S/K WILLIAtf SIEMENS, F.A\S. 387 



:"mperature of the heating chamber, as is the case when 

 ordinary f urnaces are employ t-<l, lnit at a temperature not exceeding 

 T l<>0 F., thus rendering nearly all the heat produced in 

 actual combustion available for accomplishing useful work. It 

 will I) readily perceived that the economy of this system must be 

 greatest in melting steel or in accomplishing operations of melting 

 or heating at very high temperatures, whereas for the attainment 

 of low temperatures, such as the heating of boilers, the economy 

 would be comparatively small. Its practical economical result for 

 ligh temperatures is well illustrated by the fact that in melting 

 steel in pots in the ordinary air furnace at Sheffield, 3 tons of 

 Din-ham coke are required to melt a ton of steel, whereas a ton of 

 small coal suffices to melt a ton of steel in the same pots when the 

 regenerative gas furnace is employed. In melting steel in bulk 

 upon the open hearth, the consumption of fuel is further reduced, 

 and does not exceed 12 cwt. of coal for the production of a ton of 

 steel. In re-heating iron, the practical economy effected in the 

 regenerative gas furnace over the ordinary furnace amounts to 

 from 40 to 50 per cent., owing to the inferior degree of tempera- 

 ture required. When applying the system to inferior tempera- 

 tures, there is advantage in suppressing the cooling tube and gas 

 regenerator, and in approaching the gas-producers to the furnace, 

 to consume the gas at its initial temperature. 



At large works such as are now erected for carrying out the 

 open-hearth steel process, a cluster of producers are put up outside 

 the works ; and the fuel is delivered from the railway at an 

 elevated point in order to be put into the producers in which it is 

 gradually consumed, and flows as a gas through the large overhead 

 tubes into the works, where a number of furnaces are supplied for 

 the production of steel. I think these observations may suffice to 

 describe the furnace which plays a most important part in the 

 process to which I shall presently refer. 



I have already stated that one of the chief objects I had in view 

 in maturing this furnace was the production of steel on the open 

 hearth, but, as usual, in introducing a new process, great difficulty 

 was encountered in first attempting to carry that idea. The 

 question arose whether steel could be melted and maintained as 

 steel upon the open hearth of a furnace at a temperature exceeding 

 the melting point of most fire-bricks. The general opinion of 



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