Abstract: The present invention relates to a method and apparatus for perforating a landfill gas well in situ. The invention allows for improved recovery of gas from a gas well without the danger of explosion.
Abstract: A guided underwater object (GUO) (100) comprises steering means, an on-board guidance system (200) for controlling the steering means, and a hydrophone unit or units (104A, 104B, 104C, 104D, 104E, 104F, 104G, 104H) arranged to pass signals induced therein by an acoustic guiding beam to the on-board guidance system to effect directional control of the self-propelled underwater object. The GUO is guided by a remote guidance system characterized by a plurality of transmitter arrays (402A, 402B, 402C, 402D; 412A, 412B, 412C, 412D; 422P, 422Q, 422R) arranged to transmit a plurality of contiguous acoustic beams (302A, 302B, 302C, 302D) each having a different frequency or frequency chirp (or other acoustic signal coding) and enclosing a guidance corridor of lower sound level (‘null’) (304) extending approximately in the direction of propagation of the acoustic beams and defining a flight path of the object.
Type:
Grant
Filed:
September 10, 2004
Date of Patent:
March 13, 2007
Assignee:
Qinetiq Limited
Inventors:
Benjamin Scott Evans, Richard John Gibson
Abstract: Size reduction machines including a screen holder that positions and secures a screen associated with the size reduction machine in place and also including an adjustable impeller for setting and changing a desired known gap between the size reduction machine impeller and frusto-conical screen.
Type:
Grant
Filed:
January 11, 2002
Date of Patent:
May 17, 2005
Assignee:
The Fitzpatrick Company
Inventors:
Albert Kircher, Thomas E. Sotomayor, Ronald D. Selner, Elbert D. Wilson