Mechanism of Dry Molten Slag Granulation Using a Rotating Multi‐Nozzle Cup Atomizer

Abstract

As the main by‐product in the iron‐making process, blast furnace slag (BF slag) contains a high amount of sensible heat which is a potential heat source with great value if treated properly. Although several technologies have been investigated during recent decades, few of them can be commercialized successfully. In the previous study, we developed a rotating multi‐nozzle cup atomizer (RMCA) for granulating the molten slag. The particle size distribution of the produced slag particle is narrow, the shape is spherical, and the degree of non‐crystallization is over 95%. In the current study, the models of the disintegration mechanism, the traveling trajectories and the temperature profile of the slag droplet are established. The particle size is analyzed theoretically and then compared with experimental results. It is found that the predicted results agreed with the experimental results very well. The models can provide guidance for designing commercialized atomizer and optimizing the operation parameters.

Mineral Wool Primary Layer Formation in Collecting Chamber

“…The model in Eq. (10) indicates that the bulk density of the primary layer increases with the flow rate of the blow-away and suction air as well as with the layer mass. As said, this can be explained by layer compression due to increased pressure drop over the accumulation grid.…”

“…Two most commonly used spinner geometries are solid spinning wheels, used mainly for rock wool production, and hollow perforated rotors, used for glass wool production. The melt fiberization process was a subject of several experimental and numerical studies for both solid wheel spinners (Czygany et al [2], Vad and Morlin [3], Zhao et al [4]) and perforated rotors (Panda et al [5], Mukundan and Panda [6], Marheineke and Wegener [7], Marheineke et al [8], Qin et al [9] and [10], Kraševec et al [11]). …”

Analogue Experimental Study of Fiber Formation on Two-Wheel Spinner

“…Turbulent fiber-laden flows are of great importance in manufacturing of fiber-based materials such as mineral wool insulation, paper, composites and nonwoven fabrics [1] and [2]. Fibers for these applications are commonly produced by air-assisted spinning machines (also known as spinners) with two prevailing designs: hollow rotors with perforated walls [3] and [4] and multi wheel spinners where melt cascades between wheels and is fiberized from a free surface [5] and [6]. The former type is used for fiberization of melts with temperatures up to 1000 °C, while the latter type is employed with very high temperature melts (up to 1600 °C) in the manufacturing of stone and slag wool and will be the focus of research presented in this paper.…”

The Influence of Airflow Characteristics and Accumulation Grid Velocity on the Formation of a Stone Wool Primary Layer

“…The first method is used mostly for stone wool and the second for glass wool. The fiberization process was a subject of several experimental and numerical studies for both solid wheel spinners (Širok et al [1] and [2], Westerlund and Hoikka [3]) and perforated rotors (Panda [4], Qin et al [5] and [6], Kraševec et al [7] and [8]). …”