Research Article
Effect of Parameters of Guide Vanes on Separation Characteristics in a Turbo Air Classifier
Kum-Song Ku*
,
Myong-Il Kim,
Kwang-Chol Jong,
Gi-Song Hong
Issue:
Volume 10, Issue 3, September 2025
Pages:
50-67
Received:
9 July 2025
Accepted:
4 August 2025
Published:
30 August 2025
Abstract: In this paper, the influence of angle and number of guide vanes on the classification performance in a turbo air classifier is investigated. In this paper, a two-fluid model coupled with a population balance equation was used to consider the classification characteristics. This model is superior to the DPM (Discrete Phase Model) method because the distribution of volume fraction and velocity vector along the grain size of each particle can be considered from the Eulerian point of view. First, the validation of the computational model was verified by comparing the calculation results with the experimental data of the previous study. Next, the classification characteristics with the change of the guide vane parameters in a turbo air classifier were investigated. The calculations were performed for the cases that the coarse particle exit was open and blocked. The number and angle of guide vanes had a significant effect on the classification efficiency when the coarse particle exit was blocked. For the guide vanes angle of 36°, the cut size (d50) decreases with the increase of the number of guide vanes. For 54°, cut size decreases with the increase of the number of guide vanes to 24, but it does not change for more than 24 and for 72°, the cut size shows a rather increasing trend when the number of guide vanes increases above 24. Also, in the case of the coarse particle exit opening, the number of guide vanes does not significantly affect the classification performance, in which case the fine particles are mixed with the gas and discharged to the coarse particle exit by 40%. The parameters of the guide vanes generally do not have a large influence on the classification sharpness index, but the classification sharpness index decreases when the angle of the guide vanes is 72° and the number of guide vanes is more than 36.
Abstract: In this paper, the influence of angle and number of guide vanes on the classification performance in a turbo air classifier is investigated. In this paper, a two-fluid model coupled with a population balance equation was used to consider the classification characteristics. This model is superior to the DPM (Discrete Phase Model) method because the ...
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Review Article
Enhancing Physics Teachers’ Practices Through Problem-based Learning in Uganda Secondary Schools
Issue:
Volume 10, Issue 3, September 2025
Pages:
68-77
Received:
23 December 2024
Accepted:
6 January 2025
Published:
15 September 2025
DOI:
10.11648/j.wjap.20251003.12
Downloads:
Views:
Abstract: The study assessed the impact of aligning teaching practices with reformed pedagogical principles when problem-based learning was implemented in a physics class at lower secondary schools in Sheema District, Western Uganda. The research focused on understanding how teaching practices evolved and aligned with contemporary educational reforms when PBL was introduced as a teaching method. Method: Teachers in the treatment group were first trained in the PBL method by Lecturers from the National Teacher College, who were specifically hired for this purpose. The training sessions aimed to equip teachers with the necessary knowledge and skills to implement PBL effectively in their classrooms. These lecturers provided continuous support to the teachers, guiding them in developing schemes of work, detailed lesson plans, relevant instructional materials, and strategies for delivering PBL-based physics lessons. To evaluate the implementation process, the researcher, together with trained assistants, conducted lesson observations using the Reformed Teaching Observation Protocol (RTOP). This protocol is designed to measure the extent to which teaching practices align with reformed pedagogical principles. Findings: The study revealed an overall positive alignment with reformed teaching practices, as indicated by a mean RTOP score of 79.625%. This score reflects a significant improvement in teaching practices among teachers who adopted PBL, suggesting that the method is interactive, student-centered, and inquiry-based. The findings highlight that the Ugandan physics classrooms, particularly in Sheema District, are capable of embracing reformed teaching practices that can lead to enhanced teaching and learning experiences. Recommendation: Based on these findings, it is recommended that teachers continue to use PBL as a primary teaching method in physics. The adoption of PBL aligns teaching practices with reformed educational principles and also has the potential to improve students’ academic achievement and overall learning outcomes. Additionally, ongoing professional development opportunities should be provided for teachers to sustain and deepen their understanding and application of PBL.
Abstract: The study assessed the impact of aligning teaching practices with reformed pedagogical principles when problem-based learning was implemented in a physics class at lower secondary schools in Sheema District, Western Uganda. The research focused on understanding how teaching practices evolved and aligned with contemporary educational reforms when PB...
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