부분압력균일화 단계를 포함하는 PSA공정의 성능평가

申興秀 홍익대학교 산업기술연구소 1997 産業技術 Vol.7 No.-

Process performance for a two-bed PSA process with partial pressure equalization(PE) is determined by a numerical simulation. An equilibrium cell model is used with the assumption of Langmuir, uncoupled isotherms for both components and isothermal operation. Effects of purge amount and extent of equalization on process performances is examined in view of productivity, light-component recovery, and power consumption. Also, performance contours are constructed from the simulation results, 95% oxygen production from an air with zeolite 13X is considered as a case study. For the case of feed-pressurization. optimum specific purge and extent of equalization for the maximum productivity is observed. At the optimum specific purge improvement of all performances parameters or a trade-off among performance parameters are shown depending on the range of the extent of equalization. The optimum operation condition for oxygen production from air is 0.1mol/cycle ㎏ of specific purge and 0.75 if extent of equalization. For the case of product-pressurization, the optimum specific purge is identical to that for the feed-pressurization. At the optimum specific purge a trade-off among performance parameters is shown for the entire range of extent of equalization.

압력스윙흡착공정에 의한 다성분계 가스분리 : 다탑공정의 수학적 모델 개발 Development of a Mathematical Model for Multi-bed Processes

申興秀 홍익대학교 산업기술연구소 1999 産業技術 Vol.9 No.-

Mathematical model is developed for separation of a multicomponent gas mixture by multi-bed pressure swing adsorption (PSA) process. Equilibrium cell model is used with the assumption of uncoupled Langmuir isotherms for components and isothermal operation. Multi-bed cycles considered in this study are 4 and 5-bed cycles shown in the patent. The developed model is applied to the separation of hydrogen from reformer off-gas by a PCB activated carbon. The effect of purging amount was examined in view of recovery and productivity and optimum amount is observed. Since the developed model simulates successfully multi-bed PSA processes, it can be used for selecting suitable adsorbent and comparing different PSA cycles quantitatively before experiments. Also, this model can be extended to a more elaborate one to simulate an actual process accurately by including effects that are omitted in this study.

PSA 법에 의한 CH_4/CO_2 혼합가스 분리

申興秀,李炳哲 홍익대학교 산업기술연구소 1993 産業技術 Vol.2 No.-

Mathematical simulation was performed to study the separation of CH_4/CO_2 gas mixture by pressure swing adsorption (PSA) process. The PSA processes considered in this study was 3-step PSA process for CH_4 or CO_2 production only and 4-step PSA process for simultaneous production of CH_4 and CO_2 using 5A zeolite and PCB activated carbon. Performance of separation by 3-PSA for CH_4 or CO_2 production only and 4-step PSA for simultaneous production of CH_4 and CO_2 operated below atmospheric pressure using 5A zeolite is better than that using activated carbon. PSA process operated below atmospheric pressure using both adsorbents is more advantageous than that above atmospheric pressure. 4-step PSA for simultaneous production of CH_4 and CO_2 operated below atmospheric pressure using 5A zeolite resulted in a little less inferior performance of separation than that for CH_4 production only, but in a far better performance than that for CO_2 production only. However, such an improvement in performance of CO_2 separation by 4-step PSA cycle disappeared when using activated carbon instead of 5A zeolite. The typical results for a PSA cycle between 1.01bar and 0.267bar using 5A zeolite were : 97.8 ㏖% CH_4 purity at 58.4% CH_4 recovery for CH_4 production only, 98.1 ㏖% CO_2 purity at 32.0% CO_2 recovery for CO_2 production only, and 97.3 ㏖% CH_4 purity at 50.9% CH_4 recovery for CH_4 and 95.8 ㏖% CO_2 purity at 71.6% CO_2 recovery for simultaneous production of CH_4 and CO_2.

