Core box with air vents integrated in pins

Abstract

The invention relates to sand casting and more specifically to sand casting of a heat exchanger element with pins and/or fins. The invention provides a core box for sand casting of workpieces comprising pins and/or fins. The core box molding surface comprises at least one air vent and pins and/or fins. The at least one air vent is integrated in at least one pin or fin.

1 - 10 . (canceled) 
     
     
         11 . A core box for sand casting comprising at least one air vent and pins and/or fins of a particular heat exchanger geometry and being fixed to the core box, wherein said at least one air vent is integrated in at least one of said pins and/or fins. 
     
     
         12 . A core box for sand casting according to  claim 11 , wherein said at least one air vent being located at the base section of said pins and/or fins. 
     
     
         13 . A core box for sand casting according to  claim 11 , wherein said at least one air vent being located at the surface of the body of said pins and/or fins. 
     
     
         14 . A core box for sand casting comprising pins according  claim 11 , wherein said pins and/or fins have a diameter equal to or smaller than 3 mm. 
     
     
         15 . A core box for sand casting according to  claim 11 , said core box comprising equal to or more than 250 pins and/or fins per square meter. 
     
     
         16 . Method for the production of a pinned and/or finned heat exchanger element, said method comprising:
 providing a core box, said core box comprising pins and/or fins of a particular heat exchanger geometry and being fixed to the core box, said core box further comprising at least one air vent, wherein said at least one air vent is integrated in at least one of said pins and/or fins;   shooting a mixture of sand and binder into said core box, which is subsequently left to harden;   removing said core box, thereby obtaining a sand core;   placing said sand core in a molding box;   pouring molten metal into said molding box thereby obtaining a heat exchanger element around said sand core;   cooling of the cast heat exchanger element;   removing said sand core.   
     
     
         17 . A sand cast heat exchanger element comprising walls provided with pins and/or fins which enlarge the heat-exchanging surface, as obtained by the method of  claim 16 . 
     
     
         18 . Use of the core box as defined in  claim 11  for the production of pinned and/or finned heat exchanger element. 
     
     
         19 . Use of the heat exchanger as defined in  claim 17  in a heating boiler. 
     
     
         20 . A heating boiler provided with a heat exchanger element according to  claim 17 .