Carbon Black Injection Hose
Eaton industrial hose assembly helps make steel mills more productive
Based on parts alone, these new hose assemblies could save steel mills more than $10 million in the first year.
Background
Steel mills are among the most demanding work environments in any industry. Equipment used in making steel has to endure severe heat, chemical reactions and abrasion. A new product from Eaton stands up to these extreme conditions, helping reduce downtime and increase productivity.
During the melt cycle, carbon black is injected with compressed air through hoses into an electric arc furnace. The carbon black creates a foamy slag layer, which helps regulate the chemistry and temperature of the molten steel, and shields it from the electric arc. But the carbon black is so abrasive that it quickly wears through most rubber hose.
Challenge
For years, steel mills have used traditional “gunite” hose, named for its use in spray concrete applications, in 1½-inch inside diameters and lengths from 3 to 25 feet. This hose is usually fitted using male pipe threads on the hose and female threads on the furnace. Carbon black is moved through the hose in slurry or granular form at pressures of 100 psi or less.
Carbon black eventually wears completely through gum rubber hose—and even through conventional fittings, especially if the assembly includes any 90-degree bends.
Fugitt Rubber Supply, an Eaton Aeroquip Premiere Select distributor, has served the steel making industry for more than 20 years. One of its customers asked Fugitt if there was any way to increase the service life of injection hose to reduce scheduled maintenance requirements and increase furnace uptime.
A better hose product for this application could improve productivity for all the steelmills served by Fugitt—and by the customers of other Eaton distributors across the globe.
Solution
Fugitt Rubber employees applied their knowledge of the application and connection systems to develop a custom stainless steel fitting. The hose passes completely through the inner diameter of the fitting, and ends flush with a male camlockstyle connection. This straight-through design and permanent attachment help minimize flow restrictions and abrasion failures.
In 2006, Fugitt called on Eaton to develop an industrial hose, rather than a hydraulic hose, for carbon black injection applications. Eaton engineers in Newbern, Tennessee, designed a hose that would perform optimally when paired with the Fugitt fitting. The result was a true system solution.
In extensive field testing, the new hose assemblies delivered up to five times the service life of the gum rubber hose assemblies they were designed to replace. They also provide several advantages compared to ceramic lined hoses, the previous alternative to gunite rubber hose: they are lighter, more flexible, less expensive, and easier to handle with lower risk of critical damage during installation. Eaton branded this hose product exclusively for Fugitt, and introduced it in 2007.
Results
Although several factors affect how often hose assemblies need to be replaced—hose length, number of bends, volume of carbon black, and so on—the numbers are significant. For 246 electric arc furnaces, average consumption is 2,200 feet of gum rubber hose and 176 new fittings per month. That represents 6.5 million feet of hose and more than 500,000 fittings per year.
Since its introduction, Eaton has delivered approximately 60,000 feet of carbon black injection hose to Fugitt, which in turn sells assemblies to several steel mills. Customers report that the new assemblies provide much longer service life than gum rubber hose and angled fittings, keeping furnaces in operation longer between scheduled maintenance
events.
The new carbon black injection hose assemblies reduce the need for replacement. With four to five times the service life, they reduce the chances of premature failure, which means lower risks of lost batches and cleanup costs. A 75 percent reduction in assembly changeovers also means greater uptime. Based on parts alone, these new hose assemblies could save steel mills more than $10 million in the first year. Eaton and Fugitt are proud to help these businesses become more productive and profitable.
