Choosing the Right Electromagnetic Vibratory Feeders for Processing Applications

The requirement to convey and feed materials is present in almost all industries focused on processing. Regardless of whether it's a state-of-the-art food processing facility or a basic packaging assembly line, unprocessed and partially finished products must be moved between different areas.

Vibratory feeders are versatile machines that can effectively handle a wide variety of products, including fine powders, granular materials, tacky substances, and bulk products. These feeders are ideal for conveying both fine and coarse materials that tend to cake, pack, smear, break apart, or fluidise.

Feeders are also utilised for adding ingredients to mixers and blenders, accurately measuring materials to downstream process equipment, screening out oversized or fine debris from final products, and evenly distributing salt, sugar, and various seasonings.

When placed along a production line, vibratory feeders can measure exact quantities of products from hoppers and gently transfer them onto conveyors or packaging machines. This equipment can also assist in a range of screening processes, including size separation, scalping, removing oversized products and conglomerates, as well as dedusting or removing fine particles.

Vibratory feeders are also well-suited for transporting food groups from storage to processing facilities. For instance, nuts such as pistachios, almonds, or peanuts, which are harvested in large quantities, can be efficiently handled by placing feeders underneath silos to accurately dispense these items downstream into bucket elevators. They can also be incorporated into scale systems at the end of the production line to measure and package nuts.

Numerous design changes and upgrades have enhanced the role of vibratory feeders in processing applications. The latest equipment offers increased energy savings, more precise control over material flow, easier maintenance, a multitude of options and advanced technical support.  

Eriez and other manufacturers are continuously innovating the design of vibratory feeders to meet the evolving needs and regulatory challenges of the food industry. These upgrades are necessary to meet guidelines for Safe Quality Foods (SQF), Good Manufacturing Practices (GMP), and sanitation requirements.

Vibratory feeders perform multiple tasks

There are a number of areas along the processing line where electromagnetic vibratory feeders are utilised, particularly in food manufacturing:

• Feeder models are available for both high-temperature environments, such as baking, and low-temperature environments, such as freezing. These models can operate in ambient temperatures reaching up to 300 degrees Fahrenheit for high-temperature installations and as low as – -20 degrees Fahrenheit for cold installations.
• Vibratory equipment can be easily adapted to include a screening function during the conveying process. This makes it an appropriate choice for screening fine debris and removing oversized materials. Common applications include “scalping,” which involves removing oversized material from the product, and “de-dusting,” which involves removing fines from the product.
• Vibratory feeders are frequently applied in food processing plants to meter materials into downstream processing equipment at a controlled rate. The feeder acts as a bulk metering device, providing materials at an easily adjustable and controllable rate.
• Cleanliness and sanitation are among the significant advantages of using vibratory feeders in the food industry. The straightforward construction of the feeder tray without complex geometric barriers allows for easy and rapid cleaning or washing out of the tray during product changeover.

Choosing the right feeder

The design of each vibratory feeder is unique, with varying amplitude, frequency, and angle of deflection to move different materials at specific rates. Several factors influence the design, including the food material being processed, the flow rate of the process, environmental conditions, the need to start and stop the process, equipment operating costs, and the likelihood of repairs. Therefore, choosing the right feeder for food processing applications is crucial for maximum efficiency.

Feeder units with high amplitude and low frequency are often selected for handling light, bulky, flexible, and fine powdery products, such as cereal, flaky and powdery spices, potato chips, raisins, candy, and more. These units are particularly beneficial for incorporating a screening function into the conveying process.

High-displacement, high-stroke feeders are required for some applications that involve conveying fine, leafy materials such as parsley flakes. These models provide the necessary higher deflection for conveying difficult products, while also offering the same maintenance-free service provided by an electromagnetic feeder.

Low-amplitude, high-frequency feeders are an ideal choice for handling free-flowing materials with a bulk density above 20 pounds per cubic foot, while high-speed feeders are best matched with applications that require fast travel speeds and frequent starts and stops. Feeders placed under a hopper provide a controlled supply of bulk ingredients to blenders, mixers, bucket elevators, and belt conveyors.

Customisable tray designs

Manufacturers offer a wide range of options when it comes to the shape, length, and width of feeder trays, which can be customised to meet the unique requirements of food processing applications. The trays come in various configurations, including flat, curved, v-channel, and tubular designs, and can manufactured with stainless steel to satisfy food safety standards.

Trays with added components like a tray cover or screen deck are designed with quick-release fasteners for easy removal without the use of tools. With the fasteners loosened, the component can be lifted and disconnected from the tray, expediting the cleaning process.

Case Study: California Gold Almonds

Almost 80% of the world’s almonds are produced in California, so it’s not too surprising that California Gold Almonds (CGA) is using state-of-the-art operational procedures and technologically innovate equipment to harvest and handle this increasingly popular cash crop.

Helping CGA maintain efficient processing line as a series of Eriez 66C and 46C electromagnetic feeders installed at both the company’s Tenaya and El Roya processing plants in Modesto, California, part of the lush San Joaquin Valley. The feeders help reduce human touching and handling of the almonds while seamlessly conveying raw almonds to downstream equipment.

The Tenaya and El Roya facilities are a quarter mile from each other, but they serve different customer bases. The 35,000 square-foot Tenaya facility processes almonds for domestic customers while the larger 84,000 square-foot Ely Roya plant satisfies the company’s export business.

Incoming raw almonds at the Tenaya facility fall freely through a series of Eriez Model FF Metal Separators, which are designed to detect all magnetic and non-magnetic metal contamination, even when imbedded in the almonds.

Next, the Eriez 66C and 46C electromagnetic feeders properly convey the precise amount of raw almonds—approximately 12,000 pounds per hour—that eventually pass through an optical sorting line and in the packaging process.

Meanwhile, at the El Roya plant, two Model FF Metal Separators and several rare earth plate and tube magnets help detect and remove contamination from the almonds. This Eriez equipment—along with a series of 66C and 46C electromagnetic feeders—are installed on a main processing line conveying 20,000 pounds of almonds per hour and a secondary line conveying 15,000 pounds per hour.

The Eriez feeders and other vital operational equipment help CGA meet rigid food safety guidelines, especially with the USDA, FDA and the British Retail Consortium (BRC), since the company exports almost half of its total volume to a European customer base, where almonds have always been a food mainstay.

Eriez Video Demonstrates Feeders in Difficult Product Flows

Eriez produced a video showcasing the handling of challenging bulk food materials of varying sizes and shapes by assorted electromagnetic vibratory feeders. The video demonstrates the efficient handling of different bulk materials, including light and airy, smooth, or tacky ones.

Feeder models showcased in the video include Model C and Model HS (High-Speed), both operating at 60 Hz, and Model HD (High Deflection), operating at 30 Hz. These electromagnetic feeders offer excellent feed control of a wide range of dry, bulk materials, from micron size to bulky chunks.

The video highlights various feeder models including the Model C, Model HS (High-Speed), and Model HD (High Deflection), all of which operate at different frequencies (60 Hz and 30 Hz). These electromagnetic feeders provide precise feed control for a broad range of dry, bulk materials, from small micron-sized particles to larger chunks.

The comparison shows that the HD vibratory feeder is the most efficient option for feeding popcorn, with other models taking nearly twice as long to handle the same product. In the next demonstration, flour – another difficult material to feed – flows seamlessly and easily on the HD unit.