Apparatus for shaping melts comprising inorganic oxides or minerals with an improved heating device

Abstract

Fibers, pipes, rods, strips or profiles made of high-melting inorganic oxides or minerals are used in great quantities, for example for reinforcing plastics, ceramics and metals. In order to produce said products, use is made of apparatuses comprising a melt container with an individual orifice, or orifice plate with a multiplicity of orifices, arranged in the base of the melt container. The melt in the melt container has to be kept at as homogeneous as possible an operating temperature above the individual orifice or orifice plate. For this purpose, the melt container is usually heated by a direct through flow of current. This results in high radiation losses to the surroundings and to a correspondingly high need for electric energy. It is proposed, for the heating of the melt, to arrange one or more pipes in the melt container, the pipes having at least one connection to the outside through the container casing, and electric heating elements being inserted into the pipes. This type of heating results in a homogeneous temperature distribution of the melt above the individual orifice or the orifice plate and permits an energy saving of more than 50%.

1 . An apparatus ( 1 ) for shaping melts comprising inorganic oxides or minerals, the apparatus containing a melt container ( 2 ) with a container casing ( 3 ,  4 ) and an individual orifice, or orifice plate ( 7 ) with a plurality of orifices ( 8 ), arranged in the base ( 6 ) of the melt container, wherein one or more pipes ( 9 ) are located in the melt container, the pipes having at least one connection to the outside through the container casing, and wherein electric heating elements ( 10 ) are inserted into the pipes and the melt container ( 2 ), the individual orifice or orifice plate ( 7 ) and the tubes ( 9 ) are manufactured from platinum, palladium or alloys thereof with one or more metals selected from rhodium, iridium and gold. 
     
     
         2 . The apparatus as claimed in  claim 1 , wherein the pipes ( 9 ) together with the heating elements ( 10 ) are arranged between two opposite sections of the container casing ( 3 ,  4 ) and are guided through the container casing. 
     
     
         3 . The apparatus as claimed in  claim 2 , wherein the precious metal or the precious metal alloy is stabilized by oxidic material finely distributed in the metal. 
     
     
         4 . The apparatus as claimed in  claim 1 , wherein 1 to 25 orifices per square centimeter are embedded in the orifice plate ( 7 ). 
     
     
         5 . The apparatus as claimed in  claim 1 , wherein only one individual orifice is present in the base ( 6 ) of the apparatus. 
     
     
         6 . The use of the apparatus as claimed in  claim 1  for producing fibers, pipes, rods, strips or profiles made of high-melting inorganic oxides or minerals.