Hot air device

Abstract

A hot air device comprising a heating tube and a protective tube is provided, wherein the protective tube surrounds the heating tube and is spaced apart from it, wherein the heating tube comprises a hot air outlet end, wherein the protective tube comprises a first main body and an air outlet end directed towards the hot air outlet end of the heating tube, wherein a non-uniform distance is provided between the protective tube and the heating tube, wherein the distance in the air outlet end is greater than the distance in a region adjacent to the air outlet end, and wherein the air outlet end of the protective tube comprises at least one pass-through opening in a wall, preferably in the region of a widening of the distance.

What is claimed is: 
     
         1 . A hot air device comprising
 a heating tube, and   a protective tube,   wherein the protective tube surrounds the heating tube and is spaced apart from it,   wherein the heating tube comprises a hot air outlet end,   wherein the protective tube comprises a first main body and an air outlet end directed towards the hot air outlet end of the heating tube,   wherein a non-uniform distance is provided between the protective tube and the heating tube, wherein the distance in the air outlet end is greater than the distance in a region of the first main body adjacent to the air outlet end, and   wherein the air outlet end of the protective tube comprises at least one pass-through opening in a wall.   
     
     
         2 . The hot air device according to  claim 1 , wherein the protective tube has a non-uniform first inner diameter, wherein the first inner diameter is larger in the air outlet end than in a region of the first main body directly adjacent to the air outlet end. 
     
     
         3 . The hot air device according to  claim 1 , wherein the heating tube comprises a second main body and a non-uniform second outer diameter, wherein the second outer diameter is smaller in the hot air outlet end than in a region of the second main body directly adjacent to the hot air outlet end. 
     
     
         4 . The hot air device according to  claim 1 , wherein the at least one pass-through opening is provided in a region of the widening of the distance. 
     
     
         5 . The hot air device according to  claim 1 , wherein the air outlet end comprises at least one of (a) at least 2 pass-through openings or (b) at least 6 through openings. 
     
     
         6 . The hot air device according to  claim 5 , wherein the air outlet end comprises no more than 50 through openings. 
     
     
         7 . The hot air device according to  claim 5 , wherein the at least 2 pass-through openings are arranged regularly or symmetrically along a circumference of the protective tube. 
     
     
         8 . The hot air device according to  claim 1 , wherein at least one of the at least one pass-through opening is circular or slit-shaped. 
     
     
         9 . The hot air device according to  claim 1 , wherein the air outlet end comprises a first section and a second section, wherein the second section is arranged between the first section and the main body and the distance in the first section is greater than the distance in the second section. 
     
     
         10 . The hot air device according to  claim 9 , wherein the first section has a uniform first inner diameter over its entire length. 
     
     
         11 . The hot air device according to  claim 9 , wherein the second section has a non-uniform first inner diameter which increases towards the first section 
     
     
         12 . The hot air device according to  claim 11 , wherein the first inner diameter in the second section increases evenly or continuously towards the first section. 
     
     
         13 . The hot air device according to  claim 9 , wherein the second section is formed at a right angle to the first section. 
     
     
         14 . The hot air device according to  claim 9 , wherein the at least one pass-through opening is arranged in at least one of (a) in the first section and/or (b) in the second section. 
     
     
         15 . The hot air device according to  claim 9 , wherein the at least one pass-through opening is arranged exclusively in the second section. 
     
     
         16 . The hot air device according to  claim 9 , wherein the second section extends over at least 15% and no more than 50% of the length of the air outlet end. 
     
     
         17 . The hot air device according to  claim 1 , wherein the at least one pass-through opening extends over at least one of (a) at least 30% and no more than 95% of a circumference of the protective tube, and/or (b) at least 50% and no more than 95% of a circumference of the protective tube. 
     
     
         18 . The hot air device according to  claim 1 , wherein the air outlet end extends over at least 5% and no more than 50% of the length of the protective tube. 
     
     
         19 . The hot air device according to  claim 1 , wherein the distance between the protective tube and the heating tube in the air outlet end is at least one of (a) no more than 1.5 times or (b) no more than 1.2 times as large as the distance in a region of the first main body directly adjacent to the air outlet end. 
     
     
         20 . The hot air device according to  claim 1 , wherein the protective tube surrounds the heating tube at least in sections and is spaced apart from it, so that an intermediate space is formed between the heating tube and the protective tube,
 wherein the hot air device is configured such that   a first air flow can be directed through the heating tube in direction of the hot air outlet end, such that the first air flow is heated by a heating element and exits the heating tube through the hot air outlet end, and   a second air flow in the same direction as the first air flow can be directed through the intermediate space, such that the second air flow reducing a heat transfer from the heating tube to the protective tube causes a third air flow at the air outlet end through the at least one pass-through opening into the intermediate space and exits together with the third air flow from the protective tube through the air outlet end.