PDBF® deep bed filter

Novelis PAE offers the innovative PDBF® Deep Bed Filter for integration into its own casting lines as well as those of other manufacturers. Thanks to the design of the bed and its unique heating system, this type of filter ensures premium metallurgical quality and high filtration efficiency, even for small-sized particles. Such a filter admirably meets the demanding requirements of high-end products, such as beverage cans and lithographic sheets, and those of aerospace applications.

Beverage can bodies & ends representing a typical example of high product made from liquid metal treated with a PDBF® Deep Bed Filter. For such application with very thin wall, relatively small particles have to be removed from the liquid metal to avoid any quality problems.
Beverage can bodies & ends representing a typical example of high product made from liquid metal treated with a PDBF® Deep Bed Filter. For such application with very thin wall, relatively small particles have to be removed from the liquid metal to avoid any quality problems.
Overview of a PDBF® Deep Bed Filter unit of small capacity (model 5) used to treat the liquid metal of a continuous strip casting line

PDBF® filtration efficiency

In this type of filter, the liquid metal flows through different layers of calibrated alumina balls and grits that capture more particles, even the smallest. Thanks to Novelis PAE’s expertise in designing and implementing this type of filter, filtration efficiency exceeds 95 % for particles over 10 microns in size.
Efficiency decreases with decreasing particle size, but remains higher than other technologies at all particle sizes, as shown by the following by the comparative graph below.
Curves showing the filtration efficiency (%) depending on the size of particles (µm), made for different filtration principles, including the PDBF®Deep Bed Filter
Layer of alumina balls shown inside the vessel of a PDBF® Deep Bed Filter unit

PDBF® unique heating system, efficient thermal insulation and strong static capacity

The PDBF® filter benefits from a unique heating technology, which guarantees a uniform temperature for the whole filter, including the filtering bed, and the liquid metal.
This advanced heating system incorporates:
  • several electrical radiant tubes in the lid, with air convection system
  • mini-heater(s) immersed in the metal, below the bed
Heating at the bottom of the vessel (which is not offered by other technologies) avoids any risks of overheating the melt surface.
Overview of the PDBF® Deep Bed Filter unit of high capacity (model 90) laid on the tilting device to empty the vessel after removal of its lid. This photo shows the rear of the vessel, which is equipped with three mini-heaters at the bottom.
The thermal insulation of the vessel and the lid is provided by several layers, each made of a special material designed to minimize thermal losses and to meet the highest norms in terms of safety and energy saving.
In addition, the strong static capacity facilitates start-up and provides the liquid metal and the whole system with significant thermal inertia
The above-mentioned features ensure the appropriate priming of the filtering bed as well as the uniformity and stability of the liquid metal temperature from the inlet to the outlet of the filter vessel.

PDBF® layout and associated stations

The PDBF® filtration system typically consists of the following stations:
  • One PDBF® Deep Bed Filter unit installed under the “in line” casting operation
  • One tilting station where the PDBF vessel is temporarily positioned to cool before being emptied by dropping the bed and the grids (when their lifetime is over) into a container. The inside of the vessel is then cleaned.
  • One pre-heating station where the PDBF® unit is firstly equipped with a new bed and set of grids, and then pre-heated. When the system includes two PDBF® units, one is placed under the “in line” casting operation, while the other is placed under the “off line” preparation processes (emptying, cleaning, pre-heating, etc…), so as to avoid any idle time.
PDBF® models  
5
15
20
35
55
90
Max treatment
capacity (tons/hour)
8
15
23
36
59
90
Lid heating power (kW)
18
30
45
60
84
126
Bed heating power (KW)
9
9
9
18
18
27
Typical layout of a PDBF® Deep Bed Filter and its associated stations, namely: - One PDBF® Deep Bed Filter under “in line” casting operation - One tilting station, where the PDBF vessel is temporary installed to cool, to be emptied by dropping the bed and the grids (when their lifetime is over) in a container and to be cleaned. - One pre-heating station where the PDBF® unit is firstly equipped with a new set of bed and grids, and then pre-heated. When the system includes two PDBF® units, then one is under “in line” casting operation while the other one is under “off line” preparation (emptying, cleaning, pre-heating, etc…), so as to avoid any idle time.

What you get
when you choose
Novelis PAE
PDBF® Deep Bed Filter

  • The product of a wealth of experience and technological leadership
  • Novelis PAE’s ability to design and supply the whole casting line (located downstream of the holding furnace): degasser, filtering unit, launder system, casting machine
  • 60 years of experience serving aluminium casthouses
  • Unique engineering know-how to match your specific needs and requirements
  • Technological advantages, resulting from our first class innovation policy
  • Extensive operational experience and a real understanding of the needs of users, helped by the fact that our own group is among them
  • First-class customer support and service worldwide