Two Main Classes—Cyclones and Swirl Tubes

A systematic discussion of all the configurations mentioned above would lead us to spend a disproportionate amoimt of space on devices that are seldom used in practice. We are therefore concentrating on the two types of devices most used in industry both are of the reverse-flow type  

We thus make the distinction between vane-type axial inlets and tangential inlets. By tangential inlets, we mean both slot and wra around inlets, unless we explicitly distinguish between the two. Pipe type inlets are also a type of tangential inlet, which compromises some degree of separation performance for the sake of construction simplicity. 

---