Vibratory Conveyors

Chapter 1: What Are Vibratory Conveyors? How Do They Function? What Factors Should Be Considered When Selecting Them?

Vibratory conveyors are material-handling equipment used to transport fine to coarse-grained bulk materials. These vibratory conveyors are strong conveying equipment utilized for bulk commodities with fine to coarse graininess. If the materials are transported horizontally, they are easily and efficiently transported. The suspension design is the only constraint. High conveyance rates are especially evident when directly contrasted with conveyor belts, which, when utilized in silos, block with the same material pressure or degrade too soon. Vibrating conveyors are resistant to congestion or blockages in the conveyor channel. In most cases, they resume working freely and unhindered. When organizing the design, it is important to remember that they operate most effectively in horizontal or incline orientation.

A vibratory conveyor features an accumulation track, which can be either linear or gravity-based, to guide materials and reduce vibrations. Drive units such as pneumatic, electromagnetic, or piezoelectric motors create the required rotation, force, and vibrations for efficient material movement.

The transport trough, or platform, is the primary component of a vibratory conveyor's design. It moves materials through precisely controlled linear vibrations that make the materials bounce, hop, and move. Travel speeds, which can range from a few feet per minute to over 100 feet (30 meters) per minute, are regulated by adjusting the frequency, amplitude, and slope angle of the vibrations.

Just as orifices or valves regulate fluid flow, different vibratory conveyors can control material flow. These conveyors feature frames with soft springs to dampen vibrations, allowing them to deliver bulk materials at a consistent rate, with capacities ranging from a few pounds to several tons per hour. Vibratory feeders are advantageous because they prevent bridging, which can impede processes and material flow. Their free-flow design minimizes bridging caused by friction. They achieve a smooth and uniform flow through direct force, which applies force directly to the deck, and indirect force, which relies on resonant or natural frequency.

Working Principle of Vibratory Conveyors

As the name implies, a vibratory conveyor is a mechanical device that utilizes vibration to transport and position materials along production lines. Electromagnets generate these vibrations, converting electromagnetic field energy into mechanical vibrations. These vibrations are then used to propel components down the production line. The conveyor features a fixed magnetic coil situated beneath it, which is magnetized by an external power source to produce the necessary electromagnetic actuation. This actuation causes the conveyor to move vertically due to the springs that mount it. Typically, 1 to 6 electromagnets are installed beneath the feeder base. The electromagnetic vibrations are converted into mechanical vibrations, which then move the components onto the bowl conveying rails for further production.

Considerations When Choosing Vibratory Conveyors

• Establish the span the aggregate must cross, the ideal width, and the required vibration to move the material. For instance, a broader trough and a larger drive are needed to transport rocks long distances. These concepts help one decide what vibrating conveyor will work best for their project and the appropriate drive and power requirements.
• To describe the appropriate load capacity and pieces per minute, the user must understand what the conveyor will move, how much must be transported, and at what pace. Using these numbers, the supplier can determine the ideal conveyor's approximate size, shape, and duty rating. If the user needs clarification of these numbers, the supplier can assist in figuring out the appropriate capacity and speed for that particular application.
• Control and special considerations: These conveyors are normally low-maintenance and passive, but can incorporate control if they are a part of a larger control system. Numerous passive options are effective if control is not required. Determine any additional specifications, such as those for foundational damping, containment/sterile components, or hazard protection. The supplier should share these factors with the provider and any other significant party to guide the client towards the best solutions.

Characteristics of a Vibratory Conveyor

• It is simple to regulate the discharge capacity. For example, using an inverter, the user may regulate the discharge capacity (in tons/hour).
• Vibratory conveyors are useful for moving various materials, including powder, granules, blocks, and other types.
• A vibration feeder has low maintenance costs and minimal wear-related characteristics.
• A vibratory conveyor can be utilized in unique circumstances. The vibrating feeder can be fitted with a dust cover, liner plate, sealing portion, etc., depending on the applicable operating conditions.
• Vibratory conveyors provide dependable operation and smooth vibration.
• A vibratory conveyor’s unique grid layout can avoid material blockage and the spacing between grids can be altered.
• Frequency converter motors are optional; you can alter the capacity by changing the frequency of the motor, making it simple to regulate the feeding rate without often starting the motor.

