Patents by Inventor Lars E. Ljungkvist

Lars E. Ljungkvist 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).

  • Method for producing a compostable mixture of sludge from sewage purification plants
    Patent number: 4659472
    Abstract: The invention relates to a method for producing a product from which compost can be suitably produced and which contains sludge obtained from a sewage purification process, in which method the sludge is mixed in a fluid state with a finely-divided carbon-carrier selected from the group sawdust, peat and bark, and with polyelectrolyte, and is then mechanically dewatered to a dry substance content of at least about 28 percent by weight.
    Type: Grant
    Filed: December 27, 1984
    Date of Patent: April 21, 1987
    Assignee: Purac AB
    Inventors: Tore H. Nordlund, Lars E. Ljungkvist