Baynazov U. R. 1, Arzikulov G. P

Modeling of optimal operating conditions of cyclic-flow technologies with a belt conveyor at coal mine under the “ANSYS” program
Toshov J.B.¹, Baynazov U.R.¹, Arzikulov G.P.¹, Baratov B.N.^1
1Tashkent state technical university after named Islam Karimov,
University str. 2. Tashkent 100095, Uzbekistan
[e-mail]
Abstract
In the development of open-pit mining, the most inexpensive transport is conveyor transport. Due to the difference in the physical and mechanical properties of rocks in one development, such transport requires special attention to operation and design. In this article, scientific work is being carried out to substantiate the height of the hopper of the loader used on the cyclic-flow technology of the Angrensky section. The main factor affecting the integrity of the belt and a mathematical model for determining the stress force on the belt under the unloading and loading hopper are considered.
Key words: conveyor, hopper, blow extinguisher, unloading and loading.
INTRODUCTION
Nowadays, optimization of stripping operations is of particular relevance at coal mines. The technology of stripping operations is most often complicated by climatic and geostructural features of the quarry, which requires working out the section with ledges to avoid landslides. This, in turn, requires processing large volumes of overburden during open-pit coal mining[1]. Of course, in this regard, the process of transporting overburden rocks is of particular relevance.
At present, conveyor transport is an integral part of the technological process of industrial enterprises: it regulates the pace of production, ensures its rhythmicity, increases labor productivity, effectively solves the issues of complex mechanization and automation of transport and technological processes[2].
Despite the fact that in many cases conveyor transport is the only cost-effective means of transport, in recent decades mining companies have begun to abandon belt conveyors, switching to less productive, high-maintenance rail or road transport. This fact is explained that belt conveyors of traditional design have certain disadvantages[3]:
1) low resource of the belt and supporting roller bearings;
2) high electricity of the transporting;
3) spillage, dusting and crushing of transported cargo.
Limited service life (3...5 years) and a cost of parts is 50...60% of the total cost of the conveyor, the conveyor belt simultaneously performs the functions of a load-bearing and traction body and therefore is one of the most responsible elements of the conveyor [4].
During the operation of the conveyor belt, the strength properties of the belt and its operational suitability decrease [5]. This is facilitated by the appearance of the following characteristic injuries (Fig. 1):
- transverse cracks of rubber plates;
- abrasion, breakdown and tearing of plates;
- longitudinal cuts and gusts, damage to the sides and butt joints;
- stratification of the
In many ways, the destruction of the belt is caused by the design scheme of the conveyor belt. During operation, in addition to the longitudinal stresses perceived from the tensioning device and dynamic forces arising during the start-up and braking of the conveyor, the belt experiences bending stresses when bending drums, deflecting devices, as well as supporting stationary roller supports (due to the inevitable sagging of the belt in the spans between them) (fig.1). Cyclic deformations that occur in this case lead to fatigue wear of the belt, manifested in the delamination of the traction frame and the formation of cracks in the plates [6].
traction frame.

Fig.1. Types of conveyor belt damage
The study of the mechanism of operation of the cyclic flow technology (CFT) allowed us to identify the problem areas of the rush during the operation of the conveyor belt. The main problem of overloading is the most frequent gusts of the main conveyor belt due to the fall of pieces of overburden from a considerable height. The problem is compounded by the fact that the conveyor lines are moving at a considerable speed [7]. This problem is already chronic, and interruptions in the operation of conveyors due to a stop for repairs directly affect productivity, which adversely affects the operation of the transportation complex as a whole.