What are Scroll Compressors?

Are you looking for a way to improve the energy efficiency of your compressed air systems? By switching from a traditional piston compressor (reciprocating compressor) to a scroll compressor (rotary compressor), you could not only reduce your electricity bills but also minimise maintenance, gain greater control over the pressure of your compressed air, and improve your compressed air quality. But what exactly are scroll compressors, how do they work, and what are their pros and cons?

Anglian Compressors has been at the cutting edge of compressed air technology since 1977 and a premier distributor for the highly esteemed Atlas Copco, for almost 50 years. In this article, we explain everything you need to know about scroll air compressors so that you can decide whether upgrading is worth the expense for your business. If you have any questions or want to know how much a scroll compressor could save you in the long run, do not hesitate to call us.

Understanding Scroll Compressors

A scroll compressor – often called a scroll pump or spiral compressor – works by internally compressing air between a stationary scroll and an orbiting scroll, a process known as positive displacement. There are two main types of scroll compressors – oil-free and oil-lubricated. While oil-lubricated systems tend to be the most popular and budget-friendly choice, you will need to use an oil-free alternative if you require dry air without any risk of contamination, such as if you operate in the food and drinks or pharmaceutical industries.

How do Scroll Compressors Work?

Scroll compressors operate with a pair of spiral-shaped scroll members—one stationary and one orbiting. The orbiting scroll, driven by a motor, moves around the stationary scroll, creating air pockets that get progressively smaller as the air is compressed toward the centre of the scroll. This continuous compression reduces energy loss and minimises leakage, ensuring high-quality, pressurised air output that meets stringent air quality requirements.

Air is drawn in through an inlet valve, where it enters the scroll. As the scroll moves, it captures and compresses the air efficiently, whether the application requires an oil-lubricated or oil-free system. The compressed air exits through an outlet port, with a non-return valve preventing backflow, maintaining pressure.

Scroll compressors are becoming increasingly popular in applications like HVAC systems, air conditioning, and transportation of food, due to their quiet operation, efficiency, and durability. Their design, with fewer moving parts, leads to less wear and tear, making them a reliable choice for industries with specific air quality needs.

Modular versus Single Scroll Compressors

Scroll compressors can either be modular or be a single compressor. Modular scroll compressors utilise variable flow technology to adjust the output of up to four modules. Most modular systems feature a controller that monitors the compression elements to make sure that the compressed air output matches the demand.

Single scroll compressors, on the other hand, only have a fixed output.  This lowers the cost, but can use more energy.

Applications of Scroll Compressors

Thanks to their efficiency, reliability, and compact design, scroll compressors are commonly used in air-conditioning and heating pumps, pneumatic equipment, labs, and applications that include:

• Heating, ventilation and air conditioning (HVAC)
• Refrigeration
• Food and drinks industry (cold storage, ice-making machines, food processing)
• Transportation (refrigerated lorries)
• Medical and dental equipment
• Electronics cooling
• Plastic moulding
• Metal fabrication
• Data centre cooling
• Gas boosting
• Pneumatic conveying

Advantages of Scroll Compressors

Scroll compressors offer several key benefits that make them a popular choice across industries:

Energy Efficiency
Scroll compressors, including digital scroll compressors, operate with a smooth, continuous compression process that reduces energy consumption. The scroll members work without metal-to-metal contact, minimising friction and leakage, resulting in lower electricity bills and a more cost-effective solution over time.

Reliability and Durability
With fewer moving parts inside the scroll, these compressors are more reliable and less prone to mechanical failure. The design also minimises the need for clean environments, making them durable for various applications, including air conditioning systems and other demanding settings.

Quiet Operation
Scroll compressors, especially in HVAC applications, are known for their quiet performance. They generate less vibration and noise, which is crucial for noise-sensitive environments like medical facilities and offices.

Compact Design
The compact design of scroll compressors allows for easy installation in tight spaces, making them ideal for applications such as air conditioners and refrigeration, where space is limited. Their smaller size doesn’t compromise performance, ensuring high-quality compressed air.

Consistent Air Quality
Scroll compressors produce high-quality compressed air with minimised leakage, which is essential for industries with strict air quality requirements. Oil-free models are particularly beneficial in applications requiring absolutely Class Zero air purity, such as food and pharmaceuticals.

Reduced Maintenance
The simple, robust design, including components like the elektronikon® control, requires less maintenance. This leads to lower overall costs, minimal downtime, and an economical long-term solution for businesses.

Disadvantages/advantages of Scroll Compressors

Scroll compressors almost always work out cheaper than piston compressors in the long run while providing greater control over the pressure of your compressed air systems. Nevertheless, you should be aware of the following disadvantages before committing to a purchase:

Higher purchase price

Scroll compressors tend to cost more to purchase and install than piston compressors. However, given their efficiency and reduced maintenance requirements, scroll air compressors are a smart long-term investment.

Maintenance difficulties

While you are less likely to experience issues with a scroll compressor than a piston compressor, it is worth noting that scroll compressors can be challenging to service and repair because of their complex and precise structures. Some components are not easily accessible and may need to be replaced as a whole.

Discover Our Range of Technologically Advanced Scroll Compressors

If you want to reduce your energy costs while gaining more control over the accuracy, pressure, and purity of your compressed air systems, you might benefit by switching from a piston compressor to a scroll compressor. Fortunately, if you are looking for versatile, cost-effective and durable solutions, you have come to the right place.

At Anglian Compressors, we have been an industry-leading supplier and installer of top-quality compressors by manufacturers such as Atlas Copco for over half a century. Whether you have questions about our products or want to know more about the latest technology, we are only a phone call away. Contact us today to learn more about us and our products.