US2161181A - Melting furnace - Google Patents

Description

6, 1939. P MARX 2,161,181

l MELTING FURNAGE Filed NOV. 4, 1957 Patented June 6, 1939 umm-:DA STATES PATENToFFlcr;

2,161,181 MELTING FURNAUE Peter Marx, Hennef-on-thc-Sieg, Germany Application November 4, 1937, Serial No. 172,659

'- In Germany November 12, 1936 .z claims. (o1. zes- 9) The invention relates to melting furnaces for iron, steel and the like, and more particularly to the type adapted to be fired with powdered fuel.

One object of the invention is to provide a furnace comprising a cupola or stack for melting the constituents of the metal and a refining chamber into which the melted metal flows from the stack, and which is adaptedv to and has sumcient capacity for highly heating the metal for the 10 vproduction of metal of high quality and to overl5 ber and producing high come certain disadvantages and insufciencies inherent in prior furnaces of this type.

Another object of the invention is to provide for retaining the hot gases in the refining chamtemperatures and efficient refining of the metal in the refining chamber by means of a tangential duct between the stack and the refining chamber` with openwork refractory in the duct which delivers the hot gases into the stack for distribution throughout the crosssectional area of the stack for rapid melting and also for heatingthe metal from the stack to the refining chamber.

Other objects of the invention will appear from 25 the detailed. description.

The invention consists in the several novel features which are hereinafter set forth and are more particularly defined by claims at the conclusion hereof. f. y

In the drawing: Fig. 1 is a vertical section of a melting furnace embodying the invention, on line of Fig. 2. Fig. 2 is a horizontal section on line 2-2 of Fig.l. Fig. 3 isua plan of the remov-l able hearth of the refining chamber.

35 The invention is exemplified in a furnace com- 50 deliver prising a circular cupola or stack I6 into which the charge of materials to be rmelted for iron, steel or.other metal, is fed and in the lower end of which they are melted. This stack is provided .with a removable bottom I I covered by refractory I2 to provide access to the cupola for repairs. A circular refining chamber I3 is set from the cupola, and comprises a convex roof I4 and a depending annular wall I5 which is built integrally with, or as an extension of, the wall of the stack I0. 'The stack and refining chamber are built of refractory material. A duct I6 leads tangentially from the refining chamber I3 and tangentially into the lower end of the stack I to the combustion gases into the stack. Duct I6. is inclined downwardly from the cupola, and passes through the side of dependingvwall I5 of the refining chamber. Duct I6 has an inclined and stepped bottom I1 over which the melted metal from thel stack will slowly flow into the between the horizontally oifrefining chamber.Y Duct I6 is filled with openwork refractory I8 to retard the flow of heat from the rening chamber sufficiently so in said chamber will be highly heated for the p roduction of highly refined metal, while permitting the remainder to pass into the stack and melt the material inthe stack. The .refining chamber also comprises a hearth I9 with a central dome 20 andan upstanding annular wall 2| conforming to the wall I5 depending from the roof I4 of the refining chamber. This forms an annular space cylindrical circular wall 2| and the dome for the metal being refined.

A series of three ducts 22 extend through the depending wall I5 of the rening chamber, for the burners for delivering blasts of fuel, preferably powdered fuel, for axes of these openings are arranged to blow the fuel tangentially into the refining chamber and cause it to swirl around, and over the metal on the hearth in the annular space around the dome.

The tangential delivery of the fuel under pressure through openings 22 will cause the products of combustionto travel in a circular path over the metal on the hearth to heat and agitate the metal to a high degree', so as to eliminatethe sulphur and carbon and produce pure metal of' a high quality. The `hot gases, after heating the bath in the refining chamber,l pass tangentially through duct I6 from said chamber into'vthe stack I0. The tangential course 'of the cupola and contact with the refractory I8 and walls of duct I6, cause the gases to contact thoroughly with. the charge in the stack and results in full utilization of the heat-units contained in the gases.

