Arrangement for installation of monitoring sensors of a treatment vessel for lignocellulosic material

Abstract

An arrangement for installations of monitoring sensors of a vessel for treatment of lignocellulosic material, which vessel ( 1 ) has a central pipe ( 2 ) including at least one concentric pipe ( 3 ), 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 ).

1 . A digester vessel oriented vertically and configured to continuously treat a lignocellulosic material, the digester vessel comprising:
 an outer wall defining an interior chamber configured to treat the lignocellulosic material flowing continuously down through the digester vessel from an upper inlet to a lower outlet for the material;   a central pipe coaxial with the outer vessel and extending downward at least ten meters within the interior chamber, wherein the central pipe is configured to deliver liquor to the lignocellulosic material in the interior chamber;   a sensor channel mounted to an outermost wall of the central pipe and extending at least a meter in the interior chamber, wherein the sensor channel supports sensors arranged at various elevations within the digester vessel;   a cable conduit extending from the sensor channel, through the interior chamber and to an outlet at or external to the outer wall; and   at least one sensor cable connected to the sensors and extending through the sensor channel and through the cable conduit, wherein the at least one sensor cable is configured to carry signals generated by the sensors outside of the digester vessel.   
     
     
         2 . The digester vessel of  claim 1 , further comprising a sealed channel extending through the cable conduit and the sensor channel, wherein the sealed channel is configured to be pressurized. 
     
     
         3 . The digester vessel of  claim 1 , wherein the sensor channel includes an outer wall exposed to the lignocellulosic material moving through the interior chamber and the sensor channel is configured to shield the sensors from the lignocellulosic material. 
     
     
         4 . The digester vessel of  claim 1 , further comprising an evacuation tube extending from an outlet external to the outer wall and the interior chamber and extending to at least a bottom of the sensor channel, wherein the evacuation tube is configured to evacuate liquid from the sensor channel and out of the digester vessel. 
     
     
         5 . The digester vessel of  claim 1 , wherein the cable conduit and the sensor channel are sealed and configured to isolate an interior channel through the cable conduit and the sensor channel from the lignocellulosic material. 
     
     
         6 . The digester vessel of  claim 1 , wherein the sensor channel is concentric with the central pipe and extends around an outermost wall of the central pipe. 
     
     
         7 . The digester vessel of  claim 1 , wherein the sensors include at least one of: a temperature sensor, a chip level sensor, a liquid interface sensor, a liquid level sensor, or a residual alkali concentration sensor. 
     
     
         8 . The digester vessel of  claim 1 , wherein the central pipe extends down through the interior chamber into a lower half of the digester vessel. 
     
     
         9 . The digester vessel of  claim 8 , wherein the sensor channel extends to the lower half of the digester vessel. 
     
     
         10 . The digester vessel of  claim 1 , wherein an interior of the sensor channel is divided into at least two sensor channels along the length of the sensor channel. 
     
     
         11 . The digester vessel of  claim 1 , wherein an outer wall of the sensor channel is attached along opposite longitudinal sides of the sensor channel to an outermost wall of the central pipe. 
     
     
         12 . The digester vessel of  claim 1 , wherein the sensor channel includes a plurality of sensor subchannels and at least one of the sensor subchannels is entirely supported by an outer wall of another of the sensor subchannels. 
     
     
         13 . The digester vessel of  claim 1 , wherein the sensor channel is or includes a sealed channel connected to a source of pressurized fluid. 
     
     
         14 . The digester vessel of  claim 1 , wherein the sensor channel:
 extends vertically downward beyond the central pipe, or   has an end proximate vertically an outlet of the concentric pipe.   
     
     
         15 . The digester vessel of  claim 1 , further comprising at least one additional central pipe concentric to the central pipe. 
     
     
         16 . The digester vessel arrangement of  claim 1 , wherein the cable conduit is connected to a lowermost portion of the sensor channel and extends radially and downwardly to the outer wall. 
     
     
         17 . The digester vessel of  claim 16  wherein the cable conduit extends through the outer wall at an elevation of the digester vessel immediately above an expansion section of the digester vessel where a cross-sectional area of the digester vessel expands in a downward direction. 
     
     
         18 . The digester vessel of  claim 1 , wherein the sensor channel is insulated from an outer wall of the concentric pipe. 
     
     
         19 . The digester vessel of  claim 18 , wherein the sensors in the sensor channel include thermal sensors which do not extend out of the sensor channel into an interior chamber of the digester vessel. 
     
     
         20 . A digester vessel oriented vertically and configured to continuously treat a lignocellulosic material, the digester vessel comprising:
 an outer wall defining an interior chamber configured to treat the lignocellulosic material flowing continuously down through the digester vessel from an upper inlet to a lower outlet for the material;   a central pipe extending downward at least ten meters within the interior chamber and to a lower half of the digester vessel, wherein the central pipe is configured to deliver liquor to the lignocellulosic material in the interior chamber;   a sensor channel mounted to an outer wall of the central pipe and extending meters in the interior chamber, wherein the sensor channel supports sensors arranged at various elevations within the digester vessel;   a cable conduit extending from the sensor channel, through the interior chamber and to an outlet at or external to the outer wall; and   a sensor cable connected to at least one the sensors and extending through the sensor channel and through the cable conduit, wherein the sensor cable is configured to carry signals generated by the at least one sensor outside of the digester vessel.