How do they work?
Conveyor belts consist of a continuous loop of belt wrapped around and driven by one or more pulleys (known as drums) and powered by an electric motor. A metal plate bed or rollers normally support the belt from the underside. The pulley that is powered is called the drive pulley, whilst the unpowered is known as an idler pulley.
The frame construction of a standard belt conveyor usually consists of a metal such as powder coated mild steel or stainless steel for example. The belt or conveyor surface belting itself is available in a wide range of materials, such as plastic, leather, rubber, and also coated fabric. Usually the belt is manufactured from several layers of material, the structural or strengthening layer of which is known as a carcass. For example, in fabric coated belts cotton is often used for the carcass, whilst the cover material might be PVC.
Why Are Belt Conveyors Used?
Conveyor systems remain popular due to their time and labor saving benefits. The manual handling of materials reduces when using a conveyor system. As a result, much more efficient transport of large volumes of goods is achieved, allowing for higher volumes to be processed.
The use of conveyors is also space efficient, as less space and personnel is needed to move the items. As a result transporting products between stations in production and processing lines is simple and efficient with a conveyor.
Some industries and businesses may require only part-time or occasional use of a belt conveyor. A landscaping company or builder for example may need to hire a belt conveyor to clear their worksite more efficiently.
The belt conveyor system is also very versatile and can transport a wide range of objects, of all shapes and sizes. It is generally less expensive than other conveyor systems. Conveyor belts are also useful in instances where the use of a roller conveyor system for example would be unsuitable due to items being too light, having irregular bottomed surfaces, or also being too small. Consequently, these items may not move, could slip, or even get stuck in the rollers.
Portable Belt Conveyors
Portable conveyors are useful to aid in loading and unloading vehicles, railcars, and also silos. Packaging facilities also make use of conveyors with casters, allowing for movement required.
Metering Conveyors
This type of conveyor allows for the separation or accumulation of items. Often used prior to sorters and merges in the conveyor system. As the items are separated, then assessed using sensors to determine the items width, or to allow space in between items if a minimum gap is required for the next step of the sorting process.
These metering conveyors must be made with durable components to withstand many stops and starts. The products can also be weighed with the inclusion of a beltweigher into the conveyor system.
Sandwich Belt Conveyors
These differ from the standard design in that it uses two conveyors as opposed to one. These two belts are placed face to face, therefore allowing for the material being transported to be held (or sandwiched) firmly in between them. This allows the material to travel up steep inclines.
Pipe Conveyors
Pipe conveyors have a belt which rolls together to form a tube or pipe. The use of idler rollers around the outside of the belt maintains the circular shape.
A pipe conveyor is desirable for environments where space is extremely limited, or relatively steep inclines or bends are required. They are used in industrial applications where material spillage is undesirable.
If you are interested in a conveyor system from Spaceguard, you can find our belt conveyor products page here. Please feel free to contact the helpful Spaceguard team if you have any questions regarding our products.
Belt Conveyor Specification
The specification of the belt conveyor is normally dependent on the application, industry, and product type. Manufacturers of bespoke and custom belt conveyor systems will ask about what the end usage of the conveyor will be, this is to ensure the conveyor system is built to suit that application. Things you should consider include the maximum load capacity, the conveyor belt system speed, throughput, the frame material or shape, and also drive configuration.
As well as this the type of product or material to be conveyed must be considered. Conveyor belts for the food industry for example must be suitable for washdowns and disinfecting. These conveyors often have a blue belt material, to denote they are washdown suitable which is a requirement of food hygiene laws. The belt surface itself also needs to be resistant to scratches or damage, as that could harbour bacteria.
Another consideration for your belt conveyor supplier is static electricity, as conveyor belts can generate static as they travel around the pulleys. Where static sensitive components need to be conveyed, this could be harmful to the product. A conveyor belt manufactured with anti-static technology, for example conductive belting, or static control brushes solves this problem.
Some items may be sensitive to vibration, pressure, or could be hazardous materials. These should therefore be discussed with the conveyor manufacturer so they can counter risks, thus ensuring the conveyor designed is fit for purpose.
The environment the conveyor will be running in is also important as humidity or temperature can affect operation. Consequently the conveyor needs to meet certain specifications to be able to continue optimal performance.
What About Conveyor Safety?
Conveyor systems have different safety requirements depending on the usage & environment. The belt conveyor manufacturer should ensure that any risks are properly accounted for, and any workplace safety regulations are also adhered to. Industrial belt conveyors should be fitted with start-stop buttons, they can also be set up with remote stops. They can also have belt sway switches, which will stop the conveyor if the belt loses alignment.
If the belt conveyor is moving at a speed other than what has been specified, a speed switch can stop the belt to ensure the users, products, and the belt itself do not become damaged. If the belt however does become damaged, a belt rip switch is triggered. Fitted guards ensure products remain on the conveyor system when moving goods on an incline.
Conveyor systems controls can be as simple as on and off, or soft-starts which cushion loads on start up. Variable frequency drives also control the speed and acceleration of the motors.
History & Facts
- 1892 - Thomas Robins’ inventions led to the development of conveyor belts.
- 1913 - Henry Ford introduced conveyors into the Ford Motor Company factory.
- 1972 - Friedrich Krupp GmbH built the longest conveyor belt system in the world at 61 miles / 98 km.
- 2008 - Siemens installed the longest airport conveyor system at the Dubai International Airport. It measures 39 miles / 63 km.
