• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.198-201
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• 2002

An internal finishing process by the application of magnetic abrasive machining has been developed as a new technology to obtain a fine inner surface of pipe. In this paper, a slurry circulation system was designed and manufactured. Its finishing characteristics was experimently investigated by various effective factors such as dry, water flow, oil flow with a slurry. From the experimental results, it was found that the materal removal and surface roughness were good in oil flow with slurry. The slurry circulation system is effective on the internal finishing of non-ferromagnetic pipe(SUS304).

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.3 no.1
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• pp.38-44
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• 2004

An internal finishing process by the application of magnetic abrasive machining has been developed as a new technology to obtain a fine inner surface of non-ferromagnetic pipe. In this paper, an abrasive slurry circulation system was designed and manufactured. As a result, it was found that a fine inner surface of pipe was available by the use of these machining methods. The basic machining characteristics of pin-type magnetic tools were analyzed experimentally. In addition, the experimental results show that pin-type magnetic tools have more machining efficiency than Iron particles as magnetic tools.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.1002-1007
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• 2009

The research are performed to check the characteristics of the ice slurry transport system for the district cooling. The system are installed at the 1st floored building which is as large as the $1204\;m^2$ ($86\;m{\times}14\;m$). Three kinds of heat exchanger are selected, such as, plate, spiral and shell & tube type, to apply to the ice slurry systems. Experiment was done in the two cases. The first case, circulation water flow fixed at the design conditions for the state to change the flow of the supply of ice slurry. The second case, Ice slurry flow fixed at the design conditions for the state to change the flow of circulation water. Both side of Energy balance was calculated. The performance of plate heat exchanger is higher than others and it's enthalpy effectiveness is higher too.

• Journal of Environmental Science International
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• v.28 no.1
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• pp.137-145
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• 2019

The purpose of this study was to evaluate the effect of implementing a Liquid Manure Circulation System (LMCS) on the environmental improvement of swine farms. Bacterial counts at different circulation phases of the LMCS were measured. Air in the swine facility and the liquid manure in each step of LMCS were sampled and gaseous composition detected in swine farms both with and without LMCS to compare the environmental conditions in either case. There were no differences in the total bacteria count at any circulation phase in the LMCS. Escherichia coli were detected at a very low abundance only at the outlet of the slurry pit ($1.5{\times}10^2CFU/m{\ell}$). Salmonella were not detected at any phase. The LMCS clearly affected the odor strength of the swine farm and improved the air quality in the swine facility. On-site odor strength - inside, at the exhaust, and at the border of the swine facility - were clearly lowered in farms applying LMCS. Furthermore, the levels of ammonia, hydrogen sulfide, and carbon dioxide were improved in swine facilities applying LMCS.

• Geomechanics and Engineering
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• v.28 no.3
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• pp.265-281
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• 2022

A set of slurry shield test system capable of cutter cutting and slurry automatic circulation is used to investigate the deformation characteristics, the evolution characteristics of support resistance and the distribution and evolution process of earth pressure during excavating and collapsing of slurry shield tunneling in circular-gravel layer. The influence of cover-span ratio on surface subsidence, support resistance and failure mode of excavation face is also discussed. Three-dimensional numerical calculations are performed to verify the reliability of the test results. The results show that, with the decrease of the supporting force of the excavation face, the surface subsidence goes through four stages: insensitivity, slow growth, rapid growth and stability. The influence of shield excavation on the axial earth pressure of the front soil is greater than that of the vertical earth pressure. When the support resistance of the excavation face decreases to the critical value, the soil in front of the excavation face collapses. The shape of the collapse is similar to that of a bucket. The ultimate support resistance increase with the increase of the cover-span ratio, however, the angle between the bottom of the collapsed body and the direction of the tunnel excavation axis when the excavation face is damaged increase first and then becomes stable. The surface settlement value and the range of settlement trough decrease with the increase of cover-span ratio. The numerical results are basically consistent with the model test results.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.915-918
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• 1997

An internal finishing process by the application of magnetic abrasive machining has been developed as a new technology to obtain a fine inner surface of pipe. In this paper, an abrasive circulation system was designed and manufactured. As a result, it was found that a fine inner surface abrasive of pipe was available by the use of this machining methods. The basic machining characteristics of pin-type magnetic tools were analyzed experimentally. In addition, the experimental results show that we can realize that pin-type magnetic tools have more machining efficiency than iron particles as magnetic tools.

• Journal of Biosystems Engineering
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• v.31 no.3 s.116
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• pp.161-167
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• 2006

The purpose of this study is to find the optimal conditions of PCM slurry manufacturing equipment for saving the marketing cost and keeping the original quality of products. In addition, the characteristics of the movable container for shipping or distributing products is analysed. The major results are as follows. 1. PCM thermal storage system is designed with the conditions of temperature($-5{\sim}10^{\circ}C$), cold chain time(30 minutes), and one time usage(50 liter). This system includes tank, freezer, circulating pump, cycle type heat exchanger, swelling tank, equipment of supplying PCM supplying unit includes cold tank, cycle type heat exchanger, suction unit and control equipments, etc. 2. After ability test of PCM thermal storage system, it shows that the required freezing time of PCM thermal storage system is less than one of the previous system. The reason is that churn (top and bottom) and compulsion circulation are occurred simultaneously and unit cooler type method is better than chiller type method. 3. By the experiment of transportation latent heat container, it is decided that the best container is $K_1$ with latent heat temperature($0{\sim}5^{\circ}C$) and density(0.15%). However, for $K_l\;and\;K_2$, it is necessary more studies on latent heat thermal conditions and conditions of making method.

• Journal of the Korea Organic Resources Recycling Association
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• v.22 no.4
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• pp.62-71
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• 2014

Three types of diffuser systems were manufactured and applied to investigate the effect of liquid fertilization of pig manure slurry by application of aeration processes. In the first type reactor, commonly used diffuser system, which diffuse air upward by diffusing aerator fixed at the bottom of the reactor is installed. In case of the second type, air diffuser is installed 10 cm above of the bottom of a reactor. In the third type reactor, the venturi-type air diffuser is installed at circulation pipe, which return pig slurry in the reactor(mixing-in-pipe process). The pig manure slurry separated to solid/liquid was flowed into the experimental reactor, and left as it for one week to precipitate solids. The concentration of organic matter, T-N, T-P and BOD in the raw pig manure slurry flowed into the reactor of bottom-fixed type aeration process were 1.82%, 4,400 mg/L, 360 mg/L and 13,542 mg/L, respectively. After aeration the concentration of organic matters, T-N, T-P and BOD in the slurry were 2.01%, 4,400 mg/L, 420 mg/L and 16,824 mg/L, respectively. The concentration of organic matter, T-N, T-P and BOD in the mixing-in-pipe type changed from 1.58%, 3,700 mg/L, 260 mg/L and 15,735 mg/L to 1.96%, 4,000 mg/L, 340 mg/L, and 18,098 mg/L, respectively. Changes of the concentration of organic matter, T-N, T-P and BOD of the pig manure slurry collected from the middle layers of two aeration reactors; bottom aeration process and the mixing-in-pipe process, were 10.4%, 0%, 16.7% and 24.2% and 24.0%, 8.1%, 30.8% and 15.0%, respectively. The thickness of foam layer generated on the surface of pig manure slurry in aeration tank was thinner in mixing-in-pipe reactor than bottom-fixed type aeration reactor.