A water-model experimental study of vortex characteristics due to nozzle clogging in slab caster mould

Abstract

Vortex formation in the continuous slab casting mould is a troublesome phenomenon that can pull mould powder/slag deep down into the liquid core and potentially damage the product quality. Submerged entry nozzle (SEN) clogging is one of the prime causes of vortex formation. This work is designed to investigate and quantify the inter-related effects of nozzle clogging, casting speed (CS) and SEN submergence depth on vortex frequency and penetration depth through water-model experiments. It is observed that the increase in degree of clogging and CS has an inter-related effect on flow asymmetry and impacted the vortex characteristics. At the combination of highest values of degree of clogging and CS, vortices formed are found to have high values of top-diameter, rotational speed, penetration depth, frequency and life. On the contrary, the SEN submergence depth has showed limited effect on these aspects except the penetration depth. With the increase in SEN submergence depth values, it is found that the number of vortices having depth greater than 80 mm is increased.

Physical Modeling of Asymmetrical Flow in Slab Continuous Casting Mold due to Submerged Entry Nozzle Clogging with the Effect of Electromagnetic Stirring

“…[19][20][21] But, only few are performed to study the influence of the rate of the SEN clogging on the flow field in the mold. Srinivas et al 22) studied the influence of the clogging degree on the flow field through a water model. As an effective method, electromagnetic stirring (EMS) technology [23][24][25][26][27][28] can control the molten steel flow in the mold, and has been widely applied in continuous casting process.…”

Influence of EMS on Asymmetric Flow with Different SEN Clogging Rates in a Slab Continuous Casting Mold

“…By clogging one of the SEN ports, Cho et al [15] applied the computational and experimental approaches with a one-third scale water model to investigate the effect of the nozzle clogging rate on the surface flow and vortex formation in a continuous casting mold. Srinivas et al [16] used a water model to study the vortex characteristics induced by the nozzle clogging rate in a slab mold. However, research of the quantitative relationship between the clogging rate and the mold flow is still lacking.…”

Multiphase Vortex Flow Patterns in Slab Caster Mold: Experimental Study

“…24) This data is tabulated in 2nd to 4th columns of Table 5. For instance, data from the 4th columnof Table 5 reveals that vortex frequencies at clogging 66% and water flow rate 50 l/min are 9.4, 9.2 and 9.4 for the corresponding SEN submergence depth values 40, 60 and 80 mm respectively.…”

“…24) In this section, the integrative effects of partial clogging and air flow rates are discussed. best representation of the data, y axis scales are chosen differently for positions 150, 250 and port exit and reader is requested to take a note of it.…”

“…8,12,[21][22][23] Cho et al 23) have explained the effect of nozzle clogging on flow bias and the resultant vortex formation using water model experiments. Srinivas et al 24) have investigated the interactive effects of process parameters like casting speed, degree of clogging and SEN submergence depth on vortex formation. However, both have dealt with single phase flow only.…”