This page contains a Flash digital edition of a book.
Optimizing Melting Expansion at ME Elecmetal


Adding capacity is not as simple as adding a furnace. PAUL HENRIKSEN AND TRAVIS NEEDHAM, ME ELECMETAL, DULUTH, MINNESOTA


and white iron wear parts for the mining industry. Parts range from 200 to 10,000 lbs. and are produced from a unique vac- uum molding process. Among vacuum process metalcasting facilities, Duluth produces the world’s largest tonnage of abrasion resistant castings. In late 2012, the Duluth plant expanded its capacity by installing a third electric arc furnace identical to the two existing furnaces. Te furnace was installed to upgrade the foundry’s capacity from 130 to 160 tons/day, with the potential for higher output depending on market demand (Fig. 1). Te furnace addition resulted in a more continuous process, producing a heat every 65 minutes improving upon the 90 minute cycle times for two furnaces. Just adding furnaces to a melt


M


process will not always increase plant capacity. Te entire metalcasting facil- ity also was augmented to keep pace with the furnace install. Staffing was increased from 140 to 175 employees, and the company added heat treat ovens to match the production rate. Molding and finishing processes were expanded from two to three shifts. Minor process changes also were required to eliminate


22 | MODERN CASTING August 2015


E Elecmetal’s Duluth, Minn., casting facility produces chromium- molybdenum steel


potential delays the melting department may have encountered transitioning to 160 tons/day. Other minor issues regarding slag


accumulation, refractory consumption and energy usage have appeared as a result of the decrease in furnace utiliza- tion. Efforts to correct these issues and further optimize the plant currently are being realized and implemented.


Process Comparison of Two vs. Three Furnaces


Multiple processes in a metalcasting


facility rely on the output of another process to function. Te Duluth plant can be summarized into four main departments, each critical for the facil- ity to operate: • Melting: the processing of scrap metal into molten metal of specific chemical identity.


• Pouring: pouring the molten metal into molds.


• Molding: making the molds to pour into.


• Finishing: heat treating and clean- ing the castings.


Figure 1. Shown are the daily average production levels by month for 2012. October marked the first month of production with all three furnaces running.


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68