Cross-flow heat exchanger and manufacture thereof

PURPOSE: To facilitate wash coat and catalyzation processing and inspection by stacking first and second layers having closed passageways transversely and then firing at a temperature for a time sufficient to form a monolithic ceramic structure. CONSTITUTION: A heat exchanger 10 comprises a plurality of laminates of direction layers 12, 14 having through flow channels of intersecting direction wherein each direction layer 12, 14 has a double layer of square cell and single layers of square cell are laminated transversely. After being laminated, the direction layers 12, 14 are dried from raw state in order to remove excess moisture and fired at a temperature for a time sufficient to form a monolithic ceramic. According to the method, wash coat and/or catalyzation processing van be facilitated.