Monitoring and Analysis of Solvent Emissions from Metal Cleaning Processes for Practical Process Improvement

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Emi Kikuchi*, Yasunori Kikuchi and Masahiko Hirao

Department of Chemical System Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, 113-8656 Tokyo, Japan?* Author to whom correspondence should be addressed. Tel: +81-3-5841-7227; fax: +81-3-5841-6876; e-mail: e-kikuchi{at}pse.t.u-tokyo.ac.jp Received September 12, 2011. Accepted November 8, 2011. Objectives: Industrial cleaning processes are a major source of emissions of chlorinated organic solvents in Japan. Solvent emission mechanisms from metal cleaning processes were analysed to support process improvement aimed at emission reductions.

Methods: The amounts of solvents directly emitted from a washing machine and solvents taken out by metal parts to be cleaned were measured in laboratory experiments using an industrial washing machine. Direct emissions to a local ventilation system and to the workplace were analysed, while several process conditions were changed. The drying rate of solvents on surfaces was analysed for seven metal parts to clarify the effects of their materials and shape. Results: The results for direct solvent emissions show that solvents emitted because of the movement of metal parts inside a washing machine can be mainly exhausted through a local ventilation system, while the operation of an ultrasonic device can increase solvent diffusion to the workplace. Lowering the cooling water temperature can be effective in avoiding such solvent diffusion to the workplace. The results also show that the heat capacity and shape complexity of metal parts can affect the drying rate of solvents on their surfaces. Conclusions: Analysis of the results shows the effectiveness of using a local ventilation system and cooling pipes in controlling solvent emissions for several work tasks. The minimum time required to dry all solvents on the surface of metal parts was also estimated. Analyses of the emission mechanisms in this study clarified the major factors in solvent emissions and the effectiveness of process modifications for emission reductions. The findings are applicable to practical process improvement aimed at emission reductions in cleaning sites. © The Author 2012. Published by Oxford University Press on behalf of the British Occupational Hygiene SocietyThis ArticleAnn Occup Hyg (2012) 56 (7): 829-842. doi: 10.1093/annhyg/mer115 First published online: December 19, 2011 Current Issue
Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.

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A Detailed Urinary Excretion Time Course Study of Captan and Folpet Biomarkers in Workers for the Estimation of Dose, Main Route-of-Entry and Most Appropriate Sampling and Analysis Strategies

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Theoretical Analysis of Three Methods for Calculating Thermal Insulation of Clothing from Thermal Manikin

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Jianhua Huang*

College of Textiles, Wuhan Textile University, Wuhan, Hubei 430073, China?* Tel. +86-27-59367572; fax 0086-27-87450870; e-mail: huang2010{at}wtu.edu.cn Received April 29, 2011. Accepted November 25, 2011. There are three methods for calculating thermal insulation of clothing measured with a thermal manikin, i.e. the global method, the serial method, and the parallel method. Under the condition of homogeneous clothing insulation, these three methods yield the same insulation values. If the local heat flux is uniform over the manikin body, the global and serial methods provide the same insulation value. In most cases, the serial method gives a higher insulation value than the global method. There is a possibility that the insulation value from the serial method is lower than the value from the global method. The serial method always gives higher insulation value than the parallel method. The insulation value from the parallel method is higher or lower than the value from the global method, depending on the relationship between the heat loss distribution and the surface temperatures. Under the circumstance of uniform surface temperature distribution over the manikin body, the global and parallel methods give the same insulation value. If the constant surface temperature mode is used in the manikin test, the parallel method can be used to calculate the thermal insulation of clothing. If the constant heat flux mode is used in the manikin test, the serial method can be used to calculate the thermal insulation of clothing. The global method should be used for calculating thermal insulation of clothing for all manikin control modes, especially for thermal comfort regulation mode. The global method should be chosen by clothing manufacturers for labelling their products. The serial and parallel methods provide more information with respect to the different parts of clothing.

© The Author 2011. Published by Oxford University Press on behalf of the British Occupational Hygiene SocietyThis ArticleAnn Occup Hyg (2012) 56 (6): 728-735. doi: 10.1093/annhyg/mer118 Current Issue
Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.

View the original article here

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Monitoring and Analysis of Solvent Emissions from Metal Cleaning Processes for Practical Process Improvement

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Emi Kikuchi*, Yasunori Kikuchi and Masahiko Hirao

Department of Chemical System Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, 113-8656 Tokyo, Japan?* Author to whom correspondence should be addressed. Tel: +81-3-5841-7227; fax: +81-3-5841-6876; e-mail: e-kikuchi{at}pse.t.u-tokyo.ac.jp Received September 12, 2011. Accepted November 8, 2011. Objectives: Industrial cleaning processes are a major source of emissions of chlorinated organic solvents in Japan. Solvent emission mechanisms from metal cleaning processes were analysed to support process improvement aimed at emission reductions.

Methods: The amounts of solvents directly emitted from a washing machine and solvents taken out by metal parts to be cleaned were measured in laboratory experiments using an industrial washing machine. Direct emissions to a local ventilation system and to the workplace were analysed, while several process conditions were changed. The drying rate of solvents on surfaces was analysed for seven metal parts to clarify the effects of their materials and shape. Results: The results for direct solvent emissions show that solvents emitted because of the movement of metal parts inside a washing machine can be mainly exhausted through a local ventilation system, while the operation of an ultrasonic device can increase solvent diffusion to the workplace. Lowering the cooling water temperature can be effective in avoiding such solvent diffusion to the workplace. The results also show that the heat capacity and shape complexity of metal parts can affect the drying rate of solvents on their surfaces. Conclusions: Analysis of the results shows the effectiveness of using a local ventilation system and cooling pipes in controlling solvent emissions for several work tasks. The minimum time required to dry all solvents on the surface of metal parts was also estimated. Analyses of the emission mechanisms in this study clarified the major factors in solvent emissions and the effectiveness of process modifications for emission reductions. The findings are applicable to practical process improvement aimed at emission reductions in cleaning sites. © The Author 2012. Published by Oxford University Press on behalf of the British Occupational Hygiene SocietyThis ArticleAnn Occup Hyg (2012) 56 (7): 829-842. doi: 10.1093/annhyg/mer115 First published online: December 19, 2011 Current Issue
Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.

View the original article here

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