METHOD FOR DETERMINING DIFFUSION COEFFICIENT OF SOLVENT IN SHEET ORTHOTROPIC CAPILLARY-POROUS MATERIALS

摘要

FIELD: measuring equipment.;SUBSTANCE: invention relates to measuring equipment and can be used in the study of mass transfer processes and to determine the coefficients of diffusion of solvents in articles made of orthotropic sheet capillary-porous materials in paper, light, construction and other industries. Method for determining the diffusion coefficient of solvents in sheet orthotropic capillary-porous materials is proposed, which consists in that a uniform initial content of the solvent distributed in the solid phase is created in the studied sheet material. Then the test material is placed on a flat substrate made of a solvent impermeable material, upper surface of the material is waterproofed. At the initial moment of time, material under study is pulsed moistened along a straight line by a moving constant-productivity solvent source in a given direction of the orthotropic material. Electrodes of a galvanic converter are made in the form of rectilinear segments and placed on both sides of the line of pulsed moistening on straight lines parallel to the line of pulsed moistening located at the same predetermined distance from it. Two time moments τ₁ and τ₂ are recorded, at which equal values of the signal of the galvanic converter are reached, respectively, before and after the moment of the maximum of the converter signal. Diffusion coefficient is calculated by the formula: ; ;where x₀ – distance between the pulse moistening line and the distance to the location line of galvanic converter electrodes.;EFFECT: increase in the accuracy of measurement of the diffusion coefficient of solvents in sheet orthotropic capillary-porous materials.;1 cl