ALCOA

ALCOA, PINJARRA, WA

Juan Kotze
Business Development Manager WA - Centrifugal Air, Service

The Problem

Alcoa produces over 40% of Australia’s alumina and almost 20% of the country’s aluminium. Alcoa Western Australia manufactures around 7% of the global production of alumina.

The team at CAPS was contracted to overhaul Alcoa Pinjarra Powerhouse and Alcoa Kwinana refinery Powerhouse centrifugal compressors in 2017 to prevent them from failing due to condensation, harsh cooling water and poor lubrication. These works were to minimise the company’s overhaul spare parts holdings that were housed in multiple locations as well as posing a significant risk to operations.

Alcoa Kwinana and Pinjarra Powerhouse objectives were to:

1) Prevent catastrophic failure of their centrifugal compressors due to intercooler failures, causing condensation carry-over between rotating stages.

2) Ensure intercoolers were resilient against harsh cooling water.

3) Effectively remove condensate from centrifugal compressors, mitigating any risk of condensate build-up within the compressor.

4) Apply a high-quality lubricator for oil-wetted components within centrifugal compressors to mitigate oil varnishing and build-up on all oil-wetted high-speed components.

5) Minimise massive overhaul spare parts holdings in multiple locations.

Key Takeaways

3x
3C70MX4 Four Stage Centac Centrifugal Air Compressor
1x
3C2MX3 Three Stage Centrifugal Air Compressor
$660k
saving in the last 4 years of operation

Solution

3x 3C70MX4 Four Stage Centac Centrifugal Air Compressor
1x 3C2MX3 Three Stage Centrifugal Air Compressor
8x Central Atmosphere Coating Coolers
4x Centac Techtrol Gold III synthetic lubricant
18x zero loss drain trap
3x Overhaul Kits for overhaul spare parts

To find alternative high-quality intercoolers and zero loss condensate drains supplied by Ingersoll Rand, as well as superior grade lubricant for four centrifugal compressors.

These alternatives were then applied to Alcoa Kwinana and Pinjarra’s centrifugal compressors as part of their five yearly overhaul strategy.

In partnership with Ingersoll Rand, customised Overhaul Kits were built for each asset to reduce multiple spare parts holdings at various locations. All the necessary spare parts for a machine overhaul were held in one box, to be distributed from the centralised Alcoa warehouse.

The annual change previously completed once every twelve months has now been reduced to once every five years, or oil-analysis based, which is sampled once every 2,000 hours. In addition, standard coolers were changed out at least every 9 – 12 months at a cost of $35,000 per cooler, four (4) per machine.

Results/Benefit/Outcome

The undertaking of multiple servicing work orders to complete the overhaul resulted in a sizable decrease in operational risks of the centrifugal compressors. This was made possible by utilising zero loss condensate drains and high quality Techtrol Gold lubricant during the servicing process.

Alcoa Pinjarra and Kwinana was previously changing its mineral oil once every twelve months at a cost of $15K per compressor. By replacing the mineral oil with Techtrol Gold lubricant, oil change now only occurs on oil analysis indication. No changes were flagged to be made in the past three years.

The overall efficiency regarding customer spare parts allocation has improved, with costs being massively reduced through the supply of a compact Overhaul Kit by CAPS Australia instead of stocking multiple spare parts at multiple locations.

A significant risk reduction in ensuring Alcoa’s Powerhouse centrifugal compressors has been operating risk-free, referencing enhanced high-quality coolers, a higher quality lubricant for oil-weighted parts, as well as efficient condensate dispersion, ensuring no condensate carry-over between high-speed rotating elements/aero parts.