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2007, Piran, Slovenia

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Personal protective equipment<br />

Profiles of the measured temperature and the estimated water vapour are given in Figure 2.<br />

The distribution of the water vapour differs remarkably from that of temperature with<br />

irradiation. The highest temperature was seen inside the PC while that of the water vapour<br />

was observed on the underwear surface. This indicates that the water vapour from the<br />

underwear transfers not only to the environment, but also to the modelled skin. Therefore,<br />

transferred mass flux through the PC system is affected by the condition either with or<br />

without radiation, as shown in Figure 3. In case of the with irradiation, the mass flux indicates<br />

a remarkably lower value, which fell down to ~60% of that found without radiation.<br />

Water vapour evaporates from the underwear surface. A part of the evaporated water vapour<br />

is transferred to the modelled skin, condenses there due to its temperature being lower than<br />

the underwear, and it is then wicked (or absorbed) into the underwear again. The<br />

condensation converts the latent heat in the vapour into sensible heat loss over the modelled<br />

skin. In this study, the released sensible heat due to condensation in the underwear becomes<br />

250 W·m -2 to 320 W·m -2 . These values are remarkably large in terms of the heat load for the<br />

human body.<br />

Our analysis of the radiation heat transfer [Fukazawa et al., 2005] indicates that during the<br />

exposure to the radiation, the skin is imposed with a quite large heat flux due to the incident<br />

heat from the radiation source. It can be considered that injury by steam burn occurs not only<br />

by the released sensible heat due to the condensation in the underwear, but also by the<br />

increased heat flux due to the enhanced conduction through the wet underwear.<br />

DISCUSSION<br />

Heat and water vapour transfer in the protective clothing system during exposure to solar<br />

radiation has been described in this experiment. In the presence of radiation, distributions of<br />

water vapour in the system show a different distribution tendency than that of temperature.<br />

Figure 3. Transferred mass flux through the PC with and without the solar radiation.<br />

Blank bar represent without radiation, and filled bars with radiation.<br />

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