Our metal separation expert Koen Böggemann recently visited a large paper mill in the Netherlands. The company was looking for a solution for removing steel wires from the paper pulp. These steel wires end up in the pulp as a result of incomplete removal of the binding wires that hold the bales of cellulose together. This is done before the cellulose is processed into pulp.
Koen: “As a result of the automated process in combination with the human control there is a chance of steel wire ending up in the paper pulp. This wire is particularly damaging for the equipment used to process the pulp. The result is production downtime, but this can be prevented through the use of a magnet.”
Koen: “We have designed large magnetic filters for such processes, with bore sizes ranging from DN100 to DN400. The inside of the product chute is completely surrounded with very strong magnetic bars with a high flux density (or Gauss value), making it possible to capture the steel wires even at a relatively high flow rate. In addition, the magnetic insert is fitted with a sturdy guide and pneumatic rods, which simplifies handling for operators. This is not only ergonomic but also ensures that regular inspection takes place.”
Koen continues: “It is surprising that magnetic filters are not yet standard in paper lines. This seems to be an under-recognized problem that is often only considered after the first damage incident occurs. The investment for these filters is not small, but the payback time is very short, since the cost of damage or downtime is many times greater than the purchase price of the filter.”
In a nutshell, a magnetic filter removes iron baling wire from paper that is to be processed for cellulose, serves as protection for the installation and prevents downtime of the production process. Several large Dutch paper manufacturers have built a magnetic filter into their process, and producers from Sweden, France and Indonesia have now also sought us out for our expertise. The paper filter is considered a true safeguard!