Browsing by Author "Lu, HC"

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A pilot-scale study of the design and operation parameters of a pulse-jet baghouse
(1998-12-01)
Lu, HC
;
Tsai, CJ
;
環境工程研究所
;
Institute of Environmental Engineering
Filtration curves and pulse-jet cleaning performance of different design and operating conditions of a pilot-scale pulse-jet baghouse are investigated. The effective residual pressure loss is used as an index of bag cleaning effect, while the average pulse overpressure inside the bag is used as an index of bag cleaning intensity. It is found that filtration curves vary with the initial tank pressure and the nozzle diameter of the bag cleaning system. The filtration time increases with increasing initial tank pressure or nozzle diameter. However, a critical value of the tank pressure exists for an effective bag cleaning. It is also found that a critical effective residual pressure loss value exists for the pulse-jet cleaning system. Too large an initial tank pressure and nozzle diameter result in a waste of cleaning energy. The addition of a venturi increases the average pulse overpressure appreciably, hence increasing the cleaning effect. A venturi is suggested to be installed to increase the bag cleaning effect and maximize cleaning energy in this study. (C) 1998 American Association for Aerosol Research.
A pilot-scale study of the design and operation parameters of a pulse-jet baghouse
(1998-12-01)
Lu, HC
;
Tsai, CJ
;
環境工程研究所
;
Institute of Environmental Engineering
Filtration curves and pulse-jet cleaning performance of different design and operating conditions of a pilot-scale pulse-jet baghouse are investigated. The effective residual pressure loss is used as an index of bag cleaning effect, while the average pulse overpressure inside the bag is used as an index of bag cleaning intensity. It is found that filtration curves vary with the initial tank pressure and the nozzle diameter of the bag cleaning system. The filtration time increases with increasing initial tank pressure or nozzle diameter. However, a critical value of the tank pressure exists for an effective bag cleaning. It is also found that a critical effective residual pressure loss value exists for the pulse-jet cleaning system. Too large an initial tank pressure and nozzle diameter result in a waste of cleaning energy. The addition of a venturi increases the average pulse overpressure appreciably, hence increasing the cleaning effect. A venturi is suggested to be installed to increase the bag cleaning effect and maximize cleaning energy in this study. (C) 1998 American Association for Aerosol Research.
A real time collaboration system for teleradiology consultation
(2003-12-01)
Lee, JS
;
Tsai, CT
;
Pen, CH
;
Lu, HC
;
資訊工程學系
Real time collaboration systems, in which participants share multimedia data and applications in real time, have attracted many researchers in recent years. A teleradiology consultation system based on the real time collaboration technology is presented in this paper. Under the platform-independence consideration, Java technologies are employed to construct the system. Applying this system, an off-duty on-call radiologist can make diagnoses and report easily by viewing the transferred images at home. Owing to the accessibility of image, all users can examine and manipulate images consistently such that a secluded hospital can be assisted to hold remote consultation. To reduce the network transmission time, the command-passing and local command execution techniques are utilized to achieve the screen synchronization. A pointer function is also developed to maintain the cursor consistency in a more efficient manner during consultation when a detail indication of the examined image is needed. Besides, a dialog window is also designed for on-line conversation. Since Java programs can run on heterogeneous platforms, the need for system maintenance and user training can be substantially reduced. (C) 2003 Elsevier Ireland All rights reserved.
Atmospheric lead concentration distribution in Northern Taiwan
(2003-08-01)
Lu, HC
;
Tsai, CJ
;
Hung, IF
;
環境工程研究所
;
Institute of Environmental Engineering
Atmospheric lead concentrations were measured randomly, approximately once per week, at five traffic sites in northern Taiwan from September 1994 to May 1995. Three types,of theoretical distributions, lognormal, Weibull and gamma were selected to fit the frequency distribution of the measured lead concentration. Four goodness-of-fit criteria were used to judge which theoretical distribution is the most appropriate to represent the frequency distributions of atmospheric lead. The results show that atmospheric lead concentrations in total suspended particulates fit the lognormal distribution reasonably well in northern Taiwan. The intervals of fitted theoretical cumulative frequency distributions (CFDs) can successfully contain the measured data when the population mean is estimated with a 95% confidence interval. In addition, atmospheric lead concentration exceeding a critical concentration is also predicted from the fitted theoretical CFDs. (C) 2003 Elsevier Science Ltd. All rights reserved.
