Patents by Inventor Hans-Goran Hedlund

Hans-Goran Hedlund has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5728307
    Abstract: The present invention relates to a method pertaining to press filters of the kind which include a plurality of press plates that can be brought towards and into mutual abutment and pairs of which form therebetween at least one pressure chamber, wherein there is formed in each pressure chamber as the aqueous suspension of solid particles is dewatered a filter cake which upon completion of the dewatering process is released from the chamber by separating the press plates so that the chamber will empty itself of its contents. The method is characterized in that emptying of the pressure chambers is achieved by permitting each press plate to rotate freely and swing about an axis which extends generally horizontally through the plane of the plate, under the influence of the released filter cake. The press filter is constructed so that each press plate is able to pivot in relation to the rails.
    Type: Grant
    Filed: September 22, 1995
    Date of Patent: March 17, 1998
    Assignee: Sala International AB
    Inventors: Jorgen Goltermann, Hans-Goran Hedlund
  • Patent number: 5167832
    Abstract: The invention relates to a method for dewatering particle collections with the aid of a filter press in a cyclic sequence comprising filling, dewatering and emptying stages. The various stages within each cycle and between consecutive cycles are followed-up and determined by measuring continuously a magnitude which varies with the mass of the press and its contents, preferably the pressure exerted by the press and its contents on the surface supporting the press.
    Type: Grant
    Filed: January 17, 1991
    Date of Patent: December 1, 1992
    Assignee: Sala International AB
    Inventors: Mats Carlsson, Torbjorn Jonsson, Per-Erik Sandgren, Hans-Goran Hedlund
  • Patent number: 4900454
    Abstract: Method and apparatus for pressure filtering in a pressure filter (1) comprising a frame carrying press plates (3-6), which can be brought together and apart, said press plates between themselves forming pressure chambers (8). In each pressure chamber there are two filter cloths (9) forming a filter element, said filter cloths being connected to each other in one piece and hanging down from a suspension rod (58) resting on guide rails (86). During operation a suspension of solid particles in a liquid is introduced between the filter cloths (9) in the pressure chambers (8). The liquid is pressed through the filter cloths (9) under the influence of membranes (7) loaded by a pressurized medium and by blowing through a gas and is removed through drain channels (10, 12, 14). The filter cakes (40) remaining between the filter cloths (9) are discharged after bringing apart the press plates (3-6) by vibrating (98) of the filter cloths (9).
    Type: Grant
    Filed: January 6, 1989
    Date of Patent: February 13, 1990
    Assignee: Sala International AB
    Inventors: Hans-Goran Hedlund, Lennart Backstrom