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In this work, a new method is proposed to utilize a magnetic filter material to suppress the escape of fugitive particles in the iron and steel industry. The magnetic filter material was prepared using the impregnation method, exhibiting superior demagnetization resistance. The magnetic field effect generated by magnetic filter material was combined with the diffusion, interception, and inertial effects of traditional filtration mechanisms to enhance the removal of fugitive particles. The magnetic polyimide filter material improves the filtration efficiency of particles with a diameter less than 2.0 μm by approximately 20% compared with polyimide filter materials. In addition, the filtration performance was further enhanced through electrostatic agglomeration. When the positive electrode voltage is +18 kV, and the negative electrode voltage is −16 kV, after the bipolar pre-charging treatment of fugitive particles with a diameter of 0.1–1.0 μm, the magnetic polyimide filter material can achieve a filtration efficiency of more than 90%, the magnetic polyimide (P84), magnetic polyphenylene sulfide (PPS), and magnetic fiberglass filter materials all achieve a filtration efficiency of over 94% with a diameter of 0.5–1.0 μm. This study lays the foundation for the proposal new dust removal methods for the iron and steel industry. [ABSTRACT FROM AUTHOR]

A novel hood structure has been designed for the dust control system in the foundry in order to improve the working environment. A composite strategy has been applied for comparative analysis of the optimal venting volume and the airflow distribution between the conventional hood and the novel one in this study. A Computational Fluid Dynamic (CFD) method is used to simulate the airflow fields and dust-polluted air moving paths. The CFD results show that a two-outlet hood, with one outlet located on the left of the hood, is better for improving dust-polluted air than the hood with one outlet only. It can be concluded that the number of the outlets as well as their location on the hood has a significant influence on the air flow pattern in the hood. The optimal venting volume is also a major consideration that is discussed in the study. The venting volume should be designed by considering both the effective level of air flow velocity around the dust source and the energy saving. The optimal airflow distribution may reduce the turbulence in the hood system.

In this work, a new method of simulating fiber capturing particles was proposed, aiming to reveal the effects of fine particles turbulent aggregation on the capture performance of single fibers in the flow field. The process was numerically simulated based on a computational fluid dynamics–population balance method (CFD-PBM) and Eulerian wall film (EWF) model. The CFD-PBM method was used to calculate the turbulent aggregation of fine particles, and the EWF model was used to calculate the particle deposition of the fiber surface. The results showed that the numerical simulation results were consistent with the formulas. For the particle diameter range of 0.5–5.0 µm, the error of the numerical simulation results of capturing efficiency was reduced from 16.14% to 4.500% after considering the turbulent aggregation of fine particles. The deposition thickness of single fibers surface had a linear functional relationship with the residence time and the particle diameter. Moreover, when 0.5 µm ≤ dp ≤ 2.5 µm, the capture of single fibers had an inhibitory effect on the turbulent aggregation of particles. These studies provided a research clue for developing methods for scientific researchers to improve numerical simulation accuracy. [ABSTRACT FROM AUTHOR]

In this work, a new method using an external magnetic field enhanced the capture of Fe-based fine particles by magnetic fibers was proposed. The process of Fe-based fine particle capture by magnetic fibers in two structure arrangements (staggered/parallel) was numerically simulated based on a computational fluid dynamics-discrete phase model (CFD-DPM) method. Different magnetic fields could be formed by adding uniform magnetic fields along with the X-, Y-, and Z-axes were added to the domain where the magnetic fibers were located. The movement trajectories and filtration efficiencies in two structure arrangements under different magnetic fields were compared. The results showed that when v = 0.1 m/s, and 0.5 µm ≤ dp ≤ 2.5 µm, the results were relatively stable when the external magnetic field was along the X-, and Y-axes, and the filtration efficiency of the staggered structure was higher than that of the parallel structure. The results fluctuated greatly when the external magnetic field was along the Z-axis. Within the same fibrous structure arrangement, when the direction of the uniform magnetic field was the same as the direction of the face velocity ( H → // v → ⊥ l → fiber ), the performance of Fe-based fine particle capture by the magnetic fibers was the best. [ABSTRACT FROM AUTHOR]

Built Environment and Energy Application Engineering (BEEAE),namely Heating,Ventilating, Air Conditioning and Refrigerating (HVAC & R), is one of the international accreditation programs. Its knowledge system of professional theory and professional education in accredited engineering academic programs must meet the requirements of the relevant international engineering certification. In view of professional engineers and technicians training of BEEAE,the professional training programs and the knowledge system are compared and explored in line with the international certification criteria. This study compares the items and requirements of different international certification criteria, and summarizes the experienced methods of education training. The undergraduate education and training programs are then improved in accordance with the requirements from international certification criteria. The BEEAE education training schemes should combine the knowledge system of the national professional guidance standards with the items from international certification criteria. [ABSTRACT FROM AUTHOR]

New principal component analysis (PCA) respirator fit test panels had been developed for current American and Chinese civilian workers based on anthropometric surveys. The PCA panels used the first two principal components (PCs) obtained from a set of 10 facial dimensions. Although the PCA panels for American and Chinese subjects adopted the bivairate framework with two PCs, the number of the PCs retained in the PCA analysis was different between Chinese subjects and Americans. For the Chinese youth group, the third PC should be retained in the PCA analysis for developing new fit test panels. In this article, an additional number label (ANL) is used to explain the third PC in PCA analysis when the first two PCs are used to construct the PCA half-facepiece respirator fit test panel for Chinese group. The three-dimensional box-counting method is proposed to estimate the ANLs by calculating fractal dimensions of the facial anthropometric data of the Chinese youth. The linear regression coefficients of scale-free range R2 are all over 0.960, which demonstrates that the facial anthropometric data of the Chinese youth has fractal characteristic. The youth subjects born in Henan province has an ANL of 2.002, which is lower than the composite facial anthropometric data of Chinese subjects born in many provinces. Hence, Henan youth subjects have the self-similar facial anthropometric characteristic and should use the particular ANL (2.002) as the important tool along with using the PCA panel. The ANL method proposed in this article not only provides a new methodology in quantifying the characteristics of facial anthropometric dimensions for any ethnic/racial group, but also extends the scope of PCA panel studies to higher dimensions. [ABSTRACT FROM AUTHOR]