Vibratory Conveyors vs Belt Conveyors
Vibrating conveyors and belt conveyors are two of the most commonly used mechanical conveyor systems in the bulk materials handling industries. They are available in numerous configurations and operating modes to process a variety of different materials, capacity rates and transfer distances.
This article will illustrate the main differences between vibratory conveyors and belt conveyors, and also provide advice for selecting the one that would most suit your needs. When deciding between a vibrating conveyor or belt conveyor, it is important to consider some essentials such as how much available space you have, what sort of material you will be transporting and at what rate, the capital cost of the conveyor and how much maintenance will be required in the short and long term.
Standard Belt Conveyor
Belt conveyors are material handling systems that use continuous wide belts and powered pulleys to transport products or material. They are easily the most commonly used conveyor systems due to their versatility and affordability.
Belt conveyors consist of a metal frame with rollers at either end of a flat metal bed. The wide continuous belt is looped around each of the rollers. Belts can be made from nylon, rubber, steel or a combination of different materials. An electrical motor powers the rollers thus allowing the belting to smoothly slide across the metal frame bed which in turn moves the product.
The product is conveyed directly on the belt thus allowing both regular and irregular shaped objects, of varying sizes and weights to be transported effectively over distances exceeding 100m. Belt conveyors are capable of elevating or lowering product up to 20 degrees from horizontal without the use of a specialised belt with ribbing or flights. Regardless of whether the conveyor is moving on a slope or on a level path, the material being conveyed remains stationary on the belt through the entire conveying distance. Average belt speeds reach up to 100m per minute thus allowing capacity rates of up to hundreds of tonnes per hour.
Since belt conveyors do not vibrate, they do not require a vibration isolation system. Some belt conveyors are even able to be operated in reverse depending on the location of the drive pulley. Short conveyors can be started and stopped regularly however stopping a longer conveyor involves applying an external force to aid speeding up the stopping process. Continual stops contribute to electrical complications.
Little to no maintenance is required in the first year of operation, however, more service is required in the following years due to bearing failure, wear and tear of the belt, belt misalignment, belt stretching and debris making their way into the belt conveyor's moving parts.
While belt conveyors have a lower capital cost than vibrating conveyors, they have significantly higher maintenance and operating costs over the long term. Cleaning belt conveyors require a lot more effort and frequency than cleaning a trough. If debris gets stuck between the pulleys and the belt, the belt can travel off track, which is damaging to the belt and can lead to eventual failure of the belt.
A belt conveyor is right for you if:
- You require conveying over very long distances.
- A lower capital cost has a higher priority than the maintenance and long term operating costs of the conveyor.
- You require a high conveying rate.
- Your material does not require sanitary handling .
- You require inclines greater than 5 degrees.
Vibrating conveyors consist of either a mild steel or stainless steel trough typically mounted on a support system with electromechanical or electromagnetic motors that impart a horizontal motion to the trough that moves product forward. The material shuffles along the trough at relatively low speeds, typically ranging from 50mm/s and reaching up to about 500mm/s.
Vibrating conveyors can convey material more than 60m depending on the trough size however, any length exceeding 12m becomes relatively expensive to build. The tensile and compressive forces that the trough is subjected to limits the conveying distance. Vibrating troughs can be designed to handle materials 300 degrees C or higher and can be enclosed with covers to prevent contaminants from entering or leaving.
These conveyors are limited to conveying material at inclines less than 5 degrees from the horizontal and can be either supported or suspended. The drive mechanism can be located either above or below the trough thus allowing the flexibility of placing the trough under other equipment if necessary.
The conveying speed of the vibrating conveyor can be controlled by a variable speed drive system however to avoid structural damage, the conveyor should not be operated in the speed range of the conveyor's natural frequency. Unlike the belt conveyor, the vibrating trough does not require dynamic breaking when quick stops are required, making it more suitable for an application that requires frequent stops and starts.
Vibratory conveyors require less maintenance than belt conveyors as there are no belts and no belt to pulley/gear laminations. This results in a lower total cost of ownership over the life of the conveyor.
The vibrating conveyor is right for you if:
- You need to handle large material flow surges.
- You need to convey at variable speeds.
- Your material requires sanitary handling .
- You require the material to be sealed with covers .
- Your material is wet and/or sticky .
A wide variety of variables, ranging from costs to performance, should be considered when determining the ideal conveyor for each situation.
To calculate the total cost of the conveyor system, begin with the initial capital cost plus installation cost and add the maintenance and sanitation costs over the anticipated life of the equipment. In the long term, vibrating conveyors have a lower total cost whereas belt conveyors have a lower initial capital cost.
The strengths and weaknesses of either conveyor type should be considered and realise that each one excels in different applications.