Bluhm Burton Engineering (BBE) has selected Johnson Controls' YD Dual Centrifugal Chiller to meet the mine cooling requirements for Newmont's Subika Underground Project in Ghana. The YORK chiller was selected for its efficiency, small footprint and its proven reliability – a crucial requirement for mission critical equipment in a harsh African environment.
Newmont's Subika Project will expand the original open-pit Ahafo mine into an underground operation thereby extending the life of the mine. BBE, a leader in mine ventilation, refrigeration and cooling practices, was asked to assess and design a suitable ventilation and cooling system for the project.
Explains Andrew Branch, general manager of BBE Projects: 'For the development in the current scope of works, BBE conducted a ventilation study and created a mine cooling concept design. We were then awarded a turnkey tender for the detailed design and supply of cooling equipment and, on investigation of possible refrigeration solutions, selected the YD chiller.
'We are familiar with Johnson Controls' YORK chillers, having used them for a number of mining projects in Africa where they have proven themselves highly reliable. In this case, the YD Dual Centrifugal Chiller met the needs of our surface air cooling plant design – its 7 500 kW of cooling capability will get the water required for cooling to the right temperature, modulating cooling capacity and delivering good efficiency over a wide operating range.
'With two compressors on one machine it can deliver a substantial amount of cooling and we are assured of redundancy. This chiller was also ideal in terms of the phasing required — another YD chiller will be implemented in a phased approach as capacity requirements grow.'
Notes Russell Hattingh of Johnson Controls: 'The YD Dual Centrifugal Chiller utilises two York centrifugal compressors operating in parallel and features a very compact configuration for a chiller providing this many kW's of cooling. It is designed with advanced controls, ensuring enhanced reliability and operational efficiency, at full and part load, delivering year round energy savings.
'These chillers will be built to specifications for BBE, packaged and delivered on site. A Johnson Controls team will then install and commission it.'
An advantage of the Johnson Controls chillers is that they are knocked down at the factory in a manner that makes them easy to economical to ship and easy to reassemble. Says Hattingh: 'Depending on the site and chiller size, chillers can be shipped completely packaged to reduce shipping, rigging, and site assembly costs. For larger chillers, the compressors, drivelines, evaporator and condenser can be shipped as modules for easy assembly.'
Hattingh adds: 'BBE is recognised as a leader in the design of ventilation and cooling systems for mines and we are pleased that they have once again selected a Johnson Controls chiller for one of their projects – it's great recognition of the quality and capability of the Johnson Controls YORK brand.'