Scale is an iron oxide impurity on the surface of metals. Descaling removes these residues. Descaling is very important in hot rolling plants for forming steel applications where the risk of contamination of the final product by iron oxide is increased.
For descaling, various methods can be used:
In hydromechanical blasting, high water pressure removes the scale. The plants, also referred to as scale scrubber, consist of several bars with special nozzles, through which the water radiates at high pressure obliquely to the surface. The process, also referred to as scale scrubber, consists of several bars with special nozzles. The special nozzle aligment creates an angular impact of the water jet to the surface of the steel. The operating pressure of the scale scrubbers is between 100 and 400 bar.
The workpiece is cleaned by breaking the scale by the effect of temperature shock and removing the scale with high water pressure. Temperature, evaporation and refractive effects act together in the hydromechanical process on the workpiece and reinforce. Evaporating water acts like small explosions and blows up the scale. Compared to mechanical processes, descaling with water is much more economical and effective.
In order to produce the required pressure of the water one uses special oscillating high-pressure plunger pumps developed for the hard continuous use under difficult conditions. Pump units must be design to cover frequent circulation between high pressure and pressureless operation since the processing of the steel workpieces usually does not run continously.
Another challenge: The descaling water used is usually in a cycle and accumulates with solid particles. Despite pre-filtration, not all particles can be removed from the water. Solid particle accumulation in the process water can be harmful for the sealing in the liquid end and other wetted parts.
URACA pump design is considering this effection during development of the pumps.
Important applications of descaling are hot rolling mills for forming steel. The scale scrubbers are an elementary component of the plants in steelworks and prevent the rolling in of the iron oxide.
Scale scrubbers are also used in the production of heavy plates, wires or metal profiles. Further areas of application are forging lines and fully automated production lines, as are customary, for example, in the production of railway wheels.
For descaling with high pressure technology, URACA offers a wide range of suitable pumps, nozzles and accessories.
Descaling in continuous casting and rolling processes requires high operating pressures of currently up to 400 bar and poses special challenges for the pumps. They must be suitable for descaling water used in circulation operation with its corrosive and abrasive components. URACA delivers tailor-made solutions with reliable and extremely robust technology. This has proven itself for many decades worldwide in continuous use. If you are looking for suitable solutions for descaling, contact the experts at URACA now. We advise you comprehensively and find the best solutions for you.
