Compact heat exchanger made of ceramics having corrosion resistance at high temperature

Abstract

Ceramic materials that are highly resistant to strong acids such as concentrated sulfuric acid and halides such as hydrogen iodide are employed to make block elements through which a large number of circular ingress channels extend in perpendicular directions and which are joined and piled in the heat exchanging medium section to provide a compact heat exchanger that excels not only in corrosion resistance but also in high-temperature strength.

1 . A heat exchanger having corrosion resistance at high temperature comprising a heat exchanging section, 
 said heat exchanging section comprising ceramic blocks made from silicon carbide or silicon nitride having a first and a second group of channels opened in two sides of each block, the blocks being stacked to fabricate a ceramic pillar vaporizer, said first group of channels oriented vertically to carry a corrosive solution of sulfuric acid or hydrogen iodide upward, and said second group of channels oriented horizontally to carry a hot helium gas laterally throughout the horizontal channels, 
 wherein the corrosive solution is supplied from the bottom of the vaporizer, and a hot helium gas is introduced laterally through the vaporizer; and the solution and gas are respectively vertically and horizontally guided to the channels through each of the ceramic blocks in the vaporizer, where they undergo heat exchange until the corrosive solution is gasified.  
   
   
   
       2 . A heat exchanger of which the heat exchanging section comprises ceramic blocks made from silicon carbide and silicon nitride.  
   
   
       3 . A heat exchanger of which the heat exchanging section comprises a bundle of pillar structures each consisting of ceramic blocks joined together.  
   
   
       4 . A heat exchanger for use in a chemical plant comprising a heat exchange section, in which a corrosive solution of sulfuric acid or hydrogen iodide near 600° C. can be gasified by heating with hot helium, SO2 and/or hydrogen iodide gas.  
   
   
       5 . A corrosion-resistant heat exchanger comprising a heat exchange section which permits heat exchange between a gas having a maximum temperature of 1000° C. and a maximum pressure of 6 MPa and a gasified corrosive solution.  
   
   
       6 . A compact heat exchanger comprising a heat exchange section which enables the heat exchange of a primary helium coolant/a secondary helium coolant near at 1000° C. between a hot gas furnace and a chemical plant.  
   
   
       7 . A heat exchanger comprising a heat exchanger section which enables heat exchange in the heat exchanging section through perpendicular channels provided in ceramic blocks.  
   
   
       8 . A heat exchanger according to  claim 1 , wherein a concentrated sulfuric acid solution near 600° C. can be gasified by heating the hot helium gas.  
   
   
       9 . A heat exchanger according to  claim 1 , which enables heat exchange in the vaporizer through perpendicular channels provided in ceramic blocks  
   
   
       10 . A heat exchanger according to  claim 8 , which enables heat exchange in the vaporizer through perpendicular channels provided in ceramic blocks