Chapter 2: What Are the Different Types of Vibratory Conveyors?

Standard-Duty Vibratory Conveyors

Standard-duty vibrating conveyors are engineered for handling medium-to-light-density materials like plastics, wood, and porous rock. They can be designed to be portable and modular, with capacities ranging from 1 to 40 tons per hour and speeds up to 60 feet per minute. These conveyors provide a reliable and safe solution for transporting aggregate and are known for their durability and minimal wear. They are commonly used in industries such as polymer manufacturing, chemical processing, and food production, among others.

Base-Balanced Vibratory Conveyors

Base-balanced vibrating conveyors feature a robust frame that is isolated from the primary support structure and operates near resonant frequencies. This design allows them to be installed on less durable structures compared to unbalanced conveyors. The heavier frame helps minimize the reaction forces generated by the dynamic movement of the conveyor trough, thereby reducing the transfer of motion to the surrounding building.

The conveyor trough is connected to the frame using an eccentric drive connection installed on a shaft and driven by a belt. The springs used to fasten the trough to the frame are commonly made of fiberglass or coil. Conveyors are set to run at a particular speed using a number of springs, and the eccentric drive connection regulates the amount of throw. In addition, the conveyor's power requirements are decreased thanks to an elastomeric coupling between the eccentric (an electrically-mounted wheel or disk) and the trough, shielding the connection between the two from severe loads that could lead to failure.

Base-balanced vibratory conveyors are typically limited to lengths of around 40 feet because longer lengths can cause the frame to resonate at higher frequencies. Despite this limitation, they are effective for applications such as fluidizing, dewatering, classifying, and screening.

This conveyor requires regular bearing lubrication, belt inspection, and overall unit checks. Base-balanced vibratory conveyors are used in both industrial and sanitary environments.

Unbalanced Vibratory Conveyors

Unbalanced vibratory conveyors are designed to be earth-grounded and are typically used near sources of resonant frequency. Due to the vibrations they produce, these conveyors must be securely mounted to a robust structure, often a thick concrete slab provided by the customer, to handle the reaction forces generated by the dynamic motion of the conveyor trough.

The trough is mounted to the anchored frame using several springs, typically made of fiberglass or coil. An eccentric drive connection, which is belt-driven and shaft-mounted, operates the conveyor trough. The conveyor speed is determined by the number of springs, while the eccentric drive controls the throw distance. Additionally, an elastomeric coupling between the eccentric drive and the trough reduces power requirements and protects the connection from severe loads that could cause failure.

Unbalanced vibratory conveyors can extend beyond 100 feet in length if a suitable mounting structure is provided. These gadgets are helpful for fluidizing, dewatering, classifying, and screening. This conveyor requires periodic bearing lubrication, belt inspection, and overall unit inspection. Industrial applications often employ unbalanced vibratory conveyors.

Dynamically-Balanced Vibratory Conveyors

Dynamically balanced vibrating conveyors feature an evenly distributed mass that operates close to the resonant frequency. Unlike unbalanced designs, this allows them to be installed on less durable structures. Their heavier frame helps to minimize the reaction forces generated by the dynamic motion of the conveyor trough, and the reduced frame movement is effectively isolated from nearby buildings.

The conveyor trough is attached to the frame using an eccentric drive connection mounted on a shaft and powered by a belt. Springs, typically made of fiberglass or coil, secure the trough to the frame. The conveyor's operating speed is adjusted by varying the number of springs, while the eccentric drive connection controls the throw distance. An elastomeric coupling between the eccentric drive and the trough reduces power requirements and protects the connection from severe loads that could cause failure.

Base-balanced vibratory conveyors are typically limited to lengths of around 40 feet, as longer lengths can cause the frame to resonate at higher frequencies. Despite this limitation, they are effective for applications such as fluidizing, dewatering, classifying, and screening.

This conveyor needs regular bearing lubrication, belt inspections, and overall unit maintenance.

Base-balanced vibratory conveyors are used in both industrial and sanitary environments.

Feeder Vibratory Conveyors

The feeder-style vibrating conveyor is the simplest type of vibrating conveyor. It operates on brute force without the need for tuning and has minimal external working components. Brute force-style vibratory feeders are available for both sanitary and commercial applications. Typically, trough lengths are 12 feet or shorter, and these conveyors are used for controlled feeding from a storage vessel positioned above the unit. The trough width can range from 4 inches to several feet, with sizes selected based on the specific application.

