• Title/Summary/Keyword: Operating condition

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Optimal Operation Condition of Spray Drying Sorber for Simultaneous Removal of Acidic and Organic Gaseous Pollutants (산성 및 유기성 가스의 동시제거를 위한 준건식 세정시스템의 적정 운전 조건)

  • 백경렬;구자공
    • Journal of Environmental Science International
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    • v.10 no.1
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    • pp.59-64
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    • 2001
  • The effect of major operating parameters in spray drying sorber(=SDS) for automatic control for the simultaneous removal of acidic and organic gaseous pollutants from solid waste incinerator was performed. The field experiment was carried out in pilot scale test for the quantification of major operating parameters of hydrophilic and the hydrophobic pollutants. The removal efficiencies of $SO_2$and HCI in the 5wt% slurry condition were being increased with the increase of the stoichiometric ration which is the molecular ratio of lime to the pollutant concentration, and with the decrease of inflow flue gas temperature in the pilot SDS reactor. The removal efficiency along the height of spray drying sorber was closely related to the temperature profile, and more than 90% of total removal efficiency was achieved in an absorption region. For the removal of acidic gas the optimum operating condition considering the economics and a stable operation is the 5wt% of slurry concentration, 1.2 of stoichiometric ratio and 25$0^{\circ}C$ of inflow flue gas temperature. For the organic gases of benzene and toluene the removal efficiencies were 20-60% which is much lower than that of acidic gas. The best removal efficiency was obtained at 1.5 of stoichiometric ratio and 25$0^{\circ}C$ of inflow flue gas temperature. The organic\`s removal efficiency along the height of spray drying sorber was quite different from that of acidic gas, that is, more than 60% of the total removal efficiency for benzene and 90% of the total removal for toluene were achieved in the dried adsorption region, which was formed at the lower or exit part of the reactor.

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Optimization of Operating Condition on Gasification of Ash-free Coal by Using the Sensitivity Analysis of ASPEN Plus (민감도 해석을 통한 무회분 석탄의 가스화 최적 운전조건 도출)

  • Park, Sung-Ho;Jeon, Dong-Hwan;Yun, Sung-Phil;Chung, Seok-Woo;Choi, Ho-Kyung;Lee, Si-Hyun
    • Clean Technology
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    • v.20 no.3
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    • pp.298-305
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    • 2014
  • Ash included in coal can cause environmental pollution and it can decrease efficiency of mass and heat transfer by getting scorched and stick in the facilities operated at high temperature. To solve this problem, a feasibility study on pulverized coal fired power plant and integrated gasification combined cycle (IGCC) using the AFC (Ash-Free Coal) as well as the development to remove the ash from the coal was conducted. In this research, optimization of operating condition was proposed by using sensitivity analysis of ASPEN $Plus^{(R)}$ to apply the coal containing under the 200 ppm ash for integrated gasification combined cycle. Particularly, the coal gasification process was classified as three parts : pyrolysis process, volatile matter combustion process and char gasification process. The dimension and operating condition of 1.5 ton/day class non-slagging gasifier are reflected in the coal gasification process model.

Design of the Fixed-Bed Catalytic Reactor for the Maleic Anhydride Production (무수마레인산 생산을 위한 고정층 촉매 반응기 설계)

  • Yoon, Young Sam;Koo, Eun Hwa;Park, Pan Wook
    • Applied Chemistry for Engineering
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    • v.10 no.3
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    • pp.467-476
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    • 1999
  • This paper analyzed the behavior of fixed-bed catalytic reactor (FBCR) which synthesizing maleic anhydride(MA) from the selective oxidation of n-butane. The behavior of FBCR describing convection-diffusion-reaction mechanism is examined by using two-dimensional pseudohomogeneous plug-flow transient model, with the kinetics of Langmuir-Hinshelwood type. Prediction model is composed by optimum parameter estimation from temperature profile, yield and conversion of single FBCR on operating condition variations of Sharma's pilot-plant experiment. A double FBCR with same yield and conversion for single FBCR generated a $8.96^{\circ}C$ lower hot spot temperature than a single FBCR. We could predict parametric sensitivity according to the variation of possible operating condition (temperature, concentration, volumetric flow of feed reactant and coolant flow rate) of single and double FBCR. Double FBCR showed the behavior of more operating range than single FBCR. Double FBCR with nonuniform activities could assure safety operation condition for the possible variation of operating condition. Also, double FBCR had slightly higher than the single FBCR in conversion and yield.

