• Title, Summary, Keyword: chimney

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Oceanographic Characteristics of the Jspan Sea Proper Water II. The Japan Sea Proper Water and Chimney (동해고유수의 해양학적 특성 II. 동해고유수와 chimney)

  • Choi, Yong-Kyu;Cho, Kyu-Dae;Yang, Sung-Kee
    • Journal of Environmental Science International
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    • v.4 no.2
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    • pp.121-139
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    • 1995
  • Based on the Results of Marine Meteorological and Oceanographical Observations (1966 -1987), the phenomenon of chimney is found as a candidate for the formation of the Japan Sea Proper Water (JSPW). The chimney phenomenon occurs twelve times Inuring 1966∼ 1987. The water types in the chimney denoting the deep convection are similar to those of the JSPW 0∼ 1℃ in potential temperature, 34.0∼34.1 ‰ in salinity and 68∼80 cl/t in potential thermosteric anomaly from the sea surface to the deep layer. The static stabilities in the chimney stations are unstable or neutral. This indicates that the winter time convection occurs. The JSPW sunken from the surface layer of chimney in winter spreads out under the Tsushima Warm Current area, following the isosteric surface of about 76 cl/t in Potential thermosteric anomaly. The formation of the deep water of the JSPW is mainly affected by the cooling of the sea surface than the evaporation of winds because the temperature and the salinity on the isoteric surface of about 76 cl/t in potential thermosteric anomaly ate cold and low The phenomenon of chimney occurred in here and there of the area in the north of 40" 30'N, west of 138" E. This suggests that the deep water of the JSPW is formed not in a limited area but probably in the overall region of the northern open ocean.

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Geochemistry of the Hydrothermal Chimneys in the Manus Basin, Southwestern Pacific Ocean (남서태평양 Manus Basin에서 산출되는 열수 분출구에 대한 지화학적 연구)

  • 이경용;최상훈;박숭현
    • Economic and Environmental Geology
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    • v.35 no.1
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    • pp.1-12
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    • 2002
  • Manus Basin, located in the equatorial western Pacific, is a back arc basin formed by collision between the IndoAustralian and the Pacific Plates. The basin is host to numerous hydrothermal vent fields and ore deposits. The basement rocks of the Manus Basin consist primarily of dacite and basaltic andesite. Some of the minerals that form the hydrothermal chimneys that were dredged on the Manus basin include pyrite, chalcopyrite, marcasite, sphalerite and galena. The chimneys can be classified into chalcopyrite dominant Cu-rich type and sphalerite dominant Zn-rich type. The concentration of Zn shows good positive correlation with that of Sb, Cd and Ag. The content of Cu, on the other hand, positively correlates with that of Mo, Mn and Co. For samples that were taken from Zn-rich chimney, a strong positive correlation is found between Au and Zn contents. The chimney also shows enrichments of Cd, Mn and Sb. On the other hand, the samples from Cu-rich chimney exhibit strong correlation among Au, Zn and Pb, and are enriched in Mo and Co concentration. Average contents of Au in Cu-rich and Znrich chimneys were 15.9 ppm and 29.0 ppm, respectively. Because of high concentration of Au with Ag and Cu, the ore deposit have high economic potential. Homogenization temperatures and salinities of fluid inclusions in anhydrite and amorphous silica from Zn-rich chimney are estimated to be l74-220$^{\circ}$C and 2.7-3.6 equiv. wt. % NaCI, respectively. These value suggest that ore forming processes were occurred at around 200$^{\circ}$C and that the oxygen fugacity changed from 2: 10$^{-39.5}$bar to -s: 10$^{-40.8}$bar and the sulfur fugacity from -s: 10$^{-14.7}$bar to 10$^{-13.4}$bar during the process. It appears that the temperature at which the ores formed on Cu-rich chimney was higher than that on Zn-rich chimney.

A study on YEON-GA(chimney head cover) (백제 연가(煙家)에 대하여)

  • Kim, Yong-Min
    • MUNHWAJAE Korean Journal of Cultural Heritage Studies
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    • v.35
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    • pp.58-81
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    • 2002
  • This article exemines YEON-GA(煙家), a kind of chimney head cover, made and used during the Baekjae Period. YEON-GA was recently excavated in Buyo and Iksan, and it generally accepted as a kind of pottery stand. However, this paper will argue that it functioned as a chimney head cover during the Baekjae Period. The design of YEON-GA is the lotus flower bud which were popular during the Sabi-Baekjae Period.It seems highly likely that it functioned to ornament a chimney head and to send up smoke smoothly. It was also found that, beside a chimnery head cover, a chimney body was made and used. It is very difficult to trace the origin of YEON-GA but it seems that it had been used until the Chosun Dynasty, based on the historical documents.

