Air Conditioning Services
IT is well known that there are a number of safety issues in regards to underground mining in Australia and around the world.
One of the hottest topics associated with this form of mining is the high risk of heat illness which can lead to a loss of productivity, health issues and high worker turnover rates.
Auto compression, strata heat, water, people, explosives, oxidation, compressed air equipment, electric and diesel machinery are all heat load sources in underground mining that can result in operating temperature conditions well above safe working limits.
Often excessive heat load problems can be controlled through various ventilation techniques — but if the heat loads are too high and safe working limits are exceeded, then the only means of maintaining acceptable working temperatures is through correct application of refrigeration.
Most mines in Australia make use of Bulk Air Cooling (BAC) prior to entry of the mine’s air intakes.
This method is ideal where most of the air cooled will be utilised and has the advantage of all maintenance activities on the refrigeration system being surface based.
If the mine is very deep, or only a small proportion of the air chilled on the surface is of benefit, then other forms of cooling may be considered.
There are two main refrigeration systems that can provide the refrigeration required by the bulk air coolers; vapour compression systems and absorption systems.
Vapour compression refrigeration systems are the most common refrigeration system for the mining sector offering high COP’s (coefficient of performance), flexibility, and versatility; refrigerant vapour is compressed, condensed, expanded, and then evaporated in a continuous cycle.
Absorption refrigeration systems are similar to vapour compression systems except that, instead of a refrigerant passing through a compressor, it now passes through a generator, an absorber, and an absorbent pump.
The primary advantage of absorption systems is they can be driven by waste heat or low cost forms of heat, which supply the energy for the internal chemical reactions to take place instead of electrical power.
The waste heat required can be obtained from a variety of sources such as exhaust heat generated from gas and diesel power station exhausts and jacketing, and via the burning of coal seam methane.
Through the installation of bulk air cooling equipment utilising vapour compression and absorption refrigeration systems, it is possible to provide the required cooling to maintain safe working temperatures for employees, maintain or increase production, and take a mine to new depths.
Readers that would like to know more about industrial refrigeration can visit www.gordonbrothers.com.au.