• 한국물환경학회지
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• 제36권5호
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• pp.453-467
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• 2020

This study aimed to inventory the water pollutant discharge of wastewater from two facilities, one primary steel manufacturing facility and one petroleum refinery, both of which are located in Korea, and to identify ways to improve the wastewater treatment process through field investigation. Probability evaluation was used to inventory the substances in polluted water. The samples collected in this study included original wastewater, on processing wastewater, and treated water. The general description of wastewater occurrence, major sources, and treatment facilities were also investigated to obtain an integrated database of the pollutants created by different industrial categories. Based on our analysis of raw wastewater and final effluent, the detected pollutants were confirmed by analyzing their presence in the raw or supplemental materials, the potential of formation as byproducts, and the possibility of inclusion as impurities. The compounds detected for each category were screened via investigation of their possible sources and confirmed as the final water pollutant inventories. Thirty kinds of water pollutants were emitted by the primary steel manufacturing facility (reference in case A), including 14 specified hazardous water pollutants. The petroleum refinery (reference in case B) emitted 36 water pollutants, including 16 specified hazardous water pollutants.

• Nuclear Engineering and Technology
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• 제54권1호
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• pp.244-254
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• 2022

For tensile tests, Vickers hardness tests and microstructure tests, plate-type and box-type specimens of austenitic 316L stainless steels were produced by a conventional machining (CM) process as well as two additive manufacturing processes such as direct metal laser sintering (DMLS) and direct metal tooling (DMT). The specimens were irradiated up to a fast neutron fluence of 3.3 × 10⁹ n/cm² at a neutron irradiation facility. Mechanical performance of the unirradiated and irradiated specimens were investigated at room temperature and 300 ℃, respectively. The tensile strengths of the DMLS, DMT and CM 316L specimens are in descending order but the elongations are in reverse order, regardless of irradiation and temperature. The ratio of Vickers hardness to ultimate tensile strength was derived to be between 3.21 and 4.01. The additive manufacturing processes exhibit suitable mechanical performance, comparing the tensile strengths and elongations of the conventional machining process.

• 한국기계가공학회지
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• 제21권1호
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• pp.28-33
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• 2022

The heating roller of an actual pulse output device (POD) production facility is composed of a steel roller and a rubber roller. The time to reach a specific temperature and the temperature distribution on the roller surface were analyzed and compared according to the change in the number of cartridge heaters inside the heating roller. In this analysis, a steady-state thermal analysis of a steel roller was performed for the cases of a 5-cartridge heater and 9-cartridge heater. Finite element analysis was applied with reference to the surface temperature data of the heating roller during operation and the calorific value of the cartridge heater. Using the 9-cartridge heater, faster target temperature achievement and more uniform temperature distribution were confirmed than for the 5-cartridge heater.

• 대한안전경영과학회지
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• 제20권3호
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• pp.27-36
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• 2018

The steel pipe manufacturing industry deals with facilities and materials. Especially thermal facilities are close to vapor cloud explosion (VCE) and may cause secondary damage to facilities because they deal with corrosive substances such as hydrofluoric acid, sulfuric acid and acid, fire, explosion, leakage etc. It is in danger. In this study, hazard identification method was conducted using HAZOP techniques and quantitative risk analysis was conducted using e-CA, a program that supports accident impact analysis. Equipment in the influence range of ERPG - 3 was determined to be a facility requiring replacement. It was decided that neutralization is necessary using slaked lime. Based on the cost of loss, We presented the proper replacement which is the timing of the dangerous facility. As a result, It was ideal to replace the facilities with 20 years of heat treatment facilities, one year of hydrofluoric acid storage tank, 20 years of sulfuric acid storage tank, and 5 years of hydrochloric acid storage tank.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.149-156
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• 2003

Recently, the importance of plant maintenance(PM) was highly raised to provide efficient plant operation which highly affects the productivity. For this reason, a number of engineering methodologies, such as riskbased inspection(RBI), fitness for service guidelines(FFS), plant lifecycle management(PLM), have been applied to improve the plant operation efficiency. Also, a network-based business operation system, which is called ERP(Enterprise Resource Planning), has been introduced in the field of plant maintenance. However, there was no attempt to connect engineering methodologies to the ERP PM system. In this paper, a knowledge-based information system for the plant operation of steel making company has been proposed. This system, which is named as K-VRS(Knowledge-based Virtual Reality System), provides a connection between ERP plant maintenance module and knowledge-based engineering methodologies, and thus, enables network-based highly effective plant maintenance process. The developed system is expected to play a great role for more efficient and safer plant maintenance.

