Charakterisierung der Kühlleistung unterschiedlicher Düsen beim Stranggießen von Stahl

Research output: ThesisMaster's Thesis

Organisational units

Abstract

In continuous casting, the heat is dissipated in the secondary cooling zone by spraying cooling water onto the strand. An excessive or uneven cooling increases the possibility of cracks on the product, while too weak cooling leads to an increase of the center segregations. To achieve high product quality it is necessary to know the exact characteristics of the cooling water nozzles. To measure the cooling behavior of spray nozzles, the nozzle measuring stand was therefore constructed during 2008-2010 at the Department of Metallurgy. This work includes a reference section that deals with the transfer of heat from hot metal surfaces to water and the subsequent influence of participating parameters, as well as a set of experiments, in which the heat transfer coefficients of flat fan and full cone nozzles are determined under conditions similar to those in continuous casting. The cooling tests took place in a temperature range from 1000 to 1200 ° C and for water impact densities from 1 to 30 kg/m²s. In addition, the position of the sample in the spray cone varies, to cover a wide parameter field. The heat transfer coefficients from the nozzles were determined by inverse simulation. The experiments confirm that in the region of stable film boiling the heat transfer coefficient is a function of the water impact density. Furthermore an influence of the surface temperature can be determined.

Details

Translated title of the contributionCharacterization of the cooling performance of different nozzles in continuous casting of steel
Original languageGerman
QualificationDipl.-Ing.
Supervisors/Advisors
Award date16 Dec 2011
Publication statusPublished - 2011