Cincinnati Extrusion offers innovative complete systems for energy-efficient pipe production
Cincinnati’s presentation of KryoSys, its completely new system for manufacturing polyolefin pipes, met with an enthusiastic response from the professional visitors attending the company’s in-house pipe symposium in Vienna. KryoSys opens 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%.
The gain in efficiency with KryoSys 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. For example, a total length of 40 m is sufficient to produce a 400-mm PO pipe with a wall thickness of 36.4 mm, using a Monos+ 90-37G extruder. On the assumption of an identical output level of 1,300 kg/h, the total length of a comparable, “normal” pipe extrusion line would be 85 m. At the same time, the total investment cost for a KryoSys line is highly competitive compared to conventional extrusion equipment.
To ensure optimal melt distribution, the KryoS pipe die, specially developed for Kryosys, has been designed on the basis of a spiral mandrel die. The great advantage of this particular pipe die is an innovative melt cooling system inside the die. Thanks to this system, it has become 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, KryoS features 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.
Another advantage of KryoSys, which is just as vital in times of soaring energy costs, is the system’s great in-production energy saving potential. Thanks to its direct drive, the Rapidex high-speed extruder operates with an extremely high level of energy-efficiency. Through a reduction in the number of vacuum and spray cooling baths required for the downstream aggregates and the optimized cooling system consisting of water and air cooling, energy consumption can be cut by up to 71kW (about 27 kW are saved by the reduction in the number of circulation pumps, and about 44 kW by the fact the less water is circulated). Another source of energy savings is utilization of the heat set free by the pipe cooling system in the die. With KryoSys, this energy can be used for material pre-heating. Thus the torque of the extruder can be reduced, resulting in energy savings of up to 95 kW. By combining all of these measures, a total reduction in energy consumption of roughly 186 kW can be achieved. 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.
