Apparatus for sensing the thickness of a pulp suspension on the forming wire of a paper machine
AssigneeImpact Systems, Inc.
InventorPekka Typpo
Life of this patent
Estimating the term…
Abstract
Apparatus for sensing the thickness of a pulp suspension, having zones or slices, on the forming wire of a paper making machine includes an array of ultrasonic transducers located in the apertures of a structural member mounted in a cross-direction under the forming wire near the headbox of the machine. Each ultrasonic transducer is mounted on a flexible sheet which is mounted to an aperture and the transducer moved into close proximity to the bottom of the forming wire by means of air pressure in the structural member. A second array of transducers downstream of the first can be utilized for diagnostics.
Claims7
Apparatus for sensing the thickness of a pulp suspension, having zones on the forming wire of a papermaking machine during operation of the machine comprising:
- an elongated hollow structural member having a length corresponding to the cross-directional (CD) width of said suspension and having a top face with a plurality of apertures, mounted in said cross-direction in proximity to the side of said forming wire opposite said pulp suspension, each of said apertures of said top face corresponding to one of said zones on the forming wire;
- ultrasonic transducer means for transmitting and receiving ultrasonic pulses located at each said aperture;
- a flexible sheet mounted across each aperture and carrying a window for said ultrasonic transducer means and forming a substantially airtight chamber with said hollow structural member;
- and air pressure means having a source of compressed air and fluidly connected to said air tight chamber for moving said sheet and said window into close proximity to said wire.
Dependencies are inferred from the claim text.