Influence of Temperature on Sticking Behavior of Iron Powder in Fluidized Bed

Abstract

The influence that temperature has on bed pressure drop, grain size and morphology of iron fines in a hot-state visualizable fluidized bed was investigated in this work. It was found that there are both a start sticking temperature (Ts, 673 K-773 K) and a critical defluidization temperature (Tc, 923 K-973 K) of the iron particles in the fluidized bed. Not only the bed pressure drop but the agglomeration degree of the iron particles shows a strong dependence on temperature. It is also confirmed experimentally that the crystallized iron fines without whisker show a certain viscosity even at a temperature far from the melting point.

Characterization of Precipitated Carbon by XPS and Its Prevention Mechanism of Sticking during Reduction of Fe2O3 Particles in the Fluidized Bed

“…In Fig. 8, the defluidization of the pure iron particles happened at 952 K that also was reported by Y. W. Zhong et al 19) and J. H. Shao et al, 20) which was mostly consistent with above theory. If Fe 3 C was regarded as a specific metal and the relationship between Tammann temperature and the melting temperature of Fe 3 C was the same as the metallic iron, its Tammann temperature was 1 054 K based on its melting temperature of 2 110 K. The result in Fig.…”

Efficient synthesis of iron nanoparticles by self‐agglomeration in a fluidized bed

“…The fluidization time decreased sharply from 90 min at 400°C to 11 min at 600°C. This sintering is a common phenomenon that causes defluidization . Defluidization may be caused by the sticking of fibrous iron, which appears above 600°C, the formation of eutectic melting phases that occur only above 850°C, or the high sintering activity of the newly formed Fe NPs .…”

Characterization and measurement of apparent viscosity of solid particles in fixed beds under high temperature

“…and higher adhesion property among the particles, which is more likely to cause defluidization problem inside fluidized bed. In order to verify the relationship between the proposed particle apparent viscosity and the adhesion property of the particles, we used the visual fluidized bed apparatus in the laboratory, whose structure and operating procedure have been described in details in literature [29], to measure the defluidization temperature of solid iron powder (Types 3, 4, and 6 shown in Table 1) and Copper particles (Type 1 shown in Table 1). In the experiment, 50 g of the metal particles are placed in the visual fluidized bed reactor and fluidized in Ar (2 L/min) environment.…”