• 대한기계학회논문집A
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• 제24권12호
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• pp.2989-2994
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• 2000

A mechanical face seal is a tribo-element intended to control leakage of working fluid at the interface of a rotating shaft and its housing. Leakage of working fluid decreases drastically as the clearance between mating seal faces gets smaller. But the very small clearance may result in an increased reduction of seal life because of high wear and heat generation. Therefore, in the design of mechanical face seals a compromise between low leakage and acceptable seal life is important, ant it present a difficult and practical design problem. A fluid film or sealing dam geometry of the seal clearance affects seal lubrication performance very much, and thereby is optimization is one of the main design consideration. in this study the Reynolds equation for the sealing dam of mechanical face seals is numerically analyzed, using the Galerkin finite element method, which is readily applied to various seal geometries, to give lubrication performances, such as opening force, restoring moment, leakage, and axial and angular stiffness coefficients. Then, to improve the seal performance an optimization is performed, considering various design variables simultaneously. For the tested case the optimization ha successfully resulted in the optimal design values of outer and inner seal radii, coning, seal clearance, and balance radius while satisfying all the operation subjected constraints and design variable side-constraints, and improvements of axial and angular stiffness coefficients by 16.8% and 2.4% respectively and reduction of leakage by 38.4% have been achieved.

• 웰빙융합연구
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• 제6권2호
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• pp.9-13
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• 2023

Purpose: In this study, we would like to make a technical proposal to solve the odor problem in pig houses. Through this, we would like to suggest an effective way to reduce the odor generated in the pig house as a solution to civil complaints. Research design, data and methodology: Conduct direct visits to pig farms where many civil complaints about bad odor occur, and identify the problems of each farm. Identify elements related to odor control, such as structure, facility, equipment, odor management method, and ventilation type. Through this, the technology to be applied to reduce odor and the solution to the odor problem are presented. Results: The results of major improvements are as follows: 1. Improvement of the structure of the barn or composting shed to an airtight type 2. Improvement of the pig manure treatment structure using the slope inside the barn 3. Establishment of ventilation and cooling systems 4. Automation of the mist spray system. Conclusions: As a result, as practical measures, sealing of facilities using winch curtains, construction of air conditioning systems using negative pressure ventilation, and management systems using AIoT systems were presented. It is judged that this study can be helpful in determining the grievances caused by civil complaints of tenant livestock farms and the direction of facility improvement in the future.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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• pp.129-132
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• 2007

Advanced structure of metal-supported solid oxide fuel cells was devised to overcome sealing problem and mechanical instability in ceramic-supported solid oxide fuel cells. STS430 whose dimensions were 26mm diameter, 1mm thickness and 0.4mm channel width was used as metal support. Thin ceramic layer composed of anode(Ni/YSZ) and electrolyte(YSZ) was joined with STS430 metal support by using a cermet adhesive. $La_{0.8}Sr_{0.2}Co_{0.4}Mn_{0.6}O_{3}$ perovskite oxide was used as cathode material. It was noted that oxygen reduction reaction of cathode governed the overall cell performance from oxygen partial pressure dependance.

• 한국신뢰성학회지:신뢰성응용연구
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• 제9권1호
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• pp.29-35
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• 2009

Due to the excellent durability of Timing Chain, it has been widely used for vehicle engine system. Unlike the timing belt, since the timing chain is operated with the metallic sprocket, the lubrication system is absolutely needed to get this system start. As frequently met at the field, the lubricant has a strong tendency to leak out from the engine due to its severe operating environment. In this paper, results of investigation for thermal movement of aluminum chain cover were described to maximize the sealing ability which is desperately needed at the development stage of engine. Based on these results, some ideas for reproducing the leakage phenomenon and solving methods were proposed.

• 항공우주시스템공학회지
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• 제10권3호
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• pp.52-58
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• 2016

The elastomeric O-ring is the most-commonly-used seal due to its excellent sealing capacity, and its availability in various costs and sizes; furthermore, its importance has lasted over a long duration. However, a dearth of research exists in Korea regarding the elastomeric O-ring and the corresponding techniques. The constituent parts of elastomeric rubber are important; to determine their properties, the uni-axial tension and equi-biaxial tension need to be tested. Also, the non-linear analysis method reduces the design cost. An O-ring failure causes leaks and vibration. In this paper, foreign objects are used to affect an O-ring and its performance so that all angles of the O-ring design can be considered. This paper presents a solution for the O-ring-failure problem using a finite-element analysis.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.391-394
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• 2003

It is inevitable that reconsideration of the use of lead oxides in the electronics industry be undertaken as long as detrimental effects to the environment remain. To solve this problem, many recent studies on Pb-free compositions for PDP (plasma display panel) dielectric layers and also sealing glass compositions have been made. The present study was conducted to investigate whether the alternative systems for leadfree low firing glasses, detailed below, are available for use in PDP materials. The results suggest that low-melting phosphate glasses would be suitable as an alternative material for the Pb-based dielectric layer, sealants and barrier ribs in PDP.

• 한국유체기계학회 논문집
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• 제17권2호
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• pp.54-58
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• 2014

The method of residential waste and food waste collecting is changed into automatic waste collection(AWC) system from direct collection by human resource. To solve the problem caused by odour from AWC facilities, the structure of input facilities, conveying pipes and collecting facilities have been changed into closed and sealed construction to enclosed the facilities and collect odour efficiently. Based on cases and experiences, to treat variable odour matters which are caused by food waste, chemical cleaning method is preferable method to cope with odour caused by food waste.

• 반도체디스플레이기술학회지
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• 제3권3호
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• pp.5-9
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• 2004

A new wafer level packaging scheme is presented as an alternative to MEMS package. The proof-of-concept structure is fabricated and evaluated to confirm the feasibility of the idea for MEMS wafer level packaging. The scheme of this work is developed using an electroplated tin (Sn) solder. The critical difference over conventional ones is that wafers are laterally bonded by solder reflow after LEGO-like assembly. This lateral bonding scheme has merits basically in morphological insensitivity and its better bonding strength over conventional ones and also enables not only the hermetic sealing but also its electrical interconnection solving an open-circuit problem by notching through via-hole. The bonding strength of the lateral bonding is over 30 Mpa as evaluated under shear and the hermeticity of the encapsulation is 2.0$\times10^{-9}$mbar.$l$/sec as examined by pressurized Helium leak rate. Results show that the new scheme is feasible and could be an alternative method for high yield wafer level packaging.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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• pp.1059-1061
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• 2005

The bushing currently applied to pole-mounted type loadbreak switch has porcelain bushing which is connected with the mold cone. This type has potential problems of uncertainty of sealing of the interface part and gas leakage on the connected part between bushing and switch tank due to the weight of the porcelain. The Composite Bushing can solve these problems and also the secondary problem of the potential accident owing to the fragment of the porcelain bushing in breakage due to the outer impact.

• Design & Manufacturing
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• 제15권1호
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• pp.57-65
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• 2021

Pump cap is a product that is widely used due to its ease of use and simple operation. These pump caps are applied to heterogeneous functional cosmetics and are being developed as dual pump caps. However, the conventional dual pump cap has a problem in that it is inconvenient to use and leakage occurs. In addition, it is formed of a plurality of materials, and there is a problem that is difficult to recycle. Lately, since the problem of environmental pollution is getting serious, the dual pump cap, which is difficult to recycle, cannot be used. Currently, eco-friendliness has been considered in Korea, and there are no dual pump cap containers with excellent sealing performance. Therefore, in this study, a dual pump cap container made of eco-friendly material was designed. In addition, finite element analysis was performed to verify the design feasibility of the product.