What are the different types of air compressors available?
There is mainly two generic principles for the compression of air or gas: positive displacement compression and dynamic compression.
Positive displacement compressors include the following:
- Piston compressors (Reciprocating)
- Scroll compressors (Double Rotor)
- Rotary screw compressors (Single Rotor)
Dynamic compressors, also called centrifugal compressors work at a constant pressure instead of flow. Here are the principles behind each of these technologies.
Air quality: Oil-Free vs Oil-Injected air compressors
Atlas Copco has an extensive range of products and can feasibly meet any compressed air requirement out there. So why don’t we start with air quality, the main categories of which are Oil-Flooded / Oil-Injected technology and Oil-Free compressor technology. Most air compressors on the market rely on oil in the compression chamber for lubrication, sealing and cooling, but, of course, this means that some of the oil will get mixed into the air and microscopic droplets of oil will carry through the machine and end up in the air network - and eventually in the process or product.
Fixed Speed Compressors vs. Variable Speed Driven Compressors
Why does Variable Speed Drive (VSD) technology saves energy if compared to fixed speed?
It's obvious from the name itself! Fixed speed compressors run at one fixed speed which is very efficient when operating fully on load 100% of the time, when the motor is running & compressed air is being produced.
However, The inefficiency comes when the unit unloads (stops making air). Although eventually the compressor will stop, it spends some of the time turning the motor & using energy whilst not actually producing anything, and therefore wasting energy.
A VSD or the variable speed drive unit, turns the motor relative to the amount of air required exactly How?
If the demand increases then the motor speeds up, if the demand decreases the motor slows down, and uses only the energy required to produce the air required – therefore no energy is wasted.
In fact, a VSD can reduce energy consumption by up to 35% or even 50%, depending on the VSD technology. It is therefore definitely worthwhile getting our FREE air usage audit to see if your energy consumption could be reduced by using a VSD compressor.
Check out the more detailed comparison of fixed vs. variable speed compressed air technology.
At the end of the day, there is a need in the market place for a mix of both technologies depending on the air requirement for the given application. We hope that this brief overview offers some insights into air compression, a process which is often overlooked, but much depended on in manufacturing.
How to pick the right type of compressor for you?
When choosing the right type of compressor, you should ask yourself these questions:
- What is the application
- How much flow does my facility/workshop use
- What pressure is needed within the facility
- Do I need clean/dry air (use of dryer and filters)
- How many hours per year does my compressor operate
- How many shifts do I run per day
- Is there fluctuation in flow demand between shifts (if so, a VSD compressor could be a good option and offer great savings)
- Are there any plans for future expansion
Do you need guidance on what air compressors types systems would work best in your facility?
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.
Use our selection of calculators to measure your on-site conditions and determine equipment specifications.
You could also call one of our sales representatives directly.
