| 摘要 |
1489845 Outlet for an electric furnace JOHNS-MANVILLE CORP 24 June 1975 [25 July 1974] 26676/75 Heading F4B An electric furnace for glass and other high melting paint materials, has a central tapping block 30 and electrodes 32 made from molybdenum or other suitable refactory metal, and an outlet 34 of a two stage structure 22. The structure 22 comprises a first stage 36 having a tubular block 38 supported on a member 42 and a second stage 46 having a tubular block 48 supported on a cooling jacket 50 which may have either gaseous or liquid coolant. The first stage sturcture is made of a material to withstand high temperatures but which will be susceptible to oxidation at these high temperatures. The second stage is insulated from the first stage and is cooled, so that the materials do not have to withstand such high temperatures and can be made of materials less susceptible to oxidation at the operating temperature to which they are subjected. The first stage block 38 and member 42 are made of refractory metals having a melting point in excess of 3000‹ F. such as molybdenum, chromium, tungsten, columbium, tantalum, and alloys of these metals. The second stage block 48 may be made of metals such as platinum, palladium, rhodium or alloys of these metals or equivalent metals. The jacket 50 can be made of stainless steel, copper, or equivalent metals. A refractory insulation 66 is provided between the first and second stages of the outlet structure. In a further embodiment of the invention the cooling jacket (82) may be disc-shaped, Fig. 3 (not shown), and in another version the cooling jacket may overlap part of the first stage orifice, Fig. 4 (not shown). In a further version the second stage may have a pair of cooling jackets (142) and (144), Fig. 5 (not shown), which enables continued operation of the furnace should one of the cooling jackets develop a leak.
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