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Reaction Characteristics of WGS Catalyst for SEWGS Process in a Pressurized Fluidized Bed Reactor (가압 유동층 반응기에서 SEWGS 공정을 위한 WGS 촉매의 반응특성)

  • Kim, Ha-Na;Lee, Dong-Ho;Lee, Seung-Yong;Hwang, Taek-Sung;Ryu, Ho-Jung
    • Transactions of the Korean hydrogen and new energy society
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    • v.23 no.4
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    • pp.337-345
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    • 2012
  • To check effects of operating variables on reaction characteristics of WGS catalyst for SEWGS process, water gas shift reaction tests were carried out in a pressurized fluidized bed reactor using commercial WGS catalyst and sand(as a substitute for $CO_2$ absorbent) as bed materials. Simulated syngas(mixed with $N_2$) was used as a reactant gas. Operating temperature was $210^{\circ}C$ and operating pressure was 20 bar. WGS catalyst content, steam/CO ratio, gas velocity, and syngas concentration were considered as experimental variables. CO conversion increased as the catalyst content and steam/CO ratio increased. CO conversion at fluidized bed condition was higher than that of fixed bed condition. However, CO conversion were maintained almost same value within the fluidized bed condition. CO conversion decreased as the syngas concentration increased. The optimum operation condition was confirmed and long time water gas shift reaction test up to 24 hours at the optimum operating conditions was carried out.

Experimental Study on Regenerator Under Cryogenic Temperature and Pulsating Pressure Conditions (극저온 맥동 압력 조건에서의 재생기에 관한 실험적 연구)

  • Nam, Gwan-U;Jeong, Sang-Gwon;Jeong, Eun-Su
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.26 no.8
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    • pp.1095-1101
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    • 2002
  • An experimental apparatus was prepared to investigate thermal and hydrodynamic characteristics of regenerator at cryogenic temperature under pulsating pressure condition. The regenerator was pressurized and depressurized by a compressor with various operating frequencies. Cold end of the regenerator was maintained around 100 K by means of a liquid nitrogen heat exchanger. Instantaneous gas temperature and mass flow rate were measured at both ends of the regenerator during the whole pressure cycle. Pulsating pressure drop across the regenerator was also measured to see if it could be predicted by a friction factor at steady flow condition. The operating frequency of pressure cycle was varied between 3 and 60 Hz, which are typical operating frequencies of Gifford-McMahon, pulse tube, and Stilting cryocoolers. First, the measured friction factor for typical wire screen mesh regenerator was nearly same as steady flow friction factor for maximum oscillating Reynolds number up to 100 at less than 9 Hz. For 60 Hz operations, however, the discrepancy between oscillating flow friction factor and steady flow one was noticeable if Reynolds number was higher than 50. Second, the ineffectiveness of regenerator was directly calculated from experimental data when the cold-end was maintained around 100 K and the warm-end around 293 K, which simulates an actual operating condition of cryogenic regenerator. Influence of the operating frequency on ineffectiveness was discussed at low frequency range.

Effect of Operating Condition of Stripping Process on Ammonia Removal for Pre-treatment of Swine Wastewater (축산폐수 전처리를 위한 암모니아 탈기공정의 운전조건이 암모니아 제거에 미치는 영향)

  • Whang, Gye-Dae;Cho, Young-Moo
    • Journal of Korean Society on Water Environment
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    • v.20 no.1
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    • pp.86-92
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    • 2004
  • Lab-scale experiments have been carried out to investigate ammonia stripping with a modified spray tower for removing ammonia nitrogen from swine wastewater. The operating conditions such as initial pH, temperature, air flow, hole size of distributor determining the diameter of water drops, and influent solids concentration were closely examined focusing on removal efficiency of ammonia. As a result of the experiment, in order to achieve high rate of ammonia removal by the air stripping system, the air flow rate must be supplied at high rate with sufficiently high initial pH, temperature. The optimum operating condition to meet the residual ammonia concentration of 300 mg/L was the initial pH of 11.0 at $35^{\circ}C$ with the air flow rate of 20 L/min. It also showed that the smaller hole size is, the higher removal rate of ammonia is expected. However, when used a small sized distributor (2 mm), the flooding problem at the upper column occurred due to clogging of the hole. With regard to the influent solids concentration, it was showed that the lower concentration of solids, the higher removal rate of ammonia. The removal of particulate materials in influent led to improve the removal efficiency of ammonia, rather than to control the operating condition including initial pH, temperature, and air flow. The empirical correlation between KLa and operating parameters would be driven as, $K_{La}=(0.0003T-0.0047){\cdot}G^{0.3926}{\cdot}L^{-0.5169}{\cdot}C^{-0. 1849}$. The calculated $K_{La}$ from proposed formula can be used effectively to estimate the optimum reaction time and to calculate the volume of modified spray tower system.

