Atlas Copco claims that its ZD high-pressure compressors are the first to offer PET packaging production the security of 100 per cent certified oil-free air with a Class 0 certification. Risk of any contamination by oil is therefore effectively eliminated during PET bottle blowing for the bottled water, soft drinks, fruit juice and beverage industry. Testing for the ISO 8573-1 Class 0 certification was carried out using the most stringent test methods available, simulating realistic industrial environments. At all test conditions, no traces of oil could be detected and the compressed air was certified to be Class 0 in terms of oil content. The Atlas Copco ZD is claimed to be the most energy-efficient and quietest 40-bar compressor available, while maintaining the flexibility and reliability required by the high-volume PET blowing market.
Oil contamination is an invisible enemy in all bottling installations and aseptic environments. Many bottlers take extra steps towards achieving purity with decontamination after blow-moulding of the preforms. Even the slightest traces of oil can result in altered or toxic product batches and health hazards for the consumers, recalls and reputation damage, as well as production downtime and cleanup. Atlas Copco's 40-bar ZD compressor eliminates the risks of oil contamination by virtue of the design itself.
Testing of the Atlas Copco ZD compressor was carried out by Technische Überwachungs-Verein (German Technical Monitoring Association, or TÜV), using the most stringent test methods available. All possible forms of oil contamination in liquids, aerosols or vapours were measured at three different temperatures (20, 40 and 50degC) and pressures (25, 30 and 40bar(e)) at the measurement point. No traces of oil were found in the output air stream.
The ZD 40-bar compressor is the most recent of Atlas Copco's oil-free technologies to obtain the ISO 8573-1 Class 0 certification with regard to air oil content. Atlas Copco has also received certification of other oil-free technologies such as the centrifugal, tooth, scroll, piston and water-injected screw. Together, these span the pressure range from 300mbar to 40bar and up to 26000m3/h.
Ronnie Leten, Atlas Copco's Business Area President, Compressor Technique, explains: "The ZD reflects what Atlas Copco calls 'Reliability by design.' The ZD's unique combination of oil-free rotary screw technology for the first two stages and piston technology for the last two stages has resulted in the best-in-class product in terms of safety, energy efficiency, reliability and flexibility."
Atlas Copco's ZD with integrated heat of compression dryer has a specific energy requirement. With the ZD, Atlas Copco claims to have pioneered four-stage compression in the industry (thermodynamically, the four-stage build-up helps to lower energy consumption by seven per cent compared to a three-stage build-up). An integrated variable-speed drive (VSD) is available, which is particularly useful if bottle sizes change frequently. With the VSD, energy savings of up to 35 per cent can be achieved. Suitable for all re-injection installations, the RI VSD model can provide extra energy savings.
The high volumes of PET production lines and their continuous operation mean that the reliability of PET blowing compressors is very important. Atlas Copco produces high-pressure air in four stages, achieving lower pressure ratios per stage. This means less wear and tear and reduced maintenance costs.
With a model at 76.4dBA, the ZD is believed to be the quietest high-pressure compressor available. Atlas Copco fits all of its ZDs with silencing canopies as standard, therefore eliminating the need and cost for a separate compressor room. The ZD is delivered with a concrete base-plate to absorb vibrations, so no foundation or fixation bolts are required; handling is via forklift.
Able to deliver simultaneously high-pressure air for blowing needs and medium-pressure air for labelling, instrumentation and capping, the ZD eliminates the supplementary investment in a standalone medium-pressure compressor. Both segments of the ZD can be installed directly adjacent to the blower.