Major Differences in the Quality of Magnetic Filter Systems
A manufacturer of rolled steel profiles uses approx. 4000 liters of coolant to lubricate and cool the rollers. The cold rolling of steel profiles produces extremely fine metal abrasion, which is generally not captured by conventional belt filters. The particle sizes are usually less than 10 micron. The company initially procured a magnetic filter for a smaller coolant system. However, the performance was not satisfactory.
The Problem
A press report drew the attention of the maintenance manager to the Friess magnetic filter systems. During an on-site meeting, the operator of the system was very skeptical due to the poor results achieved with the magnetic filter used to date. As the poor results achieved there were not compatible with our customers’ previous experience, we checked the magnetic filter used. It turned out that cleaning the magnetic filter was extremely difficult and unnecessarily complicated.
Complicated cleaning of the magnetic filter rods
The dirt had not only accumulated on the cladding tubes, but also on the magnets inside the cladding tubes, making disassembly, cleaning and reassembly very time-consuming.
Weak magnetic field with only 1500 Gauss
As the poor filtration results were not plausible, we measured the performance of the magnets used. This revealed that the magnets only have an extremely low flux density of just 1500 Gauss.
Instead of the relatively expensive, powerful neodymium magnets, inexpensive, simple hard ferrite magnets were used. Although this made the price of the magnetic filter very attractive, the performance was not sufficient.
Solution: Friess magnetic filter FMF 420/3 with magnetic filter rods
After installing the Friess magnetic filter FMF 420/3 with magnetic filter rods with a magnetic flux density of approx. 10800 gauss, the purity of the emulsion was significantly improved.
High magnetic flux density
High magnetic flux density of approx. 10800 gauss.
The dirt is simply wiped off
The dirt on the magnetic filter rods is simply wiped off with the tool supplied.
Result
Within just one week, the Friess magnetic filter FMF 420/3 removed as much dirt from the system as the previous filter did within twelve months.
This clearly shows that the actual magnetic flux density on the outside of the magnetic filter rods is a decisive factor for the performance of the magnetic filter.
Although the high-performance neodymium magnets are significantly more expensive than conventional hard ferrite magnets, these highly efficient filter magnets are clearly the better choice due to their high separation efficiency.
When comparing prices between magnetic filter systems from different manufacturers, the magnetic flux density must always be compared.