Magnetic Separation
Magnetic separators are particularly effective for applications aimed at extracting ferrous and certain stainless-steel contaminants before food products pass through metal detectors. The magnetic separation industry continuously evolves to meet customer demands, with companies like Eriez® advancing their products through state-of-the-art material sciences, engineering developments, and manufacturing processes.
Eriez commissioned The Pennsylvania State University (Penn State) to study the effectiveness of commercial tube magnets in removing dangerous ferrous metals and weakly magnetic contaminants from process flows. Penn State, Behrend College, tested thirteen unbranded tube magnets from various suppliers, concluding that Eriez’ Xtreme® RE7 Tube Circuit had substantially stronger pull force and magnetic flux density than any of the other samples tested. (For the full Penn State performance report, visit here.)
The RE7 magnet circuit is now incorporated into tube magnets, grate magnets, and liquid line trap-style magnets. These advancements increase product purity and plant productivity, using a balance of high gauss and high pull force to influence tramp metal trajectory and retain particulates, even during wash-off processes.
Metal Detection
Metal detectors are essential for inspecting both raw materials and finished goods. Magnetic traps are especially effective for removing tramp iron contaminants in liquid line applications. Many confectionery companies, for instance, install a series of liquid line B-Traps or dry pneumatic RF cartridge magnets at their processing facility entrances to ensure that contaminants do not enter their plants.
Magnetic separation and metal detection equipment should ideally be used throughout the entire food processing flow, especially at the start. While some companies focus on detecting contaminants in final packaging, monitoring the process from the beginning greatly enhances purity and safety.
Plant operators cannot simply assume that every supplier is sending contamination-free products, as there are multiple opportunities for contaminants to enter during transport and handling. Metal could come from the walls of a railcar, or a fastener, nut, or bolt may fall from a truck, even from the clamps in the factory. Such contamination events are more common than anticipated.
Today’s metal detection products combine precise mechanical design with advanced electronics, multiple frequency ranges, vibration immunity, and sophisticated algorithms to detect the smallest metals in challenging products. Designed to withstand harsh wash-down environments, industrial metal detectors are essential for the most demanding applications, often exposed to intense temperatures and high-pressure environments.
In a survey, field representatives and food processors highlighted key requirements for modern metal detection systems:
- Systems must function reliably in extreme low and high temperatures and withstand high-pressure washdowns.
- Contamination monitoring, record keeping, and sophisticated electronics are crucial in avoiding costly recalls.
- Food processors seek the ability to detect the smallest contaminants possible while minimizing false rejects.
Driven by government regulations, companies are developing policies, procedures, and protocols to guarantee food safety. New metal detection systems can locate smaller metal contaminants than their predecessors, even in difficult applications.
