Inline Magnet Benefits and Drawbacks

Inline magnets are popular for a good reason—these versatile, non-obstructive magnetic separators are used to capture tramp ferrous metal contamination in many different applications, including food processing and plastics. This blog will go over the different designs of inline magnets, as well as their key advantages and disadvantages.

Inline Magnet Models

Inline magnets are designed to facilitate easy installation, and quickly connect into pipelines with diameters between 50mm and 250mm. Within the inline magnet, there is a plate magnet mounted on one side of the internal tube that attracts ferrous metal contamination and holds it to its surface. To perform scheduled maintenance, the hinged plate magnet is unfastened, removed from the product stream, and cleaned.

Within the inline magnet, the plate magnet can be constructed with either ceramic ferrite or neodymium rare earth magnets. Ceramic ferrite magnets are able to produce a deep magnetic field, but they are not as powerful as neodymium rare earth magnets. Similarly, neodymium magnets are much stronger than ceramic ferrite magnets, but produce a shallower field. The nature of the ferrous metal contamination being handled determines what type of magnet should be used in the application.

Two designs of inline magnets have construction featuring a plate magnet: gravity inline magnets (GIM) and pneumatic inline magnets (PIM).

Benefits and Drawbacks of Inline Magnets

Because inline magnets are highly versatile, they are used across a wide range of industries, including food processing, plastics, ceramics, recycling, mineral processing, chemicals, and bulk handling. However, an inline magnet will not be the ideal choice for every metal separation application. When you consult a Bunting engineer about using an inline magnet for a specific application, they will be able to advise you on specific benefits and drawbacks related to your unique application.

Benefits of the Inline Magnet

Limited restriction to product flow: Because a plate magnet is mounted on one side of the inline magnet, product flow is unimpeded. This significantly reduces the risk of blockage.

Deep magnetic field: Ceramic ferrite magnets produce a deep magnetic field that reaches across the product flow, with enough power to drag ferrous metal into the magnet’s capture zone. Once material comes into contact with the magnet’s face, it will be securely held in place until it is manually removed.

Securing held ferrous metal contamination: Both the ceramic ferrite and neodymium rare earth models of inline magnets produce a strong magnetic field that ensures captured ferrous will remain firmly held to the magnet’s face, and will not be knocked off by product flow.

Easy cleaning: When maintenance occurs, the hinged plate magnet is disconnected from the pipe. Then, captured ferrous metal is manually removed from its surface.

Installation: Inline magnets have a wide range of pipe diameters and pipe adapters to suit any process, making them easy to install in new and existing process lines.

Drawbacks of the Inline Magnet

Internal pipe diameter: All plate magnets have limits to the depths of their magnetic fields. As a result, the maximum diameter of an internal pipe is nominally 250mm for the ceramic ferrite magnet—and lower for the neodymium rare earth magnet option.

Manual cleaning: Captured ferrous metal is periodically cleaned off a plate magnet’s surface. This cleaning occurs manually, typically on a designated schedule. For certain applications, magnetic separators that provide automatic, continuous ferrous metal separation and removal (such as the Drum Magnet) may be desired instead. However, inline magnets tend to integrate more seamlessly with existing processes.

Non-ferrous metal: Magnetic separators are only capable of capturing magnetically susceptible metals, including ferrous metals, magnetic stainless steel, and some work-hardened stainless steel. For detecting non-ferrous metals, we suggest using a metal detector such as the pTRON.

The selection of a magnetic separator or metal detector for any application depends on the installation and separation objective. Bunting’s applications engineers use years of experience to recommend the optimum solution for any metal-contamination problem.

Consult with a Bunting Engineer