• Title/Summary/Keyword: Chlorine gas

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Effect of Chlorine Treatment on the Rheological Properties of Wheat Flour (염소처리가 밀가루의 리올로지 특성에 미치는 영향)

  • Han, Myung-Kyu;Chang, Hak-Gil;Shin, Hyo-Sun
    • Korean Journal of Food Science and Technology
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    • v.24 no.2
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    • pp.127-131
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    • 1992
  • The effects of chlorine treatment on the rheological properties (farinogram, extensogram, amylogram) of soft white wheat flour were studied by treating flour with different amounts (1, 2 and 4 ounces per 100 pounds of flour) of liquidized chlorine gas. Departure time, water absorption and dough stability increased while mechanical tolerance index decreased as the level of chlorine increased. It was appeared that extensibility and resistance at chlorine level of 1 to 2 oz was appropriate for baking properties of flour compared to those of untreated wheat flour. The temperature at maximum viscosity increased gradually with increasing levels of chlorine. It was noted that maximum viscosity was greatly increased at 4 oz compared to those of lower levels of chlorine treatment.

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He-Polymer Microchip Plasma (PMP) System Incorporating a Gas Liquid Separator for the Determination of Chlorine Levels in a Sanitizer Liquid

  • Oh, Joo-Suck;Kim, Y.H.;Lim, H.B.
    • Bulletin of the Korean Chemical Society
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    • v.30 no.3
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    • pp.595-598
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    • 2009
  • The authors describe an analytical method to determine total chlorine in a sanitizer liquid, incorporating a lab-made He-rf-plasma within a PDMS polymer microchip. Helium was used instead of Ar to produce a plasma to achieve efficient Cl excitation. A quartz tube 1 mm i.d. was embedded in the central channel of the polymer microchip to protect it from damage. Rotational temperature of the He-microchip plasma was in the range 1350-3600 K, as estimated from the spectrum of the OH radical. Chlorine was generated in a volatilization reaction vessel containing potassium permanganate in combination of sulfuric acid and then introduced into the polymer microchip plasma (PMP). Atomic emission lines of Cl at 438.2 nm and 837.7 nm were used for analysis; no emission was observed for Ar plasma. The achieved limit of detection was 0.81 ${\mu}g\;mL^{-1}$ (rf powers of 30-70 W), which was sensitive enough to analyze sanitizers that typically contained 100-200 ${\mu}g\;mL^{-1}$ of free chlorine in chlorinated water. This study demonstrates the usefulness of the devised PMP system in the food sciences and related industries.

Corrosion at the Grain Boundary and a Fluorine-Related Passivation Layer on Etched Al-Cu (1%) Alloy Surfaces

  • Baek, Kyu-Ha;Yoon, Yong-Sun;Park, Jong-Moon;Kwon, Kwang-Ho;Kim, Chang-Il;Nam, Kee-Soo
    • ETRI Journal
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    • v.21 no.3
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    • pp.16-21
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    • 1999
  • After etching Al-Cu alloy films using SiCl4/Cl_2/He/CHF3 mixed gas plasma, the corrosion phenomenon at the grain boundary of the etched surface and a passivation layer on the etched surface with an SF6 plasma treatment subsequent to the etching were studied. In Al-Cu alloy system, corrosion occurs rapidly on the etched surface by residual chlorine atoms, and it occurs dominantly at the grain boundaries rather than the crystalline surfaces. To prevent corrosion, the SF6 gas plasma treatment subsequent to etching was carried out. The passivation layer is composed of fluorine-related compounds on the etched Al-Cu surface after the SF6 treatment, and it suppresses effectively corrosion on the surface as the SF6 treatment pressure increases. Corrosion could be suppressed successfully with the SF6 treatment at a total pressure of 300 mTorr. To investigate the reason why corrosion could be suppressed with the SF6 treatment, behaviors of chlorine and fluorine were studied by various analysis techniques. It was also found that the residual chlorine incorporated at the grain boundary of the etched surface accelerated corrosion and could not be removed after the SF6 plasma treatment.

