US1214763A - Electrically-heated steel-furnace. - Google Patents

Description

J. L. DIXON.

ELECTRICALLY HEATED STEE L FURNACE. APPLICATION FILED 001:14. 1916.

1,214,763. Patented Feb. 6,1917;

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ELFSTJTEKJALLY-HEATED STEEL-FURNACE.

Specification of Letters ;Patent.

Patented Feb. 6, 1917.

Application sctcber 14, 1916. Serial No. 125,558.

To all wiwmmay concern: Be it known Jesse DIXGN, o subjec t Great Britain, residcounty of VJ yne and State of Michigan, have invented certain new usezul improvements in Electrically-Elected steel-Furnaces; I do hereby declare the iiol owing to be a full, clear, and exact description of the invention, such others sgilled in the art to nppcitsins to make end use the invention has particular refelectrical metallurgical furnaces, cl furnaces, of the type which supply the heat are formed by currents passing from and to movable electrodes suitec cispended above the bath or ma er-is act a npcn. in other Words has reference to elec wherein he crucible is not included within the el means electrodes, eiliner sutozna simple and certain.

'ruct furnaces two phase four movable to be treated "sioodl, it is highly deform heating; ccndingths of the four arcs equsl arrnngement each in of electrodes oelongs virtually to en 'ndependent single hose circuit, since all possible.

be current passing through either member f either its way hucic through he other member ofthe same pain In conequence, indicator of lmngcs in currenttrengtli associated with either crlootli members of :1 pair would not alone give a sig nificsnt inv cation, since any change of current shown is due to a change in the sum of the lengths of the pair of arcs and not to any change in either arc clone. Such c sys tern must therefore be furnished with both nmmeter and. voltmeter apparatus, whether hand or regulation. T 1? ome ai n oi re s man which may be considered as a special case analogous to a delta connection. I then so connect the four movable electrodes that they appear at the four corners of the square in the vector dingram.

In the drawings, Figure 1 is a diagram showing a .preferred connection for carryout this general plum-and Fig. 2 is a vector .diay'ram corresponding to the connections shown in Fig. 1.

In the particular embodiment of my invention herein illustrated. three phase current is supplied on the mains 10, 11 and 12, to the primaries 13 and l-l of two Scottconnccted transformers The secondary associated with the primar} winding 13 is divided into two equal portions 15 and 16, and the secondary associated with the prinmry 1% is similarly divided into sections 1? and 18. As shown in Fig. l. the left hand terminal of the winding 15 is connected. with the left hand terminal of the winding 17, while the right hand terminal of i5 is connected with the left hand tenninul of the winding 18. Similarly the left hand terminal of the winding 16 is con nected with the right hand terminal of the winding 17, and the right hand terminal of 16 is connected with the right hand termizeal of the winding 18.

will, of course, be understood that the terms left and right hand, as used herein are not necessarily expressive of physical.

positions on relations in the actual wind-- ings as used. They derive their si ificancefrom the electrical relations expressed by the diagram in Fig. 1, and, as so used, these terms will be readily understood by those skilled in tl cisrt. lVith this understanding, then it willmo seen that in the arrange ment illustrated thesecondary windings are found in two pairs corresponding respectively t0 the two primaries 13 and 14; and that the left and right terminals of the left hand member of each pair are connected respectively with the left hand terminal of the left hand member and with the left hand terminal of the right hand member of the l These connections being made, free only the right hand ten band members of the two and being connectvinolings 16 and 17.

ed, the proper relation of the windings is established. This relation is illustrated in the vector diagram, Fig. These windings supply current to the four electrodes 19, 20, 21 and 22 suspended movably in a well known manner over the bath 23 in the crucible 2%. For the purposes of my invention these electrodes are connected as follows: Electrode 19 is connected with the left hand terminals of windings 15 and 17. Electrode 22 is connected with theright hand terminals of windings 16 and 18. Electrode 20 is connected with the remaining. terminals of windings 15 and 1S; and electrode 21 is connected with the remaining. terminals of Each electrode is therefore connected with. two' secondary windings. It will, of course, be understood that the particular relative positions of the four electrodes shown in the drawing are not essential to the invention. Upon analysis it will be seen that two of the electrodes are connected to the right and left terminals respectively of the left hand member (15) of one pair of secondary windings. while the other two electrodes are similarly connected with the right and left terminals respectively of the right hand winding (16) of the same pair. The connections of these electrodes with the windings in the other pair of secondaries are determined by the permanent inter-connection of the secondary windings already described.

'By employing the arrangement described,

the current leaving any one of the four electrodes does not return exclusively through any single electrode. Consequently, if any of the four approaches the bath too closely or does not approach itclosely enough, a single ammeter related exclusively to the 1 supply conductor of that electrode will indicate an increase or decrease of current betraying the existing diiiiculty. Such an ammeter can then either serve to guide hand control or to govern automatic control in any well known manner, without the necessity of using voltmeters.

In Fig. 1 l have indicated. four individual ammeters'25, 26., 27 and 28, shown diagrammatically as suitably related to the feeding conductors of the four electrodes.

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necting the terminals of said secondary windings so as to produce a delta connection expressed by a rectangular vector diagram, a crucible, four electrodes over the same, and conductors connecting said electrodes to said secondary windings at the corners of the square in said vector diagram.

3. In an arcing electric furnace, a two phase transformer having two primaries and a pair of secondary windings for each pri- .mary, and conductors inter-connecting said secondary windings so that the left and right terminals of the left hand member of each pair are connected respectively with the left hand terminal of the left hand memher and with theleft hand terminal of the right hand member of the other pair, the remaining free terminals being mutually connected.

4C. In an arcing electric furnace, a two phase transformer having two primary.

windings and apair of secondary windings for each primary winding, said secondary windings being inter-connected so as to produce a delta connection expressed by a rectangular vector diagram; in combination with a crucible, and four electrodes over the same, two of said electrodes being connected respectively with the right and left terminals of the left band member of one of said pairs of secondary windings, while the other two electrodes are connected respectively with the right and left terminals of the right hand winding of the same pair.

In testimony whereof, I affix my signature. 1

JUSEPH LAWTON DIXON.

topics of this patent may be obtained for five cents each, by addressing the @ommissioner of Patents, Washington, ll). 43.

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