OMA of model chimney using Bench-Scale earthquake simulator

  • Tuhta, Sertac
    • Earthquakes and Structures
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    • v.16 no.3
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    • pp.321-327
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    • 2019
  • This study investigated the possibility of using the recorded micro tremor data on ground level as ambient vibration input excitation data for investigation and application Operational Modal Analysis (OMA) on the bench-scale earthquake simulator (The Quanser Shake Table) for model chimney. As known OMA methods (such as EFDD, SSI and so on) are supposed to deal with the ambient responses. For this purpose, analytical and experimental modal analysis of a model chimney for dynamic characteristics was performed. 3D Finite element model of the chimney was evaluated based on the design drawing. Ambient excitation was provided by shake table from the recorded micro tremor ambient vibration data on ground level. Enhanced Frequency Domain Decomposition is used for the output only modal identification. From this study, best correlation is found between mode shapes. Natural frequencies and analytical frequencies in average (only) 1.996% are different.

Numerical study of particle dispersion from a power plant chimney (발전소 굴뚝에서의 입자 분산에 대한 수치해석)

  • Shim, Jeongbo;You, Donghyun
    • Particle and aerosol research
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    • v.13 no.4
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    • pp.173-182
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    • 2017
  • An Eulerian-Lagrangin approach is used to compute particle dispersion from a power plant chimney. For air flow, three-dimensional incompressible filtered Navier-Stokes equations are solved with a subgrid-scale model by integrating the Newton's equation, while the dispersed phase is solved in a Lagrangian framework. The velocity ratios between crossflow and a jet of 0.455 and 0.727 are considered. Flow fields and particle distribution of both cases are evaluated and compared. When the velocity ratio is 0.455, it demonstrates a Kelvin-Helmholtz vortex structure above the chimney caused by the interaction between crossflow and a jet, whereas the other case shows flow structures at the top of the chimney collapsed by fast crossflow. Also, complex wake structures cause different particle distributions behind the chimney. The case with the velocity ratio of 0.727 demonstrates strong particle concentration at the vortical region, whereas the case with the velocity ratio of 0.455 shows more dispersive particle distribution. The simulation result shows similar tendency to the experimental result.

Wind fragility analysis of RC chimney with temperature effects by dual response surface method

  • Datta, Gaurav;Sahoo, Avinandan;Bhattacharjya, Soumya
    • Wind and Structures
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    • v.31 no.1
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    • pp.59-73
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    • 2020
  • Wind fragility analysis (WFA) of concrete chimney is often executed disregarding temperature effects. But combined wind and temperature effect is the most critical limit state to define the safety of a chimney. Hence, in this study, WFA of a 70 m tall RC chimney for combined wind and temperature effects is explored. The wind force time-history is generated by spectral representation method. The safety of chimney is assessed considering limit states of stress failure in concrete and steel. A moving-least-squares method based dual response surface method (DRSM) procedure is proposed in WFA to alleviate huge computational time requirement by the conventional direct Monte Carlo simulation (MCS) approach. The DRSM captures the record-to-record variation of wind force time-histories and uncertainty in system parameters. The proposed DRSM approach yields fragility curves which are in close conformity with the most accurate direct MCS approach within substantially less computational time. In this regard, the error by the single-level RSM and least-squares method based DRSM can be easily noted. The WFA results indicate that over temperature difference of 150℃, the temperature stress is so pronounced that the probability of failure is very high even at 30 m/s wind speed. However, below 100℃, wind governs the design.

Flow Characteristics for Guide Tube of Circular Irradiation Hole in HANARO (하나로 원형 조사공의 안내관 유동특성)

  • Park, Y.C.;Wu, J.S.
    • Proceedings of the KSME Conference
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    • pp.1835-1840
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    • 2004
  • The HANARO, a multi-purpose research reactor of 30 MWth, open-tank-in-pool type, has been under normal operation since its initial criticality in February, 1995. The HANARO is composed of inlet plenum, grid plate, core channel with flow tubes and chimney. The reactor core channel is located at about twelve meters (12 m) depth of the reactor pool and cooled by the upward flow that the coolant enters the lower inlet of the plenum,. rises up through the grid plate and the core channel and comes out from the outlet of chimney. A guide tube is extended from the reactor core to the top of the reactor chimney for easily un/loading a target under the reactor normal operation. But active coolant through the core can be quickly raised up to the top of the chimney through the guide tube by a jet flow. This paper describes an analytical analysis that is the study of the flow behavior through the guide tube under reactor normal operation and unloading the target. As results, it was conformed through the analysis results that the guide jet is suppressed under the top of the chimney after modifying the orifice diameter of 37.5 mm to 31 mm.

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Chimney Construction (굴뚝의 설계2)

  • Jang, Gi-In
    • Korean Architects
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    • v.3 no.9
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    • pp.44-51
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    • 1968
  • This article discusses at a basic level the of chimney construction. The concept, design, and operation can be understood easily. This, of course, is the first step to orderly construction. The selection of the boiler as to type, capacity, etc., was summarized in brief. The over all planning of the boiler and chimney together was the main object of this article. The architectural books covering this subject are very technical and this article tries to make the understanding of the basic principles more easy for the beginner in architecture.

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