심미성 수복재료의 착색경향에 관한 연구

신흥수,황호길,조영곤 大韓齒科保存學會 1995 Restorative Dentistry & Endodontics Vol.20 No.1

향류흐름 효과를 주는 다탑 압력스윙흡착 공정의 모사

申興秀 홍익대학교 산업기술연구소 1996 産業技術 Vol.6 No.-

Mathematical simulation of a multibed pressure swing adsorption(PSA) process simulate a countercurrent flow for separation of a binary gas mixture is performed. The multibed PSA cycle is simplified to one-bed cycle in order to overcome difficulties simulation a multibed cycle. The mathematcal simulation involves the fomulation of material balances in gas and solid phases. The mass transfer within an adsorbent is described by linear driving force model. The resulting equations are solved numerically with pertinent boundary conditions for each step. Orthogonal collocation is applied for the formulated mathematical model and the resulting ordinary differential equations are integrated by Gear's method. The system considered in this study is nitrogen production from air by carbon molecular sieve. Complete clean-up during purging step is assumed. The simulation results indicate that increase in performance is greastest when the bed number increases from two to three however, it is negligible for more than four beds. The extent of performance improvement is larger for lower product plurity.

이성분계 분리를 위한 다탑 압력스윙흡착 공정의 모사

申興秀 홍익대학교 산업기술연구소 1994 産業技術 Vol.4 No.-

Mathematical simulation of multi-bed pressure swing adsorption(MPSA) cycle with pressure equalization(PE) steps is performed. In order to overcome mathematical difficulties in simulating MPSA cycle with PE steps a simplified PSA cycly is proposed. The simplified cycle a cycle for one bed is obtained by modifying PE and cocurrent blowdown steps. The simplified one-bed cycles are simulated by applying equilibrium cell model with the assumption of linear uncoupled isotherms for both components and isothermal operation. Performances of the simplified cyces are compared in view of a light-component recovery and a productivity. The simulation results indicate that MPSA cycle with PE steps show a higher recovery than the Skarstrom's cycle with a product pressurization. As the number of bed increases the recovery generally becomes higher. However, in low-pressure operation the extent of an incrased in recovery is negligible for MPSA cycles with more than 5 beds and in high-pressure operation 4-bed cyle shows a lower recovery than 2-bed.

1. 06㎛ Nd : YAG Laser를 이용한 요추간판탈출증의 경피적 수핵감압술

이흥선,변박장,최순관,신원한,권귀향,이인수,이경석,김범태 순천향대학교 1994 논문집 Vol.17 No.4

The 1.06㎛ Neodymium-YAG Laser(800 micron hemisherical) is revealed a useful tool for percutaneous laser disc decompression(PLDD). Especially PLDD would be applied to the management of lumbar disc herniation with minimal intervention. Total irradiated energy to one level of disc space was bout 1000 to 2000 joules. We performed this method at 10 levels, in 7 cases of patients, consisting of 4 males and 3 females with an average age of 37.7 years. Five cases showed excellent and good results, were observed. In two cases, open surgery was required because of unsatisfactory results. The best results were obtained in the protrusion type of disc herniation. We have summarized some advantages of PLDD: a) safe and simple procedure in an outpatient setting, b) avoiding general anesthesia, late spinal instability, c) possibility of repetitive use.

