382 THE SCIENTIFIC PAPERS OF 



regenerative gas furnace in the form in which it is now applied 

 for the production of steel on the hearth, in quantities of from 

 5 to 10 tons at a time. 



The regenerative gas furnace is so essential a part of the process 

 of open hearth steel-making that it is indispensable to describe its 

 principle and construction to some extent. It consists of two 

 distinct parts the furnace proper, with its reversing valves, 

 regenerators, and melting chamber, and the gas-producer, in which 

 the raw fuel (mostly small coal) is converted into gaseous fuel, 

 which is thus separated from all the drossy and dirty constituents 

 in the coal. It would appear, at first sight, a roundabout opera- 

 tion to convert fuel from the solid into the gaseous condition and 

 then to take and burn this gas in a furnace elsewhere ; the gas, as 

 it passes from the producer, is in a heated state, and in its transit 

 to the furnace a great deal of that heat must necessarily be lost ; 

 therefore, it might well be asked, why make this conversion of 

 solid into gaseous fuel ? Surely, in burning the gas less heat is 

 obtained than if the fuel were burnt in the heating chamber of 

 the furnace, and produced its effect there. That would be per- 

 fectly sound argument, if it was not for the regenerators of the 

 furnace. These regenerators are by far the most important part 

 of the whole arrangement, and, in order to understand the general 

 principle of the furnace. I will first describe their action. 



Plate 46, represents the furnace in longitudinal section ; the 

 gas from the gas-producer passes in through a reversing valve, 

 by means of which it is directed into the bottom part of the re- 

 generator chamber-. The gas flowing up through the mass of 

 brickwork the chamber contains, and which is placed so as to form a 

 large aggregate surface, with intricate zigzag passages, will become 

 heated, providing any heat has been accumulated therein. In the 

 first place, there will be no heat, and the gas will pass unheated 

 through this chamber and thence to the combustion chamber of 

 the furnace. At the same time, a current of air is admitted 

 through the air-reversing valve into the air regenerator chamber, 

 which is larger than the gas chamber. The air passing up through 

 the chequer work will reach the same point as the gas does at the 

 entrance into the combustion chamber of the furnace. Now, 

 since both the air and gas are cold, and as they meet for the first 

 time at the entrance into the furnace, they will, if there ignited, 



