aluminium Scrap Decoating (USA)
CASE STUDY 11. Aluminium Scrap Decoating US Granules (USA) 2001
HCl emissions reduced from 1000mg/Nm3 to 5mg/Nm3.
Process: To recover aluminium scrap from plastic foil.
A Glosfume high temperature ceramic filter system replaced an existing bag filter that had suffered severe corrosion. This was due to being operated at low temperatures, combined with extremely high HCl levels, during aluminium scrap decoating.
Lime injection provided inadequate HCl removal and led to problems with CaCl2 'setting' in the bag filter house. The problem was eventually overcome by utilising sodium bicarbonate at high temperature in conjunction with the new Glosfume high temperature ceramic filter system.
This aluminium scrap decoating customer benefited from a more appropriate hot air filtration solution, giving greater efficiency and reliability, as well as consultancy to diagnose and rectify the CaCl2 'setting' problem - again leading to enhanced decoating plant performance.
- Installation date: 2001
- Process: Decoating plastic backed aluminium foil
- Location: USA
- Filter unit: HTMC6(400)
- Filtration area: 456 m2
- Operating temperature: 315°C
- Dry scrubbing: Sodium bicarbonate injection
- Gas flow: Up to 30,000 Am3/hr
Emissions levels after the Glosfume filter.
- Particulate from 400 mg/Nm3 down to 3 mg/Nm3
- HCl from 1000 mg/Nm3 down to 5 mg/Nm3
Element life span 6 years