Thermal insulations of multilayer clothing systems measured by a bench scale test in low level heat exposures

Purpose – The purpose of this paper is to measure the thermal insulation of protective clothing with multilayer gaps in low-level heat exposures. Design/methodology/approach – Nine different combinations of protective clothing systems with multiple air gaps are used to measure the thermal insulation by a self-designed bench-scale test apparatus in different levels of an external thermal radiation of 2-10 kW/m2. The outside and inside surface temperatures of each fabric layer are also measured to calculate the local thermal insulation of each fabric layer and each air gap. Findings – The results show that the total thermal insulation of protective clothing under thermal radiation is less than that in normal environments, and the exposed thermal radiation will worsen the total thermal insulation of the multilayer fabric systems. Air gap plays a positive role in the total thermal insulation, and thus provides the enhanced thermal protection. It is also suggested that the local resistance of the air gap closer to the external thermal radiation is more easily affected by the thermal radiation, due to the different heat transfer ways in the fabric system and the external thermal radiation. Originality/value – Effects of air gap on the thermal insulation of protective clothing, and contribution of the local thermal resistance of each fabric layer and each air gap to the total thermal insulation.

Download Full-text

Performance Study of Protective Clothing against Hot Water Splashes: from Bench Scale Test to Instrumented Manikin Test

The Annals of Occupational Hygiene ◽

10.1093/annhyg/meu087 ◽

2014 ◽

Cited By ~ 2

Keyword(s):

Protective Clothing ◽

Hot Water ◽

Performance Study ◽

Bench Scale ◽

Scale Test ◽

Bench Scale Test

Download Full-text

A prediction method to evaluate thermal performance of protective clothing based on the correlation analysis of the bench scale and flame manikin tests

International Journal of Clothing Science and Technology ◽

10.1108/ijcst-02-2019-0017 ◽

2020 ◽

Vol 32 (4) ◽

pp. 499-510

Author(s):

Chang Xu ◽

Shifei Shen ◽

Ming Fu ◽

Yayun Li

Keyword(s):

Correlation Analysis ◽

Thermal Performance ◽

Protective Clothing ◽

Burn Injury ◽

Prediction Method ◽

Air Gap ◽

The Body ◽

Thermal Shrinkage ◽

Content Type ◽

Bench Scale

PurposeBench scale and flame manikin tests are two typical methods to evaluate thermal protective performance (TPP) of fire protective clothing. However, flame manikin test is limited to be widely used for its complication and high cost. The purpose of this paper is to develop a method to evaluate the thermal performance of protective clothing from the bench scale test results and garment parameters, which predicts the body burn injuries without conducting flame manikin tests.Design/methodology/approachBench scale and flame manikin tests’ data were collected from the previous research literature and then statistical analysis was performed to quantitatively investigate the correlations between the two test methods. Equations were established to predict the TPP values accounting for the effects of entrapped air gap and thermal shrinkage. Fitting analysis was conducted to analyze the relationship between the predicted TPP values and total burn injury. Finally, a method to predict total burn injury from the TPP values was proposed and validated.FindingsThe results showed that when the TPP value was predicted with the effects of air gap and thermal shrinkage considered, there was an approximate linear relationship between the predicted TPP values and total burn injury from the manikin test. Therefore, the prediction model of burn injury was developed based on the correlation analysis and verified with a generally good accuracy.Originality/valueThis paper presented a new prediction method to evaluate the thermal performance of protective clothing, which saved significant time and cost compared to the conventional methods. It can provide useful information for burn injury prediction of protective clothing.

Download Full-text

Experimental study of heat and moisture transfer in vertical air gap under protective clothing against dry and wet heat exposures

International Journal of Clothing Science and Technology ◽

10.1108/ijcst-06-2020-0091 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Yun Su ◽

Miao Tian ◽

Yunyi Wang ◽

Xianghui Zhang ◽

Jun Li

Keyword(s):

Natural Convection ◽

Protective Clothing ◽

Moisture Transfer ◽

Heat Exposure ◽

Air Gap ◽

Gap Size ◽

Heat And Moisture Transfer ◽

Content Type ◽

Wet Heat ◽

Heat And Moisture

PurposeThe purpose of this paper is to study heat and steam transfer in a vertical air gap and improve thermal protective performance of protective clothing under thermal radiation and hot steam.Design/methodology/approachAn experiment-based model was introduced to analyze heat and moisture transfer in the vertical air gap between the protective clothing and human body. A developed test apparatus was used to simulate different air gap sizes (3, 6, 9, 12, 15, 18, 21 and 24 mm). The protective clothing with different air gap sizes was subjected to dry and wet heat exposures.FindingsThe increase of the air gap size reduced the heat and moisture transfer from the protective clothing to the skin surface under both heat exposures. The minimum air gap size for the initiation of natural convection in the dry heat exposure was between 6 and 9 mm, while the air gap size for the occurrence of natural convection was increased in the wet heat exposure. In addition, the steam mass flux presented a sharp decrease with the rising of the air gap size, followed by a stable state, mainly depending on the molecular diffusion and the convection mass transfer.Originality/valueThis research provides a better understanding of the optimum air gap under the protective clothing, which contributes to the design of optimum air gap size that provided higher thermal protection against dry and wet heat exposures.

Download Full-text