The use of new Mini descaling nozzles on ordinary slab hot-rolled strips

1. Development trend of common slab descaling at home and abroad
In recent years, in order to meet the descaling requirements of thin slab short-process hot rolling (hereinafter referred to as CSP) production lines, American Spray Systems Company has developed the latest generation of descaling nozzles – the Mini HiScaleJet D41832 nozzle, which has the characteristics of high pressure resistance, water saving, Energy saving, small slab temperature drop and other advantages. With the increase in CSP production lines, Mini descaling nozzles have received more and more attention and development.
In order to occupy a favorable position in the increasingly competitive steel market for ordinary hot slab rolling (hereinafter referred to as HSM), HSM at home and abroad have also begun to transform the descaling system in the following aspects:
1) Increase the system pressure of the high-pressure water descaling system;
2) Increase the number of descaling header passes and increase the number of descaling points;
3) Reduce the injection height;
4) An increase in the types of descaling nozzles and the use of small flow nozzles;
The ultimate goal is to increase the impact force, control the temperature drop of the slab, and reduce water consumption; and the Mini descaling nozzle has become the first choice for the transformation of the HSM descaling system due to its successful application in the CSP production line.
2. Characteristics of the Mini descaling nozzle from American Spray Systems Company
Almost all domestic CSP production lines use Mini descaling nozzles, which can better meet the descaling requirements of CSP lines; some domestic HSM production lines also use Mini descaling nozzles when transforming the descaling system. The following are the features of the D41832 series Mini descaling nozzle:
1) The internal smooth design greatly reduces turbulence, and the impact force is 15-30% higher than that of ordinary descaling nozzles;
2) The spray shape is like a “knife”, the fan-shaped thickness of the spray painting is very thin, and the density of the water flow is high;
3) Water consumption is very small;
4) Maximum withstand pressure – 400bar;
5) Small outer diameter of 32mm, – the injection height is greatly reduced, the minimum can be 70mm;
6) The injection angle remains constant within the pressure range of 80 to 400 bar;
7) The optimized BL tungsten carbide inlay makes the nozzle have a long service life, which is 4 times that of ordinary tungsten carbide.
3 Conclusion
American Spray Systems Company’s Mini descaling nozzle has brought real benefits to customers in actual production, such as water saving, slab temperature drop reduction, and product surface quality improvement. It can be predicted that the Mini descaling nozzle, which has been widely used in CSP production lines, will also be promoted in HSM production lines.