# Energy Balance of the Dynamic Impact Stressing of Conveyor Belts
## 1 Introduction  
In many industrial companies, the costs of transporting bulk materials represent 10-30% of the total production costs. With a constant increase in electricity prices, there is an increasing necessity to implement energy management for applications with high rates of energy consumption, such as belt conveyors [1; 2; 3]. Increasing the performance of a belt conveyor and optimizing its operating parameters may reduce its rate of energy consumption [4]. A decisive factor in designing energy-efficient conveyors is the correct choice of its structural components [5; 6]. The results of extensive theoretical and experimental research described in multiple papers [7; 8; 9; 10; 11; 12; 13; 14] have identified a potential for energy saving in the individual components of belt conveyors, such as conveyor belts [7; 8], transfer points [9; 10], drives [11; 12; 13] and support systems [14]. A transfer chute is also a critical place on a belt conveyor in terms of energy loss as that is where the concentrated dispersion of energy occurs. Designing an optimal chute is a complex process. Papers [15; 16; 17] presented optimal loading chute profiles when selecting an optimal curve or profile that the chute follows. In Paper [18], the authors applied laser scanning as a contactless method for measuring the speed of a belt in real time with a possibility of identifying the profile of bulk materials on a belt conveyor. In Papers [19; 20], the authors applied the discrete element method (DEM) to analyze transfer chute designs in terms of their flow rate characteristics. A smooth flow of material particles results in the lower consumption of energy, and, hence, the higher reliability of the chute. For the purpose of energy saving in belt conveyance, the belt conveyance development efforts are aimed at using long conveyors with a minimum number of chutes and with a high speed of the conveyor belt [3; 10; 21; 22; 23]. The elimination of material transfer points reduces not only the consumption of electrical energy [10; 23] but also operating costs. Another solution is an intermediate linear booster drive as an alternative to conventionaldrives. This type of drive facilitates reducing energy consumption in long conveyors, as presented in Paper [24]. An important area of research in the handling of bulk materials from the point of view of energy losses is the dynamics of the impact of the material at the transfer point. Currently, several methods of designs and solutions are presented. There are various experimental approaches [24; 25; 26]: simulation models using the MATLAB platform [27], DEM [28], specialized FEM (finite element method) software [29], or QNK-TT [30]. Much less attention is paid to the problem of addressing the structure of the chute from the aspect of dynamic impact stress, despite the fact that it causes up to 60% of all damage to conveyor belts. Most of the damage is associated with piercing or cutting the upper covering layer [31]. If the belt is damaged, there are serious consequences for the safety [32] and the efficiency of the operation of the belt conveyor [33; 34]. The incorrect setting of the impact height and incorrect selection of the type of conveyor belt at the transfer point is a frequent cause of mechanical damage to the conveyor belt. In the worst case, the support system and the supporting structure of the conveyor may also be damaged. The resistance of the conveyor belt against puncture is an important criterion in achieving the sustainability of belt transport. The research presented in this article aims to supplement the knowledge of the impact dynamic loading of conveyor belts when determining energy balances at the chute, especially from the point of view of the type of transported material. Specifically, the impact of sharp-edged material (pyramidal impactor) or the impact of material with rounded edges (spherical impactor) is simulated.