A particle separator for the separation of solid particles out of a flowing fluid, the input mass flow, which is characterized in that a particle chamber for concentrating the solid particles to be separated is disposed in the flow path of the input mass flow and that at least one region of the wall of the particle chamber is implemented as a filter element through which a primary mass flow of the fluid can flow and that, additionally, at least one bypass opening is disposed in the wall of the particle chamber for the through-flow of the fluid with a secondary mass flow at higher filtration resistance.

A filtration apparatus includes: a filtration tank; a layer of filter medium disposed in an interior of the filtration tank, the layer of filter medium being used to pass supplied raw water therethrough from bottom to top to filter the raw water; and a filter medium washing device having a helical screw placed upright in the layer of filter medium and a screw driving unit configured to rotate the screw about a screw axis, the filter medium washing device being configured to rotate the screw to scrub and wash the filter medium. The filter medium washing device, which does not include an outer cylinder surrounding the screw, is further configured to transport the filter medium upward in a state in which an outer peripheral edge of the screw is in direct contact with the layer of filter medium.