the dispersion element is formed by a metal fabric 41 in this embodiment it spans the entire top side of the blowout device 4 it lies on a support structure 42 that is designed as a supporting grid and supports the metal fabric 41 from below the supporting grid 42 is formed from a plurality of plate type segments 43 that are joined in a cross connected fashion the upper edges of the segments 43 are in one plane and form a support for the metal fabric 41 the result of this is that the metal fabric 41 is not deformed or damaged even under the weight of a resting layer of cooling material the cooling gas fed via the connecting pieces 40 is distributed between the segments 43 of the supporting grid 42 such that it is fed to the metal fabric 41 from below it flows through the metal fabric 41 being finely distributed in the process and entering the resting material layer from the metal fabric 41 over a large area this results in the cooling gas passing over into the cooling material both over a large area and uniformly the low cooling gas speeds thereby obtained cause a low pressure loss on the one hand and an optimum cooling of the cooling material on the other hand these two together enable a low energy requirement the metal fabric 41 is a sufficiently fine mesh in this case to prevent cooling material falling undesirably through the metal fabric 41 in order to further counteract the risk of the cooling material choking the blowout device.