Patent ID: 6905611
Filing Date: 2005-06-14
Classification: B01D

Abstract:
1. A device for separating a surface layer of a liquid, including a container, which is intended to be submerged in the liquid and which includes: a bottom; a wall member, which has a centre axis (x) extending substantially vertically when the container is submerged in the liquid, which wall member is connected to the bottom at a lower end of the wall member and has a variable length along the centre axis (x); and a separating member connected to an upper end of the wall member, which separating member has an opening, communicating with a space formed in the container, and an overflow portion, arranged, during separation of liquid from the surface layer having a free liquid surface, to be located at least below and adjacent to this liquid surface and to permit the flowing of liquid from the surface layer over the overflow portion through the opening into the space, in which a volume of separated liquid is collected, the device also includes a discharge conduit, which extends from a part of the space, said part being filled with liquid during separation, and is arranged to discharge liquid from the space, and a floating member, which is connected to the separating member and which is arranged to float on the liquid located outside the container and to exert a lifting force upon the separating member in a direction prolonging the wall member, a submerging member provided in the space, which submerging member is attached directly to, and positioned proximate to the separating member and located at a certain vertical distance from and below the overflow portion, the submerging member has a certain mass and is arranged to exert a downwardly direded force upon the separating member, which is of such an order that it is able to press the separating member so far down into the liquid surrounding the container against the action of the lifting force from the floating member that the overflow portion becomes located below the free liquid surface, and wherein the submerging member also is arranged in such way that the submerging member and the separating member are influenced by a force in a lifting direction by the liquid pressure acting upon the submerging member from the liquid, which is located above the lowest point of the submerging member when the space has been filled with such a quantity of liquid that a part of the submerging member is located in this liquid.