underground cooling for the next 15 years. ▪ Photo contributed
CSA Mine now has the benefit of a new refrigeration plant that has been designed with Cobar’s hot summer in mind and will ensure cooler temperatures are delivered to underground workers even when the temperature is over 40 degrees outside.
CSA Mine Projects Manager, Tom Mackay reports the mine’s new 134a refrigeration plant commenced operation last week and is part of the mine’s $78 million ventilation upgrade.
The ventilation project includes the upgrade of surface ventilation fans, a site power increase and related underground development work.
“The new plant has been designed to provide cooling to the underground mine for the next 15 years via a new raise system,” Mr Mackay said.
Gordon Brothers Industries (GBI) were contracted to design, construct and commission the new plant.
Based in Victoria, GBI has been designing and building industrial refrigeration plants for over 100 years.
“GBI is also familiar with Cobar having installed CSA’s Ammonia plant in 2006,” Mr Mackay said.
“Central to the new plant are twin York YK series chillers installed in lead and lag configuration.
“The chillers produce water at approximately six degrees Celsius at a rate of 400 litres per second.
“This water is pumped to a large Bulk Air Cooler (BAC) structure through which air is drawn into the mine.
“The BAC structure works on a similar principle to a very large radiator being three storeys tall and 30m wide!
“As air flows through the BAC coils, the temperature is reduced to below seven degrees before entering the mine.”
Mr Mackay explained heat rejection from two chillers is achieved with three open circuit cooling towers.
As part of the project, new high voltage (HV) and low voltage switch rooms have also been built along with transformers and the site’s HV reticulation has been modified to provide the connection.
The ventilation project also includes a minor modification of equipment at hoisting shaft 1 and 2 to optimize the plant’s layout and efficiency.
