Optimising roadheader performance based on laboratory and field work
This thesis covers in detail a study of the excavation of rock salt by roadheader, the factors affecting performance and finally a specification with operational results of a new production machine to suit the South African Coal Mining Industry. Dosco Overseas Engineering Ltd. the author's employer, is introduced. Reference is made to how, over the years, performance prediction has radically changed from a mere approximation to a position where an accurate value with a performance guarantee is a necessity. Reference is made to the Universities of Newcastle-upon-Tyne, Nottingham and Leeds who have been the main suppliers of rock testing facilities. The University of Newcastle-upon-Tyne has had further responsibilities for a specific test programme, funded by Dosco, to establish a Performance Prediction Methodology. A general introduction to the trial site at Domtar Salt, located in Canada, is given, along with the current mining methods and the particular aspects requiring consideration if machine mining were to be adopted. A detailed study over a twelve month period covering three main topics; fines production, performance rates, and cutter pick suitability is described. Results are discussed at length and valuable conclusions are drawn. Extrapolation of the results to predict the performance of a larger machine suitable to Domtar's high production requirements is shown. The ability to relate this study to other applications and, in particular, the aspect of pick penetration and its effect on machine design is discussed. A prediction curve suitable for South African coal is shown, along with the necessary calculations to enable a high production rate and the corresponding effect on machine design. Specification features, such as boom force, cutter head design and cutter motor power, are considered at length. The implications for the machine manufacturer for even larger, more powerful machines is shown. An early correlation· of findings is established by comparison to field results from a smaller single boom, Dosco roadheader. The study concludes that current or new machine design can be favourably influenced to reflect varying market requirements and that accurate prediction of machine performance is possible. A later, overall study of the TB2500 shows achieved production rates and comments in particular, on machine mining rate and available mining time. Recommendations having particular reference to the equipment suppliers involvement in the sales procedure are given.