Electricity and Control January 2020

CONTROL SYSTEMS + AUTOMATION

Optimising boiler efficiencies with a customised control system No matter the application, the priority of any steam operation is cost effectiveness. Finding the most cost-effective solution requires an optimal balance of reliability, energy efficiency and asset preservation. As projects get bigger, running at peak efficiency becomes exponentially more important, and energy-related cost becomes a bigger component of total lifecycle cost – over 70% in many cases. This is something that Energy Partners can attest to, having recently completed one of its largest boiler installations to date.

J ohan Kritzinger, Divisional Head at Energy Partners Steam – a division of Energy Partners and part of the PSG group – provides some insight into the installation of this large steam plant at the Nokeng fluorspar mine, north- east of Pretoria. “The mine is a R1.7 billion open-pit project. Once it is fully operational it will produce 180 000 tons of acid grade fluorspar and 30 000 tons of metallurgical grade fluorspar per year. The processing plant for this operation requires coal-fired boilers that can handle the production volumes.” Kritzinger explains that while the equipment used for this project was stock standard, there was nothing ordinary about the project scope. “Based on the client’s requirements, we installed four Cochrane Mk7 10-tonne- per-hour coal-fired boiler units, supplied to us by Cochrane Engineering in Zimbabwe. In addition to this, Energy Partners selected, manufactured and supplied the associated infrastructure, which includes grit collectors, chimneys, a deaerator, and coal feed and ash extraction systems. We also had to design the boiler house where the system would be contained.” Aside from the scope of the installation, Kritzinger notes that the other unique feature of this project is the boiler control system developed by Energy Partners. “There are few service providers in our sector who can design, manufacture and install a system of this complexity, so the client’s decision to award the contract to us can largely be attributed to the fact that our control system has the ability to integrate seamlessly into the mine’s control and monitoring systems.” He explains that while most suppliers do not share control system information with third parties because they need to protect their intellectual property, Energy Partners has been developing ways of creating transparent systems that can be integrated more easily into clients’ existing control systems. The client was also presented with the option to outsource the operation and maintenance of the system to Energy Partners. “Initially, the client was reluctant to extend the contract to include outsourcing. However, on a project

The installation at the Nokeng fluorspar mine comprises four 10-tonne-per-hour coal-fired boiler units and associated infrastructure.

Energy Partners also installed its boiler control system, which serves to optimise efficiencies and control costs.

A key advantage of the control system was that it could be integrated seamlessly into the mine’s existing control systems.

6 Electricity + Control

JANUARY 2020