Refractory lining increases furnace uptime to 6 days on, 1 day off. (Case History).John Deere Foundry, Waterloo, Iowa Waterloo is the county seat of Black Hawk County, Iowa, United States. As of the 2000 census, the city had a total population of 68,747. It belongs to the Cedar Falls-Waterloo Metropolitan Statistical Area, and is the larger of the two cities, by population. , a 286-employee iron foundry that produces components for agricultural equipment, was experiencing a recurring problem with iron penetration in its furnace refractory. Molten iron was penetrating between the working lining and the 24-in. top cap of its three 20-metric-ton, medium frequency coreless induction furnaces, The separation in the refractory layers was allowing iron to reach the coils, and on occasion forcing Deere to shut down its mold lines. The problem required the plant to tear out to pull or draw out by violence; as, to tear out the eyes s>. See also: Tear the top 30 in. of the refractory lining to locate and remove the penetrated iron. If all of the iron finning couldn't be found or retrieved, the entire refractory lining required replacement. This downtime was occurring several times during a typical production week. To help John Deere eliminate the problem and the resulting downtime, United Refractories Co., McMurray, Pennsylvania McMurray is a community in Peters Township, Washington County in the U.S. state of Pennsylvania. The U.S. Census Bureau defined the community as a census-designated place (CDP), though it has no legal status as a separately incorporated municipality. , worked with the foundry to develop a hybrid refractory. According to according to prep. 1. As stated or indicated by; on the authority of: according to historians. 2. In keeping with: according to instructions. 3. the refractory manufacturer, none of its standard products could be modified to provide a successful solution. Working in conjunction with John Deere, the supplier developed UniRam VRS (Video Relay Service) A communications service for the hearing or speech impaired. A VRS is the video counterpart of a TTY relay service, in which the user types on a terminal, and the relay operator speaks the messages to the recipient (see TDD/TTY). Top Gap, a hybrid dry vibratable. The typical characteristics of a Uni-Ram refractory include controlled grain sizes that result in dense lining installation and an easy-flow technology that improves installation flowability. The refractory has a density of 136 lb/cu ft, and the bond is heat set using boric acid boric acid, any one of the three chemical compounds, orthoboric (or boracic) acid, metaboric acid, and tetraboric (or pyroboric) acid; the term often refers simply to orthoboric acid. The acids may be thought of as hydrates of boric oxide, B2O3. or boron boron (bōr`ŏn) [New Gr. from borax], chemical element; symbol B; at. no. 5; at. wt. 10.81; m.p. about 2,300°C;; sublimation point about 2,550°C;; sp. gr. 2.3 at 25°C;; valence +3. oxide. The properties of the hybrid refractory minimized the separation that was occurring between the top cap and the working lining caused by expansion! differential stress cracking. Minimizing this cracking prevented iron penetration. Since the introduction of the hybrid refractory, the furnaces have been operating six days for each day of maintenance. The reduced furnace downtime has helped John Deere to follow a consistent production schedule with optimized melt efficiency. Circle No. 001 an last page. |
|
||||||||||||||||||||||
Printer friendly
Cite/link
Email
Feedback
Reader Opinion