Descaling
Reliable descaling with powerful high pressure technology
Descaling removes the impurities from iron oxide formed on the surface during the manufacturing process of metal products. In continuous casting and rolling processes, reliable descaling with high-pressure water is possible. The blasting machines work with the individually required pressures. Corrosive and abrasive components of the descaling water place high demands on the pumps used.
URACA high-pressure pump units have been proving themselves in this market worldwide for decades.
Our services for your benefit
- many years of experience in this application
- tailor-made solutions for different plants
- reliable, extremely robust technology
- suitable for continuous operation in steelworks
- high efficiency of the pump units
- reliable spare parts supply over many years
- technical assistance in selecting suitable pumps
Descaling
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.
Method of descaling with high-pressure technology
For descaling, various methods can be used:
- pickling
- brushing
- descaling by bending
- flame cleaning
- High pressure water jetting
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.
- Breaking of the scale layer by temperature shock and steam bubbles
- clean removal of the scale by water jet
- suitable for large hot rolling mills
- Large-scale application possible with multiple beams and special nozzles
- benefitial or cost effective cleaning medium water
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.