• 열처리공학회지
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• 제36권2호
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• pp.86-95
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• 2023

This paper explained the equipment and process development to secure the source technology of controlled nitrification technology. The nitriding potential in the furnace was controlled only by adjusting the flow rate of ammonia gas introduced into the furnace. In addition, a control system was introduced to automate the nitriding process. The equipment's hardware was designed to enable controlled nitriding based on the conventional gas nitriding furnace, and an automation device was attached. As a result of measuring the temperature and quality uniformity for the equipment, the temperature and compound uniformity were ±1.2℃ and 14.3 ± 0.2 ㎛, respectively. And, it was confirmed that nitriding potential was controlled within the tolerance range of AMS2759-10B standard. In addition to parts for controlled nitriding, it was applied to products produced in existing conventional nitriding furnaces, and as a result, gas consumption was reduced by up to 80%.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2012년도 추계 학술논문 발표대회
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• pp.249-251
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• 2012

Concrete based on blast-furnace slag has a problem that its deterioration occurs process and quality of concrete are difficult to control. Therefore, it is judged that organized and comprehensive R&D will be continuously performed. In this study, the durability of concrete replaced with blast-furnace slag was evaluated for a solution. Experimental results, Concrete based on blast-furnace slag improved the durability.

• 전자공학회논문지 IE
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• 제46권4호
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• pp.25-30
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• 2009

용광로는 외피 부분에 내부 내화물의 온도를 낮추기 위하여 냉각수를 공급하는 냉각판 또는 스테이브를 사용하고 있다. 주변 조업 조건의 열악으로 냉각수를 공급하는 배관의 부식으로 냉각수가 내화물에 침투하여 내화물의 수명을 떨어뜨리고, 노황을 악화시키는 원인이 되고 있다. 이에 본 연구는 용광로 냉각설비장치에 이상 현상이 발생하였을 때 위치를 정확히 확인함에 따라 신속하게 누수된 부위를 파악하여 대처할 수 있는 기능을 갖춘 냉각관 누수 자동감지장치를 개발하였다. 주된 연구는 전자제어 장치인 마이크로프로세서를 응용한 전자변 제어장치를 이용하여 냉각설비의 파손으로 발생되는 누수현상으로 인한 고열과 분진 일산화탄소 등의 산출로 작업환경의 재해를 자동방지 하고자 하였으며, 작업환경이 친환경적이며 작업의 가치를 재창출할 수 있는 방법들이 연구되고 있다. 용광로 분위기의 일산화탄소 자동 감지장치와 그에 따른 출력신호를 자동 전송하는 무선중계기 장치를 개발함으로 용광로 냉각설비 장치의 분위기 작업환경을 수동방식에서 무인자동화방식으로 개선하였다.

• 제어로봇시스템학회논문지
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• 제3권3호
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• pp.318-322
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• 1997

A prototype of combustion zone monitoring system as been developed and installed into tuyeres of the blast furnace. The system consists of CCD(charge coupled device) cameras, sonic flow meters, an image processor and a personal computer. The personal computer collects raceway luminance data and operational data from the image processor that is connected to the color CCD camera from the blast furnace process computer, respectively. In addition, the sonic flow meters supply coal injection rate data to the personal computer. Then, the personal computer evaluates the combustion conditions with the raceway inspection algorithm. This integrated monitoring system allows us to detect abnormal raceway conditions and the clogging status of coal injection pipe. The image processing techniques of the system enable us to effectively monitor unburnt coal sticking to tuyere tip and injection lance wear conditions. Such a developed system ensures rapid and precise raceway inspection. The image processing capability of the system has helped operator to early detect both the unburnt coal sticking problem and the errosion problem of injection lance. Furthermore, the system could control the abnormal raceway condition based the the analysis results obtained from combustion monitoring.

• 한국기계가공학회지
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• 제19권2호
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• pp.47-54
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• 2020

Themo-mechanical analysis was carried out using the finite element method for the steel shell of a cupola furnace. When the outer surface of the shell was cooled with water to within the temperature range of 35-80 ℃ during operation of the cupola, the inner surface of the shell was expected to exhibit a temperature of 65-248 ℃ based on heat transfer analysis. The shell was also expected to have an equivalent stress range of 100-280 MPa in the outer surface over the temperature range examined. Upon cooling the shell to obtain an outer surface temperature <80 ℃, the maximum equivalent stress of the shell did not exceed the yield strength. Although the temperature of the outer surface varied between 35 and 80 ℃ periodically due to the cooling control problem, the fatigue stress at the outer surface of the shell was calculated to be within the fatigue strength. During a non-operational period to examine the system between furnace operations, the thermal stress presented in the shell was sufficiently low to reach the desired yield strength and fatigue limit.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2003년도 추계학술대회 및 정기총회
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• pp.201-204
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• 2003

