MODERN BLAST FURNACE PRACTICE. 



BY FRANK HEARNE CROCKARD. 



[Frank Hcarne Crockard, engineer; is one of the best knowTi metallurgists in the 

 United States, his specialty being the iron industry; he is manager of the Riverside 

 department of the National Tube company's great plant at Wheeling, ^^■. Va.: he has 

 written several articles on the economics of the iron industries for technical peri- 

 odicals, and among them is the following which appeared originally in the Engineering 

 Magazine, and is printed herewith by special arrangiBent.] 



The last three decades have been epochal in American 

 bxast furnace practice and construction. The Lucy furnace 

 of Pittsburg may be named as the primordial furnace of the 

 present type. This furnace in the year 1878 had a cubic 

 capacit}^ of 15,400 ^eet, and was driven at the rate of 16,000 

 cubic feet of air per minute. The results of the first year 

 showed a daily production of 91 tons, so that each ton of 

 iron required 169 cubic feet of furnace volume. The coke 

 consumption during this period averaged 2,850 pounds per 

 ton of iron. The promising bud of siderurgical progress thus 

 started reserved a later day for blossoming, and this we find 

 in the Edgar Thomson furnace blown in during April, 1880. 

 Furnace B of this group was 80 feet high, and contained 17,- 

 868 cubic feet. The hearth measured 11 feet in diameter 

 and was fitted with eight 5 J inch bronze tuyeres, through 

 which were forced 30,000 cubic feet of air per minute, at a 

 temperature averaging 1,100 degrees Fahrenheit. This fur- 

 nace produced 132 tons daily, requiring 135 cubic feet of 

 furnace volume per ton of iron. The coke consumption 

 during this period averaged 2,859 pounds. Small as they 

 now seem, these tonnage records were regarded as phenom- 

 enal, if not incredible. This period was distinctively, there- 

 fore, one of rapid driving, wonderful production, and high 

 fuel, and so continued until the blowing in of the North Chicago 

 Rolling j\Iill company's Number 7 furnace. This furnace 

 was blown in during March, 1885; for the period covering 

 the last six months of that year the production aggregated 

 36,680 tons, the average coke for the same period falUng 



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