How Vibrating Feeders Improve Bulk Material Flow and Process Control

Consistent material flow is fundamental to an efficient production process.

When product leaves a hopper too quickly, too slowly or intermittently, problems can develop throughout the rest of the production line.

Packaging machines may receive inconsistent quantities.

Screens may become overloaded.

Conveyors can experience surges.

Mixing and processing equipment may not receive a predictable supply of material.

An industrial vibrating feeder provides a controlled method of moving bulk material from one process stage to another.

What Is a Vibrating Feeder?

A vibrating feeder uses controlled vibration to move product along a trough.

Instead of relying entirely on gravity or mechanical screws, vibration causes the material to move progressively forward.

The feeder can be installed beneath a:

• Hopper

• Silo

• Storage bin

• Process machine

• Vibrating screen

• Conveyor

• Mixing system

• Production vessel
  

Its purpose is not simply to transport material.

One of its most useful functions is controlling the rate at which material enters the next stage of production.

Spiral Elevators designs industrial vibrating feeders for controlled movement of bulk materials, including conventional trough feeders and enclosed tube-feeder configurations.

Why Use a Vibrating Feeder?

A well-designed vibrating feeder can provide several process advantages.

Controlled material flow

Rather than allowing a hopper to discharge unrestricted quantities of material, a vibrating feeder meters the product into the next process.

Consistent production

A more predictable feed rate can help downstream equipment operate under stable conditions.

Relatively simple conveying mechanism

The material is moved by the vibration of the trough rather than by a screw rotating directly through the product.

Gentle product handling

This can be beneficial for products that could be damaged by aggressive mechanical conveying.

Suitable for many bulk materials

Vibrating feeders can handle powders, granules, pellets, components and many other industrial products when designed correctly.

How Does a Vibrating Feeder Work?

A trough is mounted on a spring system and driven by a vibration source.

Depending on the feeder design, this may consist of vibrator motors or an electromagnetic drive.

The vibration creates a controlled movement that repeatedly lifts and advances the product along the trough.

The resulting material movement depends on several interacting factors:

• Frequency

• Amplitude

• Trough angle

• Spring characteristics

• Motor configuration

• Material properties

• Feed depth

• Machine geometry
  

This is why two materials can behave very differently on the same feeder.

Vibrating Feeders for Powders

Powders can be difficult to feed consistently.

Some powders flow freely.

Others may:

• Bridge

• Compact

• Aerate

• Become cohesive

• Absorb moisture

• Form lumps

• Rat-hole in a hopper
  

A feeder therefore needs to be considered alongside the design of the hopper above it.

If the product cannot leave the hopper consistently, the feeder cannot produce a consistent downstream flow.

What Is Hopper Bridging?

Bridging occurs when material forms a stable arch above the hopper outlet.

Material underneath the bridge leaves the hopper, but the remaining product no longer falls into the outlet.

Production can then stop even though the hopper still contains material.

Vibration can be used as part of a properly designed solution to disturb cohesive material and maintain flow.

Spiral Elevators also produces vibratory hopper-discharge systems intended to improve flow and help reduce bridging and rat-holing.

What Is Rat-Holing?

Rat-holing occurs when material flows through a narrow central channel while product around the outside remains stationary.

This reduces the effective capacity of the hopper and can cause inconsistent discharge.

It is particularly troublesome with cohesive powders and materials that compact during storage.

The solution may involve changes to:

• Hopper geometry

• Outlet size

• Surface finish

• Vibration

• Agitation

• Feeder design
  

There is rarely one universal solution because bulk solids behave differently.

Vibrating Feeders for Granules and Pellets

Granular products usually have better flow characteristics than cohesive powders, but control is still important.

A vibrating feeder can deliver granules progressively to equipment including:

• Packaging machines

• Weighing systems

• Screens

• Elevators

• Conveyors

• Mixers

• Processing machinery
  

Applications may involve plastics, food products, chemicals, pet food, fertiliser, recycled materials and many other bulk solids.

Open Trough or Enclosed Vibrating Tube Feeder?

Traditional vibrating feeders frequently use an open trough.

This makes the product easy to inspect and can simplify cleaning and maintenance.

However, an enclosed feeder may be preferable when dust containment or product isolation is important.

A vibrating tube feeder moves the material through an enclosed tube while maintaining controlled vibratory conveying.

Spiral Elevators' tube feeders are designed for enclosed bulk-material transport and can be used where dust-controlled conveying of fine or sensitive products is required.

Vibrating Feeder or Screw Feeder?

Both systems can move bulk materials, but they operate differently.

A screw feeder uses a rotating screw or auger inside a trough or tube.

A vibrating feeder moves the supporting trough itself.

A screw may be useful where positive displacement or a contained mechanical feeding action is required.

A vibrating feeder can be attractive where gentle handling, simple product contact geometry or controlled vibratory movement is preferred.

The best choice depends on:

• Product characteristics

• Required accuracy

• Feed rate

• Hygiene requirements

• Product degradation

• Space

• Maintenance requirements

• Downstream process
  

Vibrating Feeder or Belt Feeder?

A belt feeder carries material on a continuously moving belt.

It can be useful for high throughput and certain heavier materials.

A vibrating feeder instead uses vibratory movement and can offer compact integration under hoppers and process equipment.

Again, the application should determine the equipment.

Electromagnetic Dosing Feeders

Where particularly fine feed-rate control is needed, an electromagnetic feeder may be suitable.

Electromagnetic feeders create vibration using an electromagnetic drive rather than rotating vibrator motors.

The feed rate can be changed quickly by adjusting the drive control.

They can be useful for dosing powders and granules into:

• Packaging equipment

• Weighing systems

• Mixers

• Processing machines

• Batching systems
  

Spiral Elevators' electromagnetic dosing feeders are designed for controlled and repeatable material feeding from hoppers, bins and silos.

Common Vibrating Feeder Problems

If a vibrating feeder is not performing correctly, the symptoms can provide useful clues.

Product is not moving

Possible causes include insufficient vibration, mechanical restriction, incorrect machine setup or product build-up.

Feed rate is inconsistent

Check the hopper discharge as well as the feeder.

Bridging in the hopper can cause intermittent feeding even when the feeder itself is operating correctly.

Excessive vibration

Check the motor settings, spring system, mounting condition and machine structure.

Feeder suddenly becomes noisy

Loose fasteners, damaged springs, structural contact or mechanical wear should be investigated.

Material moves to one side

Uneven loading, machine alignment or drive configuration may be contributing.

Information Needed to Specify a Vibrating Feeder

Before requesting a feeder quotation, try to collect the following information:

• Material name

• Bulk density

• Particle size

• Required throughput

• Product temperature

• Moisture content

• Feed source

• Required discharge point

• Available dimensions

• Construction material

• Hygiene requirements

• Electrical supply

• Dust-containment requirements
  

Providing this information allows the feeder to be designed around the application rather than selecting equipment purely from overall dimensions.

Designed Around Your Material

The most important part of any vibrating feeder application is the product being handled.

A machine carrying dry plastic pellets may require a very different design from one feeding sticky food ingredients or fine chemical powder.

The objective is to create controlled, repeatable movement without creating unnecessary complexity.

Spiral Elevators designs and manufactures bespoke vibratory conveying and handling equipment in the UK for food, pharmaceutical and industrial applications.

Looking for a vibrating feeder?

Send Spiral Elevators details of your product, required throughput and process layout and we can discuss a suitable industrial vibrating feeder, vibrating tube feeder or dosing system for the application.