This type of vibratory conveyor is powered by dual eccentric motors connected to the conveying trough. The motors are mounted in parallel and coupled to the trough at a precise pitch angle to ensure motion is directed only along the conveying path. Additionally, coil spring isolators support the trough to minimize vibration transfer to the conveyor’s supporting structure.

The product flow velocity along the conveyor trough can be adjusted with a variable-frequency drive, which controls the speed of the eccentric motors and regulates the amount of product delivered to the next stage. By adjusting the eccentric weight force on the motors, users can modify the conveyor’s maximum throw distance. Additionally, users can control the rate at which materials are fed into their process line from hoppers or overhead bins. Flow rates can be adjusted manually or automatically, ranging from 0 to 60 feet per minute.

These conveyors are known for their exceptional sanitation, safety, reliability, and affordability due to their simple design and operation. Their construction minimizes cracks and crevices where dirt could accumulate, making cleaning easier. Standard sealed exciter motors are permanently lubricated, requiring only occasional inspections to ensure they meet design specifications. Additionally, this conveyor type can be configured as a shaking table to level products in containers before sealing.

Coil spring isolators support these brute-force feeder-style conveyors to reduce residual vibration transmitted to nearby support structures. Depending on customer requirements, coil spring isolators can be mounted either above or below the conveyor.

Centrifugal Vibratory Conveyors

Centrifugal vibratory conveyors, also called rotary feeders, feature a revolving bowl that propels pieces outward. They have bowl-shaped walls enclosing a conical, centrally powered rotor. Rotational force separates parts and components as the feeder spins. The rotating components are pushed and dragged toward the bowl's outside rim as they rotate quickly.

Centrifugal feeder systems are employed in industries such as food processing, pharmaceuticals, and medical supplies to handle small, irregularly shaped parts that require rapid processing. These systems can efficiently sort and orient components, regardless of their size and shape, at speeds of up to 3,000 parts per minute.

Natural-Frequency Vibratory Conveyors

Natural-frequency vibratory feeders, also known as "tuned" or "resonant" feeders, use two or more spring-connected masses. The most common configuration is the two-mass system, where the response or excitation mass is separate from the trough mass. These feeders leverage the natural magnification of oscillations when operated near their natural frequency or resonance. This allows them to generate the required vibratory forces with minimal input. Additionally, rotating electromagnets or eccentric weights are used to produce the vibratory force.

The damping capability of the bulk material is more critical than the material's weight or load. Damping refers to the material's ability to absorb energy, which reduces the amplitude of oscillations. For instance, granular and powdered materials dissipate energy through intergranular friction and deformation when they are vibrated.

Vibratory feeders are categorized based on their interaction with supporting structures and foundations. When selecting a vibratory feeder, it's important to consider the rigidity of the structure and the permissible stresses it can handle.

Oscillating Conveyors

Some conveyor manufacturers categorize their products as oscillating conveyors, which are a specific type of vibrating conveyor. Oscillating conveyors operate at a lower frequency and with a larger amplitude compared to other vibrating conveyors. This makes them suitable for transporting bulk materials in industries such as waste management, recycling, and timber. For example, they can be used to move wood waste from an upstream system to a discharge point. Compared to vibrating conveyors, oscillating conveyors provide a gentler material movement due to their lower frequency and higher amplitude. In quarrying, oscillating conveyors are also known as jump conveyors, and in hard rock mining, they are referred to as grasshopper conveyors.

Heavy-Duty Vibratory Conveyors

Heavy-duty vibratory conveyors are designed to handle large, heavy materials such as rock, metal, and bulk quantities of cumbersome products, requiring substantial power and speed. These conveyors are typically installed units with capacities exceeding 500 tons per hour and speeds up to 90 feet per minute. They are supported by foundation elements including dampers, dashpots, and stands. Heavy-duty vibratory conveyors are usually powered by motors that provide more power compared to those used in standard-duty conveyors. They are employed in large-scale industries such as foundries, industrial manufacturing, lumber, and rubber processing.