Effect of filtration velocity and filtration pressure drop on the bag-cleaning performance of a pulse-jet baghouse
(1999)
Tsai, CJ
;
Tsai, ML
;
Lu, HC
;
環境工程研究所
;
Institute of Environmental Engineering
In this study the filtration velocity and filtration pressure drop at the beginning of bag cleaning were used as experimental parameters to evaluate the bag-cleaning performance of a pulse-jet baghouse. The effective residual pressure loss was used to indicate the cleaning performance after bag cleaning. Two different test dusts, fly ash and limestone, were used. The critical cleaning indices under different operation conditions for bag cleaning were also investigated. A critical average pulse overpressure was found to exist beyond which bag-cleaning performance did not improve much. It was found the filter's final filtration resistance is an important parameter to decide whether a Venturi is necessary for a good bag-cleaning performance or not. Use of a Venturi was found to increase the average pulse overpressure for a system with a filter's final resistance coefficient greater than about 500 Pa.s/cm. However, no Venturi is recommended when the filter's final resistance coefficient is smaller than 500 Pa.s/cm.
Effect of filtration velocity and filtration pressure drop on the bag-cleaning performance of a pulse-jet baghouse
(2000)
Tsai, CJ
;
Tsai, ML
;
Lu, HC
;
環境工程研究所
;
Institute of Environmental Engineering
In this study the filtration velocity and filtration pressure drop at the beginning of bag cleaning were used as experimental parameters to evaluate the bag-cleaning performance of a pulse-jet baghouse. The effective residual pressure loss was used to indicate the cleaning performance after bag cleaning. Two different test dusts, fly ash and limestone, were used. The critical cleaning indices under different operation conditions for bag cleaning were also investigated. A critical average pulse overpressure was found to exist beyond which bag-cleaning performance did not improve much. It was found the filter's final filtration resistance is an important parameter to decide whether a Venturi is necessary for a good bag-cleaning performance or not. Use of a Venturi was found to increase the average pulse overpressure for a system with a filter's final resistance coefficient greater than about 500 Pa.s/cm. However, no Venturi is recommended when the filter's final resistance coefficient is smaller than 500 Pa.s/cm.
Influence of design and operation parameters on bag-cleaning performance of pulse-jet baghouse
(1999-06-01)
Lu, HC
;
Tsai, CJ
;
環境工程研究所
;
Institute of Environmental Engineering
In this study, a filter test system with clean new fabric bags was used to measure the pulse pressure and acceleration of the filter bag. Fabric acceleration and pulse pressure were used as an index of bag-cleaning intensity. The jet pump curves, which relate the flow rate through the venturi to the average developed pressure by the venturi, were determined by the similar system. The intersection of the jet pump curve and the bag operating line, which relates the pressure drop to flow rate across the bag during pulse-jet cleaning, is the system operating point that was used to predict the average pulse pressure in the bag during pulse-jet cleaning. Experimental results of this study show that a higher pulse pressure can be achieved without the venturi at the top of the bag for bag materials with low resistance coefficient. For bags with higher resistance coefficients, higher pulse pressure is obtained with a venturi installed at the top of the bag. The predicted pressure values are in good agreement with experimental data. Dimensional analysis for jet pump performance was developed to reduce the experimental data. The results show that the jet pump curves obtained under different operating conditions can be reduced to the same nondimensional curve, which can be used to facilitate the design and operation of a pulse-jet cleaning system.
Influence of different cleaning conditions on cleaning performance of pilot-scale pulse-jet baghouse
(2003-09-01)
Lu, HC
;
Tsai, CJ
;
環境工程研究所
;
Institute of Environmental Engineering
In this study, a pilot-scale pulse-jet baghouse is utilized to control the particulate emission of an oil-fired boiler. The operating and design parameters, such as filtration velocity, initial tank pressure, and nozzle diameter, were varied to evaluate the cleaning effect of the pulse-jet baghouse. Two different cleaning types, (1) high initial tank pressure and one bag cleaning; and (2) low initial tank pressure and two consecutive bag cleanings, are used to compare the bag-cleaning performance in this study. It is found that the cleaning effect increases with the initial tank pressure. However, the cleaning intensity (overpressure) does not increase with the nozzle diameter. There exists an optimum nozzle diameter to achieve higher cleaning intensity and a better cleaning effect. This phenomenon results from the small volume of the baghouse compartment in this study. If an industrial size baghouse was used, it suggests that a nozzle diameter larger than 13 mm and initial tank pressure greater than 2.5 kg/cm(2) should be adopted to achieve a higher cleaning effect. Between the two cleaning types, type 2 is found to be more effective to clean the bag and the energy consumption for compressed air is reduced significantly from type 1. Therefore, type 2 bag cleaning is suggested to be a better method to clean the baghouse.