그레이브스병 환자에서 방사성 옥소(^131Ⅰ)치료의 효과

노흥규,안봉수,신재규,주언찬,송민호 충남대학교 의과대학 지역사회의학연구소 1996 충남의대잡지 Vol.23 No.2

Graves' disease is characterized by diffuse hyperplasia of thyroid gland, hypersecretion of thyroid hormones, ophthalmopathy, and localized pretibial myxema. Although the pathogenesis of Graves' disease is still obscure, but the TSH receptor antibodies have pathophysiological role in the hyperplasia of the gland and autonomous over production of thyroid hormones through the stimulation of TSH receptor. Radioiodine (^1311I) has been used for the treatment of Graves' disease for many years and is regarded as an treatment for the cases who is not remit following a course of antithyroid drug. To evaluate the efficacy and side effects of radioiodine treatment in Graves' disease, we studied clincal outcome after fixed dose(5-20mCi) of ^131I The results were as followings; 1) The mean dose of 9. 1mCi of ^131I administration makes 12 patients euthyroid out of 41 patients with Graves' disease. The dose of radioiodine(^131I) used for the treatment was not significantly different in hypothyroid group (3/41; 7.3%) or hyperthyroid group(26/41; 63.4%) after ^131I treatment. 2) The clinical outcomes after radioiodine (131I) treatment was not depend on the age and sex and thyrotropin receptor binding inhibitory immunoglobulins(TBII) of radioiodine(^131I) administered patients, but only the short duration of antithyroid drug treatment(the period of observation of the responce to antithyroid drug) before the radioiodine administration increase the incidence of radioiodine induced hypothyroidism. 3) The cumulative incidence of hypothyoidism after radioiodine(^131I) administration was 39.4% after third treatment. In conlusion, radioiodine treatment in fixed-dose is effective; it can induce euthyroidism or hypothyroidism in 33 out of 41 patients without major complications. With this study, we could confirm the efficacy of radioiodine treatment in a minor groups of patient who its difficult to maintain remission after antithyroid drug.

조직확장기 사용의 임상적 고찰

한흥수,김우경,김수신,백세민 大韓成形外科學會 1991 Archives of Plastic Surgery Vol.18 No.1

Recently, soft tissue expansion technique using tissue expanders has become a popular method for reconstruction of soft tissue defect because it provides high quality tissue with similar color, texture and hair bearing characteristics without significant donor site problems. During the period September, 1983 to December, 1988, we used tissue expanders to treat 36 patients with soft tissue defect, 3 scalp, 10 face, 6 neck, 4 trunk, 10 upper extremity, 3 lower extremity and evaluated the operative techniques, results and complications as follows. 1. We achieved favorable results in 31 cases(86.1%), especially in scalp, face and upper extremity, but poor results in lower extremity, especially below knee in location. 2. We experienced major complications in 2 cases(5.6%) such as implant exposure and minor complications in 7 cases(19.4%) such as hematoma, partial necrosis, infection, underlying bony depression etc. 3. Capsular excision is not desirable, but capsular release may permitted to acquire maximal length of the advancing flap. 4. In case of microtia, expanded tissue which was obtained from expanders is defficient for elevation of framework without skin graft. 5. Accurate and meticulous preoperative evaluation is the most important factor in achieving good and results.

車輛燃料節減을 위한 세라믹히터裝置 開發硏究

전흥신,김흥수,김준수 慶熙大學校 1998 論文集 Vol.27 No.-

In a carburating system, the fuel keeps vaporizing after sprayed to the carburator as droplets. But in the case of cold weather, plenty of them remain in the liquid phase, causing the increase of fuel consumption rates and harmful exhaust gas amounts. Those problems were known to be solved using the PTC ceramic heater for heating up the fuel into the cylinder in being supplied. Purpose of this research is the development of a PTC ceramic heater for automotive fuel saying. This research emphasized the fabrication of newly developed step-shaped PTC heaters assembly and the obtaining the application result after installing them on the 1500cc engine. The combustion pressure, the indicated mean effective pressure, the fuel consumption rate, the heat release, tile burned mass fraction of gas of the engine between with and without the PTC heater were compared as a function of crank angle. The reults were as follow: 1) With the PTC heater installed, the deviations of the maximum combustion pressure and the indicated mean effective pressure were improved by 2.0% and 0.8%, which brought the smoothing of drivability and the increase of engine power compared with engine without the heater. 2) The fuel consumption rates per unit power with PTC heater installed at 2000 rpm and the boost pressure of 300 mmHg and 400 mmHg were increased by 0.6∼8.1% compared with no PTC heater. 3) With 180℃ newly developed PTC heater installed, heat release time delays at the boost pressure of 300mmHg were made quicker by 1∼3 deg and the main combustion time by 5 deg compared with no PTC heater. 4) The 180℃ heater was the most effective of the three developed ones. 5) The introduction of new PTC heater improved the engine performance, which could bring the fuel saving and reduction of the harmful exhaust gas.