• Corrosion Science and Technology
• /
• v.7 no.2
• /
• pp.69-76
• /
• 2008

Common methods for large scale hydrogen production, such as steam reforming and coal gasification, also involve production of carbonaceous gases. It is therefore necessary to handle process gas streams involving various mixtures of hydrocarbons, $H_2$, $H_2O$, CO and $CO_2$ at moderate to high temperatures. These gases pose a variety of corrosion threats to the alloys used in plant construction. Carbon is a particularly aggressive corrodent, leading to carburisation and, at high carbon activities, to metal dusting. The behaviour of commercial heat resisting alloys 602CA and 800, together with that of 304 stainless steel, was studied during thermal cycling in $CO/CO_2$ at $650-750^{\circ}C$, and also in $CO/H_2/H_2O$ at $680^{\circ}C$. Thermal cycling caused repeated scale separation, which accelerated chromium depletion from the alloy subsurface regions. The $CO/H_2/H_2O$ gas, with $a_C=2.9$ and $p(O_2)=5\times10^{-23}$ atm, caused relatively rapid metal dusting, accompanied by some internal carburisation. In contrast, the $CO/CO_2$ gas, with $a_C=7$ and $p(O_2)=10^{-23}-10^{-24}$ atm caused internal precipitation in all three alloys, but no dusting. Inward diffusion of oxygen led to in situ oxidation of internal carbides. The very different reaction morphologies produced by the two gas mixtures are discussed in terms of competing gas-alloy reaction steps.

• Particle and aerosol research
• /
• v.5 no.4
• /
• pp.189-197
• /
• 2009

Wet-type particulate removal system is employed in most of ironmaking processes. These de-dusting systems require additional downstream aggregates for treatment of water and for drying of the collected slurry. Thus dried slurry can be pressed in shape of briquettes and recycled in the steelmaking process. Different from the wet-type, the dry-type particulate removal systems generate no slurry. A high-temperature, high-pressure de-dusting system with inertial inlet was developed. The target application of this system was to remove particulate matter generated from the novel ironmaking process and other steelmaking processes. In this study we conducted tests with this newly developed system to evaluate the performance of the silica-carbide (SiC) ceramic filters. In addition, for purpose of comparison, we also conducted tests with a unit which has conventional direct inlet. Fe-Particles collected from the novel ironmaking process were used in our tests as test dusts. The temperature and the pressure were kept constant at their respective values $800^{\circ}C$ and $3kg_f/cm^2$.

• YAKHAK HOEJI
• /
• v.5 no.1
• /
• pp.31-36
• /
• 1960

The importance of enteric coating technique among the pharmaceutical firms has recently risen very significantly. This study of enteric coating bases was made in order to determine the most suitable bases and dusting powders. Materials and equipment used in this experiment are shown in table 1 and kinds of enteric coating bases and their formulas are shown in table 2. The evaluation of the suitability for enteric coating bases and dusting powder was made by disintergration test after measuring the thickness of the enteric coated layer as shown in the tables 4 and 5. Based on the results of this study, the base D(shellac 20 Gm, anhydrous lanoline 5 Gm, 96% alcohol 75 ml) and the base E (shellac 10 Gm, cetyl alcohol 10 Gm. acetone 80 ml) are selected among the 8 kinds of bases studied in a preliminary test and it was found that Mg-stearate and CA-stearate were in most suitable dusting powders among the 6 kinds studied for the bases D and E. Further study on base D and E was carried out by varying the proportions of the materials which were the original constituents of bases D and E. According to the result of this further study shown in table 6, the shellac 15 Gm cetyl alcohol 5 Gm Acetone 80 ml of base E is recommended as the most suitable dusting powder.

• 베이커리
• /
• no.7 s.444
• /
• pp.146-146
• /
• 2005

제품을 만들다보면 기대했던 대로 제품이 나오지 않거나 여러가지 궁금한 점들이 많이 생기게 마련이다. 이럴 땐 주저 없이 '테크닉 상담실"의 문을 두드려 보자. 전문가의 컨설팅을 통해 생산 현장에서 마주치는 여러 가지 기술 문제에 대해 명쾌한 해결을 도와준다.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.7 no.5
• /
• pp.1125-1131
• /
• 2012

According to abrupt decrese in number of farmer and ageing society, there has been a need for development of low cost agricultural robot. In this paper, a H/W and S/W platform of caterpillar type agricultural chemical dusting robot based on XP embedded system were described. The developed agricultural robot has 2 d.o.f caterpillar type driving wheel and 2 d.o.f chemical dusting spray mechanical system. The H/W platform of the agricultural robot consists of robot controller, remote controller and sensor controller. In S/W platform, 5 processes work concurrently, which are task manager, TCP-IP communication process, localization process, wheel control, and sensor control process. This robot platform has been developed for chemical dusting robot. We proved this system's validity through field test.

