Abstract: The invention relates to an equipment for gas-phase polymerization of olefin(s), including a reactor with a fluidized and optionally mechanically stirred bed, and a conduit for withdrawing polymer, provided with an isolation valve, and a conduit for emptying polymer, provided with an isolation valve, the said conduits connecting the side wall of the reactor to a single recovery gas lock equipped with a discharge valve, equipment characterized in that the withdrawal conduit leaves the side wall of the reactor at a height of the reactor wall, above the fluidization grid, ranging from 0.60.times.H to 0.95.times.H, while being directed downwards, with the result that any part of the said conduit forms with a horizontal plane an angle A ranging from 35 to 90.degree., and in that the emptying conduit leaves the side wall of the reactor at a height of the reactor wall, above the fluidization grid, ranging from 0.01.times.H to 0.20.times.H.

Abstract: An apparatus and method for introducing a predetermined volume of suspension into a reactor from a storage vessel. According to the invention the storage vessel is connected via a first conduit to an intermediate vessel which is in turn connected to a feed vessel via a second conduit, the feed vessel is connected via a third conduit to the reactor, each of the first, second and third conduits, is provided with a shut-off valve, the vessels, conduits and valves being so arranged that the suspension can be transferred by gravity from the storage vessel to the intermediate vessel and from the intermediate vessel to the feed vessel and can be transferred from the feed vessel to the reactor by gravity and/or the effect of pressure difference between the feed vessel and the reactor. The present invention also relates to a process for introducing a predetermined volume of suspension into a reactor using the apparatus.