Cincinnati Extrusion had recently unveiled KryoSys, its completely new system for manufacturing polyolefin pipes which is set to open up new dimensions in pipe extrusion: an option to halve the length of the cooling section and to reduce energy consumption by up to 30%. As per the company, the gain in efficiency in the system is achieved by a perfect combination of a high-speed extruder with a newly developed pipe die, a highly efficient pipe cooling section and a heat recovery system. KryoSys lines lend themselves to the production of smooth mono-layer and multi-layer PE or PP pipes with diameters ranging from 110 to 2,000 mm. They are also suitable for the production of corrugated pipes. The length of the cooling section can be halved compared to conventional extrusion lines, even for large pipe diameters. At the same time, the total investment cost for a KryoSys line is highly competitive compared to conventional extrusion equipment.
The KryoS pipe die, specially developed for Kryosys, has been designed on the basis of a spiral mandrel die which provides for an innovative melt cooling system inside the die. Accordingly, it is possible to start cooling the melt in the die, which allows a substantial reduction in the length of the cooling section. The lower melt temperature also brings about a significant increase in viscosity at the point of exit from the die, which counteracts sagging especially in thick-walled pipes. Moreover, this pipe die has a large internal aperture, which allows air cooling of the extruded melt. The KryoSys system is rounded off by a highly efficient pipe cooling section. In this aggregate, the pipe is cooled simultaneously from the outside and the inside by an ingenious combination of water and air cooling, which permits a further shortening of the cooling section.
The company claims that the new system can offer energy saving potential upto 186 kW while in production. Through its direct drive, the Rapidex high-speed extruder operates with an extremely high level of energy-efficiency reduces the number of vacuum and spray cooling baths required for the downstream aggregates and the optimized cooling system consisting of water and air cooling cuts energy consumption by up to 71kW. Further, the utilization of the heat set free by the pipe cooling system in the die also saves energy which is then used for material pre-heating. Thus the torque of the extruder can be reduced, resulting in energy savings of up to 95 kW. With energy costs of 0.10 EUR/kWh and 6,000 operating hours per year, this adds up to about 100,000 EUR in annual savings for a single extrusion line.