| 摘要 |
<p>1,004,587. Muffle furnaces. UNITED STATES BORAX AND CHEMICAL CORPORATION. May 14, 1962 [May 15, 1961], No. 17688/61. Heading F4B. [Also in Division H5] A T-shaped muffle furnace for the production of titanium diboride by the reaction of titanium dioxide, boric oxide and carbon above 1550‹ C. comprises an outer graphite tube 1, a " splittube " graphite resistance heating element 7 and an inner graphite reaction tube 6 in each arm of the T, and a water-jacketed cooling chamber 3 with a gas-tight door 5 below a discharge conduit 2 forming the leg of the T. A tubular casing 17 surrounds the furnace, the space between it and the outer tube 1 being packed with carbon black. Each half 10 of the element has an aluminium contact block 11 disposed between a water-cooled ring 12 supporting one end of the tube 1 and watercooled plates 13 and 14, insulating washers 15 and 18 being provided, the former having a rubber 0-ring 16. The element 7, Fig. 2, has a longitudinal slot 9 in each half inducing a substantially uniform heating effect. An offtake for gases is provided in the tube 1 above the discharge conduit 2. Although graphite studs 20 space each element 7 from the reaction tube 6 no substantial length of the latter will carry heating current. Specifications 1,004,585 and 1,004,586 are referred to.</p> |
