Different types of alumina bed offline preheating systems can be provided to guarantee smooth, fast and efficient heating of the vessel and filter bed. This can be achieved using either gas or blown/compressed air. Air is blown from the top of the lid around the heating resistors to preheat the bed equally, thus avoiding cold spots and potential frozen areas during the casting process. Hot air can also be recycled using a heavy-duty fan on the heating lid. Other automated handling or draining equipment can be offered according to customer needs or casthouse configuration in order to facilitate equipment handling and maintenance. Typical options such as an integrated O2 analyser, an inerting lid, or airlock spouts are particularly recommended for 5xxx casting to avoid surface oxidation.
The concrete cartridge’s material lining has been carefully selected and designed to guarantee efficient filtering without risks of pollution or corrosion that could threaten the metal’s cleanliness. Specific solutions have been developed for high purity aluminium filtration. An improved four-layer insulation method using the most up to date and effective materials guarantees a high degree of insulation to limit heat loss and heating time. In terms of safety, it also drastically reduces the risk of burns caused by touching the filter vessel’s outer surface.
The filter bed’s composition can be adapted according to cast product and expected lifetime. It is created by stacking various layers of alumina balls and gravel. Optimal filtration depends on alumina quality selected from a range of regular international suppliers. Novelis PAE’s Customer Service team remains available to offer selected grids, as well as high-quality alumina balls and gravel kept in stock to face any urgent production needs you may have.