• Title/Summary/Keyword: ROT 공정

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Independent Cooling Controller for Temperature Control of High Strength and Atmosphere Corrosion Resisting Steel in Hot Strip Mills (고강도 내후성강의 온도제어를 위한 ICC 제어기 개발)

  • Park, Cheol Jae
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.39 no.3
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    • pp.327-335
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    • 2015
  • In this paper, we propose an independent cooling control (ICC) scheme for high strength and atmosphere corrosion resisting steel to obtain the desired temperature and properties along the longitudinal direction of the steel in the run-out table (ROT) process. A temperature model of the independent process is developed to divide the ROT into front and back sections. The control concept uses field data, problem analysis, and a time-temperature transformation diagram. The effectiveness of the proposed control is verified using simulation results under a temperature disturbance by the transformation in the middle of the ROT. The results of a hot strip mill field test show that the temperature control performance is significantly improved by the proposed control scheme.

SPDR Scheme for Disturbance Reduction in ROT Process with Measurement Delay (측정지연이 있는 ROT 공정의 외란제거를 위한 SPDR 제어기 설계)

  • Park, Cheol Jae
    • Journal of Institute of Control, Robotics and Systems
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    • v.20 no.10
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    • pp.1023-1029
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    • 2014
  • In this paper, we propose an SPDR (Smith Predictor for Disturbance Reduction) scheme to improve the temperature control by reduction of the disturbance in ROT process with measurement delay. The proposed controller is a combination of Astrom's modified Smith predictor with a disturbance reduction controller and a grey predictor. The grey prediction is used to calculate the inverse of the measurement delay and to predict future variations and tendencies of system output. The simulation results demonstrate the successful performance of the proposed disturbance reduction controller and enhance the robustness of the proposed control scheme.

Residual Stress Analysis of Rot Rolled Strip in Coiling Process (권취 공정 중 열연 강판의 잔류 응력 해석)

  • 구진모;김홍준;이재곤;황상무
    • Transactions of Materials Processing
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    • v.12 no.4
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    • pp.302-307
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    • 2003
  • Hot rolled strip is cooled by air and water in Run-Out-Table. In this process, phase transformation and shape deformation occurs due to temperature drop. Because of un-ideal cooling condition of ROT, irregular shape deformation and phase transformation arise in the strip. which affect the strip property and lead to the residual stress of strip. And these exert effects on the following processes, coiling process, coil cooling process, and re-coiling process. Through these processes, the residual stress becomes higher and severe. For the prediction of residual stress distribution and shape deformation of final product, Finite element(FE) based model was used. It consists of non-steady state heat transfer analysis, elasto-plastic analysis. thermodynamic analysis and phase transformation kinetics. Successive FEM simulation were applied from ROT process to coil cooling process. In each process simulation, previous process simulation results were used for the next process simulation. The simulation results were matched well with the experimental results.

Characterization of Aerobic Decolorization of Remazol Black B by White Rot Fungi (Remazol Black B의 호기성 탈색을 위한 백색부후균의 분해 특성 분석)

  • 이재화;이은열
    • Journal of Life Science
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    • v.13 no.4
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    • pp.511-515
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    • 2003
  • White rot fungi, Phanerochaete sp. EJ-31L, was evaluated for its ability to decolorize Remazol Black B, an azo dye that is a widespread pollutant in the wastewater of textile industry. It was observed that extent of decolorization by Phanerochaete sp. EJ-31L was dependent on the concentrations of co-carbon and nitrogen source. Effects of agitation and aeration were studied, and agitated culture at aeration condition resulted in greater extent of decolorization than static culture. Remazol Black B was readily decolorized up to 95% within 64 hr by Phanerochaete sp. EJ-31L.

Temperature and Property Control of High Strength Steel in Hot Strip Mills (열간압연 고강도강의 온도 및 재질제어)

  • Park, Cheol-Jae
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.20 no.6
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    • pp.817-823
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    • 2011
  • This paper proposes a cooling stop temperature control(CST) and a phase transformation control(PTR) which aim at obtaining the uniform temperature and quality along the longitudinal direction of the high strength steel on the run-out table(ROT) process. The problems of the temperature control are analyzed for the conventional steel and the new control concepts are derived from a time-temperature transformation(TTT) diagram. The proposed control technologies are verified from the simulation results under the temperature prediction model by the heat transfer governing equation, and the temperature estimation simulator. It is shown through the field test of the hot strip mills that the phase transformation ratio of the high strength steel is considerably improved by the proposed temperature controls.

Application of Microorganism to Pulping and Bleaching Processes (펄프 및 표백공정(漂白工程)에서의 미생물응용(微生物應用))

  • Sakai, Koki
    • Journal of the Korean Wood Science and Technology
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    • v.20 no.3
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    • pp.67-78
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    • 1992
  • The application of white-rot fungi to pulping and bleaching processes has been studied at the Wood Chemistry Laboratory in Kyushu University, cooperatively with the Biotechnology Laboratory of Kobe Steel, Ltd. Some successful results of the studies for a biomechanical pulping process, biobleaching of hardwood and softwood kraft pulp, as well as chlorine free biobleaching of oxygen-prebleached hardwood kraft pulp are dealt with. Biological treatment of the pulp bleaching effluent is also described.

