Guo B.Y.,University of New South Wales |
Guo J.,Fujian Longking Co. |
Yu A.B.,University of New South Wales
Journal of Electrostatics | Year: 2014
The paper presents a general Control Volume model for electric field simulation in wire-plate type electrostatic precipitators, along with a new injection law for charge density. The model is validated against empirical equations and experimental data in the literature when applied to the wire-plate and point-plate configurations. The voltage current characteristics and detailed distribution of field and charge density are characterized, particularly for the case of barbed wire electrode. The effects of geometric variations, such as the sharpness of the tip and the direction of the needles with respect to the plate, are investigated. © 2014 Elsevier B.V.
Zheng K.,Fujian Longking Co.
Chinese Journal of Environmental Engineering | Year: 2014
An experimental setup for large-scale pulse-jet cleaning system was established. And systematic tests for blowing performance in the systems combining unused filter bags without dust or used filter bags with dust (both were 8 m length) and different sizes (76 mm and bigger than 76 mm) and types of pulse valve were performed by testing the pressure peak in the pulse-jet tubes, the acceleration and pressure peak in the filter bags. The results show that the high-speed return airflows result in a second pressure peak. Test results also prove that, due to its lower gas permeability, a filter bag with dust has a higher lowest pressure peak than a new one and the change of pressure peak for the whole filter bag decreases with the decrease of the air permeability of filter bags. Furthermore, the gas permeability of filter bags is inversely proportional to engineering using time, but is also influenced by dust characteristics under different flue gas conditions. Experiments also indicate that in order to ensure that a single pulse valve could perform effective pulse-jet cleaning on filter bags, the number of filter bags and the size of pulse valve should be carefully chosen according to the obtained lowest pressure peak. ©, 2014, Science Press. All right reserved.
Setia G.,Thapar University |
Mallick S.S.,Thapar University |
Pan R.,Fujian Longking Co. |
Wypych P.W.,University of Wollongong
Powder Technology | Year: 2016
Fluidized dense-phase pneumatic conveying of powders is becoming increasingly popular in various industries, such as power, chemical, cement, refinery, alumina, pharmaceutical, limestone, to list a few, due to the reasons of reduced gas flows and power consumption, improved product quality control, reduced pipeline sizing and wear rate, increased workplace safety etc. An accurate estimation of total pipeline pressure drop is of paramount importance for the reliable design of a pneumatic conveying system. However, because of the highly concentrated and turbulent nature of the gas-solids mixture, fundamentally understanding the flow mechanism and accurately predicting the pressure drop as an important design parameter has only made limited progress so far. This paper results from an ongoing investigation into developing a validated modeling procedure for solids friction factor for the accurate prediction of pressure drop and optimal operating conditions for fluidized dense-phase pneumatic conveying systems. Under the present study, a two-layer based model has been developed by separately considering the solids friction contributions of the non-suspension (dense) bed of powders flowing along the bottom of pipe and the suspension (dilute-phase flow) of particles occurring on top of the non-suspension layer. Volumetric loading ratio and dimensionless velocity have been used to model the non-suspension dune flow layer. A solids impact and friction term and dimensionless velocity have been employed to model the dilute-phase flow due their established reliability. Models have been developed using the straight-pipe conveying data of two types of fly ash, cement and ESP dust (median particle diameter: 7 to 30 μm; particle density: 2300 to 3637 kg/m3; loose-poured bulk density: 610-1080 kg/m3). The developed models for solids friction were validated for their scale-up accuracy by using them to predict the pressure drops in five larger and longer pipelines (69 mm I.D. × 168 m long; 105 mm I.D. × 168 m long; 69 mm I.D. × 554 m long, 65 mm I.D. × 254 m long and 80/100 mm I.D. × 407 m long pipes) and by comparing the experimental versus predicted pneumatic conveying characteristics. The two-layer model provided improved accuracy compared to existing models indicating that the model is able to adequately address the dense- to dilute-phase transition criteria. © 2016 Elsevier B.V.
Guo B.-Y.,University of New South Wales |
Yang S.-Y.,University of New South Wales |
Xing M.,University of New South Wales |
Dong K.-J.,University of New South Wales |
And 2 more authors.
Industrial and Engineering Chemistry Research | Year: 2013
This paper reports our attempts in developing an integrated multiscale mathematical model to describe the wire-plate-type electrostatic precipitator (ESP), aiming to understand the underlying physics and to develop a computer tool for process design and control. In the model, various phenomena in a wide range of length/time scales related to the electric field, gas-particle flow, dust deposition, cake formation, and their interactions are resolved. We apply different numerical methods for different fields in different local regions, leading to various submodels, including a continuum-based electric field model, Euler-Lagrange gas-particle flow model, and discrete-based cake formation model. These submodels are eventually integrated to form an ESP process model, which can generate results useful for better understanding the phenomena and assessing the ESP performance under different conditions. © 2013 American Chemical Society.
Zhang Z.,South China University of Technology |
Xie Y.,South China University of Technology |
Yuan Z.,Fujian Longking Co.
Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering | Year: 2011
The series-parallel resonant converter is known to have combined merits of the series resonant converter and parallel resonant converter. However, it has a three-element LCC structure with multi-resonant modes, which makes it difficult to analyze and control. In order to study the converter performance under continuous current mode, this paper demonstrated the operation principle of this converter, drew the state track diagram, and derived the trajectory equations. Finally, a simple and effective trajectory control method was given. The experimental result shows that the analysis and design method of the state-plane is effective. Trajectory control system has excellent transient performance and can achieve the new steady state in minimum time. © Chin. Soc. for Elec. Eng.