Study of mean residence time in novel U-type fluidized bed reactor: Model prediction and experimental validation

• Published in: Powder technology Vol. 458; p. 120992
• Main Authors: Tang, Zhidong, Cheng, Shaokai, Gao, Peng, Han, Yuexin, Li, Yanjun
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 31.05.2025
• Subjects: air flow; cold; fluidized beds; hematite; Hematite powder; Mean residence time prediction; Model validation; particle size; prediction; product quality; technology; U-type fluidized bed reactor; Hematite powder; Mean residence time prediction; U-type fluidized bed reactor; Model validation
• ISSN: 0032-5910
• DOI: 10.1016/j.powtec.2025.120992

Fluidized bed roasting exhibits excellent application prospects for processing refractory iron ores, with the residence time of hematite powders in reactor being a critical factor that affects roasted product quality. In this study, a model for the mean residence time of materials in a U-type reactor was established and validated through cold experiment system. The effects of fluidization chamber airflow, supply chamber airflow and delivery rate were explored with different particle size of hematite. The results showed that the mean residence time of hematite powders predicted by the model and obtained from the experimental data decreased gradually with the increase of the fluidization chamber airflow, supply chamber airflow, and delivery rate. 70 groups of mean residence times for different working conditions matched very well with the model-predicted, with an error margin of less than ±8.58 %, which confirmed the validity of the proposed model. This model holds significant importance for regulating and optimizing the operational parameters of hematite during suspension roasting. [Display omitted] •The mean residence time of hematite powder in U- type reactor was studied.•A predictive model was established and validated with cold-state tests.•Model accuracy was confirmed with error margin of less than 8.58 %.•The effect of operating conditions on mean residence time was explored.