Experimental study of hydraulic descaling

Paper presented at the 5th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 1-4 July, 2007.Experimental work was concentrated on the study of descaling in relation to heat transfer and the quality of removing scale from the surface. Three types of measurements were implemented. The first one is a measurement of impact pressure distribution on spraying surface. The second is a measurement of temperature drop when a product is passing under the nozzle. The third type is a study of the surface quality where a defined layer of oxides is sprayed and its remaining thickness is evaluated. The heat transfer test is evaluated by inverse task and the results are prepared in a form of boundary conditions suitable for using in a numerical model.cs201

Validation report which details the advanced models developed to describe a) static and continuous and b) dynamic force transfer standards taking into account sensitivity stability, temperature and other parasitic influences on the measurement uncertainty (target uncertainty is 1 % up to 100 Hz and 2 % between 100 - 1000 Hz)

Current document reports on the development and validation of advanced practical models for describing force measuring devices used for the measurement of static, continuous forces in part A as well as dynamic forces in part B of the report. In the force measurement applications, the sensitivity curve of the force measuring devices determined in the calibration gives the traceability to national standards. The measurement uncertainty in an application is mainly affected by the sensitivity stability, the influence of temperature and other parasitic components. To capture these effects an advanced model for static and continuous forces was developed in part A which describes these influences especially in respect of their contribution to the measurement uncertainty. In contrast to the static calibration procedure, the dynamic calibration of the sensor has been always challenging because of several reasons such as the sophisticated nature of dynamic measurement, insufficient structural equipment, and parasitic effects which yield higher measurement uncertainty in comparison to static measurements and therefore inappropriate characterization of the force transducers. To close this knowledge gap in the dynamic calibration, the advanced model for dynamic forces was developed in part B. To consider the dynamic properties of force measuring devices the frequency dependency of the sensitivity and the influence of parasitic influences from temperature of the force measuring devices was considered and described. The target uncertainty is 1 % for up to 100 Hz and the target uncertainty is 2 % for higher frequency range from 100 Hz up to 1000 Hz