Brute-Force Vibratory Feeders

A brute-force vibratory feeder is referred to as a single-mass system because its vibratory drive is directly coupled to the trough assembly. These feeders are typically used in heavy-duty applications. While electromagnetic drive systems are available, electromechanical drives are more common. Brute-force feeders generate oscillating forces by rotating a large centrifugal counterweight. They feature the simplest design among vibratory feeders but have limited feed-rate regulation and range, as they are designed for constant-rate feeding. Feed rate adjustments can be made by changing the trough slope, aperture, counterweight quantity, and stroke length. Since the trough stroke is only slightly affected by the motor's speed, variable-speed drives are rarely used, and tuning the motor speed is not necessary for brute-force feeders.

Leading Manufacturers and Suppliers

Chapter 3: What Are the Advantages, Disadvantages, Applications, and Maintenance Requirements of Vibratory Conveyors?

Advantages of Vibratory Conveyors

• Regulating the flow of material for spreading across inspection belts or filling containers: The same time-saving benefits of easy cleanup and reduced wear is also present in a vibratory conveyor, which also uses an electromagnetic drive to control material flow. This flow control is very helpful in recycling when trying to control flow or fill a container to a specific weight. Instantaneous stop/start control and the flexibility to slow down or speed up product flow enable adaptability in feeding various materials, as is frequently the case with recycling processes. In addition, these features enable accuracy in precision-filling applications.
• Dewatering and size-based material separation are typically required to distinguish between waste and recyclable materials. A linear vibratory screen effectively separates material by size while feeding it into the conveyor. To police the material and separate the useful product from anything that needs further processing, this is frequently used to separate dust from useful materials or eliminate large parts from the bulk product. In addition, a dewatering screen is used to tackle the issue of liquid residue in bottle cases, especially glass or plastic cases. Vibrating machinery can separate the liquid from the material by running the glass or plastic over a screen. The liquid drains out to a designated area, and the material flows onward for additional processing or into a container. This approach is practical and efficient, and attention has been paid to the vibrating screens' design to make cleanup simple.
• One of the most frequent requirements in the recycling sector is the effective movement of materials and transportation of those resources between two places. A vibratory conveyor is powered by dual vibrator motor drives and is an effective high-volume conveying solution with little power usage. Since there are no spots where material could become stranded, and the conveying trough does not rapidly wear out, vibrating conveyors do not need routine maintenance as belt conveyors do. Additionally, cleaning up is simple, cutting down on wasted time in this field that values efficiency.
• Compressing materials to smooth out peaks and fill can be challenging when filling bulk bags or IBC (intermediate bulk containers) containers with recycled plastic, glass, or metal materials. The uneven portions can start to "cone" and form a peak at the top and frequently stack on top of one another rather than spreading out to the container's corners. A vibrating table can compact the material, promoting a movement towards the container's corners and leveling out the peaked material at the top of the bag. This vibration will ensure filling capacity and bag stability. In addition, low-level vibratory tables are close to the ground. Therefore, they can be made to fit already-existing filling setups because container-filling problems are typically discovered before hopper additions.
• Vibratory containers have no moving parts and are simple to clean. Due to their lack of moving parts, vibratory conveyors are easier to clean and require less maintenance than other mechanical conveyors.
• Vibratory conveyors feature horsepower requirements that are energy efficient. Vibrating conveyors only need a little horsepower to transport goods. Lower horsepower results in improved energy efficiency and lower running expenses.
• Super-quiet operation: A further advantage of the low horsepower is the operation's resulting low noise level, which frequently ranges between 60 and 75 A-weighted decibels (dBA).
• Vibratory conveyors feature a strong and maintenance-free design. The robust design enables continuous operation while guarding against spills and leaks that would otherwise need repair and downtime.
• There is less need for spare components with vibratory conveyors than with other conveyors.
• Vibratory conveyors usually require little energy use (as low as 14p per hour).
• Vibratory conveyors’ efficiency leads to increased productivity.
• Vibratory conveyors include gentle-start possibilities.
• Vibratory conveyors are programmable with a PLC interface.
• Vibratory conveyors offer choices for variable speeds that provide complete control of processing rates.

