Deep gold mines use a vast amount of water for various purposes. After use, the water is pumped back to the surface. This process is energy intensive. The control is traditionally done with manual interventions. The purpose of this study is to investigate the effects of automated control on mine dewatering pumps. Automating mine dewatering pumps may hold a great number of benefits for the client. The benefits include electricity cost savings through load shifting, as well as preventative maintenance and pump protection procedures. By automating pumps, the client will benefit from operating more cost effectively and realising electricity cost savings. The equipment needed for pump automation and the procedures involved in the process are discussed as part of this study. A DSM project was implemented in the form of a pump automation project. All safety and quality procedures were followed and training was provided where needed to ensure that personnel understand their duties and responsibilities. This ensures the sustainability of the project after completion. The performance of the project was tested in manual mode, manual scheduled control, manual scheduled surface control and auto control. Manual intervention achieved the highest electricity cost saving of R8.25 million (11.4 MW load shift saving). To achieve this saving the system was exhausted to a point where columns and infrastructure started failing. Auto intervention achieved an electricity cost saving of R5.57 million (7.7 MW load shift savings). The auto intervention achieved a lower electricity cost savings compared to the manual intervention. However, taking all factors into account, such as the damage to infrastructure after a period of manual control, the auto intervention proved the best balance for controlling mine dewatering pumps to achieve savings on the cost of electricity and system sustainability for optimal control. Automated systems can avoid system overload and protect the infrastructure from exhaustion. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2015

Deep gold mines use a vast amount of water for various purposes. After use, the water is pumped back to the surface. This process is energy intensive. The control is traditionally done with manual interventions. The purpose of this study is to investigate the effects of automated control on mine dewatering pumps. Automating mine dewatering pumps may hold a great number of benefits for the client. The benefits include electricity cost savings through load shifting, as well as preventative maintenance and pump protection procedures. By automating pumps, the client will benefit from operating more cost effectively and realising electricity cost savings. The equipment needed for pump automation and the procedures involved in the process are discussed as part of this study. A DSM project was implemented in the form of a pump automation project. All safety and quality procedures were followed and training was provided where needed to ensure that personnel understand their duties and responsibilities. This ensures the sustainability of the project after completion. The performance of the project was tested in manual mode, manual scheduled control, manual scheduled surface control and auto control. Manual intervention achieved the highest electricity cost saving of R8.25 million (11.4 MW load shift saving). To achieve this saving the system was exhausted to a point where columns and infrastructure started failing. Auto intervention achieved an electricity cost saving of R5.57 million (7.7 MW load shift savings). The auto intervention achieved a lower electricity cost savings compared to the manual intervention. However, taking all factors into account, such as the damage to infrastructure after a period of manual control, the auto intervention proved the best balance for controlling mine dewatering pumps to achieve savings on the cost of electricity and system sustainability for optimal control. Automated systems can avoid system overload and protect the infrastructure from exhaustion. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2015

Using chilled water within South African gold mines is paramount to the purpose of extracting gold ore efficiently. Using water for cooling, drilling and sweeping and the release of underground fissure water causes the accumulation of vast amounts of water in underground dams. Deep mines use cascading pump systems for dewatering, which is an electrical energy intensive dewatering method. Due to the recent equalisation of demand to generation capacity of electrical energy in South Africa, various methods towards demand side reduction have been implemented. With the introduction of a time-of-use (TOU) tariff structure by Eskom, the implementation of projects that shift load from peak TOU times to times of the day when electrical energy is less expensive has increased. To enable load shifting on mine dewatering pumps, preparation before and recovery after peak TOU is needed for effective results. This induces a preparation- and comeback load in the standard TOU. With an annual increase in TOU tariffs and the rate of increase of standard TOU being greater than that of the peak TOU, a reduction in electrical energy consumption before and after peak TOU is needed. To enable this, a step-by-step control technique was developed to promote the shifting of load from standard- to off-peak TOU, while still realising a full load shift from peak TOU. This technique entails dynamic control ranges of underground dam levels as opposed to the conventional constant control range method. Two case studies were used to test the developed technique. Results indicated significant additional financial savings when compared to conventional control methods. Additional savings of R1,096,056.65 and R579,394.27 per annum were respectively achieved for both case studies. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2014

Using chilled water within South African gold mines is paramount to the purpose of extracting gold ore efficiently. Using water for cooling, drilling and sweeping and the release of underground fissure water causes the accumulation of vast amounts of water in underground dams. Deep mines use cascading pump systems for dewatering, which is an electrical energy intensive dewatering method. Due to the recent equalisation of demand to generation capacity of electrical energy in South Africa, various methods towards demand side reduction have been implemented. With the introduction of a time-of-use (TOU) tariff structure by Eskom, the implementation of projects that shift load from peak TOU times to times of the day when electrical energy is less expensive has increased. To enable load shifting on mine dewatering pumps, preparation before and recovery after peak TOU is needed for effective results. This induces a preparation- and comeback load in the standard TOU. With an annual increase in TOU tariffs and the rate of increase of standard TOU being greater than that of the peak TOU, a reduction in electrical energy consumption before and after peak TOU is needed. To enable this, a step-by-step control technique was developed to promote the shifting of load from standard- to off-peak TOU, while still realising a full load shift from peak TOU. This technique entails dynamic control ranges of underground dam levels as opposed to the conventional constant control range method. Two case studies were used to test the developed technique. Results indicated significant additional financial savings when compared to conventional control methods. Additional savings of R1,096,056.65 and R579,394.27 per annum were respectively achieved for both case studies. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2014