水力旋流器是根据不同粒度的矿物做回旋运动时所受到的离心力不同而达到分离矿物的目的的设备。但水力旋流器的作用不仅仅局限于分离矿物，在水体净化、溶液除杂等也有运用。矿浆在一定的压力下经给矿管沿切线方向进入倒锥形壳体，在壳体内做回旋运动，矿浆中大粒度矿物由于受到较大离心力而进入旋流器外围，最终成为沉砂由底部沉砂嘴排出；小粒度旋流器因受到的离心力较小而处于旋流器中心并随液流向上运动，最后由溢流管排出行沉溢流。这样便实现了分离矿物的目的。

A hydrocyclone (often referred to by the shortened form cyclone) is a device to classify, separate or sort particles in a liquid suspension based on the ratio of their centripetal force to fluid resistance. This ratio is high for dense (where separation by density is required) and coarse (where separation by size is required) particles, and low for light and fine particles. Hydrocyclones also find application in the separation of liquids of different densities.