Disadvantages of Vibratory Conveyors

• Vibratory conveyors are an expensive investment.
• Vibratory conveyors can create “excessive” noise; sound-reduction devices are available at an additional expense.
• One must carefully study which vibratory conveyor is most suitable for their specific application.

Industries Where Vibratory Conveyors are Utilized

• There are several applications for vibratory conveyors in the agriculture sector. First, they are employed in procedures that prepare vegetables, fruits, and other agricultural products for packaging and shipment to retailers or other processing facilities. In addition, these conveyors are successfully utilized to load large parcels of agricultural products into vehicles so they can be delivered to their intended location. Additionally, vibratory conveyors help process, dry, and store agricultural products very effectively. Vibratory conveyors are used for feeding livestock and moving and processing sugar, tobacco, fertilizer, and fruits. These conveyor belts reduce an agricultural-based facility’s workforce and help decrease operating costs.
• These belts make it simple to synchronize agricultural procedures. They handle the methodical materials expertly and produce great turnaround time. These agricultural conveyor belts are created specifically to meet the demands of the industry. As a result, they are both efficient and cost-effective. In addition, they are capable of adapting to any temperature. As a result, various conveyor belts are employed in agricultural applications.

  

  
  
• Mining Industry: Through various phases of the mining cycle, ores, concentrates, and tailings are transported using vibratory conveyors. Vibratory conveyors move commodities to stockpiles and ore to feed processing facilities. Depending on the type of mine, conveyors can run for short distances or long distances, such as those used for deep mines or underground activities. The material to be carried and the needed capacity, among other things, affect the vibratory conveyor belts' width. Carry-back and spillage of material, noise, and vibration are a few issues associated with vibratory conveyor systems in mining applications. One must maintain these conveyor systems for mining operations to be highly efficient, effective, and productive.

  

  
  
• Chemical Industry: Vibratory conveyors transport fertilizers and chemical powders to make different products like detergents.
• Food Industry: The use of vibratory conveyors in the food sector is always significant since they impact how quickly items are transported for cooking. Different conveyor belts are needed for different foods, such as confectionery, baking, dough processing, meat, poultry processing, etc., to transport them from one location to another more effectively and efficiently. In addition, conveyor belts need to be cleaned and sterilized since they come into direct contact with the food that needs to be conveyed. Therefore, always keep a vibratory conveyor’s ability to be easily cleaned in mind when selecting the appropriate conveyor belt within the food industry to ensure that the food's quality is maintained and that there are no losses from contamination. The food industry has always been known for its high standards of quality. Thus, it is important to take great care and precaution when selecting any equipment used in producing or near food.

Maintenance Tips for Vibratory Conveyors

• Constant vibration can occasionally cause bolts to become loose in places where they clearly shouldn't be, which could mean they need to be held to the proper tolerances.
• Valuable energy is being wasted on making rattling noises rather than driving parts when vibrations occur.
• Vibrations cause bowl components that would otherwise be fixed together to rub against each other, causing premature wear and tear.Ensure the system is secure on the surface: A vibratory feeder is designed to function on a level surface, most frequently a heavy weldment or floor. Therefore, ensure the system is level and evenly secured to the floor/weldment. In addition, check that each leveling foot on the feed system support structure is firmly and evenly contacting the ground, if it has any contact. To get the best performance, leveling feet should be adjusted to bring the system as close to level as feasible.
• Check the tightness of each bolt on the vibratory feeder: Test each bolt for tightness; start at the feeder bowls and vibratory inline drive units to ensure that the feed system is locked together as intended.
• The vibratory conveyor should be equipped with electrical protection measures.
• Check the anchor bolts at least once daily during the equipment's initial operation to prevent loosening.
• Replace the lithium-based grease and oil the motor thoroughly every two weeks. Add the required amount of lithium-based grease through the oil cup while refueling. An oil cup is not included on the motor when employing sealed bearings.
• Grease nipples are present on the running parts, such as the bearing seat and tie rod bearing seat. Therefore, each operating shift should include the injection of lithium- or calcium-based grease to ensure lubrication and normal operation of the moving parts.
• The vibration conveyor should have its bearings checked after 1500 hours of operation, and if there is substantial damage, it should be changed immediately.
• When an operator notices an anomaly in their work, they should check and stop as soon as possible to fix the problem.

Leading Manufacturers and Suppliers