incorrectly, were required to submit a fully completed form. Unfortunately, during the coil
Fig. 1. An example of the iron strap locations is shown.
flasks and one without. Te iron is transferred in pouring trucks to barrel- style and truck ladles. Over time, the schedule changed to the point where the furnaces did not sit for long periods, which reduced the cooling time for the refractory. Te company then switched to a low-kilowatt hold power that never went above 300 kW. Te furnaces operated with demand controllers that helped prevent full melting power during specified hours. Motor Castings secured a special pro- duction rider from its electric supplier that allowed full melting from 10 a.m. to 12 p.m. and from 8 to 10 p.m. In 2007, Motor Castings had its
furnaces on an automatic, eight-week reline schedule with weekly repairs, but company officials wanted to extend the lining’s life. Te melt department began with daily visual inspections of the linings after the furnaces were drained to look for excessive wear or premature refractory loss. During this period, no obvious issues were discov- ered. Motor Castings personnel also took a closer look at the linings during weekend repairs to determine what, if anything, could be improved. After several weeks, the company developed a list of four issues: 1. Hand-rammed spouts were knocked out on every reline.
2. Furnace linings needed to be accurately measured.
Fig. 2. This photo shows metal behind the lining material below the spout. August 2014 MODERN CASTING | 31
3. Furnace bottoms were wearing out prematurely.
4. Iron was getting behind the furnace lining. Motor Castings’ melt depart-
ment first changed its procedure for furnace measurements. Previously, only the bottoms of the furnaces were measured to determine wear, and measurements of the side walls were not taken. Employees, who had been filling out the correlating form
installation, no center point of the inside of the furnace relative to the coil was established. To find a baseline, Motor Castings’ manage- ment directed operators to measure the lining on a new installation and used that to help determine wear. Realizing employees needed to be retrained on the proper measure- ments procedures, melt department managers demonstrated the neces- sity of removing slag and any foreign objects from the sidewalls before taking the measurements. Employees measured in four quadrants, from top to bottom, using 12, 3, 6 and 9 o’clock positions. Te depth also was mea- sured. Motor Castings was concerned the furnaces may have been super- heated, although they operated with a computerized system to prevent it. Te measurements showed the furnace bottoms required relining before the sidewalls experienced significant wear. Te company contacted its refrac- tory supplier for recommendations to improve lining life. With help from Sharp Refrac-
tories Inc., Oak Creek, Wis., the Motor Castings team determined
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