Mine ventilation and refrigeration specialist Bluhm Burton Engineering (BBE) is providing a consulting service for work on the 42-level refrigeration plant at Driefontein's No 5 subvertical shaft.
The refrigeration system will supply about 600 l/s of chilled water to a network of closed-circuit cooling coils installed from 42 to 50 level. The plant comprises four 7,5 MW multistage water chillers of which the first two machines should be operational by January 2005.
BBE senior engineer Richard Gundersen advises that the company has provided the process design, layouts, hydraulic designs and piping specifications, and technical specifications for all mechanical equipment.
The company has also been involved in the construction of the 21 MW surface refrigeration installation at Anglo Platinum's RPM Amandelbult No 2 shaft. Completed early this year, BBE, in conjunction with Read, Swatman & Voigt, was responsible for the civil, mechanical, structural and piping engineering requirements for the project, says Gundersen. The work also included concept planning and process design, layouts, technical specifications and tender adjudication.
The plant comprises three ammonia refrigeration machines that supply chilled water to a large surface horizontal spray-chamber-type air cooler and to large storage dams for underground ser-vice water.
BBE is busy with an extension to the refrigeration plant at Anglo Platinum's Union Section.
Northam Platinum recently extended its surface refrigeration installation from 45 MW to 60 MW, making it the largest single installation on a South African mine. BBE, in conjunction with Thuthuka Project Managers, provided a full turnkey project for the extension, which included two new refrigeration machines, building extensions, four new cooling towers, an additional chilled-water storage dam and associated piping.
The company's experience in planning ventilation and cooling systems allowed it, together with CSIR-Miningtek, to develop and manage a suite of specialized ventilation-management software called Ventilation of Underground Mining Atmospheres (Vuma). Gundersen notes that the Vuma network, which determines air flow, pollutant and temperature distribution throughout the ventilation circuit, was first released three years ago and is widely used locally and internationally to accurately model and predict ventilation and cooling requirements. The software suite is continually being upgraded and expanded, he says. The revisions will enable mines to keep their fingers on the pulse of ventilation facilities - this means management of temperatures and flow data for both air and water circulating in mines. The latest addition to the suite will allow online monitoring of underground conditions and will eventually allow remote control of ventilation doors and the ability to control the distribution of ventilation from inactive to active zones, says Gundersen.
Mines typically run ventilation and cooling systems around the clock at significant costs. “BBE is developing modelling tools and designing engineering systems (called ventilation-on-demand) which would allow ventilation and cooling to be operated cyclically when and where it is required,” says Gundersen.
“The software gives engineers and mine managers the ability to plan with confidence around various scenarios using the models that the program can generate,” he adds.
The company is involved in a range of services from preliminary feasibility studies, through detailed process-design work, costing, preparation of technical specifications and detailed engineering design to commissioning.