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A vertical conveyor is a machine which can be used to move products automatically from one level to another.
In internal logistics, there are various ways for getting product flows up or down. A solution which is often used is the deployment of incline or lowering belts. When placed at an angle in order to bridge a height difference, such belt conveyors also have the advantage of covering a certain distance. A disadvantage is the loss of much useful floor space as a result of the presence of the necessary supports for the belt conveyor. A bigger distance over a smaller floor area can be bridged using a product lift or a vertical conveyor. A continuous conveyor or a discontinuous conveyor can be chosen as a vertical conveyor. Continuous conveyors can take the form of a spiral conveyor, an L-shaped conveyor or platform lift or a product lift fitted with a fork.
Discontinuous and continuous conveyors
A discontinuous conveyor also called a reciprocating elevator, lifts the product on to a platform using a platform, roller conveyor or belt conveyor and then moves the platform with the product to another level. Because of the cycle time required for input and output as well as lifting/lowering movements, such a conveyor can only be used for smaller capacities. Continuous conveyors are more suitable for bigger capacities. There are two important solutions which can be used for this group. It is possible to choose a spiral conveyor or a continuous product lift. Both solutions are able to handle several products at a time.
The advantage of a spiral conveyor is that it can be used with a minimum amount[clarification needed] of control software. The disadvantages are that a relatively large area (floor space) is required compared with other product lifts and vertical transport takes a great deal[clarification needed] of time on account of the number of cycles which the transport belt completes. Certain products can also become misshapen since they are transported at an angle. One only has to think of plastic bottles which are wrapped in clingfilm which can become permanently misshapen if the clingfilm has still not completely cooled. A product is only supported at two angles on a spiral conveyor, because of the lifting angle and the radius within which the transport conveyor is placed. If a product has to be supported so that it is flat during transport, this will not be possible with a spiral conveyor. The drive motor of a spiral conveyor must always be controlled with a frequency regulator in order to prevent excessive slippage of the transport belt. It is also necessary to take account that products must not touch at intake. If products are touching each other at intake, the products can become jammed, which can result in the transport belt breaking down. It is, therefore, recommended that a good feed mechanism be provided for a spiral conveyor. In the case of most spiral conveyors, products must also be presented centrally, as the eccentric loading of spiral conveyors can cause excessive slippage. If a product becomes stuck for any reason, there is a good to a very good chance that the lamellae of the transport belt will disintegrate, which can cause a considerable loss in production along the whole of the production line, something which is associated with huge additional costs for replacements.
L-shaped conveyor or platform lift
A continuous product lift or reciprocating elevator can be chosen for the upright transporting of products. Such lifts are found in two forms: an L-shaped conveyor or mat lift and a fork-lift. An L-shaped conveyor or platform lift is a goods lift in which the products lie on a support which is suspended between a number of chains. This means that there is a considerable risk of contamination (with oil or grease) where use is made of traditional chains. A possible disadvantage of such a lift is that it requires more control, but the area required is again appreciably less than with a spiral conveyor. The difference in height which is able to be bridged with only one drive motor is almost unlimited. When bridging a greater height, it is necessary with spiral conveyors to place several systems one above the other. Another disadvantage of an L-shaped conveyor or a platform lift is the fact that it is difficult to control the transfer of products on intake to the system, with the incorrect receiving of a product being able to cause considerable consequential damage and with considerable additional costs to be expected as a result of lost production just as in the case of a spiral conveyor.
A Fork lift can be arranged in more ways than an L-shaped conveyor or a platform lift and a spiral conveyor. A fork-lift is a product lift which lifts products from a conveyor using a fork and then places them at a different level on another conveyor. Such a fork-lift makes it possible to introduce or remove products at an angle of 90 degrees. As a result, the number of possible input and output combinations is somewhat larger. Because of the possibility of sliding conveyors in or out of the lift, a fork-lift can also be used as a vertical sorting system. With such a sorting installation, a product can be entered and removed at any level and a product can be lifted and lowered using one lift. The power and thus the energy consumption of the drive is considerably lower with a fork-lift than with other systems, since only the product weight needs to be transported and the forks maintain a balance between each other in the rising and lowering section. Another difference between a fork-lift and an L-shaped conveyor or platform lift is the complexity of the control. With an L-shaped conveyor or platform lift, input and output must be completely synchronous, whereas this is not necessary with a fork-lift. This ensures considerably simpler controls.
- product lift
- case elevator
- incline belt conveyor
- box lift
- spiral conveyor
- L-shaped conveyor
- reciprocating elevator
- material lift
- freight lift