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Dry etching properties of PST thin films using chlorine-based inductively coupled plasma (Chlorine-based 유도결합 플라즈마를 이용한 PST 박막의 건식 식각 특성)

  • Kim, Gwan-Ha;Kim, Kyoung-Tae;Kim, Dong-Pyo;Lee, Cheol-In;Kim, Chang-Il
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.07a
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    • pp.400-403
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    • 2003
  • Etching characteristics of (Pb,Sr)$TiO_3$(PST) thin films were investigated using inductively coupled chlorine based plasma system as functions of gas mixing ratio, RF power and DC bias voltage. It was found that increasing of Ar content in gas mixture lead to sufficient increasing of etch rate and selectivity of PST to Pt. The maximum etch rate of PST film is $562\;{\AA}$/min and the selectivity of PST film to Pt is 0.8 at $Cl_2/(Cl_2+Ar)$ of 20 %. It was proposed that sputter etching is dominant etching mechanism while the contribution of chemical reaction is relatively low due to low volatility of etching products.

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A Study on the NOx Reduction of Flue Gas Using Seawater Electrolysis (해수 전기분해를 적용한 배연 탈질 기술에 관한 연구)

  • Kim, Tae-Woo;Kim, Jong-Hwa;Song, Ju-Yeong
    • Journal of the Korean Applied Science and Technology
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    • v.29 no.4
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    • pp.570-576
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    • 2012
  • In this study, we investigated the characteristics of NO oxidation using un-divided electrolyzed seawater as oxidant. The concentration of available chlorine and the temperature of electrolyzed seawater are increased with electrolysis time in the closed-loop constant current electrolysis system. While NO gas flow through bubbling reactor which is filled with electrolyzed seawater, the oxidation rate of NO to $NO_2$ is increased with the concentration of available chlorine and the temperature. $NO_2$, generated by oxidation reaction, is dissolved in electrolyzed seawater and existed as $HNO_3{^-}$ ion.

Quality Changes of Centella asiatica by Slow-released ClO2 Gas Gel-pack during Storage (서방형 이산화염소 가스 젤팩을 이용한 병풀의 저장 중 품질 변화)

  • Lee, Kyung-Haeng;Yu, Kwang-Won;Bae, Yun-Jung;Han, Ki-Jung;Jang, Da-Bin
    • The Korean Journal of Food And Nutrition
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    • v.35 no.4
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    • pp.247-252
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    • 2022
  • To improve the shelf-life of Centella asiatica, Centella asiatica was treated with gel packs containing slow-released chlorine dioxide (ClO2) gas at 3-5 ppm for 20 days at 4℃. The weight loss rate, as well as the changes in pH, color, and texture of the treated samples, were investigated. The weight of the control and ClO2 gas-treated samples was decreased during the storage period. The change in weight of the control was slightly faster than that of the samples treated with 3 and 4 ppm ClO2 gas. The pH of the control and the ClO2 gas treated samples were decreased during the storage period and there was no significant difference between the control and ClO2 gas treated samples. Concerning color (lightness, redness, and yellowness) changes of Centella asiatica during the storage period, there was no significant difference between the control and ClO2 gas treated samples. The change in shear force in the leaf and stem of Centella asiatica during the storage period was slightly lower in the 4 ppm ClO2 gas treated samples (in the leaf) compared to the control and 3 and 4 ppm ClO2 gas treated samples (in the stem) compared to the control and 5 ppm ClO2 gas treated sample.

Selective Removal of Cu in Ferrous Scrap by Chlorine gas (염소가스에 의한 철 스크랩 중 Cu의 선택적 제거)

  • Lee, So-Yeong;Sohn, Ho-Sang
    • Resources Recycling
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    • v.27 no.5
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    • pp.54-60
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    • 2018
  • The quality of steel produced from scrap can be adversely affected because of the buildup of tramp elements in recycled scrap. The tramp element of greatest concern is copper because of its effect on steel quality, even in small percentage quantities. In this study, possibility of removal of copper from ferrous scrap by using $Cl_2$ gas is experimentally examined in a small size experimental apparatus. Synthetic ferrous scraps containing copper were reacted with $Cl_2$ gas in various atmosphere. The copper was chloridized and evaporated, whereas iron was oxidized and was not reacted with Cl2 and oxygen mixture gas.

