Document OEmywywenbeX8mp9bYgkZpnqw

The Elliott 1000-hp JOOjSOO-rp, motor was installed very convenie the existing motor room. to be 1000 hp at 400/800 rpm. The study further showed that with slab reductions per pass accord ing to schedules, the motor loads were distributed so that they were within capacity ratings and the ex isting supporting motor-generator sets could carrv the increased loading. It was found possible to design the 1000-hp drive for No. 1A and 2A stands so that the new motor could be installed in the existing motor room thus saving the cost of a new building. The speed cones for both the old mill and the new mill arc shown in Spied canes for aid and new mills show the increase in speed obtained by the addition oj two new stands. STANO ~wcn chart below. The maximum fi speed of No. 10 stand was im about 45 percent, with the sp other stands raised to get the: speed cones shown. These changes were obtained by ins new gears, which was done w loss of production in the mill. With the foregoing speeds an ing schedules established, it i sible to examine the operation mill as a unit. Based on the ability of thi furnace to heat 80 tons of sla hour, this would result in 66 2500-Ib slabs about 30 ft long, and 5% in. wide availak rolling each hour. The top spi the new stand 1A is 62 fpm o fps. With a 4-in. spacing be slabs, these slabs would be roll 29 seconds in this stand. Hei operated at top speed, the roughing stand could roll 124 per hour, whereas the furnace i heat only 66 such slabs. IF we make a further check o last finishing stand we find it 1 top speed of 1692 fpm. Assumin coil is 1300 ft long leaving Nc stand, and a 20 percent reducti made in this stand, the enti length would be 1040 ft. With face speed of 1692 fpm, or 28.2 the piece would be in the roll seconds. Hence, if the pass coulkept full, 97 pieces could be n each hour. This indicates that the mill normal operations can roll all steel the furnace can heat wit comfortable margin for the u mill adjustments and delays. The new equipment for this has been installed, mill char made, and mill operation was stai PAGE 10 POWERFAX. AUTUMN 1954.