In any equipment production line, whether it is the transport of materials or workpieces, conveyors are used, and different conveyors are generally chosen according to the objects to be transported. A conveyor is a material handling machine that continuously conveys material in a certain line, also known as a continuous conveyor. Conveyors can be used for horizontal and inclined conveying, and can also form spatial conveying lines, which are generally fixed. Conveyors have a large conveying capacity, and long transport distances and can also be used to complete several process operations in the process of conveying.
In practice, it can be used as a single conveyor or as a horizontal or inclined conveying system with other conveying equipment to meet the needs of different process arrangements.
Classification of conveyors
Classification according to movement mode
Belt conveyors
The belt conveyor consists of a drive unit, a tensioning device, a conveyor belt intermediate frame, and rollers. The conveyor belt is used as a traction and load-bearing component for the continuous transport of bulk materials or finished goods. A belt conveyor is a friction-driven machine that continuously transports materials. Its application allows the material to be conveyed in a certain line, The application of this system allows the material to be conveyed continuously on a line from the initial supply point to the final discharge point. It is possible to convey both loose and broken materials.
The conveyor can be used for both loose and fragmented materials as well as for the conveying of parts. In addition to pure material handling, it can also be in conjunction with the requirements of the production processes of various industrial enterprises. The belt conveyors can be used in a rhythmic flow line. This is why belt conveyors are widely used in modern industrial and mining enterprises
The belt conveyor is generally composed of a conveyor belt, rollers, drive, brake, tensioning, redirection, loading, unloading, cleaning, and other devices.
a. Conveyor belts
There are two types of conveyor belts in common use: rubber belts and plastic belts. Rubber belts are suitable for working in an ambient temperature range of -15 °C to 40 °C, with the temperature of the material not exceeding 50 °C. The angle of inclination for conveying bulk materials upwards is generally between 12° and 24°. For large inclination angles, patterned rubber belts or sidewall belts are available.
Plastic belts have the advantage of being resistant to oil, acid, and alkali, but are poorly adapted to the climate and are prone to slipping and aging. The belt width is the main technical number of the belt conveyor.
b.Rollers
The rollers are divided into grooved rollers, parallel rollers, centering rollers, buffer rollers, etc.
Grooved rollers (consisting of 2 to 5 rollers) support the load-bearing branches and are used to transport bulk materials; the centering rollers are used to adjust the lateral position of the belt to avoid deviation; the buffer rollers are installed at the receiving point to reduce the impact of the material on the belt. The cushioning rollers are installed at the receiving point to reduce the impact of the material on the belt.
c. Pulley
Pulleys are divided into drive pulleys and redirected pulleys. The drive pulley is the main component for transmitting power and is divided into a single pulley (tape to pulley wrapping angle of 210° to 230°), double pulley (wrapping angle up to 350°), and multiple pulleys (for high power).
d. Tensioning device
The role is to bring the belt up to the necessary tension so that it does not slip on the drive pulley and to keep the deflection of the belt between the rollers within the prescribed limits.
Advantages of the belt conveyor: The belt conveyor has low power consumption. Like the material and the conveyor belt almost no relative movement, not only makes the running resistance small (about 1/3 ~ 1/5 of the scraper conveyor) but also the wear and tear of the load is relatively small and the productivity is high. All this contributes to lower production costs.
The conveyor line of the belt conveyor is flexible and highly adaptable. The length of the line can be as short as a few meters to as long as 10 km or more, depending on the requirements. They can be installed in small tunnels or can be erected over confused and dangerous areas of ground traffic.
Depending on the requirements of the process, the belt conveyor can be very flexible, receiving material from one or more points, and can also discharge material to more points or several zones. When feeding the conveyor belt at several points at the same time or any point along the length of the belt conveyor is fed at several points at the same time or any point along the length of the belt conveyor using a uniform feeding device. The belt conveyor becomes a major conveyor line.
The belt conveyor can feed material in the aisle underneath the raw material pile and, if required it is also possible to mix the different materials in the piles. The material can simply be from the head of the conveyor, or it can be discharged using a plow discharger or a mobile discharger at any point along the length of the conveyor belt. The material can simply be discharged from the head of the conveyor, or it can be discharged at any point along the length of the conveyor belt through a plow discharger or a mobile discharger.
Screw conveyors
Screw conveyors are suitable for horizontal, inclined, and vertical conveying of granular or powdery materials. The conveying distance varies according to the terrain and is generally 2 m ~ 70 m.
Conveying principle: the rotating spiral blade pushes the material forward, spiral, forward conveying. The force that provides the material to rotate with the screw conveyor blades is the pressure and friction generated by the material’s mass and the forward thrust of the screw conveyor blades as they rotate.
