By: Erik Kane | On: May 12, 2016
Continuous casting is a process that revolutionized the steel-making industry after its introduction in the 1950s. Prior to that, steel was poured into a series of molds to make ingots which are individual bricks of material; a laborious process that was much slower and less efficient. By making the process continuous, molten steel could now be processed into long lengths of blooms, billets, beams, or slabs and cut accordingly without having to stop and start the process. A big part of continuous casting’s success comes from a calculated effort to cool the steel through the use of primary cooling (oscillating mold) and secondary cooling (spray chamber segments).
Primary cooling begins as the liquid steel is slowly fed from the liquid reservoir above the casting operation (Tundish) into an oscillating copper mold, which forms an outside layer that begins to harden and give it some shape. At this stage, the majority of the steel is still liquid, but the steel cast has a shell on the outside of it that can begin to be pushed through a series of rollers and cooling chambers that will continue to shape and treat the steel.
These spray chambers are a vital element of the casting process, and work in tandem with the rollers to produce steel that is desirable. Too much cooling can over-harden the product and make it difficult to roll and lower the quality of the steel, whereas insufficient cooling may cause breakouts that release the liquid inner core and ruin both the cast and surrounding equipment.
The environment in which these spray chambers operate is both hot and corrosive, and the supply lines for the cooling water are often flexible hoses as opposed to hard piping. This gives the operator greater ease and simplicity when providing connections from the surrounding piping system, as well as providing a means for cost effective maintenance when replacements need to happen due to wear and tear or exposure to liquid steel from breakouts.
Ultimately, corrugated metal hoses are best suited to handle both the ambient temperature extremes, as well as the corrosion that will inevitably effect the exterior of the hoses (and surrounding equipment areas) as a result of the combination of mold powders and cooling water that will then be turned into steam and coat the inside of the spray chamber. Because of this, utilizing hose and braid made from 316 stainless steel as well as the addition of a fire jacket in some instances will help to guarantee the maximum life of the hose assemblies.
Depending on what style of semi-finished steel is being cast, space may become an important issue. Larger strands like slabs take up more space and care must be taken when piping the surrounding equipment in spray chambers. When planning a piping system and/or installing hoses of any type, it’s important to recognize their operating bend radius. Most applications are known to have movements which mean adhering to the dynamic minimum bend radius when installing hoses so they do not fail prematurely. If additional bend radius is required due to space restrictions, utilizing a close-pitched hose construction will grant more flexibility as the corrugations per foot are increased in this style.
Because designing applications and solutions for steel mills can be challenging due to the extreme nature of the environment, all of the factors in an application can be hard to identify.
If you’re having issues with hoses in a spray chamber, a steel mill, or any industrial application, contact the Hose Master Inside Sales department at 1-800-221-2319 so that our metal hose application experts can assist you in finding the right hose for your application.
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