Here we disclose a device that filters large particles out of a mixture of particles of multiple sizes without the addition of "clean" liquid streams. Using the device in a cascade pair produces a stream of particles with a narrow and well defined particle distribution of large particles. The distinguishing features include separation without any moving parts, without the addition of a mass separating agent, and without the addition of energy (other than the energy provided by an external pump to drive fluid flow). Further distinguishing features include but are not limited to operation at Reynolds numbers high enough to be turbulent in configurations commensurate with pipe flow with a unique express lane structure. No clean (particle free stream) is necessary because the device takes one mixed input stream and provides two separated outlet streams, one of which has the large particles of interest. Cascades and arrays of the device may be used to tune the output for desired applications.