Improvements in apparatus which is subjected during use to high temperature

摘要

1,057,388. Melting furnace joints; burners. ALLM€NNA SVENSKA ELEKTRISKA A.B. Nov. 13, 1963 [Nov. 23, 1962], No. 44768/63. Headings F4B and F4T. A heat-resistant composition forming a joint between two refractory parts subject to high temperatures comprises at least 85% by weight of magnesium and chromic oxides of which at least 90% by weight are combined as magnesium chromite (MgO.Cr 2 O 3 ). The composition should contain not more than 6% of either of the free oxides and also not more than 3% of alumina and ferric oxide or 2% silica, the sum of these impurities not exceeding 6%. It should contain 20-70% by weight of particles having a grain size substantially equal to the joint thickness, the remainder being preferably below about a quarter this size. Suitable binders, which should not exceed 9% by weight, include ethylhydroxyethyl cellulose, carboxymethyl cellulose, methyl cellulose, polyvinyl compounds, starch, dextrin, melamine resins, urea resins and ester resins. The composition 17 is shown applied between a melting or holding furnace 7 and a channel type inductor unit 1 whose respective linings 8 and 5 may be neutral, basic or acidic in character and mutually different. The outer furnace casing 11 is supported by an annular plate 12 formed with a wall 14 defining a draining channel 16 and incorporating a cooling ring 13. The inductor unit 1 also incorporates cooling pipes 20 attached by lugs 21 to its casing 6. The invention is also said to be applicable to exchangeable burner heads, measuring instrument inserts, inspection openings and sealing furnace doors.