The Pressure Filtration Melt Cleanliness Analyzer Prefil-Footprinter

The Prefil^®-Footprinter from ABB is designed to measure the relative cleanliness of an aluminum melt by comparison with a benchmark inclusion level for a production process, a given alloy, or a given stage in the process.

The result is observed directly on a computer screen

The metal residue of the test may be saved and sent to ABB for metallographic analysis

The Prefil^® is the only inclusion analyzer that provides an instant result and, simultaneously, a sample for further metallographic analysis. These two qualities of the Prefil^®-Footprinter make it a powerful solution to perform process control on a daily basis, and/or on a more in-depth audit basis for process optimization.

This instrument is easy to use and designed to withstand the foundry floor. Its rugged construction is based on an open architecture. This open architecture provides users with access to improvements and upgrades over the long life expectancy of the instrument. The Prefil^® is well engineered for routine measurement and process optimization by shop floor personnel.

Application

The system is based on the filtration of a liquid aluminum sample through a fine porous ceramic filter under strict conditions.

A curve plot of the weight of metal that is filtered as a function of time is obtained as the test result. The result can be observed directly on a computer screen built into the cabinet.

Optionally, the metal residue of the test can be saved and transferred to ABB for metallographic analysis. This complementary analysis provides numbers and identification of inclusions.

Operating Principle

To start, a ready-to-use crucible equipped with a porous filter disc at the bottom is pre-heated and is installed in a pressure chamber. Next, the operator takes a sample of liquid metal using a ladle, pours it in the crucible, then shuts the pressure chamber. Finally, the test is started.

When the metal temperature reaches the specified value for the test, the system applies pressure in the chamber. This pressure forces the liquid metal to flow through the porous filter disc.

Building a database enables the determination of the variation of metal cleanliness that is found at a specific location. This database is used as a reference or comparison, providing a footprint of the process. The results for metal tested at the same location can be compared against the pre-established benchmark as a shop floor quality control.

The Prefil^® software displays this standard on the computer screen at the time of start of a test. As the metal falls in a weigh ladle, the filtration rate is measured, and the curve is graphed on top of the standard.

Prefil^® Database Software

The software enables the user to construct a database of standards and conduct live statistical analysis with any number of curves the user wishes to display on the screen, generate reports, and access the database on a system network.

The user has the possibility to define curve data based on plant, location, filter, practice, alloy, furnace, operator, date, and time. The possibilities are almost unlimited and the data can be easily retrieved.