Influence of Humidity on the Radiant, Convective and Contact Heat Transmission Through Protective Clothing Materials

2009 ◽  
pp. 269-269-12 ◽  
Author(s):  
RM Rossi ◽  
T Zimmerli
Keyword(s):  
Protective Clothing ◽  
Heat Transmission ◽  
Contact Heat

SHEET METAL FORMING PROCESSES AT ELEVATED TEMPERATURES

2008 ◽  
Vol 07 (02) ◽  
pp. 307-311 ◽  
Author(s):  
P. GROCHE ◽  
C. KLOEPSCH
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Elevated Temperatures ◽  
Heat Transmission ◽  
Contact Heat ◽  
System Parameters ◽  
Specific Strength ◽  
High Specific Strength ◽  
Metal Products

On one hand lightweight sheet materials are characterized by high specific strength but on the other hand, they are limited in the design of sheet metal products. To extend the range of producible geometries, special forming processes at elevated temperatures have been developed. For describing the forming behavior at elevated temperatures or to design forming processes, the knowledge of relevant system parameters like flow stress, friction conditions and contact heat transmission coefficient is assumed. Additionally experimental results are presented to highlight the potential of sheet metal forming processes at elevated temperatures.

A model of heat transfer in firefighting protective clothing during compression after radiant heat exposure

2016 ◽  
Vol 47 (8) ◽  
pp. 2128-2152 ◽  
Author(s):  
Yun Su ◽  
Jiazhen He ◽  
Jun Li
Keyword(s):  
Heat Transfer ◽  
Parametric Study ◽  
Protective Clothing ◽  
Heat Exposure ◽  
Radiant Heat ◽  
Heat Transfer Model ◽  
Air Gap ◽  
Transfer Model ◽  
Skin Burn ◽  
Contact Heat

This paper presents an experiment-based, multi-medium heat transfer model to study thermal responses of multi-layer protective clothing with an air gap exposed to thermal radiation and hot contact surface. The model considers the dynamical changes of air gap, each layer’s fabric thickness, and air content contained in the fabric due to the pressure applied. The fabric heat transfer model developed from this study was incorporated into a human skin burn model in order to predict skin burn injuries. The predicted results from the model were well in agreement with the experimental results. A parametric study was conducted using various contact temperatures and applied pressures and design variables of firefighting protective clothing, such as physical properties of fabric layers and air gap sizes. It was concluded from the parametric study that resistance to transmission of injurious levels of heat decreases as the test temperature and contact pressure increase, and the contact heat transfer can weaken the importance of air gap under radiant heat flux(8.5 kW/m2) for 60 s and compression (pressure: 3 kPa, temperature: 316℃) for 60 s. The findings obtained in this study can be used to engineer fabric systems that provide better protection for contact heat exposure.

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