Clothing to protect against heat and flame. Determination of contact heat transmission through clothing or constituent materials

2016 ◽  
2008 ◽  
Vol 53 (No. 5) ◽  
pp. 231-242 ◽  
Author(s):  
J. Hrázský ◽  
P. Král

The paper summarizes results of operations aimed at determining the pressing parameters of spruce water-resistant plywood and testing the suitability of particular constructions of plywood. Constant and variable parameters were determined. In pressed plywood sheets, the shearing strength of gluing according to EW 100 and the coefficient of compressibility were determined. In pressing, heat transmission through the set of veneers was analyzed and effects of the moisture of veneers on heat transmission were tested. The percentage of resin hardening was also determined. Results were statistically analyzed. The dependence was determined of shearing strength, coefficient of compressibility and heat transmission on changes in pressing parameters. Results of the study consist in the proposal of pressing parameters for particular constructions of plywood.


2020 ◽  
Vol 27 ◽  
pp. 166-176
Author(s):  
Jozef Kačur ◽  
Patrik Mihala

We are focused to the numerical modelling of heat, contaminant and water transport in unsaturated porous media in 3D. The heat exchange between water and porous media matrix is taken into the account. The determination of heat energy transmission coefficient and matrix heat conductivity is solved by means of inverse problem methods. The mathematical model represents the conservation of heat, contaminant and water mass balance. It is expressed by coupled non-linear system of parabolic-elliptic equations. Mathematical model for water transport in unsaturated porous media is represented by Richard's type equation. Heat transport by water includes water flux, molecular diffusion and dispersion. A successful experiment scenario is suggested to determine the required parameters including heat transmission and matrix heat conductivity coefficients. Additionally we investigate contaminant transport with heat transmission and contaminant adsorption. The obtained experiments support our method suitable for solution of direct and inverse problems. This problem we have discussed previously in 1D model, but preferential streamlines in 1D thin tubes shadow accurate results in determination of required parameters. In our presented setting we consider a cylindrical sample which is suitable in laboratory experiments for inverse problems.


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