How to buy the right Scroll Compressor

Upgrade to a rotary scroll compressor and save 30 to 50% on your energy costs per year.

How to buy the right scroll compressor

Broadly speaking there are two types of air compression system designs from which all commercially available air compressors are derived. They are Positive Displacement systems and Dynamic systems. In this article we’ll discuss a type of positive displacement compressor called the Rotary Scroll Compressor. You should read this before purchasing an air compression system for your workshop, plant or facility because you might find that the Scroll Compressor is the best fit for you.

How scroll compressors work

Being of the positive displacement compressor type, scroll compressors rely on a phenomenon in fluid dynamics called Boyle’s law. Boyle’s Law is relatable to us because it occurs when we breathe. Our lungs and chest cavity expand when we inhale. Since the size of the chest cavity increases the pressure inside the lungs decreases. And gases flow in the direction of high pressure to low pressure so this facilitates the drawing in of the breath. It works the opposite way when we breathe out. Boyle’s Law states that for a fixed mass of an ideal gas kept at a fixed temperature, pressure and volume are inversely proportional. This means that pressure exerted by a gas within a chamber increases as the size of the chamber decreases. In the case of a scroll compressor the chamber size is manipulated by a rotating spiral element, known as the “scroll”. The spirals are mounted with 180° phase displacement to form air pockets with a gradually varying volume. This provides the scroll elements with radial stability. One spiral orbits the other which remains static. The orbiting spiral is driven by a short-stroke crankshaft and runs eccentrically around the centre of the fixed spiral. The inlet is situated at the top of the element housing. When the orbiting spiral moves, air is drawn in and is captured in one of the air pockets, where it is compressed gradually while moving towards the centre where the outlet port and a non-return valve are situated. The compression cycle is in progress for 2.5 turns, which virtually gives constant and pulsation-free air flow. The process is relatively silent and vibration-free, as the element has hardly any torque variation as compared to a piston compressor, for example.

Why you should buy a scroll compressor

Rotary positive displacement air compressors that use a rotating element like this scroll are usually more expensive than their counterpart, the reciprocating positive displacement compressor type.

But they allow for more up-time, better energy efficiency, higher air quality, longer lifespan and are cost-effective in the long-term. They have a much higher flow rate and are also much quieter than reciprocating types. Rotary compressors like the scroll compressor are the go-to choice where the priority is flow rate and not pressure.

The scroll compressor is also known for producing very clean air because there is very little chance of oil leak. The designs of scroll compressors are usually smaller in size when compared to other rotary compressors. Scroll compressors are very easy and inexpensive to maintain because they have less moving parts than other rotary compressors. For efficient use of other compressor types you usually want a duty cycle that’s slightly less than 100% or above 50% at minimum. But scroll compressors will perform efficiently through variable duty cycles.

Below are the Atlas Copco SF & SF+ Scroll Compressor Technical Specifications. You can read more about it here.

Capacity FAD - l/s 1.9 l/s - 40.8 l/s
Working pressure - 8 bar(e) - 10 bar(e)
Installed motor power - 1.5 kW - 22 kW
Capacity FAD m³/min - 0.11 m³/min - 2.45 m³/min

Conclusion

Medical facilities and labs find scroll compressor types fit their needs perfectly. They can save on space, they can get efficient performance despite varying duty cycles, and there will be less noise. Food & Beverage production applications are also a great fit for scroll compressors because there is a need for oil-free air.

Scroll compressors can work well across multiple applications. The best way to make a decision on what type of compressor to purchase is to consult with a professional.

Atlas Copco offers a free consultation and energy efficiency audit on your request. We can send a team to your site and find out your exact requirements, highlight existing efficiencies and give you a list of alternative solutions.

Request a FREE consultation from us by filling this form.

You could also call one of our sales representatives directly.

Ask them to guide you on how to use our selection of calculators to measure your on-site conditions and determine equipment specifications.

Get in touch!

Sales: +971 4373 8216
Service: +971 4373 8280
compressor.acsme@bh.atlascopco.com

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How to buy the right Scroll Compressor