Catalyst holder and support unit

Claim 1

AN IMPROVED CATALYST HOLDER AND SUPPORT UNIT FOR USE IN THE CATALYTIC MANUFACTURE OF HYDROGEN CYANIDE COMPRISING, A PAIR OF MATING METALLIC PLATES, EACH OF SAID PLATES HAVING AN APERTURE DEFINING A GAS PASSAGEWAY, A PAIR OF STEPPED ANNULAR RECESSES ADJACENT THE APERTURE IN ONE OF SAID PLATES FOR RECEIVING AND HOLDING THE EDGES OF FORAMINOUS CATALYST AND AN ASSOCIATED CATALYST SUPPORT MEMBER, AND APERTURED INSULATING MEANS INTERPOSED BETWEEN SAID CATALYST AND THE METALLIC SURFACES OF SAID PLATES AND HAVING A GAS PASSAGEWAY SUBSTANTIALLY COEXTENSIVE WITH THE PASSAGEWAY IN SAID PLATES TO SHIELD THE CATALYST AGAINST DIRECT CONTACT WITH METALLIC SURFACES, SAID METALLIC PLATES BEING CONSTRUCTED OF AUSTENIC STAINLESS STEEL HAVING FROM ABOUT 16 TO ABOUT 26% CHROMIUM, FROM ABOUT 8% TO ABOUT 22% NICKEL AND THE REMAINDER SUBSTANTIALLY IRON, SAID SUPPORT MEMBER BEING CONSTRUCTED OF A METAL THAT IS STRUCTURALLY STABLE AT A TEMPERATURE OF ABOUT 1250*C. AND HAVING A SURFACE COATING OF A HIGH TEMPERATURE REFRACTORY, SAID HOLDER PLATES, CATALYST AND INSULATING MEANS BEING CLAMPED TOGETHER TO FORM A GAS-TIGHT SEAL ABOUT THE EDGES OF THE CATALYST.