What Magnetic Separators Should You Use for Dry Bulk Rates?

After taking a bite of fresh chocolate cake, the last thing you want is a mouthful of metal. When tramp metals and contaminants find their way into food products, it’s a disaster for everyone involved. This can result in product recalls, negative press, potential lawsuits, and worst of all, injury to customers. The ability to detect and remove hazardous objects from food products depends on the dry bulk flow rates of the materials being processed. Knowing the flow property of your materials is crucial to the success of your operation. It determines the design of your materials handling system, as well as the magnetic separators used to keep your products pure and safe to consume.

A bulk solid’s “flowability” can change due to a number of factors including: the size and shape of the particle, type of distribution, temperature, storage time, chemical composition, and moisture content. When these variables are altered, common flow problems may occur. No-flow is when a bridge or arch-shaped obstruction prevents a discharge from a silo’s outlet. Erratic flow makes consistent flow impossible, as the obstruction continuously alternates between that of an arch and rat hole. Uncontrolled flow occurs when fine powder turns into liquid form due to not having time to deaerate in the bin. As a result, it ends up flooding the equipment.

Unreliable flow rates can have devastating consequences, such as equipment failure, plant downtime, product loss, uncontrolled retention time, throughput variation, and product nonconformity. Food materials such as flour and sugar are especially vulnerable to blocking, sticking, inconsistent discharge, and other flow problems that can make it difficult for certain magnetic applications to detect hazardous materials. In order to maintain safety and quality-control standards, processors should make flow property testing a top priority.

For 60 years, Bunting Magnetics Co. has tested countless bulk solids in order to recommend magnetic separators that best fit the specific needs of an operation.

Accurately testing the properties of bulk solids is achieved by measuring the cohesive strength, wall friction, compressibility (bulk density), and permeability of the material. After determining the dry bulk rates of the materials being processed, operators are able to choose exactly which system components are best for handling these materials. Maximize the efficiencies of your operation by choosing hoppers, conveying lines, chutes, feeders, vacuum pumps and more in custom sizes and applications. The magnetic separators you choose also depends on the type of material being processed.

Magnetic cartridge drawers are the optimal solution for easy-flowing, dry material like flour, low-abrasive grains, powder, sugar, and salt. These magnet applications are used when the finest of purities are required. Magnetic cartridge drawers separate out the smallest objects (such as ground-up ball bearings) from breads to keep products pure. The configuration of the cartridge trays increases contact with the product stream and are ideal for gravity flow applications.

Plate magnets are also designed for gravity flow applications. However, they are used to handle more abrasive products (like whole kernel corn and popcorn), and products that are slightly prone to bridging (like salt pellets or damp, clumpy powders). Plate magnets are the perfect solution for larger products that have more difficult flow (such as whole grains).

Grate magnets can be easily installed in hoppers, and are often used when space limitations are an issue. Keeping them in an open face application allows the grate magnet to remove tramp metals from larger flowing materials (like fish pellets). However, using a grate magnet with diverters is more beneficial for dry, fine powders (like spices). Grate magnets are ideal for removing tramp metals from inbound materials and product ingredients.

In pneumatic lines, center flow magnets are best used with fine powders. They have more high-energy contact with materials, and are excellent at achieving purity in flours. Inline plate magnets are the choice for products with slightly clumpy flows.

When you have a high-volume product flow, hump magnets are perfect for directing fluffy material (like potato flakes) down a large chute. Hump magnets remove hazardous metals from larger, bulkier products that need higher protection. This application helps prevent build-up and bridging, while protecting your materials against entrapped ferrous metals.

For more information about magnetic separation applications and how they can best serve your operation, please Contact a Bunting Sales Representative and start the conversation. We look forward to hearing from you!