Abstract: A spiral filtering device disposed within a frame consisting of two draw bars and two end pieces. The spiral filter consists of at least one spiral plate and at least two support plates with attached filter plates inserted between two end plates. On each of their plane machined surfaces, the spiral plates have a spiral groove of approximately semicircular cross-section. In addition, each surface of the spiral plate has a round depression with a boss in the shape of the bottom of a bottle. The groove is surrounded by a circular channel which is also recessed. The helicity of both grooves on the surfaces of the spiral plates is the same. The outer ends of the grooves are interconnected by a drilled channel at a shallow angle to the surface of the spiral plate. The inner ends of the grooves are connected to their respective recesses by a drilled channel running substantially parallel to the surface of the spiral plate.