from the reaction zone, and
• d) a solids separation unit having an inlet fluidly connected to the outlet for removal of the reaction gas from the reaction zone,
• wherein
• the inlet of the solids separation unit is located at a vertical height lower than the outlet for removal of reaction gas from the reaction zone and such that the angle to the horizontal of a straight line drawn between the inlet of the solids separation unit and the outlet for removal of reaction gas from the reaction zone is greater than 20°, and
• wherein the reaction zone comprises an inlet for introduction of recycled solids to the reaction zone which is fluidly connected to a solids outlet of the solids separation unit.