Patents by Inventor John S. Ludwigsen

John S. Ludwigsen 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: 4596120
    Abstract: A method comprising feeding a liquefied refrigerant gas into direct contact with aqueous liquid in an enclosed vessel to chill or cool the liquid and/or produce ice crystals and vaporize the refrigerant by heat exchange with the aqueous liquid; feeding a mixture of cold aqueous liquid and/or ice and refrigerant from the vessel to an enclosed storage tank to provide cold aqueous liquid and/or ice therein; removing refrigerant vapor from the storage tank; converting the refrigerant vapor to liquid refrigerant in a refrigeration cycle and feeding the liquid refrigerant back to the enclosed vessel; and withdrawing aqueous liquid from the storage tank and feeding it to the enclosed vessel; with all said refrigerant and aqueous liquid streams and volumes being in a single closed system such that refrigerant and aqueous liquid are not lost except by inadvertent leaks and consumption of such materials is avoided because they are not withdrawn from the system.
    Type: Grant
    Filed: November 30, 1984
    Date of Patent: June 24, 1986
    Assignee: Chicago Bridge & Iron Company
    Inventors: Bryan D. Knodel, John S. Ludwigsen, Jill L. Ludwigsen, Terry A. Gallagher
  • Patent number: 4511115
    Abstract: A passive support structure comprises rigid compression members in which only compressive forces are generated, and extendable tensile members, which elongate as necessary to accommodate externally applied forces. The structure incorporates two spaced members, a lower base member and an upper support member, interconnected by a plurality of rigid compression members, the ends of which are pivotally attached to both the base and the support member. Because of the pivotal connections, only axial compressive forces can be generated within the compression members. Also interconnecting the base and support members are elastic tensile members, which yield as necessary to accommodate the applied force, and in which energy absorbing and dissipating elements can be incorporated.
    Type: Grant
    Filed: January 27, 1984
    Date of Patent: April 16, 1985
    Assignee: Chicago Bridge & Iron Company
    Inventor: John S. Ludwigsen
  • Patent number: 4509344
    Abstract: Apparatus comprising a freeze exchanger having an aqueous liquid feed stream inlet and an aqueous liquid stream outlet; a closed loop refrigeration system for supplying a refrigerant to the freeze exchanger for indirectly cooling aqueous liquid fed thereto; an ice storage tank; a conduit for withdrawing aqueous liquid, or a mixture of ice and aqueous liquid, from the freeze exchanger outlet and delivering it to the ice storage tank; a conduit for removing cold aqueous liquid from the ice storage tank and feeding it to a heat exchanger to cool fluid used for cooling purposes; and a conduit for removing warm aqueous liquid from the heat exchanger and feeding it to the ice storage tank, or to the freeze exchanger, or partially to both.A method of cooling making use of the apparatus is also disclosed.
    Type: Grant
    Filed: December 8, 1983
    Date of Patent: April 9, 1985
    Assignee: Chicago Bridge & Iron Company
    Inventors: John S. Ludwigsen, Jill L. Ludwigsen, Terry A. Gallagher