Abstract: An apparatus and related method are useful for compensating the pressure of drilling fluid in a drill collar disposed in a borehole. The apparatus includes a stator adapted for being secured within the drill collar against rotation relative to the drill collar, and a shaft rotatably carried within the stator so as to define a fluid-conducting annular gap between the shaft and the stator. The shaft has a fluid-conducting channel extending axially therethrough. A rotor is secured about the shaft for rotation therewith. A portion of the rotor is disposed adjacent a portion of the stator so as to define an inlet between the rotor and stator portions through which drilling fluid in the drill collar will be conducted. The rotor portion further cooperates with the stator and the shaft to define a first annular cavity that fluidly communicates with the gap and the inlet. A rotary seal is disposed in the first cavity for isolating the gap from the inlet.

Abstract: An apparatus and related method are useful for compensating the pressure of drilling fluid in a drill collar disposed in a borehole. The apparatus includes a stator adapted for being secured within the drill collar against rotation relative to the drill collar, and a shaft rotatably carried within the stator so as to define a fluid-conducting annular gap between the shaft and the stator. The shaft has a fluid-conducting channel extending axially therethrough. A rotor is secured about the shaft for rotation therewith. A portion of the rotor is disposed adjacent a portion of the stator so as to define an inlet between the rotor and stator portions through which drilling fluid in the drill collar will be conducted. The rotor portion further cooperates with the stator and the shaft to define a first annular cavity that fluidly communicates with the gap and the inlet. A rotary seal is disposed in the first cavity for isolating the gap from the inlet.

Abstract: A first electrode arrangement and a transport element are movable relative to a support. A working space is disposed between the movable elements for advancing moist material along a processing path. As the moist material advances, electrical current is passed through the material between the first electrode arrangement and a second electrode arrangement adjacent the transport element. An acoustic transducer arrangement disposed adjacent the working space simultaneously subjects the moist material to an acoustic field as the material moves along the processing path. The acoustic field is generated by an array of acoustic transducers spaced along part of the processing path.

Abstract: A first electrode arrangement and a transport element are movable relative to a support. A working space is disposed between the movable elements for advancing moist material along a processing path. As the moist material advances, electrical current is passed through the material between the first electrode arrangement and a second electrode arrangement adjacent the transport element. An acoustic transducer arrangement disposed adjacent the working space simultaneously subjects the moist material to an acoustic field as the material moves along the processing path. The acoustic field is generated by an array of acoustic transducers spaced along part of the processing path.