"离心式净气机" can be translated into English as "centrifugal air purifier" or "centrifugal gas cleaner", depending on the specific context and the type of gas being purified.
"Centrifugal air purifier" is more commonly used when referring to devices that purify air, such as in indoor air quality applications.
"Centrifugal gas cleaner" might be more appropriate in industrial settings where the purification of specific gases (other than air) is involved.
In most general contexts, especially when discussing air purification, "centrifugal air purifier" would be a suitable and widely understood translation.