The ROD baffle heat exchanger can slightly enhance the shell side heat transfer coefficient with the significant reduction of pressure, loss due to the shell side fluid flowing longitudinally through tube bundle, whic...The ROD baffle heat exchanger can slightly enhance the shell side heat transfer coefficient with the significant reduction of pressure, loss due to the shell side fluid flowing longitudinally through tube bundle, which leads to the reduction of the manufacture and running cost and in some cases to the dimensions reduction of the heat exchangers. Because of the complexities of fluid dynamics equations and the structure of heat exchangers, few theoretical researches have been accomplished to specify the shell side characteristics of the ROD baffle heat exchanger. A unit duct model in the shell side of the longitudinal flow type heat exchanger has been developed based on suitable simplification. A numerical analysis on shell side of the ROD baffle heat exchanger has been carried out at constant wall temperature to obtain the characteristics of heat transfer and pressure drop. The numerical results show that the ROD baffles placed vertically and horizontally in the unit duct continue to shear and comminute the streamline flow when the fluid crosses over the ROD-baffles, and change the fluid flow directions, and then the continuity and stability of the fluid axe destroyed. The effect of disturbing flow can promote fluid turbulent intensity and effectively enhance heat transfer. The numerical analyses can provide the theoretical bases for optimizing the structure of ROD baffle heat exchanger and improving its performance.展开更多
Introduction: Occupational dermatitis has long been an unforeseen consequence of industrial progress. Today, most occupational diseases are dermatosis throughout the world. The morbidity and the various prejudices con...Introduction: Occupational dermatitis has long been an unforeseen consequence of industrial progress. Today, most occupational diseases are dermatosis throughout the world. The morbidity and the various prejudices concern different actors, especially those of the cashew industry in Bobo-Dioulasso to Burkina Faso. We considered it appropriate to conduct this study in women who handle cashew nuts in the cashew nut shelling station at a factory. The aim is to contribute to the search for preventive and curative solutions adapted to this health risk. Methods: This was a prospective cross-sectional study with a descriptive purpose in May 2016. The study involved 112 women present in the factory in the shelling unit and having given their approval during our visit. This station is occupied by 118 women. Results: The prevalence of all dermatosis and dermatitis was estimated respectively at 98.21% and 88.39%. The manual shelling station with a shearing machine was exclusively occupied by illiterate women (72.3%) without personal protective equipment, with an average age of 33.74 ± 8.49 years. Among the clinical forms of contact dermatitis, the erythematous contact dermatitis was most observed (86.4%), followed by palmar keratoderma (70.9%), nail disorders (33.6%) and chemical burns (30%). The implication of Cashew Nut Shell Liquid (CNSL) was established with identified promoting factors. Aesthetic damage related to hand injuries had a significant psychosocial impact in 97.32% of cases. Discussion: Few studies exist on dermatitis and the health impacts in the reality of cashew because they reach vulnerable subjects without social welfare and health protection. The cashew nuts shell contains a highly irritating brown oily liquid. Dermatitis occurs during contact with this oily juice. The international literature reports this corrosive effect throughout the history of the chain. Human factors, technical factors and work environment aggravate the situation and compromize workwomen health. Conclusion: Cashew huskers had dermatitis with an impact on daily life. Working conditions and security of employment, hygiene attitudes and anacardic acid were identified as causes of this situation. It is imperious to take measures in collaboration with the occupational physicians to ensure these women’s health at work and improve their quality of life.展开更多
文摘The ROD baffle heat exchanger can slightly enhance the shell side heat transfer coefficient with the significant reduction of pressure, loss due to the shell side fluid flowing longitudinally through tube bundle, which leads to the reduction of the manufacture and running cost and in some cases to the dimensions reduction of the heat exchangers. Because of the complexities of fluid dynamics equations and the structure of heat exchangers, few theoretical researches have been accomplished to specify the shell side characteristics of the ROD baffle heat exchanger. A unit duct model in the shell side of the longitudinal flow type heat exchanger has been developed based on suitable simplification. A numerical analysis on shell side of the ROD baffle heat exchanger has been carried out at constant wall temperature to obtain the characteristics of heat transfer and pressure drop. The numerical results show that the ROD baffles placed vertically and horizontally in the unit duct continue to shear and comminute the streamline flow when the fluid crosses over the ROD-baffles, and change the fluid flow directions, and then the continuity and stability of the fluid axe destroyed. The effect of disturbing flow can promote fluid turbulent intensity and effectively enhance heat transfer. The numerical analyses can provide the theoretical bases for optimizing the structure of ROD baffle heat exchanger and improving its performance.
文摘Introduction: Occupational dermatitis has long been an unforeseen consequence of industrial progress. Today, most occupational diseases are dermatosis throughout the world. The morbidity and the various prejudices concern different actors, especially those of the cashew industry in Bobo-Dioulasso to Burkina Faso. We considered it appropriate to conduct this study in women who handle cashew nuts in the cashew nut shelling station at a factory. The aim is to contribute to the search for preventive and curative solutions adapted to this health risk. Methods: This was a prospective cross-sectional study with a descriptive purpose in May 2016. The study involved 112 women present in the factory in the shelling unit and having given their approval during our visit. This station is occupied by 118 women. Results: The prevalence of all dermatosis and dermatitis was estimated respectively at 98.21% and 88.39%. The manual shelling station with a shearing machine was exclusively occupied by illiterate women (72.3%) without personal protective equipment, with an average age of 33.74 ± 8.49 years. Among the clinical forms of contact dermatitis, the erythematous contact dermatitis was most observed (86.4%), followed by palmar keratoderma (70.9%), nail disorders (33.6%) and chemical burns (30%). The implication of Cashew Nut Shell Liquid (CNSL) was established with identified promoting factors. Aesthetic damage related to hand injuries had a significant psychosocial impact in 97.32% of cases. Discussion: Few studies exist on dermatitis and the health impacts in the reality of cashew because they reach vulnerable subjects without social welfare and health protection. The cashew nuts shell contains a highly irritating brown oily liquid. Dermatitis occurs during contact with this oily juice. The international literature reports this corrosive effect throughout the history of the chain. Human factors, technical factors and work environment aggravate the situation and compromize workwomen health. Conclusion: Cashew huskers had dermatitis with an impact on daily life. Working conditions and security of employment, hygiene attitudes and anacardic acid were identified as causes of this situation. It is imperious to take measures in collaboration with the occupational physicians to ensure these women’s health at work and improve their quality of life.
