A method for the separation of fine particles from granulate-like bulk material conveyed in a pipeline as a product flow by means of a compressed air or vacuum conveyance, characterized in that the product flow is radially dispersed at the intake end of a pipe screen integrated in the pipeline in an airtight manner, and aerated there by a cleansing airflow, flowing at an angle to the direction of the dispersed product flow, in the region of a cleansing plane, which deflects the lighter particles, fibers, clusters, dust or similar items carried in the product flow from the trajectory of the heavier granulate, and conveys said into an annular sheath through which the cleansing air flows, from which they are removed by means of a separator.