Structural characteristics: The screw conveyor rotating shaft is welded with spiral blades.
The shape of the blades is divided into a solid continuous spiral shape, a belt spiral shape, and a single blade shape, depending on the material to be conveyed. The spiral shaft of the screw conveyor has a thrust bearing at the end of the direction of material movement to carry the reverse axial force caused by the material to the spiral shaft, and when the conveying distance is long, the middle hanging bearing seat should be added.
Bucket elevators
A bucket elevator is a continuous conveying machine that uses a series of hoppers evenly fixed to an endless traction member to lift materials vertically.
The bucket elevator has a large conveying capacity, high lifting height, smooth operation.
The bucket elevator has the advantages of large conveying capacity, high lifting height, stable and reliable operation, long life, etc.
The elevator is suitable for conveying powder, granular and small pieces of non-abrasive and small abrasive materials, such as coal, cement, stone, sand, clay, ore, etc.
As the hauling mechanism of the hoist is a circular chain, it is permissible to convey materials with a high temperature (material temperature not exceeding 250 °C). When conveying materials at a low temperature, a nylon belt can be used instead of a loop chain as a traction component. The general conveying height can be up to 40 m.
The bucket elevator is simple in structure and smooth in operation, with hollowing type loading and mixed type or gravity discharge, the bucket elevator wheel edge adopts a combination of chain wheel, which is easy to replace, and the chain wheel edge has a long life by special treatment, the lower part, such as the use of gravity automatic tensioning device, can maintain constant tension to avoid slippage or chain off, at the same time, when the hopper is blocked, there is a certain tolerance can effectively The temperature of the material does not exceed 250 °C.
Classification by the presence or absence of traction elements
Conveyors with traction elements
Conveyors with traction elements generally include traction elements, load-bearing elements, drive units, tensioning devices, redirection devices, and support elements. The traction element is used to transmit the traction force and can be a conveyor belt, traction chain, or wire rope. The load-bearing elements are used to carry the material, such as hoppers, brackets, or spreaders. The driving device provides power for the conveyor and is generally composed of an electric motor, reducer, and brake. Tensioning devices are generally screwed type and hammer type, which can keep the tension and drape of the hauling parts to ensure the normal operation of the conveyor. The supporting parts are used to support the traction parts or load-bearing components, which can be used as rollers, rollers, etc.
The structure of a conveyor with a traction member is characterized by: the material being transported is loaded in the load-bearing component linked with the traction piece or directly on the traction piece (e.g. conveyor belt), and the traction piece is connected to the beginning and end around the rollers or sprockets, forming a closed-loop including the loaded branch of the transported material and the unloaded branch of the non-transported material, using the continuous movement of the traction piece to transport the material.
There is a wide range of these conveyors, mainly belt conveyors, plate conveyors, trolley conveyors, escalators, moving walkways, scrapers, etc.
conveyors, trolley conveyors, escalators, moving walkways, scraper conveyors, submerged scraper conveyors, bucket conveyors, bucket elevators, overhead hanging conveyors, aerial ropeways, etc.
Conveyors without pulling elements
The structural composition varies and the working elements used to convey the material
They are also different. Their structure is characterized by the use of rotational or reciprocating movements of the working elements or by the use of the working elements. movement or reciprocating movement, or the use of media flow in the pipe to make the material The work elements of roller conveyors, are, For example, the working elements of a roller conveyor are a series of rollers. The rollers move in a rotary motion to convey the material. Screw conveyors work with the component is a spiral, which moves in a rotating motion in a trough to push material along the trough. The working element of a screw conveyor is a spiral. The working element of a vibrating conveyor is a trough, which moves in a reciprocating motion to convey the material placed in it. The working element of a vibrating conveyor is the trough, which moves in a reciprocating motion to convey the material placed in it, etc.
Classification according to the purpose of use
Bulk material conveying machinery, such as belt conveyor, screw conveyor, bucket elevator, large inclination angle conveyor, etc.); logistics conveying machinery such as. Flow lines: flowline equipment, conveyor lines, suspension conveyor lines; lifts: pneumatic lifts, rack, and pinion lifts, scissor lifts, roller conveyor lifts.
For these classifications, belt conveyors are the most commonly used.
The most common types of belt conveyors are large inclination conveyors, waveform edge conveyors, edge divider conveyors, mobile conveyors, mobile conveyors, horizontal mobile conveyors, and large inclination tape conveyors. Fixed belt conveyors are the most widely used, they can be used for horizontal, inclined, and concave/convex arc transport, with an inclination of up to 25° and down to 18°.