AN ARRANGEMENT FOR INSTALLATION OF MONITORING SENSORS OF A TREATMENT VESSEL FOR LIGNOCELLLULOSIC MATERIAL

An arrangement for installations of monitoring sensors of a vessel 1 for treatment of lignocellulosic material， which vessel (1) has a central pipe (2) comprising at least one concentric pipe (3)， which is mounted coaxially within the vessel (1).At least one sensor channel (4) is arranged along the outermost wall of the concentric pipe (3) of the central pipe (2) and that the at least one sensor channel (4) is connected to a cable conduit (5)， which cable conduit (5) connects the exterior of the vessel (1) to the at least one sensor channel (4) ) and the sensor channel (4) is several meters long and has plurality of holders (13) for sensors (11) and/or is configured to contain plurality of thermal sensors (11) with their cables (8). An outer wall (6) of the sensor channel (4) may be a concentric pipe on the central pipe (2) or it is welded from both sides of the outer wall (6) onto the central pipe (2). The sensor channel (4) may contain subchannels (7). The sensor channel (4) may be pressurized and/or have means for evacuating leaked liquid from the bottom of the sensor channel (4). The sensor channel (4) may be thermally insulated from the center pipe (2).