The printing industry requires a dependable and clean supply of compressed air for a number of processes. However, as on-site air demand grows beyond the capacity of existing compressed-air equipment, efficiency and reliability can be affected, and this can ultimately impact the quality of the finished printed product.
When this point is reached, it is often beneficial to redesign a facility's compressed-air infrastructure to ensure the ongoing production of clean, reliable compressed air into the future. This was exactly the situation faced by Note Printing Australia (NPA). A wholly owned subsidiary of the Reserve Bank of Australia, NPA prints polymer banknotes and passports for the Australian Government, as well as banknotes for a number of overseas markets.
According to NPA Capital Engineering Manager, Neil Taylor, compressed air is crucial for a wide range of production processes at the company's Craigieburn facility in Melbourne's north, including the printing presses, the pre-press machines, the passport book-binding machines and a number of items of ancillary equipment.
"Actual demand varies widely throughout the day, and from one day to the next," he says.
"While the quality of compressed air is less essential for many of the processes on site, we have two inspection machines for which it is extremely critical. These machines inspect banknotes at speeds of 2000 notes per minute, and the air used must be very clean to avoid contamination of the notes."
Demand outgrows supply
Until recently, NPA's compressed air was mostly provided by two water-cooled compressors, each rated at 55kW, and originally supplied by Champion over 25 years ago. This supply was supplemented by two smaller units that provided 'cleaner' quality air to the inspection machines.
"Although these large compressors were designed to operate on a duty/standby basis, our growing air usage meant that a single 55kW compressor was often not big enough to meet total site demands," says Taylor.
"Increasingly, the second machine would have to cut-in to meet demand. When NPA decided to replace the four existing compressors on site, it turned to its long-term compressed-air service provider, Champion Compressors, to design and install a premium-efficiency integrated solution to meet their current and future needs. The reason we chose Champion was very simple," says Taylor.
"Its compressors have an excellent reputation for durability in tough conditions, and we know first-hand that its levels of service are second-to-none."
The premium-efficiency compressed-air solution that Champion Compressors delivered includes two weatherproof, air-cooled Champion 90kW VOC90 Variable Output Compressors (VOC), with MEPS-compliant E3 premium high-efficiency motors for even better performance.
The system is managed by on-board sequence control functionality, which allows each compressor to meet total site demand. This automatically switches-over the lead compressor on a weekly basis in order to balance operating hours.
The solution further comprises a Champion CRDii300 refrigerated air drier and Champion G18 pre- and post-drier filters. The existing air receiver was retained, but a more-efficient, zero-loss electronic drainage system was installed. The reticulation system was extended into the finishing area, to allow all processes - including the inspection machines - to be supplied from a single compressed air infrastructure.