Grate Magnet

 

The MPI grate magnet is one of the most versatile magnetic separators in terms of installation options. It can be compact and integrated into existing equipment such as hoppers, chutes, bag dump stations, or bins. Regardless of the installation location, the principle of how magnetic grate separators work remains the same.

 

The product stream typically flows through a single row of 1” diameter magnetic tubes located on 2” centers, allowing 1” space between each tube. The tubes are held in place with a stainless-steel support frame of varying designs as required by the application. As tramp metal contaminants are captured, they move to the underside of the magnetic tubes, eliminating tramp metal “wash-off.” Captured ferrous metal is held on the magnetic tube until removed from the product flow and manually cleaned off by hand or with an MPI hand-cleaning tool.

Options such as a frame at the end of the tubes make the magnetic grids easier to clean, while options such as diverters make them a more efficient magnetic separator but more difficult to clean.

The effectiveness of MPI Grate Magnets is influenced by their design and configuration, including the shape, number of magnetic tiers, the incorporation of diverters, and frame options. Below is a comprehensive breakdown of how each variation affects performance:

 

Shape Variations: Round vs. Square Grate Magnets

Grate Shape	Description	Optimal Use Case
Round Grate Magnet	Features a circular design with magnetic tubes positioned in a radial or grid arrangement, suited for round processing chutes and hoppers.	Ideal for applications where material flows through circular openings, such as pipes, chutes, and cyclones. Common in food, chemical, and plastic processing.
Square Grate Magnet	Designed with a square or rectangular format, typically featuring uniformly spaced magnetic tubes.	Best suited for square or rectangular bins, hoppers, and conveyors, providing maximum coverage in free-flowing material handling.

 

Magnet Designs: With vs. Without Diverters

Design Type	Description	Benefits
With Diverters	Incorporates stainless steel diverters that guide material flow towards the magnetic tubes, ensuring direct contact with the magnetic field.	Enhances metal capture efficiency by minimizing material bypass. Ideal for high-flow applications and finer materials like powders and granules.
Without Diverters	Magnetic tubes are arranged in a standard grid without additional flow-directing features.	Enables unrestricted material flow, reducing clogging risks in bulkier materials. Best suited for free-flowing coarse materials like pellets and large granules.

 

Magnet Configurations: With vs. Without Frames

Configuration	Description	Benefits
With Frame	Magnetic tubes are enclosed in a stainless steel frame for structural integrity and ease of installation.	·       Ensures proper alignment and durability in heavy-duty applications. Facilitates handling and maintenance.
Without Frame	Individual magnetic tubes are utilized without a supporting frame and can be placed directly in hoppers or processing equipment.	Provides flexibility for custom installations. Allows optimal placement of tubes as needed. Best for retrofitting or situations with spatial limitations.

 

Magnetic Tube Arrangements: Single-Tier vs. Two-Tier Grate Magnets

Configuration	Description	Advantages
Single-Tier Grate Magnet	It comprises a single layer of magnetic tubes arranged in a grid, allowing the material to pass over the tubes once.	Ideal for low- to medium-contamination scenarios. Facilitates maximum flow with minimal resistance. Perfect for applications where speed is a priority.
Two-Tier Grate Magnet	Contains two layers of magnetic tubes, with the upper tier offset to enhance contact with contaminants.	Increases metal capture efficiency by promoting interaction with two magnetic fields. Suitable for fine powders or high-contamination situations. Ensures thorough coverage by minimizing material bypass.

 

Selecting the Right MPI Grate Magnet Configuration

Depending on the specific processing environment, material flow characteristics, and contamination levels, choosing between round or square, single-tier or two-tier, framed or unframed, and with or without diverters is important.

• For high-contamination scenarios: A two-tier, framed grate magnet with diverters is optimal for effective metal capture.
• For high-flow bulk handling: A single-tier, non-diverter design may be advantageous to reduce clogging and maintain flow rates.
• For limited spaces or custom setups: Individual magnetic tubes without frames allow flexible placement options.
• For food-grade and sanitary needs, round grate magnets with stainless steel construction and easy-to-clean designs are recommended.