Patents by Inventor Jan B. Ronhaug

Jan B. Ronhaug 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: 5167700
    Abstract: A and apparatus for melting and refining of magnesium and magnesium alloys is used both for melting of ingots and remelting of return metal. Metal is melted by pumping an overheated salt melt from a heating zone in a salt melt furnace and distributing it over the metal, which is placed in a basket above the liquid level in the furnace. The metal melts and is immediately removed from the basket without being further heated. A melt composition rich in calcium chloride with a content of calcium fluoride is preferably used.
    Type: Grant
    Filed: October 21, 1991
    Date of Patent: December 1, 1992
    Assignee: Norsk Hydro A.S.
    Inventors: Oddmund Wallevik, Jan B. Ronhaug
  • Patent number: 4385931
    Abstract: Raw magnesium is charged into a precipitation chamber in a refining furnace beneath the metal surface as a stream directed toward a salt layer beneath the metal. The resultant precipitated sludge is directed along a sloped bottom in the chamber to an adjacent accumulating chamber. Magnesium rises in the precipitation chamber and passes through openings in partition walls between adjacent precipitation chambers. The purest magnesium from an upper metal layer in one chamber is expelled to a lower level in next chamber in the process direction. The refining furnace comprises an accumulating chamber for sludge and plurality of successively arranged precipitation chambers divided from each other by vertical walls. The openings in the partition walls between adjacent precipitation chambers are designed as skewed channels with an inlet at a higher level than an outlet in the following chamber.
    Type: Grant
    Filed: October 29, 1981
    Date of Patent: May 31, 1983
    Assignee: Norsk Hydro a.s.
    Inventors: Oddmund Wallevik, Jan B. Ronhaug
  • Patent number: D271588
    Type: Grant
    Filed: April 28, 1981
    Date of Patent: November 29, 1983
    Assignee: Norsk Hydro a.s.
    Inventors: Christian S. Bakken, Jan B. Ronhaug