FOERFARANDE BASERANDE SIG PAO EKOLODNING MED ULTRALJUD FOER AT FOELJA MED BANBILDNINGEN OCH/ELLER MASSASUSPENSIONSSTROE MMN PAO EN VIRADEL OCH/ELLER I EN INLOPPSLAODA I EN PAPPERS MAKIN OCH ANORDNING FOER TILLAEMPNING AV FOERFARANDET SAMT VANENDNING AV FOERFARANDET OCH/ELLER ANORDNINGEN

摘要

An ultrasonic echo sounding device permits observation of the web formation and/or the pulp suspension flow on the wire part and in the head box of a paper machine. The device includes a series of ultrasonic detectors connected to the wall of the flow channel in the head box and/or to the forming wire. The detectors direct an ultrasonic field at the pulp suspension layer, and the echo signals received from the pulp suspension layer are detected. The detectors operate as acoustic lenses so that the focal points thereof are located in the transverse direction of the pulp suspension flow and in the direction of thickness of the pulp suspension layer in a manner whereby information concerning fibre bundles, air bubbles, variations in consistency, corresponding parameters and their variations in the transverse direction of the pulp suspension flow and in the direction of thickness of the pulp suspension layer are indicated by the device.