Abstract: An apparatus for separating solid particles from a liquid carrying the solid particles. The liquid carrying the solid particles enters a cylindrical chamber having an upper portion with an air evacuation opening. The liquid flows down the sides of the chamber onto a funnel-shaped member. An exchangeable collecting vessel is positioned below the funnel-shaped member and retains and collects solid particles which precipitate out from the liquid. The liquid flows through an opening to a drainage container. The exchangeable collecting vessel has a self-closing resilient membrane covering its opening. The resilient membrane is pierced by a wedge-shaped projection at the drain opening when the collecting vessel is in position. When the collecting vessel is removed, the opening is closed by the resilient membrane to form a hygienic seal.