Atlas Copco Oil-Free Rotary Screw Compressors: Clean Air for Critical Applications

When compressed air comes into contact with a product, process or critical piece of equipment, oil contamination isn't something you want to discover after the fact.

That's where an oil-free rotary screw compressor can make a difference.

Atlas Copco's ZR and ZT oil-free rotary screw compressors are designed to produce compressed air without oil in the compression chamber, making them suitable for applications where air purity is critical.

What Is an Oil-Free Rotary Screw Compressor?

A rotary screw compressor uses two rotating screw elements to compress air continuously.

In an oil-free compressor, the compression chamber doesn't use oil for lubrication or cooling. Atlas Copco explains that its oil-free screw compressors use precision-engineered compression elements without oil in the compression chamber.

It's an important distinction.

Oil-free refers to the compression process and delivered compressed air, not necessarily every component inside the machine.

For example, Atlas Copco's oil-free ZR and ZT compressors can contain lubricated components outside the compression chamber.

Why Choose Oil-Free Compressed Air?

For some manufacturing processes, even small amounts of oil contamination can create problems.

Oil-free compressed air is particularly relevant where compressed air comes into direct or indirect contact with products, packaging or sensitive production equipment.

Typical applications include:

• Food and beverage production

• Pharmaceutical manufacturing

• Medical applications

• Electronics

• Automotive manufacturing

• Textiles

• Chemical processing

• Power generation

• Battery manufacturing

Atlas Copco specifically identifies food and beverage, pharmaceuticals, automotive, medical, textiles, power generation, chemicals and battery industries among the applications for its oil-free ZR and ZT compressors.

Atlas Copco ZR and ZT Oil-Free Compressors

Atlas Copco's ZR and ZT ranges provide oil-free rotary screw compression for industrial applications.

The key difference between the two is the cooling method:

ZR compressors are water-cooled, while ZT compressors are air-cooled.

The current Atlas Copco Australia range includes standard VSD models as well as higher-specification configurations with features such as integrated dryers and energy recovery.

The range covers different airflow, pressure and motor requirements, so the compressor should be selected according to the actual requirements of the application.

Class 0 Oil-Free Air

If you're specifying compressed air for a critical process, the air quality classification matters.

Atlas Copco states that its Class 0 oil-free compressor range is certified to ISO 8573-1. Class 0 is the strictest class for oil contamination under the standard.

That makes Class 0 certification an important consideration for applications where oil contamination needs to be controlled.

It's also important to look at the complete compressed air system, not just the compressor.

Filters, dryers, pipework, storage and the surrounding environment can all affect air quality.

Why VSD Can Matter

Compressed air demand isn't always constant.

A production facility might require high airflow during one part of the shift and considerably less during another.

A Variable Speed Drive compressor can adjust motor speed to better match changing demand.

Atlas Copco offers VSD configurations across its oil-free ZR and ZT ranges. The company states that its VSD technology can improve energy efficiency where the compressed air demand varies.

The actual energy saving depends on the compressor, operating pressure, load profile and system design.

Oil-Free Doesn't Mean Maintenance-Free

An oil-free compressor still needs appropriate maintenance.

Cooling systems, filters, dryers, motors, valves and other components all need to operate correctly to maintain compressor performance and air quality.

The maintenance schedule should follow the manufacturer's requirements and take into account the compressor's operating environment and duty cycle.

Don't Forget the Pipework

There's another part of an oil-free compressed air system that's easy to overlook.

The air needs to stay clean after it leaves the compressor.

A high-quality oil-free compressor won't compensate for contaminated, corroded or poorly maintained downstream pipework.

That's why the compressor, air treatment and distribution system should be considered together.

For critical applications, the pipe material can be particularly important.

Stainless steel compressed air pipe systems can provide a corrosion-resistant distribution network, while other materials may be appropriate depending on the application, installation environment and system specification.

The goal is simple:

Clean air in. Clean air through the distribution system. Clean air at the point of use.

Is an Oil-Free Compressor Right for Your Facility?

An oil-free rotary screw compressor may be worth considering when compressed air purity is critical to your process.

Before choosing a system, look at:

• Required airflow

• Operating pressure

• Air quality requirements

• Duty cycle

• Variable or constant air demand

• Ambient conditions

• Required dryer technology

• Downstream filtration

• Compressed air pipework

• Total cost of ownership

The right specification depends on the process.

A food manufacturer, pharmaceutical facility and general engineering workshop won't necessarily need the same compressed air system.

The Bottom Line

Atlas Copco oil-free rotary screw compressors are designed for industrial applications where compressed air quality matters.

The ZR and ZT ranges provide oil-free rotary screw compression, with options including Variable Speed Drive configurations and integrated air treatment on selected models.

For critical applications, selecting the compressor is only part of the job.

The compressor, dryer, filtration and compressed air pipework all need to work together to deliver the air quality your process requires.

Frequently Asked Questions

What is an oil-free rotary screw compressor?

An oil-free rotary screw compressor uses rotating screw elements to compress air without oil in the compression chamber. Atlas Copco's ZR and ZT ranges are designed to produce oil-free compressed air for applications requiring high air quality.

What is the difference between Atlas Copco ZR and ZT compressors?

The primary difference is cooling. ZR compressors use water cooling, while ZT compressors use air cooling.

Are Atlas Copco oil-free compressors Class 0?

Atlas Copco states that its Class 0 oil-free compressor range is certified to ISO 8573-1. Check the certification and specification of the exact model being considered for your application.

What industries use oil-free rotary screw compressors?

Applications include food and beverage, pharmaceutical, medical, automotive, electronics, textiles, chemicals, power generation and battery manufacturing.

Does an oil-free compressor need a dryer?

The requirement depends on the application and required pressure dew point. Where moisture control is important, a suitable dryer and air treatment system should be selected as part of the complete compressed air installation.

Why is pipework important with an oil-free compressor?

The compressor only produces the air. The distribution system carries that air to the point of use. Pipe corrosion, contamination, leaks and pressure losses can affect system performance, so pipework should be specified as part of the overall compressed air system.

Need Help Selecting a Compressed Air System?

Choosing a compressor is only the first step.

Air Energy can help you assess the compressed air equipment and distribution requirements for your application, including Atlas Copco compressors, air treatment and industrial compressed air pipe systems.

Talk to the Air Energy team about your compressed air requirements.

1300 99 55 26