Absorber tube

Abstract

An absorber tube is provided that has a metal tube and a sleeve tube, which is made of glass and encloses the metal tube such that an annular space is formed between the metal tube and the sleeve tube. The annular space is evacuated and has at least one container filled with protective gas, where the container is a solder-free pressure container.

1 - 20 . (canceled) 
     
     
         21 . An absorber tube comprising:
 a metal tube;   a sleeve tube that encloses the metal tube, the sleeve being made of material transparent to solar radiation; and   an annular space formed between the metal tube and the sleeve tube, the annular space being evacuated;   at least one container filled with protective gas in the annular space, wherein the at least one container is a solder-free pressure container.   
     
     
         22 . The absorber tube according to  claim 21 , wherein the solder-free pressure container has an opening that is sealed with a sealing part. 
     
     
         23 . The absorber tube according to  claim 22 , wherein the sealing part and the solder-free pressure container are composed of a common material. 
     
     
         24 . The absorber tube according to  claim 23 , wherein the sealing part is welded to the solder-free pressure container. 
     
     
         25 . The absorber tube according to  claim 24 , wherein the sealing part is friction welded to the solder-free pressure container. 
     
     
         26 . The absorber tube according to  claim 24 , wherein the sealing part is laser or resistance welded to the solder-free pressure container. 
     
     
         27 . The absorber tube according to  claim 21 , wherein the solder-free pressure container is steel. 
     
     
         28 . The absorber tube according to  claim 21 , wherein the solder-free pressure container has an arched bottom. 
     
     
         29 . The absorber tube according to  claim 21 , wherein the solder-free pressure container has a wall thickness of 0.5 mm to 1 mm. 
     
     
         30 . The absorber tube according to  claim 21 , wherein the solder-free pressure container has a wall thickness of 0.2 mm to less than 0.5 mm. 
     
     
         31 . The absorber tube according to  claim 21 , wherein the solder-free pressure container is arranged at the metal tube or at the sleeve tube. 
     
     
         32 . The absorber tube according to  claim 21 , further comprising a structural component joining the metal tube and the sleeve tube, wherein the solder-free pressure container is arranged at the structural component. 
     
     
         33 . The absorber tube according to  claim 21 , further comprising at least one optical element arranged in the annular space adjacent to the solder-free pressure container. 
     
     
         34 . The absorber tube according to  claim 33 , wherein the at least one optical element is arranged at a location selected from the group consisting of at the sleeve tube, at the metal tube, and at the solder-free pressure container. 
     
     
         35 . The absorber tube according to  claim 33 , wherein the at least one optical element is arranged in a region between the solder-free pressure container and the sleeve tube. 
     
     
         36 . The absorber tube according to  claim 33 , wherein the at least one optical element is a glass plate. 
     
     
         37 . The absorber tube according to  claim 33 , wherein the at least one optical element is a glass tube in which the solder-free pressure container is arranged. 
     
     
         38 . The absorber tube according to  claim 33 , wherein the at least one optical element is an aperture. 
     
     
         39 . The absorber tube according to  claim 33 , wherein the at least one optical element is arranged laterally next to the solder-free pressure container. 
     
     
         40 . The absorber tube according to  claim 39 , wherein the at least one optical element is a mirror.