• Journal of the Korean Ceramic Society
• /
• v.38 no.1
• /
• pp.68-73
• /
• 2001

Active belite cement clinker 합성을 위하여 안정제로 borax (3 wt%)를 사용하였으며, 1300, 1350, 140$0^{\circ}C$에서 소성하고, 각각의 소성온도에서 아세톤 급냉, 공냉, 로냉의 3가지 방법으로 냉각속도를 달리하여 합성하였다. 클링커의 특성분석은 TG-DTA, XRD, FT-IR, SEM-EDS로 조사 분석하였으며, free-CaO 함량은 KSL 5120의 ethylene glycol법으로 정량하였다. Borax(3 wt%)를 첨가한 시료의 시차열분석에서 ${\gamma}$상으로의 전이는 관찰되지 않았으며, 각각의 소성온도와 냉각속도에 따른 free-CaO 분석에서 0.07~0.14%의 범위로 낮게 나타났으며, borax가 첨가되지 않은 시료는 140$0^{\circ}C$에서 소성하고 급냉시켰지만 ${\gamma}$상으로 전이되어 dusting 현상을 나타내었다. Borax(3 wt%) 첨가된 시료의 SEM 미세구조는 140$0^{\circ}C$에서 소성하고 급냉시켰지만 ${\gamma}$상으로 전이되어 dusting 현상을 나타내었다. Borax(3 wt%) 첨가된 시료의 SEM 미세구조는 140$0^{\circ}C$에서 소성된 모든 시료와 135$0^{\circ}C$에서 소성하고 급냉과 공냉시킨 시료는 type I belite, type III belite($\alpha$상) 구조를 나타낸다. 135$0^{\circ}C$에서 소성하고 로냉한 시료와 130$0^{\circ}C$에서 소성된 모든 시료는 type II belite($\beta$상) 구조를 나타내었다.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.3 no.2
• /
• pp.73-85
• /
• 1983

We occasionally find a thin layer of imperfectly hardened concrete surface when the wood form is stripped off. It has been generally believed that the principal causes were the effects of reactive form oil, adhesive agent or formalin which has been used in the course of plywood manufacturing. However, in this experiment, it became clear that the concrete surface could be influenced more harmfully by a certain species of wood form and the storage conditions of wood form rather than any other causes. Especially, the main cause of the severely dusty layer is the use of wood form exposed to sun for a long period. Countermeasures, therefore, for preventing concrete surface from dusting are also discussed in this paper.

• Proceedings of the Korean Powder Metallurgy Institute Conference
• /
• 2006.09b
• /
• pp.706-707
• /
• 2006

Premixes treated with a binder, such as in the FLOMET process, exhibit better flow, reduced dusting and segregation and improved productivity and part consistency compared to conventional premixes. The binder treatment is highly suitable for high performance P/M applications which often require premixes containing very fine alloying additives and excellent die filling characteristics. With this process, various binders and lubricants can be utilized in order to make premixes with unique properties. In this paper, the characteristics and performances of bonded premixes are reported.

• Journal of Ginseng Research
• /
• v.14 no.1
• /
• pp.50-56
• /
• 1990

Root-rot of ginseng caused by Fusarium solani is one of the most obstacles to ginseng cultivation. We evaluated some inoculating techniques of ginseng with Fusarium solani, for selection of disease resistant breeding lines. The most effective inoculating techniques evaluated were inserting toothpicks colonized by F. solani into the seedling roots in laboratory test and dusting seedlings with vermiculite after dipping in conidial sllspension and then replanting method in field test. The resistance to diseased by F. solani was lines of 82022 and 82066 in laboratory test. 82920-1 and 78093 in field test.

• Proceedings of the Korean Magnestics Society Conference
• /
• 2011.12a
• /
• pp.82-83
• /
• 2011