Patents Assigned to Trigen Energy Corporation
  • Patent number: 5732742
    Abstract: A method and apparatus for re-insulating underground steam pipe in situ includes the steps of creating at least one hole in the ground, inserting a liner into the hole, using a drill string to drill a hole in the conduit, inserting a tubing into the liner so that a first end of the tubing is positioned next to the pipe and a second end of the tubing is attached to a pumping system. The foam is then pumped through the tubing around the pipe and then the tubing is removed and the foam is allowed to cure and become rigid, thereby functioning as insulation.The plastic foam may be a polyisocyanurate or a urethane-modified polyisocyanurate.
    Type: Grant
    Filed: July 1, 1996
    Date of Patent: March 31, 1998
    Assignee: Trigen Energy Corporation
    Inventors: H. Timothy Mentzer, Leif Berquist
  • Patent number: 5655377
    Abstract: The lower-most temperature of the thermal mass in a chilled water stratified storage tank is lowered without reducing its density by the addition of sodium nitrite and sodium nitrate, alone or in combination, preserving thermal stratification so that both warm and chilled water may be stored in the tank, a benefit not previously obtained without the use of chemicals damaging to the environment. A solution of sodium nitrite and sodium nitrate lowers the freezing point of the cooling water to -13.2.degree. C. (8.3.degree. F.) yet still permits the chilled water to stratify in the storage tank.
    Type: Grant
    Filed: October 2, 1995
    Date of Patent: August 12, 1997
    Assignee: Trigen Energy Corporation
    Inventors: Goran Mornhed, John Young, Harvey W. Thompson
  • Patent number: 5465585
    Abstract: The lower-most temperature of the thermal mass in a chilled water stratified storage tank is lowered without reducing its density by the addition of sodium nitrite and sodium nitrate, alone or in combination, preserving thermal stratification so that both warm and chilled water may be stored in the tank, a benefit not previously obtained without the use of chemicals damaging to the environment. A 7% solution of sodium nitrite and sodium nitrate in a 2 to 1 ratio lowers the freezing point of the cooling water to -3.75.degree. C. (25.25.degree. F.) yet still permits the chilled water to stratify in the storage tank.
    Type: Grant
    Filed: June 16, 1994
    Date of Patent: November 14, 1995
    Assignee: Trigen Energy Corporation
    Inventors: Goran Mornhed, John Young, Harvey W. Thompson
  • Patent number: 5391925
    Abstract: A method of driving a large cooling system having a compressor operating as a chiller driven by a prime mover, such as a gas turbine, reciprocating engine or steam turbine, in conjunction with an electric motor/generator coaxially arranged on a common shaft with the other units, so that as the ambient temperature rises and the power needed to produce the cooling output increases, and as there is a corresponding drop in power output if the prime mover is a gas turbine or condensing steam turbine, the required additional driving power is supplied by the motor. Conversely, as the ambient temperature drops and required cooling power lessens, the electric motor operates as a generator to convert the excess prime mover power to electrical power.
    Type: Grant
    Filed: September 10, 1993
    Date of Patent: February 21, 1995
    Assignee: Trigen Energy Corporation
    Inventors: Thomas Casten, Goran Mornhed, Leif Bergquist, John M. Malahieude