8 16 before the pumping from the lower part of the stand pipe takes place in this manner exclusively under the influence of the hydrodynamic effect from the addition of the dilution fluid through the said nozzles fig3 and fig4 show an embodiment of the manner in which addition of the dilution fluid can be realised the dilution fluid is added by a pump to a distribution chamber 60 that is arranged concentrically around the stand pipe 22 the pump pressurises the fluid to a suitable level an excess pressure of approximately 0 1 0 8 bar alternatively high pressure nozzles can be used which finely distribute the dilution fluid in the form of fanned plumes of fluid oriented at a suitable angle relative to the vertical a suitable angle being 30 90 u00b0 a number of nozzles 62 are arranged at the bottom of the distribution chamber oriented obliquely downwards in the direction of flow of the granulate and inwards towards the centre of the flow the amount of obliqueness in the mounting is appropriately 45 u00b1 15 u00b0 relative to the vertical the oblique orientation downwards is favourable for achieving an ejecting influence on the granulate flow and for avoiding the risk that the dilution fluid splashes upwards in the stand pipe a number of nozzles at least four are arranged around the stand pipe 22 40 u2032 preferably with equal distances between them with a stand pipe 22 having a diameter of 800 1 500 mm it is appropriate that 10 40 nozzles are arranged around the periphery of the stand pipe it is appropriate that the distance between adjacent nozzles be less than 50 300 mm if high pressure nozzles with fanned plumes of fluid are.