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Screening of White Rot Fungi with Selective Delignification Capacity for Biopulping (백색목재부후균중 Biopulping에 이용가능한 선택적 리그닌분해균의 스크리닝)

  • Lee, Jong-Kyu;Oh, Eun-Sung
    • The Korean Journal of Mycology
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    • v.26 no.2 s.85
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    • pp.144-152
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    • 1998
  • To obtain white rot fungi which have selective delignification capacity and can be used in biopulping processes, 94 different wood rotting fungi were screened and the capabilities of selected species were evaluated on deciduous and coniferous wood blocks. White rot fungi, first of all, were selected by simple enzyme tests, i.e., cellulase activity test; phenol oxidase activity test; laccase and peroxidase activity test. Most organisms that gave a positive Bavendamm gave a strongly positive laccase test with syringaldazine whereas most of those that gave a negative Bavendamm test also negative test for laccase and peroxidase, even if some exceptions were noted. Wood decay experiement were carried out to select fungal species with selective lignin-degrading ability by inoculating selected fungi to both wood blocks of Populus tomentiglandulosa and Larix leptolepis. After 12 weeks of incubation, weight losses, lignin losses, and morphological characteristics of the decayed wood were investigated. Almost all fungi tested caused 2 or more times of weight losses in P. tomentiglandulosa than in L. leptolepis, while no weight losses were detected from the un-inoculated wood blocks. Ceriporiopsis subvermispora and Phanerochaete chrysosporium were the best delignifiers for both hardwood and softwood. P. chrysosporium, however, was less effective than C. subvermispora. Bjerkandera adusta and two unidentified spp. caused delignification for only P. tomentiglandulosa. B. adusta caused simultaneous rot of all cell wall components, resulted in thinning of the secondary cell wall layers. Other fungi caused selective delignification resulting in the removal of lignin from middle lamella and separation of cells from each other.

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Kraft Pulping Characteristics by Bio-pretreatment with White-rot Fungus (백색부후균 생물 전처리에 의한 Kraft Pulp화 특성)

  • Kang, Kyu-Young;Jo, Byoung-Muk;Oh, Jung-Soo
    • Journal of the Korean Wood Science and Technology
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    • v.29 no.4
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    • pp.103-110
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    • 2001
  • Bio-kraft pulping of Populus alba${\times}$glandulosa pretreated with white-rot fungus, Phanerochaete chrysosporium KCCM 34740, was investigated The biopulping efficiency was evalued based on fungal pretreatment time and properties of bio-kraft pulp (pulp yield, freeness, WRY, kappa number and brightness) in comparison to the controls. Pretreatment of poplar wood chips with Phanerochaete chrysosporium KCCM 34740 for 10days resulted in a some increase in screened yield (by 2%). According to increase of fungal incubation time, decrease in freeness (CSF) and increase in WRY were observed And bio-kraft pulping also led to improvement of physical properties of handsheet. As a result of bio-beating effect, we expect the saving of chemicals in kraft cooking process and energy consumption in beating process.

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Decay Resistance and Anti-mold Efficacy of Wood Treated with Fire Retardants (난연처리 목재의 방미 및 방부성능)

  • Son, Dong Won;Kang, Mee Ran;Lee, Dong-Heub;Park, Sang-Bum
    • Journal of the Korean Wood Science and Technology
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    • v.41 no.6
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    • pp.559-565
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    • 2013
  • This study evaluated the ability of white and brown rot fungi to decompose fire retardant-treated wood by measuring mass loss. Anti efficacy of FRT against sapstain and mold fungi was evaluated. Wood was treated with liquid sodium silicate and boric acid, ammonium borate, di-ammonium phosphate. Retardant treated wood was then subjected to fungal decay resistance tests performed according to KS standard method using a brown-rot fungus, Fomitopsis palustris and white rot fungus Trametes versicolor. Aspergillus niger, Penicillium funiculosum, Rhizopus nigricans, Aureobasidium pullulans, Tricoderma virede fungi were used anti-sapstain and mold test. Boron and phosphorus chemicals used in this study increased the resistance of fire retardant treated wood against both fungal attack. Anti mold and sapstain efficacy of the fire retardant treated wood was excellent but there were difference depend on mold. After the liquid sodium silicate treatment, the second chemical treatment process could lead chemical fixation into wood, which effects decay resistance.

Decolorization of dye solution using membrane bioreactor (MBR) by Trametes versicolor (막생물반응기(MBR)에 의한 염료용액의 처리연구)

  • Lee, Yuri;Kim, Hyun-Gi;Park, Chulhwan;Lee, Byunghwan;Kim, Sangyong
    • Clean Technology
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    • v.10 no.3
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    • pp.131-137
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    • 2004
  • Due to the low biodegradability of dyes, conventional biological wastewater treatment systems are inefficient in treating textile wastewater. In this study, white rot fungus, Trametes versicolor KCTC 16781, were investigated for the decolorization of Reactive black 5 solutions. This fungus was able to degrade the dye solutions by the ligninolytic enzymes (laccase and MnP) produced. The enzyme activity remained constant until the end of reaction. The combined process of biological treatment and ceramic membrane showed better efficiency for decolorization and TOC removal than each single process.

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