A Step-by-Step Procedure for Tests and Assessment of the Automatic Operation of a Powered Roof Support

Abstract

A powered longwall mining system comprises three basic machines: a shearer, a scraper (longwall) conveyor, and a powered roof support. The powered roof support as a component of a longwall complex has two functions. It protects the working from roof rocks that fall to the area where the machines and people work and transports the machines and devices in the longwall as the mining operation proceeds further into the seam by means of hydraulic actuators that are adequately connected to the powered support. The actuators are controlled by a hydraulic or electro-hydraulic system. The tests and analyses presented in the developed procedure are oriented towards the possibility of introducing automatic control, without the participation of an operator. This is important for the exploitation of seams that are deposited at great depths. The primary objective was to develop a comprehensive methodology for testing and evaluating the possibility of using the system under operating conditions. The conclusions based on the analysis presented are a valuable source of information for the designers in terms of increasing the efficiency of the operation of the system and improving occupational safety. The authors have proposed a procedure for testing and evaluation to introduce an automatic control system into the operating conditions. The procedure combines four areas. Tests and analyses were carried out in order to determine the extent to which the system could be potentially used in the future. The presented solution includes certification and executive documentation.

The analysis of the currently used systems related to the monitoring of the mining production process

“…The DOH pressure monitoring system for powered support sections [5]. The system works in the form of wireless communication between pressure sensors located in the DROPS-01 powered support sections.…”

“…In order to ensure work safety and work comfort a number of systems are used. These systems monitor natural phenomena as well as the operation of machines and devices [5]. Monitoring systems enable the visualization of the parameters necessary in the production process [2].…”

Development of a Hydraulic System for the Automatic Expansion of Powered Roof Support

“…In order to meet the previously mentioned requirements and constantly improve the production efficiency and safety of the crew, it is necessary to search for new solutions in the field of coal-bed selection [28][29][30][31][32][33], improve working conditions and minimize hazards [34,35] as well as conduct research aimed at improving the reliability of machines [36,37]. A key element influencing the increase in efficiency of the mining process and the increase in safety is automation of the longwall complex [38][39][40][41][42][43].…”

“…In this type of support, the canopy is pivotally connected to the sill piece by means of a shield system as well as by means of front and rear connectors, called lemniscates. This type of structure makes it possible for the end of the canopy to move along the lemniscate curve, almost perpendicularly to the floor, thanks to which the roof is protected up to the sidewall [41].…”

The effectiveness of the use of a powered roof support in the light of research and analysis

“…The concept of effectiveness is most often understood as the mutual relations between the inputs and refers to the principle of rational management. A different approach to the issues related to the powered roof support can be found in the literature [3][4][5][6]. Underground hard coal mining companies often apply the concept of technical efficiency, understood as maximising the production volume with the use of the given input [7][8].…”