Compressed air system for cardboard packaging facility

Oji Fibre Solutions opted for an energy-efficient Kaeser compressed air system for its new Green Star-rated corrugated cardboard packaging manufacturing facility in Yatala, Queensland. The company supplies corrugated cardboard packaging solutions to a range of industries, from fresh fruit and produce to meat, poultry, seafood, beverages and industrial manufacturing.

Complementing Oji’s existing plants in Melbourne and Sydney, the Yatala site houses a 2.4 ha facility, enabling the company to better serve customers in Queensland, northern NSW and the Northern Territory. The facility operates to a Green Star rating system, with a number of initiatives that assist in reducing emissions — from daylight sensors and a lighting control system to a rainwater harvesting system.

The company also chose to invest in an energy-efficient compressed air system, which is key throughout the manufacturing process — from material handling to the conveyor systems, pre-feeders and corrugator. After considering a number of packages, Oji chose a Kaeser compressed air system consisting of a Kaeser CSD 85 series fixed speed rotary screw compressor, a CSD 125 SFC Sigma frequency controlled rotary screw compressor and a comprehensive compressed air treatment package.

All CSD series models include the low-speed Sigma Profile rotary screw compressor block. Equipped with flow-optimised rotors, this achieves power savings of up to 15% compared with conventional screw compressor block rotor profiles, according to the company. Efficiency is further maximised with the IE3 drive motor, which complies with and exceeds Australian GEMS regulations for three-phase electric motors.

The 1:1 drive design eliminates the transmission losses associated with gear or V-belt driven systems, as the motor directly drives the screw compressor block. The Sigma Control 2 compressor controller enables compressor performance to be matched to actual air demand, thereby allowing additional energy savings.

In order to meet the facility’s fluctuating demands for compressed air, a frequency controlled rotary screw compressor was selected as part of the compressed air package. As the lead compressor, it is responsible for supplying the site’s initial requirements for compressed air.

In any compressed air installation where a frequency controlled compressor is installed, this will be the compressor that operates longer than any other unit within the system. The Kaeser CSD SFC series models were built with efficiency in mind and are designed to avoid extreme high-speed operation, which saves energy and maximises service life.

Operating pressure can be consistently maintained with ±0.1 bar. In turn, the consequent ability to reduce maximum system pressure also reduces energy costs. The relationship between pressure consistency and speed can be viewed directly on the Sigma Control 2 display.

The soft rise in motor starting current from zero to full load without current spikes leads to an almost unlimited motor starting frequency. The continuously variable acceleration and deceleration significantly reduces component stress.

All Kaeser SFC packages are equipped with Siemens frequency converters. They provide seamless communication between the SFC control cabinet and the compressor controller, thereby ensuring efficiency at all times.

The additional fixed-speed Kaeser CSD 85 series rotary screw compressor acts as the lag compressor. This means that it only starts up and produces compressed air when the demand exceeds that which the CSD 125 can produce alone. This ensures that the fixed-speed unit is not operating in a loaded state for extended periods of time. The result for Oji is optimum energy efficiency, by only producing the precise amount of compressed air required at any one time.

“We have been using Kaeser compressors for some time now on our other sites and they have proven to suit our application and be reliable and efficient in meeting our compressed air requirements,” said Oji Engineering Manager Peter Henley. “We have also found that they are well suited to operating in the Australian climate.”