ID 430

Latest development of hydraulic descaling nozzles

 

Abstract:

The vast majority of steel production is processed by hot rolling nowadays. The steel is heated to high tem- peratures during the process and a layer of iron oxides (scales) is formed on the surface. This layer must be removed prior and during rolling. The removal takes place in descalers by row(s) of high pressure flat jet nozzles, where the jets create a water knife that break the scale and washes it away. Heat Transfer and Fluid Flow Laboratory in cooperation with Institute of Geonics has been developing a nozzle with a pulsating jet that would increase the mechanical (water hammer) effect on the layer of the scales. So far a new fourth generation of hydrodynamic nozzle was developed. The nozzle generates an oscillating jet from side to side while maintaining the flatness of the jet. The mechanism of the oscillation is caused by the internal structure of the nozzle without any moving mechanical parts. The efficiency of the hydrodynamic nozzle is studied by the impact pressure measurements and erosion measurements. Comparison is made with conventional descaling nozzle with similar operating parameters.