Method and device for the thermally treating a material in pulverulent or granulate form

Abstract

The invention relates to a process and an apparatus for the thermal treatment of powdered or granular solid substances with gas flows ( 7, 16, 22, 23, 24 ) by means of a body ( 2 ) moved about its axis of rotation ( 1 ). In this process, the following process steps are successively carried out: Firstly, the bulk material held in segments ( 3 ) of the moved body ( 2 ) is heated by subjecting it to steam ( 22 ). Then, the heated bulk material is exposed to a feed of air ( 23 ) and/or inert gas ( 24 ), taking place in one or more subsequent steps. Finally, removal ( 17 ) of the dried or inerted bulk material from the segments ( 3 ) of the body ( 2 ) moved about its axis of rotation ( 1 ) takes place.

We claim:  
     
         1 . A process for the thermal treatment of powdered or granular solid substances with gas flows ( 7 ,  16 ,  22 ,  23 ,  24 ) by means of a body ( 2 ) moved about an axis of rotation ( 1 ), with the following process steps to be successively carried out: 
 heating the bulk material held in segments ( 3 ) of the body ( 2 ) by subjecting it to steam ( 22 ),    exposing the heated bulk material to a feed of air ( 23 ) and/or inert gas ( 24 ), taking place in one or more subsequent steps,    removal ( 17 ) of the dried or inerted bulk material from the moved body ( 2 ).    
     
     
         2 . A process as claimed in  claim 1 , wherein the segments ( 3 ) of a moved body of rotation ( 2 ) operated in vertical arrangement ( 28 ) are charged/emptied via the outer circumference of said body.  
     
     
         3 . A process as claimed in  claim 2 , wherein bulk material is fed to the segments ( 3 ) at the outer ring of the moved body ( 2 ) and said segments are emptied at the outer ring of the movable body ( 2 ).  
     
     
         4 . A process as claimed in  claim 1 , wherein inert gases ( 24 ) and/or steam ( 16 ,  22 ) laterally enter the segments ( 3 ) of the body ( 2 ) moved about its axis of rotation ( 1 ).  
     
     
         5 . A process as claimed in  claim 2 , wherein the entry of steam and air ( 7 ) takes place at the outer circumference of the movable body ( 3 ).  
     
     
         6 . A process as claimed in  claim 5 , wherein steam, air and inert gas leave at the hub ( 8 ) of the moved body ( 2 ) in the radial direction after flowing through the segments ( 3 ).  
     
     
         7 . A process as claimed in  claim 2 , wherein the segments ( 3 ) are subjected to gas in the radial direction ( 9 ) from the inside outward.  
     
     
         8 . A process as claimed in  claim 2 , wherein a bulk material feed ( 10 ,  11 ,  12 ) is assigned to the outer circumference of the body ( 2 ) for supplying the segments ( 3 ) of the body ( 2 ).  
     
     
         9 . A process as claimed in  claim 1 , wherein the segments ( 3 ) of a moved body ( 2 ), operated in horizontal arrangement ( 29 ), are subjected to gas flows ( 4 ,  16 ,  22 ,  23  and  24 ) parallel to the axis of rotation ( 1 ) of the moved body ( 2 ).  
     
     
         10 . A process as claimed in  claim 9 , wherein the moved body ( 2 ) is provided on the cover side ( 19 ) with surfaces ( 25 ) covering the segments ( 3 ) in alternating succession.  
     
     
         11 . A process as claimed in  claim 9 , wherein the moved body ( 2 ) is provided on the base side ( 20 ) with segments ( 3 ,  17 ) with an outlet for the treated bulk material and segmentally arranged covering surfaces ( 25 ) and also with segment surfaces ( 27 ) permitting gas outlet.  
     
     
         12 . A process as claimed in  claim 9 , wherein, in horizontal arrangement ( 29 ) of the moved body ( 2 ), the driving out of moisture in the direction parallel to the axis of rotation ( 1 ) is assisted.  
     
     
         13 . A process as claimed in  claim 9 , wherein the bulk material held in the segments ( 3 ) undergoes drying by air ( 7 ,  23 ) with a permissible residual oxygen content of the bulk material.  
     
     
         14 . A process as claimed in  claim 9 , wherein the bulk material to be freed of oxygen is inerted by direct introduction of steam ( 22 ) and feeding in of inert gas ( 24 ).  
     
     
         15 . An apparatus for the thermal treatment of powdered or granular solid substances with gas flows ( 7 ,  16 ,  22 ,  23 ,  24 ) by means of a cellular wheel ( 2 ) which is moved about its axis of rotation ( 1 ) and has individual segments ( 3 ), wherein coverings ( 21 ,  25 ,  27 ) which allow bulk material or gas flows ( 22 ,  23 ,  24 ) to enter or leave are provided segmentally in the cover ( 19 ) and base ( 20 ) of the moved cellular wheel ( 2 ).  
     
     
         16 . An apparatus as claimed in  claim 15 , wherein the moved body ( 2 ) is designed as a cellular wheel which is movable about its axis of rotation ( 1 ) and discharge lines ( 8 ) for steam condensate and air and supply lines for inert gas to assist the emptying of the segments ( 3 ) are provided in the hub of the cellular wheel.  
     
     
         17 . An apparatus as claimed in  claim 15 , wherein a cover ( 19 ) allowing stationary gas access and the access of bulk material is mounted above the cellular wheel ( 2 ) rotating about its axis of rotation ( 1 ), and a stationary cover ( 20 ) with bulk material removal ( 17 ) and segments ( 27 ) allowing gas passage is mounted below the cellular wheel ( 2 ) rotating about its axis of rotation ( 1 ).  
     
     
         18 . An apparatus as claimed in  claim 15 , wherein the segments ( 3 ) of the moved body ( 2 ) are flowed through in the vertical direction.  
     
     
         19 . An apparatus as claimed in  claim 15 , wherein the segments ( 3 ) of the moved body ( 2 ) are flowed through by steam, air, inert or drying gas from the outside inward or from the inside outward.