| 摘要 |
A blown film extrusion system, comprising a circular die (10) for creating a tube of molten plastic which is blown into a bubble (30). A Cooling stack (1) is provided in the centre of the circular die (10), within the bubble (30) in use, the Cooling stack(1) including an integrated IBC exhaust stack (24) a substantially cylindrical heat exchanger made up of a plurality of concentric copper tubes (90) through which water is fed. Air from within the bubble (30) is drawn into air inlet manifold (180) and spun to a high velocity into a substantially conical air distributor (150). As the air travels down the air distributor, the velocity of the air increases further as it enters the heat exchanger. The resultant centrifugal effect causes the air to be forced against the surfaces of the copper tubes (92) causing transfer of heat from the air to the tubes, and the water therein. The air is then expelled at the bottom of the Cooling stack (1), through the heat exchanger mesh screen (160), or a combination of both, back into the bubble (30), where it rises back up to cool the inner surface of the bubble (30), before being drawn back into the air inlet manifold (180) for re- cooling. |