• 대한기계학회논문집A
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• 제27권11호
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• pp.1933-1940
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• 2003

Recently, the importance of plant maintenance(PM) was highly raised to provide efficient plant operation which highly affects the productivity. For this reason, a number of engineering methodologies, such as risk-based inspection(RBI), fitness for service guidelines(FFS), plant lifecycle management(PLM), have been applied to improve the plant operation efficiency. Also, a network-based business operation system, which is called ERP(Enterprise Resource Planning), has been introduced in the field of plant maintenance. However, there was no attempt to connect engineering methodologies to the ERP PM system. In this paper, a knowledge-based information system for the plant operation of steel making company has been proposed. This system which is named as K-VRS(Knowledge-based Virtual Reality System), provides a connection between ERP plant maintenance module and knowledge-based engineering methodologies, and thus, enables network-based highly effective plant maintenance process. The developed system is expected to play a great role for more efficient and safer plant maintenance.

• 한국기계가공학회지
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• 제14권2호
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• pp.38-43
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• 2015

Tungsten inert gas (TIG) welding is commonly used in industries that require airtightness, watertightness, oiltightness, and precision. It is a non-consumable welding method that is commonly used for the welding of non-ferrous metals, but it can be used to weld most metals. The methods of TIG welding can be divided into three types. The first, manual welding is done directly on the metal by a welder with a torch. The second, semi-automatic welding, gets help from a material supplying machine, but it is conducted by a welder. Lastly, automated welding is conducted fully by a machine during its process and operation. Depending on the selection of electrode, the amount of heat that is applied to the base material and the electrode rod changes and makes the shape of welded parts different. A direct-current positive electrode was used for this study. Through the change of shielding gas type on a structural steel (SS-400) that is commonly used in industry, the composition and shape changes in welded parts were detected after welding. The heat-affected area, hardness value, and tensile strength were also identified through hardness testing and tensile testing. In this study, it was found that the higher hardness value of the heat-affected is, the weaker the tensile strength becomes.

• 한국건설순환자원학회논문집
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• 제6권3호
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• pp.190-198
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• 2018

에폭시 피복철근은 해양 및 가혹한 환경에서 철근방식 성능이 우수하여 내구수명을 연장하는 것이 가능함이 입증되어 미국 및 일본등의 선진국에서는 에폭시 피복철근의 사용이 지속적으로 증가하고 있다. 그러나 국내는 연구개발 부족, 낙후된 생산설비, 품질불량, 초기비용 증가, 현장 취급 및 관리 어려움등의 이유 때문에 아주 제한적으로 사용하고 있다. 이 연구는 최근에 개선된 제조공장에서 생산된 에폭시 피복철근의 관련 시험에 의해 증명된 제품의 시험시공을 통하여 현장 적용을 위한 제조, 운반 및 시공등의 시공품질관리의 개선방안을 제안하였다.

• 한국가스학회지
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• 제17권5호
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• pp.51-57
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• 2013

최근 들어 다양한 재료 및 제조기술의 개발로 가스관 품질이 향상되어 매설심도를 저심도화 할 수 있는 환경이 조성되고 있다. 또한 선진 외국과 비교하여 국내 매설깊이 기준이 약 50cm 정도 깊은 것으로 조사되어 시공비용, 차량지체비용 등을 고려하였을 때 비효율적인 매설깊이 규정인 것으로 판단된다. 따라서 본 연구에서는 매설깊이 변화(0.8m, 1.0m, 1.2m)에 따른 가스관의 응력 및 변형 거동을 분석하였다. 본 연구에서는 수치해석 및 현장시험을 통하여 매설심도 변화에 따른 가스관(API 5L)의 거동특성을 분석하였다. 분석결과, 매설심도의 감소가 가스관의 응력, 변형 특성에 큰 영향을 미치지 않을 것으로 판단되었다.

• 한국초전도ㆍ저온공학회논문지
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• 제20권4호
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• pp.11-15
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• 2018

Torque tubes in High Temperature Superconducting (HTS) motor transfer torque from superconducting field winding rotor to the room temperature shaft. It should have minimum heat conduction property for minimizing the load on cryo-refrigerator. Generally, these torque tubes are made with stainless steel material because of high strength, very low outgassing and low thermal contraction properties at cryogenic temperatures and vacuum conditions. With recent developments in composite materials, these torque tubes could be made of composites such as Kevlar and S-Glass, which have the required properties like high strength and low thermal conductivity at cryogenic temperatures, but with a reduced weight. Development and testing of torque tubes made of these composites for HTS motor are taken up at Bharat Heavy Electricals Limited (BHEL), Hyderabad in collaboration with Central Institute of Plastics and Engineering Technology (CIPET), Chennai and Indian Institute of Technology (IIT), Kharagpur. As these materials are subjected to vacuum, it is important to measure their outgassing rates under vacuum conditions before manufacturing prototype torque tubes. The present study focusses on the outgassing characteristics of Kevlar and S-Glass, using an Outgassing Measurement System (OMS), developed at IIT Kharagpur. The OMS facility works under vacuum environment, in which the test samples are exposed to vacuum conditions over a sufficient period of time. The outgassing measurements for the composite samples were obtained using pressure-rise technique. These studies are useful to quantify the outgassing rate of composite materials under vacuum conditions and to suggest them for manufacturing composite torque tubes used in HTS motors.