A duct 24 is formed inthe annular side wall 2| and leads outwardly from the refining chamber, for discharging slag and ash while the furnace is in operation. This outlet is controlled by a suitable valve 25 so that the escape of hot gases from the refining chamber may be controlled, and to discharge the slag when necessary. The circular blast of the gases in the refining chamber blows the ash over', and the slag on, the melted metal on the hearth so it will traverse a circular course with the metal. Abaiiie 26 projects inwardly from the wall 2| and is adapted to skim off the slag and deflect it to the tangential discharge opening 24. An opening 23 is formed in the side wall 2| for drawing off the refined melted metal from the hearth I9. f

The hearth of te refining chamber with its annular wall 2i is separately built from the roof M and its depending Wall I5 and is suitably supported so it can be lowered onto a wheeled truck that the melt firing the furnace. The

21 to permit it to be transported toand from the upper section. This makes the hearth conveniently accessible for repair or relining. A plug 29 is provided in the hearth so the residue in the refining chamber can be discharged from the hearth.

In operation of the furnace, the charge or' metal and materials to be melted is fed into the stack I0. The blasts of fuel delivered under pressure into the refining .chamber through inlets 22 cause the combustion gases to travel in a. circular path indicated by arrows in Fig. 2 so the melted metal will be highly heated and refined. From the refining chamber the hot gases pass tangentially through duct I6 and around the refractory I8, and into the lower porti'on of the -stack I0 and melt the charge therein from its bottom upward. These tangentially to contact gases enter the cupola with all portions of the charge in the stack. The refractory material I8 in the duct I6 retards the iiow of the hot gases suiiiciently to maintain a very high temperature inthe refining chamber. 'The lower portion of the charge in the stack progressively melts and slowly trickles over the stepped floor I1 of duct I6 into the refining chamber and onto hearth I9. The dome 20 confines the melted metal to the annular space between the annular wall 2| and the dome. -The cross-sectional shape of the melted;

metal over the hearth win be suchthat its topf surface will be of greater area than the portion beneath it, to provide ample space for the slag and impurities to be released from the melt in the refining chamber. f.

The circular blast in the refining chamber over the melt produces a circular motion of the metal and slag over the hearth. 'I'he baffle 26 skims the slag oi the surface of the circularly-moving melt and deiiects it to the discharge duct 24 which leads tangentially from the rening chamber. The'discharge through duct 24 is controlled by means of valve 25 to avoid unnecessary escape of heat from the rening chamber. The valve 25 may be left open sufficiently to permit the slag, ash and impurities to be discharged continuously during the operation of the furnace or may be intermittently opened.

, The furnace is adapted for continuous melting because the stack may be kept charged with metal and materials since they are melted at the bottom of the stack and then flow through the duct I6 to the rening chamber. The refined material can be discharged during the refining and melting operation.

A characteristic of the refining chamber is that the space above the melt is clear and unobstructed, and this provides ample combustion area for highly heating the melt during the refinement.

The invention is not to be understood as restricted to the details set forth, since these may be modified within the scope of the appended claims, without departing from the spirit and scope of the invention.

Having thus described the invention, what I claim as new and desire 'to secure by Letters Patent is:

1. In a melting furnace for metals, the combination of a vertical stack for retaining the charge to be melted, a round refining chamber below and oiiset horizontally relatively to the stack, means for delivering fuel tangentially into the refining chamber to cause the products of combustion to swirl around the rening chamber, and a duct leading tangentially from the refining chamber to the bottom of the stack, for delivering the products of combustion fromv the refining chamber into the stack to melt .the charge and for conducting the melted metal from the stack to the refining chamber.

2. In a melting furnace for metals, the combination of a vertical stack for retaining the charge to be melted, a round rening chamber Y below and offset horizontally relatively to the stack, means for delivering fuel tangentially into the reningchamber to cause the products of combustion to swirl around the refining chamber, and a duct leading tangentially from the refining chamber and tangentially into the bottom of the stack, for delivering the products of combustion from the refining chamber into the stack to melt the charge and for conducting the melted 45 metal from the stack to the reiining chamber.

.2 PE'I'ER MARX.

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