Analysis of Drying Efficiency for Circulating and Falling Movements on Indirected Drying Process of Food Waste (음식물류폐기물 간접건조과정에서의 순환 및 낙하이동에 따른 건조효율 평가)

  • Kim, Byung Tae
    • Journal of the Korea Organic Resources Recycling Association
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    • v.20 no.4
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    • pp.106-117
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    • 2012
  • Indirected heating dryer is used as one of the food waste treatment technologies for the production of the drier material supplied to the recycling facilities or end user. This study investigated the effect on drying efficiency for the operation of rotating screw with the circulating and falling movements on indirected drying process of food waste. The screw operating condition showed higher drying efficiency despite of the shorter drying time compared to the screw non-operating condition. The moisture content decreased to 14.4% from the initial moisture content of 77.1% after drying 5 hours in the screw operating condition. On the other hand, in the screw non-operating condition, the moisture content decreased slightly to 35.6% after drying 16 hours. During the drying process, variations of the water evaporation rate and particle size showed different tendencies depending on the moisture content regions. In the higher moisture content region above the glue zone(moisture content of about 50%-60%), the particle size increased and the water evaporation rate reached the highest peak. In the range of glue zone, the particle size maximized while the water evaporation rate decreased sharply. In the lower moisture content region below the glue zone, the water evaporation rate and particle size both decreased at the same time. The particle size distribution was widely ranged from 25.0mm to 0.25mm in the screw operating condition while it was narrowly distributed in the screw non-operating condition from 25.0mm to 3.56mm, especially highly concentrated to 25.0mm. It was regarded that the hygroscopic, capillary and gravitational water evaporated more easily from the intra-particle during the circulating and falling movement caused by the rotating of the screw and the difference of the cohesional force of water within intra-particle depending on the moisture content regions. Comparing the effect of the circulating and falling movement on drying efficiency, the water evaporation rates per time and per weight of dry solid in the screw operating condition were higher about 364% and 356%, respectively, than those of the screw non-operating condition.

The Improved Device of Seoul Subway Fare System (서울 지하철의 운임제도 개선방안)

  • Lee, Tai-Sik;Jun, Young-Joon;Kwon, Ou-Chul;Chung, Jong-Ky;Lee, Dong-Wook
    • Journal of the Korean Society for Railway
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    • v.9 no.2 s.33
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    • pp.200-205
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    • 2006
  • Subway widely used as a major mean of public transportation both at home and abroad contributes to ease chronic traffic congestion in cities. However, subway operating expense is expected to increase continuously because subway requires vast amount of money at the construction stage, huge sum of maintenance cost is spent during operation, and passenger needs for more convenient facilities is increasing. on the contrary to enormous operating expenses, fare that is occupying most of operating income doesn't come up to its prime cost causing chronic operating deficit. It is urgent to prepare fare system improvement measures to increase operating income in order to resolve financial difficulty of a subway operating organization. Therefore, the current study analyzed present condition and problems of subway fare system, and suggested improvement measures such as improvement of fare adjustment procedure, improvement of free-ride system, diversification of ticket, etc.

The research for the triggered vacuum switch which made of a copper electrode

  • Park, Ung-Hwa;Kim, Mu-Sang;Lee, Byeong-Jun
    • Proceedings of the Korean Vacuum Society Conference
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    • 2015.08a
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    • pp.144.1-144.1
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    • 2015
  • The triggered vacuum switch(TVS) is a one of the important component in consisiting high power control systems(HPCS). The operating condition is depended on material, geometry, operating power and so on. Our research is focused on the effects of thses basic properties and ptimized condition, because these are critical conditons in understanding the TVS operation. Our experiment is accomplished with a copper electrode and a tungsten trigger pin after being assembled into a vacuum chamber. The operating voltage in our system is more than dozens of kV at the 5kV trigger pulse. Our goal is up to 300kJ, therefore the currents should be more optimized in additional experiments,

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A Case study to Improve the Quality of Industrial Products cising An Experimental Design (공업제품(工業製品)의 질적(質的) 향상(向上)을 위(爲)한 실험계획(實驗計劃)의 응용사례(應用事例))

  • Kim, Yu-Song;Lee, Myeong-Ju
    • Journal of Korean Institute of Industrial Engineers
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    • v.7 no.2
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    • pp.55-59
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    • 1981
  • An Application of Experimental Designs to Improve the quality of Industrial product : optimization Methodology of statistical model. The primary object of this paper is to aid scientists and Engineers, in applying response surface procedures to obtain operating conditions for many technical fields, particularly for industrial manufacturing processes. The problem considered in this paper is to select technically and scientifically some important factors affecting the quality of products through the experimental design and analysis of response surface. Even though the mathematical model is unknown these statistical analysis can be applicable to control the quality of industrial products and to determine optimum operating conditions for many technical fields, particularly, for industrial manufacturing processes. This paper proposes a method to obtain the optimum operating condition, and how to find the condition by using table of orthogonal array experiments, and optimization methodology of statistical model.

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