Used in different areas, belt conveyors are calculated in accordance with the application features, ensuring a continuous flow of transport
When talking about belt conveyors, the immediate reaction is to associate this solution to the mining industry. But they are used in several productive processes, fitting to several areas of the industry—mainly when transporting bulk materials—allowing a continuous flow in a cheaper way and with lower environmental impact.
What determinates its application and selection is the type of project. For this reason, models have different manufacturing features. The installation of a reducing set in some sections of a belt conveyor, for example, may increase the operating productivity. “The position of the drive system in the structure of a conveyor depends on some variables of the plant, such as layout, available space, structure dimensions, power-to-weight ratio and cost, among others”, explains Renato Machado, engineering technical coordinator from Metso.
Depending on the design, the position of the reducing set is fundamental for the correct operation and maintenance of this type of equipment. In this sense, Machado recommends a technical analysis of the layout turned to cost reduction, always taking into account some data related to driving motors. “They are head-installed in the most common applications, but are limited in capacity of power and weight”, explains him. “Motor driving in the return is used to prevent excess of weight in the head—generally in conveyors of lower capacity—but the working tensions in the belt are higher if compared to the driving positioned in the head. Finally, center motor driving is generally used in higher power driving, since it is more stable and tends to be more expensive.”
From the phase of design concept to the final assemblage it is necessary much care to prevent any deviation that could compromise the equipment operation. Details that may turn the equipment dangerous or bring risks to the safety have to be eliminated, freeing the conveyor of risks such as large structural misalignments or even—in worse conditions—a general collapse.
To prevent extra costs, the equipment has to use standard conveyors, available in the market. The type of conveyor, in turn, has to be specified in accordance with the material to be transported, as well as with the equipment features, its size and speed. According to Machado, the trend is to use belts with fiber braids due to market questions and the flexibility of the material, although steel-braid belts are more appropriate when there are higher working tensions that make unfeasible the use of fiber braids.
Rubber covering tends to be thicker when handling materials of larger sizes or with sharp and cutting products that may cause damages. “Before carrying out the specification of the conveyors, it is necessary to contact the supplier and carry out the calculation”, recommends Machado. “The procedure is the same when splicing is needed, always having the care of adding a factor of length increase due to variations that may occur during the vulcanization process.”
In addition to these points, there are several safety requirements for the design of belt conveyors, such as protections for moving parts, installation of safety switches and electrical devices, appropriate accesses for maintenance, signaling, manuals and operators’ training, among others.