A hybrid artificial intelligence approach based on combining case based reasoning and neural networks is presented. The approach is designed to allow for solving blowing control of BOF(basic oxygen furnace), example of which lie at the core of steelmaking process control systems application in the steel industry. According to this hybrid approach, the system, when faced with a new problem, first retrieves similar cases and neural network is used to solve the problem. Experimental Results indicate that combining case based reasoning and neural network offers an efficient approach to solving control and prediction problem

• 콘크리트학회논문집
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• 제14권4호
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• pp.597-607
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• 2002

우리나라에서 2000년도에 발생된 전기로 및 전로슬래그를 합하면 약 600만 톤 정도로서 주로 도로포장재료 및 매립재 등과 같은 한정된 용도로만 활용되어 왔다. 그 이유는 제강과정 중 유리석회가 슬래그화 되지 않고 불안정한 상태로 슬래그 내부에 잔존하기 때문에 콘크리트 구조물 내에서 팽창을 일으킬 가능성이 클 뿐만 아니라, 팽창이 심할 경우 구조물의 균열 내지는 붕괴까지도 야기 시킬 수 있으므로 콘크리트용 골재로 사용해서는 안 된다고 규정하고 있다. 따라서 제강슬래그를 콘크리트용 골재로 사용하기 위해서는 제강슬래그 자체의 팽창성 억제 내지는 안정화 처리가 우선 해결되어야 할 과제로 생각된다. 본 연구에서는 제강슬래그 골재의 팽창성을 저감시키기 위한 목적으로 6종류의 에이징 방법을 선정하여 안정화의 효율에 대하여 비교 검토하였다. 전로슬래그 골재의 경우, 본 연구에서 실시한 에이징 처리 방법으로서는 콘크리트용 골재로서 요구되는 팽창률을 저감시키는데 한계가 있었을 뿐만 아니라, 에이징 처리한 전로슬래그 골재 사용 콘크리트의 강도도 재령과 더불어 감소하는 문제점이 있음을 확인하였다. 그러나 전기로슬래그 골재를 온수중 및 증기중 에이징 처리할 경우, 팽창률이 전로슬래그 골재의 약 2/3 정도에 지나지 않는 효율을 나타내었으며, 이를 사용한 콘크리트의 강도도 전로슬래그 골재 사용 콘크리트와는 달리 보통콘크리트의 강도에 상응하는 비교적 좋은 결과를 나타내므로 콘크리트용 골재로서 사용 가능성을 시사하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1989년도 하계종합학술대회 논문집
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• pp.98-100
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• 1989

In this paper, computer control system is introduce for the reheating furnace in the hot rolling process, and in order to support computer control system and process operation, the configuration of expert system application is demonstrated breefly, which is under fine tuning.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국제학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.378-384
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• 1993

In this paper, an intelligent adaptive controller is proposed for the process with unmodelled dynamics. The intelligent adaptive controller consists of the numeric adaptive controller and the intelligent tuning part. The continuous scheme is used for the numeric adaptive controller to avoid the problems occurred in the discrete time schemes. The adaptive controller is adopted to the process with time delay. It is an implicit adaptive algorithm based on GMV using the emulator. The tuning part changes the design parameters in the control algorithm. It is a multilayer neural network trained by robustness analysis data. The proposed method can improve the robustness of the adaptive control system because the design parameters are tuned according to the operating points of the process. Through the simulation, robustnesses are shown for intelligent adaptive controller. Finally, the proposed algorithms are implemented on the electric furnace temperature control system. The effectiveness of the proposed algorithm is shown from experiments.

• 산업경영시스템학회지
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• 제33권1호
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• pp.33-40
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• 2010

Because sampling interval for data collection tends to be short compared with the overall processing time, in chemical process, instrumental process related tanks or furnace collected data have a significant autocorrelation. Insufficient control technique and frequent control actions cause unstable condition of the process. Traditional control charts which were developed based on iid (independently and identically distributed) among data cannot be applied on the existence of autocorrelation. Also unstable process is difficult to identity or diagnose. Because large-scale process has a lot of measurable variables and multi-step-structures among data, it is difficult to find relation between measurable variables and nonconformity. In this paper, we suggested an appicable model to diagnose the process and to find relation between measurable variables (CTQ) and nonconformity in the process having autocorrelation, unstable condition frequently, a lot of measurable variables, and multi-step-structure. And we applied this model to real process, to verify that the process engineers could easily and effectively diagnose the process and control the nonconformity.