Catalyst feed system and process, process for producing olefin polymers, and olefin polymers obtainable by the same

The present invention relates to a process for feeding a polymerization catalyst into a polymerization reactor, said process comprising the steps of: (i) forming a catalyst slurry comprising oil and a solid catalyst component in a first catalyst preparation vessel; (ii) transferring the catalyst slurry from the first catalyst preparation vessel to a first catalyst feed vessel; (iii) maintaining the catalyst slurry in the first catalyst feed vessel in a homogeneous state; (iv) withdrawing a portion of the catalyst slurry from the first catalyst feed vessel, preferably continuously withdrawing the catalyst slurry from the first catalyst feed vessel, and introducing the withdrawn portion of the catalyst slurry into a polymerization reactor; wherein the oil has a dynamic viscosity of from 25 to 1500 mPa*s at the conditions within the first catalyst preparation vessel and the first catalyst feed vessel, wherein the catalyst slurry is transferred along a substantially vertical path downwards from the first catalyst