Oil-free scroll compressor vs piston compressor solutions
Compressed air powers various applications, such as machines and tools, manufacturing and processing products, and cleaning and painting surfaces. Its applications are endless. When generating high-pressure air, you'll need to choose between an oil-injected or oil-free compressor. This is because an oil-injected compressor will not meet ISO-8573-1 air quality standards required for sensitive industries like medical or food and beverage. In the following text, we cover two popular oil-free compressor options, a scroll compressor vs piston compressor, should you need clean air.
Before explaining the differences, it's important to state the reason to use oil typically is to lubricate and cool the machine. Oil-free equipment uses alternative methods. To avoid even the smallest droplets of oil in your compressed air, you'll want an oil-free compressor.
Key differences between an oil-injected and oil-free compressor
As mentioned, an oil-injected and oil-free compressor is equipment that generates high-pressure air with different cooling and lubrication methods. With that, oil-injected equipment typically has a lower investment cost, since oil is a fairly common method to regulate a machine. The only downside is it requires oil replacement, filtration, and proper drainage.
On the other hand, oil-free compressors use alternative methods for cooling including fans. Also, Teflon and water are common lubrication methods. Without the presence of oil, there is no possibility for it to end up in the produced compressed air. In addition to the industries listed above, this is useful for working with electronics.
While oil-free equipment tends to cost more upfront, you'll want to protect your business' reputation by using the right equipment. In addition, you won't need to spend money on replacing oil and filters to remove oil particles. Additional equipment like separators, condensate drains and oil waste disposal are also not necessary with oil-free compressors
The importance of oil-free compressed air
As stated, oil-free air compressors are essential for applications requiring high air purity levels. If you work in such industries and use oil-injected equipment, you risk product spoilage, health and safety hazards, and other risks. You'll find examples below of applications that need oil-free equipment.
- Medical and dental ventilators, anesthesia units, surgical instruments, and dental handpieces need compressed air. The presence of oil can endanger the sterile conditions necessary. This can lead to infections and health issues for patients and healthcare professionals.
- Pharmaceutical and food and beverage industries use compressed air for producing, processing, packaging, and transporting products. These include medication, dairy, meats, and drinks. Oil can compromise product quality, shelf life, and lead to health and legal problems for consumers and manufacturers.
- Manufacturing and electronics assembly use compressed air for running, managing, and cleaning devices and apparatuses. These include robotics, pneumatic valves, sensors, actuators, spray painters, and air knives. The presence of oil can lead to deterioration of this equipment, compromising precision and productivity.
Scroll compressor vs piston compressor
Both scroll and piston oil-free compressors have their advantages and disadvantages. The choice between them depends on the specific needs and requirements of the application.
Scroll compressors are efficient, quiet, and compact. This makes them ideal for indoor and noise-sensitive applications. Piston compressors are robust, durable, and versatile, making them suitable for high-demand applications.
You can find more about these types below.
The oil-free scroll compressor
A scroll compressor uses two spiral-shaped scrolls to squeeze air and increase its pressure. Imagine two flat pieces of metal with spiral patterns, like two snail shells.
One piece remains fixed, while the other moves around it in a circular motion. As the moving piece rotates, it traps air between the two pieces and pushes the air towards the center. The air then comes out at a high pressure.
You can find some of the main features, pros and cons of an oil-free scroll compressor below.
Pros:
- High-quality compressed air without any oil contamination.
- Simple, compact design with few moving parts and low vibration.
- Low noise level. Suitable for indoor and noise-sensitive areas.
- High efficiency and reliability.
- Low energy consumption and maintenance requirements.
Cons:
- Limited pressure and flow rate range, making them unsuitable for high-demand applications.
- High initial cost, compared to other types of oil-free compressors.
- Sensitive to dust and dirt in the air.
Why choose an oil-free piston compressor
A piston compressor or reciprocating compressor uses one or more pistons to pump air and increase its pressure. Imagine a bicycle pump, but with more cylinders and pistons. With this, the piston is a metal rod that moves up and down inside a cylinder. As the piston goes down, it creates a vacuum in the cylinder, sucking in air from the inlet valve.
As the piston goes up, it pushes air out of the cylinder through the outlet valve at a high pressure. A piston compressor can have one or more cylinders. In addition, each cylinder can have one or two pistons. This depends on the design and configuration. Throughout this process oil traditionally cools the air and lubricates the moving parts.
With an oil-free piston compressor, the components don't come in contact with each other during compression. Alternatively, materials can be used to protect the various parts without lubrication. An external fan usually takes care of cooling. This type of equipment is ideal for manufacturing, automotive, construction, and painting.
You can find pros and cons listed below.
Pros:
- High quality compressed air without any oil contamination.
- Wide pressure and flow rate range, making them suitable for high-demand applications.
- Low initial cost compared to other types of oil-free compressors.
- Long lifespan due to the durability of pistons.
Cons:
- Bulky design with many moving parts and high vibration.
- High noise level, making them unsuitable for indoor and noise-sensitive applications.
- High running temperature, requiring adequate cooling and ventilation.
Conclusion
Oil-free air compressors are essential for applications requiring clean compressed air, free of oil contamination. When comparing a scroll compressor vs a piston compressor, it's important to consider a number of factors. These include pressure and flow rate requirements, noise level, initial cost, working environment and maintenance requirements.
Doing so well helps you understand which one is right for your needs. If you have any questions, you can contact our team for further information. We're happy to help.
