Townsville Copper Refinery undergoes major compressor upgrade

The Townsville Copper Refinery proved it can handle the pressure after recently undergoing a major upgrade to its compressed air system.

Often the life-blood of mining, processing and refining, compressed air is arguably the unsung hero of modern production and industrial automation.

Like other essential utilities to our operations including electricity, gas and water, compressed air is an important energy source for many of our industrial processes and, in particular, at our Townsville Copper Refinery.

For those unaware, compressed air is simply air reduced in volume, held under greater pressure than the air in the general environment. It acts as a medium for the transfer of energy, which is critical to power equipment like air hoists, jack hammers and air cylinders.

Copper Refinery Limited's Project Engineer Chris Hodge says everything from the copper handling machines in the Tank House to the compressed air cylinders that operate Take-offs that transfer the anodes from the casting wheel relies on a consistent and reliable stream of compressed air at the refinery.

"We use compressed air as it's safer than standard hydraulic systems as with their close proximity to molten metal even a minor oil leak can cause major risks to our operations," Chris says.

"It also is highly reliable and prevents equipment from breaking down at the height of our production schedule."

Following the upgrade of the compressed air system at the Townsville Copper Refinery in 1976, the plant operated with three main Ingersoll Rand Reciprocal air compressors each producing 1500 cubic feet per minute (cfm) of air at 700 kilopascal (kPa) and a back-up manually operated reciprocal air compressor producing 1000 cfm at 700 kPa.

These three main compressors were controlled by an external control system that brought the compressors online as system demand changed. To help maintain even operating hours across the compressors, a manual switch to change the priority of the compressor was operated periodically.

This system served the refinery extremely well but due to the high number of operating hours, their age and an increase in failure rate frequency it was decided to replace all four compressors.

Chris says the refinery has two main operating envelopes, casting days and non-casting days with the plant consuming twice as much compressed air on casting days than it does on non-casting days.

"To accommodate these loads we chose to go with three new Ingersoll Rand 250kw Variable Speed Rotary Screw compressors with an increased output over the old compressors with an output of 1680 cfm at 700 kPa," says Chris.

"The small increase in capacity reduces the number of compressors required to be online to maintain compressed air to the plant."

"The new compressors have a built in control system that allows the three new air compressors to communicate with each other, eliminating the requirement for an external control system," Chris says.

This system allows for increased monitoring of the compressors and auto-rotation of the lead compressor to maintain even operating hours across all three compressors.

The installation of the new compressors was successfully completed in a staged approach with the first compressor being installed in April 2019 and the final compressor being installed in late March this year.

What is compressed air?

Compressed air is simply air reduced in volume, held under greater pressure than the air in the general environment. It acts as a medium for the transfer of energy, which is critical to power equipment like air hoists, jack hammers and air cylinders.