Conveyor systems for food processing come in all shapes and sizes and can be custom built depending on the type of material that needs to be moved, the available space for the system, and the distances and heights the materials will be transported.

Different processing plants have different conveyor requirements. While one facility may need an incline conveyor, others may need vibratory conveyors. One company may need a cable conveyor or a belt system that only moves products in a horizontal motion. 

For the nut industry, some production companies may have strict requirements for their conveyors, which may include an inspection system that consists of metal detectors and xray inspection. A snack food processing plant may need blending systems for the mixing and blending of different types of nuts. Another nut production plant may work exclusively with almonds, an edible tree nut. The almond processing plant may require a flexible design that moves the almonds through a process conveyor that takes it to be mixed with breakfast cereal. 

In this guide, we will talk about the different types of transfer systems typically used to move nuts like cashews, peanuts, brazil nuts, macadamia nuts, pine nuts, hazelnuts, pistachios, and walnuts. We will also compare the various conveyors to reveal which system works best for nuts.

Common Types of Conveyors Used to Move Nuts

Because the nut industry has unique quality standards, it’s crucial to use the right nut conveyor system to move materials during processing and packaging. Here are the most common types of conveyors used in the nut industry:

Bucket Elevator – A bucket conveyor consists of a series of buckets attached to a belt with pulleys located at the top and bottom of the structure. They are ideal for elevating materials vertically.

Chain Disc Conveyor – Chain disc conveyors enclose materials to keep them safe during transport. They can move materials in any direction and have multiple inlets and discharges.

Vacuum Conveyor – The vacuum conveyor system consists of a product intake, a transport line, vacuum conveyor, and control system. Vacuum conveying works by transferring materials through a network of tubing using suction. The material is sucked through the pipeline and collects in a collection tank.

Pneumatic Conveyor – Pneumatic conveying systems move materials by transmitting a propulsion force of air. The materials travel through enclosed convey lines due to air that is typically generated from a blower, fan, or compressor.

Screw/Auger Conveyor – A screw conveyor or auger conveyor uses a helical screw element that rotates around a central shaft. The material moves up one pitch with every revolution of the steel auger.

Aero-mechanical Conveyor – Aero-mechanical conveyors are often referred to as “rope and disc” conveyors. The system consists of several evenly spaced discs attached to a wire rope. The rope and discs travel at a high speed in a continuous loop within steel tubes. Material moves due to the airstream that is produced by the movement of the rope and discs at high speeds.

Cable and Tubular Drag Conveyor

The cable and tubular drag conveyor system was designed to handle materials gently and maintain food safety by holding materials between the discs with an enclosed tube. Tube nut conveyors feature cable and tube technology that consists of a combination of conveyance tubes with cables and discs attached at set intervals. Materials move through tubular conveyor systems by entering the conveying tube and falling between the cable’s discs, which glide the material gradually without using air or force.

What is the Best Conveyor System for Nuts?

Materials like nuts are fragile and need gentle conveyance to ensure they are not damaged, wasted, or lost during production. If you’re conveying specialty nuts from the roaster to the drying table or from a belt conveyor to a packaging machine, you want to minimize breakage and product degradation to retain the value of the specialty nut.

Companies use all types of conveyors to move nuts. Unfortunately, many don’t realize they have been using the wrong conveyor system until waste from breakage accumulates and the costs of broken nuts pile up. The problems associated with conveyors like bucket elevators, chain-disc conveyors, vacuums, aero-mechanical systems, pneumatic systems, and screw augers aren’t understood until after the conveyor is installed and in use.

For example, bucket elevators are fine until you have to clean out the fines or the nuts’ outer casings from within the bucket elevator. Bucket elevators are especially problematic with nuts like pecans, which undergo a flotation process that separates the pecan meat from its shell. Because the production process involves hydration, wet pecans may end up sticking to the bottoms and sides of the buckets when they are conveyed. And once they dry, you face issues with cleaning the buckets and maintaining sanitary processing environments.

The problem with using vacuums or pneumatic conveyor systems is the high risk of breakage. Vacuums suck the materials while a pneumatic system uses compressed air to blow the materials in the right direction. These systems are great until the nuts have to go around a sweep in the system. Being forced through a bend too quickly can cause the nut to break. Also, these systems force the nuts to come out of the discharge points and encounter gravity, which may cause the nut to become damaged on impact.

Screw augers have also been used to convey nuts; however, screw augers have a tendency to grind up nuts, especially the fragile ones, into small pieces, which results in degradation or wastage. Chain-disc conveyors, on the other hand, were designed to transport materials without degradation or breakage. Unfortunately, these systems have chain links which are heavy and occupy more space in the conveying tube. They’re also not the most cost-effective conveyance options because they use 2-3x more energy.

When it comes to which conveyor system is best for nuts, cable and tubular drag conveyors come out on top because they minimize nut attrition and keep the processing facility clean. Nut material is carried gently without being blown about, forced through sweeps, bumped, battered, or stressed by friction. This minimizes damage and imperfections to the nuts, which lead to diminished value, product loss, or low-quality products.

Enclosed tubular conveyor systems ensure materials stay clean and safe while in transit, keep wastage at a minimum, and keep the facility sanitary and dust-free. The tubular conveyor holds fines safely inside the tube until it is time to unload them during the “return” on the empty side of the conveyor. The problem with using open belt conveyors when carrying nuts from bins, elevators, or sorting stations is that dust from the nuts can escape the belts and end up on the plant’s floor and equipment. This leads to a significant amount of manual labor and housekeeping to clean and sanitize the production floor, which costs time and money.

Conclusion

Nuts are fragile, and nut production companies need a conveyor system that is designed to move materials gently and meets the unique demands of nut processing. Not all food conveyors and process equipment are compatible with the nut industry. Because conveyor systems are a diverse class of machinery, it’s important to understand the different types of nut conveyors before investing in a system for your nut production plant’s processing line. 

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