Ushirikiano
SANAA
UREMBO NA USTAWI
UJANJA
UTAMADUNI NA HISTORIA
BURUDANI
MAZINGIRA
CHAKULA NA VINYWAJI
UHANDISI WA KINYUME
SAYANSI
MICHEZO
TEKNOLOJIA
VAZI
Electric Arc Furnace: the Héroult Series-Arc Steel Furnace (Stansfield, 1914)
Héroult's steel furnace: a tilting hearth like an open-hearth furnace, lined with dolomite, with two carbon electrodes coming down through the roof. The current goes down one electrode, arcs into the slag, passes through the molten steel and arcs back up the other, so the heat goes straight into the metal.
Result: an electric steel furnace about 7 x 4 ft inside for a 3 ton charge, run at about 350 kW and 110 V.
Source: A. Stansfield, The Electric Furnace, 2nd ed. (1914), pp. 115-116, 214-216. Unknown: case and tilting gear details, electrode size. Picture: a drawn diagram (Fig. 93 is blank in the scan).
Mtaalamu
Unknown
Maagizo
1
1
Build the case and lining
Build the case and lining
Build the furnace in a steel case on a tilting mounting, about 7 x 4 ft inside, with charging doors at the ends. Line it with dolomite bricks and crushed dolomite; dolomite or magnesite on the hearth, which allows strongly basic slags. Ours: mild steel plate. Not given: the case and tilting gear, the bricks' making.
Vifaa kwa hatua hii:
Bamba la chuma laini1 case
Dolomiti (chokaa yenye magnesia)1 lining and crushed dolomite
Matofali ya magnesiti1 hearth, if magnesiteZana zinazohitajika:
Mashine ya kulehemu kwa upinde
Mwiko wa mwashi
Vipimo visivyojulikana2
2
Make the removable roof
Make the removable roof
Make the roof of silica brick, covered with steel plates and given eyes so it can be lifted off. Between the two electrode holes use bronze plates instead of steel, because steel there would raise the inductance of the AC circuit. Fit water jackets round each electrode hole for a close fit, so less heat escapes and the electrodes do not burn in the air. Ours: copper tube for the water jackets. Silica brick has no head here.
Vifaa kwa hatua hii:
Nyenzo isiyojulikana1 silica brickBamba la chuma laini1 roof plates
Bati la shaba nyeusi1 plates between electrodes
Mrija wa shaba-njekundu1 water jacketsZana zinazohitajika:
Mashine ya kulehemu kwa upinde
Kekee cha Nguzo
Maji3
3
Hang the electrodes
Hang the electrodes
Use two vertical carbon electrodes, square in section. Carry each in a holder on an arm supported by the furnace itself, so its height does not change when the furnace tilts: four contact pieces round the electrode, drawn tight by a steel strap and a screw in the arm, with the cable bolted to them. Raise and lower each electrode separately, by a regulator controlled by the voltage between it and the metal. Not given: electrode size, the regulator's build.
Vifaa kwa hatua hii:
Elektrodi ya kaboni2 electrodes
Metali isiyojulikana1 holders, arms, contact piecesZana zinazohitajika:
Kekee cha Nguzo4
4
Melt and refine a charge
Melt and refine a charge
Charge steel scrap with some iron ore and lime. Keep each electrode a little above the slag, leaving room for its arc. Regulate the current by hand while the scrap melts, then switch to automatic; full power only after about an hour. Pour off the slag and make a second, then a third, with lime and a little sand and fluorspar, before the final additions. At La Praz this took about 350 kW at 110 V: 5 hours for 1.25 tons of low-carbon steel, 8 hours for 2.33 tons of high-carbon steel. Not given: the electric supply.
Zana zinazohitajika:
MajiVifaa
8- 1 roof platesKishikilia Nafasi
- 1 lining and crushed dolomiteKishikilia Nafasi
- 1 hearth, if magnesiteKishikilia Nafasi
- 1 silica brickKishikilia Nafasi
- 1 plates between electrodesKishikilia Nafasi
- 1 water jacketsKishikilia Nafasi
- 2 electrodesKishikilia Nafasi
- 1 holders, arms, contact piecesKishikilia Nafasi
Vifaa vya Michoro Iliyounganishwa
Mchoro huu unatengeneza
CC0 Umma Wote
Mchoro huu umetolewa chini ya CC0. Uko huru kunakili, kubadilisha, kusambaza, na kutumia kazi hii kwa madhumuni yoyote, bila kuomba ruhusa.
Saidia Mtengenezaji kwa kununua bidhaa kupitia Mchoro wao ambapo wanapata Kamisheni ya Mtengenezaji iliyowekwa na Wachuuzi, au unda marudio mapya ya Mchoro huu na uiunganishe kama kiungo katika Mchoro wako kuchangia mapato.