An Implementation of an Integrated Degasing System for Aluminum Molten Metal in Continuous Casting (알루미늄 연속주조 용탕의 탈 가스 일체화 장치 개발)

  • Lee, Yong-Joong
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.17 no.1
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    • pp.1-6
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    • 2008
  • There are some methods that have been used to manage a degasing process in recent years, such as an injection method that uses aluminum molten metal powder and chemicals supplier and input method that supplies argon and nitrogen, or chlorine gas by using a gas blow-tube. However, these methods show some problems, and it shows that it is a difficult process to handle, pollution due to producing a lot of toxic gases like chlorine and fluoride gas, irregular effects, and lowering work efficiency due to the excessive processing time. The problems that are the most fatal are the producing a lot of sludge due to the reaction of aluminum molten metal with chemicals, loss of metals, and decreasing the life of refractory materials. In order to solve these problems, this paper develops a technology that is related to aluminum continuous casting molten metal and monolithic degasing apparatus. A degasing apparatus developed in this study improved the existing methods and prevented environmental pollution with smokeless, odorless, and harmlessness by using a new method that applies argon and nitrogen gas in which the methods used in the West and Japan are eliminated. The method developed in this study decreases the molten metal processing and settling time compared to the existing methods and improves the workers' health, safety, and environment because there is no pollution in processes.

Effect of an Aqueous Chlorine Dioxide Generator and Effect on Disinfection of Fresh Fruits and Vegetables by Immersion Washing (이산화염소수 생성기의 생성효율 및 과.채류에 대한 침지 세정 살균효과)

  • Park, Kee-Jai;Jeong, Jin-Woong;Lim, Jeong-Ho;Jang, Jae-Hee;Park, Hee-Joo
    • Food Science and Preservation
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    • v.15 no.2
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    • pp.236-242
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    • 2008
  • We investigated the optimum concentration of a $NaClO_2$ solution and the amount of gaseous $Cl_2$ for production of high yield and purity of aqueous $ClO_2$ by use of a gaseous chlorine-chlorite $ClO_2$ generator. This system produced lower concentrations of chlorine dioxide and is applicable for direct-use in food processing as a cleaner and sanitizer. The concentration of $NaClO_2$ solution and the amount of gaseous $Cl_2$ was varied from 0.01-0.1% and 100-1,000 g/hr, respectively. The concentrations of chlorite, chlorate, FAC (free available chlorine), and chlorine dioxide that were produced increased with increasing concentration of $NaClO_2$ solution and with the amount of gaseous $Cl_2$. The optimum concentration of $NaClO_2$ solution and amount of gaseous $Cl_2$ were 0.1% and 900 g/hr respectively. $ClO_2$ and FAC produced at these concentrations were 882.0 ppm and 8.0 ppm, with no detection of chlorite and chlorate. The yield and purity of $ClO_2$ were 97.0% and 96.0% respectively. Immersion-cleaning experiments showed that this protocol decreased the level of CFU/g by $10^3$- to $10^4$-fold, with a similar effect on fruit.

Mechanisms of $Cl_2$ Molecules Dissociation in a Gas Discharge Plasma in Mixtures with Ar, $O_2.N_2$

  • Efremov, A.M.;Kwon, Kwang-Ho
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.1 no.4
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    • pp.197-201
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    • 2001
  • The influence of argon, oxygen, and nitrogen admixtures on the dissociation of $Cl_2$ molecules in a glow discharge low-temperature plasma under the constant pressure conditions was investigated. For $Cl_2/Ar$ and $Cl_2/O_2$mixtures, the concentration of chlorine atoms was observed to be a practically constant at argon or oxygen concentrations up to 50%. This invariability is a most pro bably explained by relative increase in rate of $Cl_2$ direct electron impact dissociation due to the changes in electrophysical parameters of plasma such as EEDF, electron drift rate and mean energy. For all the considered mixtures, the contribution of stepwise dissociation involving active species from gas additives (metastable atoms and molecules, vibrationally excited molecules) was found to be negligible.

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