Centrifugal Oil-Free Air Compressors: why and when to choose them

Riem Italy, a leading company in the manufacturing of spare parts for compressors and sale of industrial compressors, is able also to supply new centrifugal oil-free compressors (turbo compressors) thanks to its partnership with Hanwha Power System. In this article we will explain more in depth what a centrifugal compressor is, what it is for, and for what activities it can be recommended. 

Why to choose a centrifugal compressor

This type of compressor is used in companies that need a big flow of compressed air. These machines are made with impellers specifically designed for every power range and are very reliable from a duration point of view. The centrifugal compressors are used in several industries such as automotive, pharmaceutics, food and beverage, chemistry and renewable energy.  

As said above, this type of compressor can be suggested for specific applications. In addition, centrifugal compressors are recommended for those who need a stable airflow: differently from screw compressors, in fact the centrifugal ones offer greater airflow stability. In many cases, the centrifugal compressor is used combined with a screw-type one: the first has the task to manage the basic load, the second one manages the higher fluctuating flow. 

For more, visit: The screw compressor: what it is and how it works?

How does a centrifugal compressor work? 

Centrifugal compressors are also defined as multi-stages because pressure increases proportionally in different steps, reaching also 13 bars.  The impeller is made of a rotating disk with palettes where the airflow enters. The palettes can be on a side only or both sides (in such a case, it is called ‘double entry impeller’).  The diffuser instead has the aim to increase the kinetic energy of the static pressure.  The Collector, in the end, collects the air flow discharged from the diffuser and distributes it to the outlet pipe.

Types of Centrifugal Compressors

How many types of centrifugal compressors are there? Clearly, each compressor can be optimized according to a customer’s needs. The possible configurations are many. We are going to list the three main ones: 

• Axial multistage centrifugal compressor: it works at low speed, driven by induction motors. The blades/palettes are axially aligned one after the other and gradually increase pressure;
• With turbo gears driven by induction motors spinning at low speed and with radial impellers spinning at high speed;
• Turbo radial compressors at high-speed without gears. In this case the motor directly drives the impeller. 

Riem Italy distributes centrifugal compressors by Hanwha Power System, a world leader in the construction of centrifugal compressors and much more.