Automation upgrade boosts productivity at Zululand colliery
17 October 2018 | Web Article Number: ME201812255
EMIS 2002, part of Becker Mining SA, has completed upgrade projects at Zululand Anthracite Colliery (ZAC) near Ulundi in KwaZulu-Natal, which encompassed the design and installation of communication, automation and protection systems, for improved productivity at the plant.
“These projects involved the upgrade of the existing switchgear at the plant substation and the installation of communication, automation and protection systems at the mine’s MacNelly Plant. Becker Mining was also responsible for the design and installation of advancements at the mine’s main washing and siding plants, as well as the establishment of a leading-edge control room,” said Frikkie Quirk, Senior General Manager, Electrical: Becker Mining South Africa.
“All Becker Mining’s upgrade projects for ZAC, which were installed and commissioned on time, have resulted in improved efficiencies, greater productivity and energy savings on the mine.”
The initial project at the colliery was the upgrade of the 11 kV plant substation, which involved replacing outdated equipment, including old circuit breakers and a ring main unit, during a planned shutdown. The new switchgear ensures a high level of operator safety and system protection, with remote switching.
The advanced SBV vacuum circuit breaker switchboard includes a main feed from the mine’s main substation and two standby generators. Once synchronisation has been done, this will allow these generators to be brought on-line, as part of the recent automation scheme at the mine.
The MacNelly Plant project involved the installation of Becker ProBeck motor protection and control relays to replace all outdated systems on chassis plates in the motor control center (MCC). Single start/stop devices throughout the plant have been replaced with sequences starting via PLC and all direct on-line motors were replaced with soft-starters. Since the installation, there has been a 20% increase in productivity at the plant.
Other advancements include PLC automation, fault recording, a belt feedback monitoring and communication system, which are installed and monitored via Becker Wi-Fi to the control room, with live data and real time values.
Upgrades at the main wash plant included the replacement of MCC buckets with Becker ProBeck motor protection and control relays. The main wash plant previously operated on the basis of manual systems – including manual stop and start push buttons; manual communication, shift reporting and outdated PLC technology, with no back-up facility. The upgrade project, which has seen a 27% increase in plant efficiency, has also resulted in a 50% reduction in pump replacements, as a result of correct motor protection.
Becker ProBeck motor protection and control relays have been replaced in MCC buckets and new PLC technology controls automatic start-up and stops, in the event of blockages. A highly efficient 10 sequence start system has replaced the previous operation, where 135 starts were used to control the plant’s sequence starting.
For optimum performance at the plant and to ensure extended service life of all components, maintenance is now planned. True data - including shift reports and maintenance information - is automatically captured and communicated back to the control room. The new control desk is less than a third of its original size.
Becker Mining’s upgrades at the siding plant include the installation of six soft starters for motor applications and one variable frequency drive motor, to replace direct online starters. All motors now have an automatic start-up via one start button to PLC and are programmed to stop in sequence. Apart from improved efficiencies, an important advantage of the new system is energy savings.
The establishment of a new control room at the plant - with an advanced Adroit SCADA system set-up via Becker WI-FI communication - provides full control over production and plant availability, as well as at the control room. All communication and data capture systems are now fully automated. More accurate forecasting can now be done, using relevant data provided, such as levels, densities and pressures. Through the use of Becker ProBeck motor protection and control relays, critical information on motor currents, trip conditions and motor status are readily available.
Proloc and ProBeck electronic relays for motors (380 V, 400 V, 525 V, 950 V and 1 100 V – 3,3 kV and 6,6 kV) have features for electronic overload protection, earth insulation lockout, frozen or vacuum contact failure and earth leakage protection. Other use-selectable features include short circuit, frequency and power factor measurement, as well as minimum load, over voltage, under voltage and cable theft protection.
Apart from the design and manufacture of a wide range of electrical products for hazardous and non-hazardous applications, Becker Mining South Africa also offers a repair and maintenance service to ensure total reliability of equipment in harsh operating environments.
Becker Mining SA’s specialist services to the mining sector include energy distribution, communications and automation solutions, mechanical and transportation systems and steel arch roof supports.