Numerical and experimental study of cleaning process of a pulse-jet fabric filtration system
(1996-11-01)
Lu, HC
;
Tsai, CJ
;
環境工程研究所
;
Institute of Environmental Engineering
A numerical model was developed to simulate the unsteady, compressible pulse-jet cleaning process for a fabric filtration system. The objective is to find the best design and operating conditions that provide more cleaning force for bag cleaning. The simulated results of air pressure and flow distributions in the system agree reasonably well with the experimental data. The study shows that tank volume, initial tank pressure, nozzle diameter, distance between nozzle a nd bag to p, a nd pulse duration are the major parameters influencing the pressure impulse in the fabric bag. For the system investigated, the optimized nozzle diameter is 30 mm, pulse duration is from 300 to 600 ms, distance between nozzle and bag top is 60 cm, and tank volume is 0.3-0.5 m(3). Given all other conditions fixed, increasing the tank pressure seems to be the most convenient way to achieve a higher bag cleaning efficiency. A new bag was used in this study that has a resistance coefficient of 864 Pa . s m(-1). The study shows that the major effect of increasing the resistance coefficient to as much as 10 times that of a clean bag is to increase the pressure pulse in the bag. The optimum design parameters remain unchanged.
Numerical and experimental study of cleaning process of a pulse-jet fabric filtration system
(1996-11-01)
Lu, HC
;
Tsai, CJ
;
環境工程研究所
;
Institute of Environmental Engineering
A numerical model was developed to simulate the unsteady, compressible pulse-jet cleaning process for a fabric filtration system. The objective is to find the best design and operating conditions that provide more cleaning force for bag cleaning. The simulated results of air pressure and flow distributions in the system agree reasonably well with the experimental data. The study shows that tank volume, initial tank pressure, nozzle diameter, distance between nozzle a nd bag to p, a nd pulse duration are the major parameters influencing the pressure impulse in the fabric bag. For the system investigated, the optimized nozzle diameter is 30 mm, pulse duration is from 300 to 600 ms, distance between nozzle and bag top is 60 cm, and tank volume is 0.3-0.5 m(3). Given all other conditions fixed, increasing the tank pressure seems to be the most convenient way to achieve a higher bag cleaning efficiency. A new bag was used in this study that has a resistance coefficient of 864 Pa . s m(-1). The study shows that the major effect of increasing the resistance coefficient to as much as 10 times that of a clean bag is to increase the pressure pulse in the bag. The optimum design parameters remain unchanged.
Object finding system based on RFID technology
(2006)
Chen, LC
;
Sheu, RK
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Lu, HC
;
Lo, WT
;
Chu, YP
Locations of moving or missing objects are getting important information for context-aware applications which try to get the locality of an object, and then provide services pertaining to the object. To position an object, most systems use a predefined coordinate to compute object location while sensing the appearance of the target object. Usually, it is troublesome and costs much to define the base coordinate in advance for most object positioning systems, especially when the target object is locating in an unknown environment. To reduce the cost and complexity of object locating system and improve the accuracy of location, this paper proposed an Object Finding System based on RFID technology to identify the localities of target objects in buildings. In this paper, we introduce the design concepts of the proposed system as well as the algorithms used to calculate the object locations. In addition, the experimental results show that it is a feasibility study.
White smoke emission from a semiconductor manufacturing plant
(1997)
Tsai, CJ
;
Miao, CC
;
Lu, HC
;
交大名義發表
;
環境工程研究所
Semiconductor manufacturing involves processes which emit various gaseous and particulate pollutants. One of the common problems in the industry is the emission of white smoke from stacks of wet scrubbers. This study analyzed the physical and chemical characteristics of the white smoke in one of the semiconductor plants in Taiwan. It was observed that the medium diameter of the emitted particles is about 0.1 mu m, which will grow further into 0.1-1.0 mu m size range due to the condensation of water vapor onto these particles under certain meteorological conditions. These 0.1-1.0 mu m particles are responsible for the white smoke since they have a high light scattering efficiency. In the waste stream from the wet scrubber, the main chemical species were found to be silica, monomeric silica, ammonium, and chloride for particulate pollutants, and ammonium and chloride for gaseous pollutants. A wet Electrostatic Precipitator (ESP) installed behind the wet scrubber was shown to be able to eliminate white smoke emission due to efficient removal of submicrometer particles. (C) 1997 Elsevier Science Ltd.