Browsing by Author "Yan, Shaw-Yi"

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An efficient wet electrostatic precipitator for removing nanoparticles, submicron and micron-sized particles
(2014-11-05)
Chen, Tzu-Ming
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Tsai, Chuen-Jinn
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Yan, Shaw-Yi
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Li, Shou-Nan
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環境工程研究所
An efficient wire-to-plate single-stage wet electrostatic precipitator (WESP) was designed and tested to control nanoparticles, submicron and micron-sized particles emitted from semiconductor manufacturing processes. Tungsten-wires of 0.36 mm in diameter were used as discharge electrodes and a fixed voltage of -15 kV was supplied to generate the electric field and corona ions. Fine water mist at room temperature was used to quench the high temperature exhaust gas to enhance particle condensation growth and improve the collection efficiency of nanoparticles. Experimental results showed that without fine water mist, nanoparticle collection efficiency was 67.9-92.9%, which was greatly enhanced to 99.2-99.7% when the WESP was operated with fine water mist. A predictive method was developed to calculate the particle collection efficiency equation eta(%) in the form as eta(%) = [1 - exp(-alpha(N-De)(beta) + gamma)] x 100%, in which alpha, beta and gamma are regression coefficients and N-De is the Deutsch number. Good agreement was obtained between present predictions and experimental data. For longer term operation, the periodic wall-cleaning water was used to clean discharge electrodes and collection electrodes regularly. In the field tests, the total collection efficiencies (40 <= d(p) <= 8100 nm) of the WESP were found to maintain greater than 98.7% and 97.3% for continuous operation for 35 and 22 day at fab A and fab B, respectively. (C) 2014 Elsevier B.V. All rights reserved.
Performance analysis of a membrane dehumidifier system subject to component characteristics - a numerical model
(1970-01-01)
Li, Shao-Ming
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Lai, Yu-Lun
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Yan, Shaw-Yi
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Wang, Chi-Chuan
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機械工程學系
In this study, a detailed modeling applicable for membrane dehumidifying system is proposed. This system contains a membrane module, 2-stage vacuum pumps, a condenser, and a regulating valve. The proposed model does not need any prior setting of the vacuum level of the permeate side, and the predictive results are in line with the benchmark. It is found that the COP (coefficient of performance) is 55% higher while the EF (energy factor) is almost 150% higher than the conventional one having the same dehumidifying capacity. For inlet with a fixed relative humidity, both COP and EF are increasd gradually when raising the inlet temperature. Yet the COP and EF reaches the peak values of 5.29 and 6.80 kg/kWh, respectively at a dry bulb temperature near 25.6 degrees C. Once surpassing this threshold temperature, a pronounced flip-over is seen for both COP and EF. The optimal COP can be obtained by simultaneously adjusting volumetric flowrate and condenser size rather than only adjusting each one individually.