Abstract: An acoustical dampening barrier, for an opening in a wall, that is translatable to an open position to allow access to the opening, the fixed barrier including a first barrier layer made of at least one of a rigid and semi-rigid material, a second barrier layer fixed to the first barrier layer on a side of the first barrier layer where a sound to dampen is emitted made of an acoustic material with sound attenuation characteristics, a third barrier layer fixed to the second barrier layer on a side of the second barrier layer where a sound to dampen is emitted made of an acoustic material with sound absorptive characteristics, and a seal material connected to at least one of the opening in the wall, the first barrier layer and the third barrier layer to further dampen a sound emitted when the fixed barrier is translated to a closed position to prevent access to the opening.

Abstract: A remotely controllable gaseous fuel burner having a burner body with a fuel inlet, a fuel outlet, and a constricted throat region immediately upstream of the fuel outlet. A concentrically disposed and longitudinally movable fuel conduit is disposed within the burner body forming an annular region between the burner body and the fuel conduit. The fuel conduit having a conduit fuel outlet forms a conduit fuel inlet in a wall of the fuel conduit. The outer surface of the conduit fuel outlet immediately upstream of the conduit fuel outlet is tapered and has an outside diameter larger than the inside diameter of the constricted throat.