Conscious of the need for energy efficiency and an increasingly vital need to safeguard the environment, Moretto, based in Massanzago, near Padua in Italy, has for many years been focused on the development, design and manufacture of equipment and machines used in the processing of plastics, such as hopper loaders, hot air dryers, dehumidifying dryers, grinders, micro-dosing, gravimetric and volumetric dosing units, storage bins, temperature controllers, chillers, cooling systems, moisture measuring equipment as well as feeding and conveying equipment, satisfying the most demanding technical standards whilst, at the same time, provide users with added value.
PET, a thermoplastic polymer resin of the polyester family, is frequently used in the production of bottles and containers in extremely high quantities, i.e. millions of tons of the material are used every year. Efficient production requires particularly precise drying criteria with low final residual moisture content not higher than 30 ppm. This can only be achieved by employing highly sophisticated equipment guaranteeing consistently high performance and a reliably high quality end product.
Among the energy-efficient and environmentally friendly dehumidifying solutions developed by Moretto in the X Technology range are the:
PET-PRO Drying System – XD Dryer 600, combined with the CTX Crossed Thermal Exchanger (CTX), stainless steel hopper and the Flowmatik Uni System (optional). The PET-PRO combination, particularly the use of the CTX, specifically designed for spent energy recovery in conjunction with the use of PET, brings maximum benefits with regard to the reduction in energy costs.
The X Technology XD 600 Dryer has been designed as an innovative exclusive dehumidifying solution in the use of technical polymers, such as PET, particularly with high throughput in mind. Control of the system is entirely based on two parameters: material to be treated and hourly throughput. This means that control of the system no longer relies on the traditional material/temperature ratio. Variable airflow, touch-screen control, high efficiency (-75°C dew point), equipped with a series of sensors controlling the polymer treated, ensure that the XD 600 adjusts the process to minimum variations in the working parameters, thus avoiding thermal stress and possible variations in viscosity. In addition, the need for the use of compressed air is eliminated.
The X PET-PRO CTX Crossed Thermal Exchanger, providing vitally important energy recovery, is located on top of the hopper so that the transfer of exhaust air heat to the processing air before entry into the heating unit can take place. This sequence results in a reduction of energy use as well as in a decrease in return air temperature. The special battery of the exchanger, combined with the exclusive characteristics of the XD 600 series dryers, results in significant energy recovery. This, in conjunction with the high performance of the XD 600 dryer(s), provides the essential platform for all polymers that require high treatment temperatures, such as for instance PET. The hopper can be opened by pneumatic control; this enables the trouble-free cleaning of the interior. Total operating safety is provided by parapets to protect the gallery. The CTX is protected by a series of easily accessible stainless steel filters.
As the second highest expense – apart from the purchase of raw materials – energy consumption forces producers to look for low energy consumption production solutions, particularly when it comes to dehumidifying, material transport, dosing, recovery and crystallisation. These Moretto X Technology solutions are designed to recover up to 30 kWh of pure energy. The graph below gives an example of annual savings possible, comparing the XD 600 PET-PRO and XD 600 drying systems with conventional dryers. The figures are based on the climate in Europe at an average temperature of 20°C, with a humidity of 80 percent. Calculations are based on a throughput of 8000 h/pa, the drying temperature is 180°C. Figures are based on a reference dryer with an airflow capacity of 2500 m³/h, a throughput of 700kg in a treatment time of six hours. The material is PET. The currency used is Euro.