• 한국정밀공학회지
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• 제25권2호
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• pp.57-64
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• 2008

This paper describes the development of a small lens molding system for manufacturing the small lens like lens of a cellular phone, a small digital camera and so on. In order to manufacture a small lens, firstly, the raw material for lens with spherical shape should be manufactured by processing a glass material, secondly, the mold inserted the raw material for lens should be heated till its molding temperature in the electric furnace, finally, the small lens is manufactured by applying the force using pressuring control system. In this paper, the small lens molding system with the function of force control and velocity control was developed. It is composed of an electric furnace and its temperature control system, a pressuring control system, a body, and so on. The temperature characteristic test of the electric furnace, the force and velocity characteristic test of the pressuring control system were carried out. It was confirmed that the developed system had good functions for manufacturing a small lens.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2006년도 제33회 KOSCO SYMPOSIUM 논문집
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• pp.229-234
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• 2006

The oxy-fuel combustion heating characteristics is investigated experimentally by measuring furnace and steel temperature variations for batch type furnace simulator with a specially designed low NOx oxy-fuel burner. Economics of using oxy-fuel combustion is confirmed and, the furnace and steel temperature variations for different heating conditions are compared to deduce optimal heating control pattern for energy savings and rapid uniform heating. High $CO_2$ concentration (> 80-90%), low NOx (< 40ppm) and CO (< 10ppm) are measured in the flue gas. Temperature differences (< $30^{circ}C$) inside the furnace and steel are reduced relatively by increasing the burner jet momentum.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2006년도 제33회 KOSCO SYMPOSIUM 논문집
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• pp.145-150
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• 2006

At the furnace top, the distribution of charging coke and ore is adjusted to control the reducing gas flow distribution in the furnace. It is necessary to predict operation condition of blast furnace according to the burden profile to judge whether charging is properly conducted In this study, We propose the model for predicting while layer structures whithin furnace when top burden profile was given. Layer structure of coke and ore could be predicted by top burden profile and solid velocity. Solid velocity is assumed as potential flow. Potential function distribution and timeline are also calculated using solid velocity field. The Calculation is conducted for different burden profile cases. As the result burden distribution and grid structure, which is deformed to match the layer structure in shaft and deadman profile. Gas flow was calculated using this grid, and calculated results are compared with each other.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집B
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• pp.511-516
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• 2001

The flow characteristics in a hot mill reheating furnace is numerically simulated in this study. Navier-Stokes equations for conservation of mass, momentum, energy are solved and the standard $k-\varepsilon$ model, mixture fraction/PDF model are used for the turbulent reacting flow in the furnace. Radiation heat transfer is incorporated by the P-1 method with the absorption coefficient evaluated using WSGGM. First, simulation results are obtained for the total furnace region with existing protective dam, and then the calculations are carried out only for the preheating zone in the furnace. In that zone, additional center darn is built in order to control the flow behavior of the inlet air and the combustion gas.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2013년도 춘계학술대회
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• pp.904-907
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• 2013

최대전력관리장치는 사용 전력량이 목표 전력량을 초과하는 것으로 예측되면 연결된 부하장치를 차단하여 사용 전력량이 목표 전력량을 초과하지 않도록 제어하는 장치이다. 이러한 ON/OFF 방식을 전기로의 전력 관리에 적용하면 전력을 공급하는 인버터와 전기히터의 기동 및 정지동작이 반복적으로 수행되게 된다. 이는 인버터와 전기히터에 전기적 손상을 가중시켜 수명을 단축시킬 수 있다는 문제점이 있다. 또한 전력 관리에 의해 전력 공급이 차단되었을 때 복귀 시점까지 온도를 조절할 수 없다는 단점이 있다. 본 논문에서는 목표 전력량을 초과하지 않는 범위 내에서 지속적인 전력의 인가를 통해 인버터와 전기히터의 전기적 손상을 방지하고 전기로로 인가되는 전력량을 유기적으로 자동 조절하기 위해 전기로 원격 제어기를 사용한 전력관리 시스템을 개발한다.

• 한국연소학회지
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• 제14권4호
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• pp.1-6
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• 2009

Analysis of the internal state of the blast furnace is necessary to predict and to control the operating conditions. Especially, it is important to develop models of the blast furnace to predict the cohesive zone because shape of the cohesive zone influences overall operating conditions of blast furnace such as gas flow, chemical reactions and temperature. Because many previous blast furnace models have assumed cohesive zone to be fixed, it was not possible to evaluate the shape change of cohesive zone in relation with operating conditions such as PCR, blast condition, and production rate. In this study, an axi-symmetric 2-dimensional steady state model is proposed to simulate blast furnace processes. In this model, cohesive zone is determined by the solid temperature. Finite volume method is employed for numerical simulation. To find location of the cohesive zone, entire calculation procedure is iterated until converged. Through this approach, shape of the cohesive zone, velocity and temperature within the furnace are predicted from the model.

• 한국기계가공학회지
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• 제13권6호
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• pp.8-14
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• 2014

Pulverized coal (PC) has become an important auxiliary fuel in the iron and steel industry since the technique of pulverized coal injection (PCI) was developed for iron making. The combustion efficiencies of pulverized coal in blowpipes and tuyeres under various operational conditions are numerically predicted to determine the performance levels with regard to different locations of the nozzles in a blast furnace. A variety of parameters, including the pulverized coal quantities, oxygen amounts, inlet temperatures of the tuyeres, and the mass flow rate of coal carrier gas are taken into consideration. Also, in order to develop greater efficiency than those of existing coal injection systems, this study applies a flame measurement system using a charge-coupled device (CCD) camera and a frame grabber. It uses auto sampling algorithms from the flame shape information to determine the device for the optimal location control for PCI. This study finds further improvements of the blast furnace performance via the control of the PCI locations.

• 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.

• 산업경영시스템학회지
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• 제29권2호
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• pp.92-96
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• 2006

Large glass furnaces to produce glass for CRT are housed in huge chambers. It is costly to maintain such a chamber in constant temperature, humidity, and(air) pressure. In this study, first, we show that the process of such a huge furnace, which requires the steady maintenance of high temperature, is badly affected by the ambient temperature of surrounding air. Second, an alternative process which not only maintains the relatively constant temperature dispersion around the furnace, but is also economical will be proposed. We calculate the necessary volume of air inflow in the appendix.

• 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.