SU623139A1 - Method of determining permeability and filtration potential conductivity of porous materials - Google Patents

Description

The invention relates to methods for determining the filtration characteristics of porous bodies.

There is a method for determining the permeability coefficient jlj of porous bodies, aklyuchakshys. in creating a measurable differential pressure in the sample.

There is a known method for determining the gas permeability coefficient of ceramic materials i, in which the test sample is placed in a measuring chamber with pressurized compressed air. The test gas is supplied to the measuring chamber through a nozzle. The gas that has diffused through the sample is taken out of the chamber through the nozzle and enters the measuring apparatus.

The known methods are complex in hardware design and do not give sufficiently reliable results.

The closest technical solution to the proposed one is a method for determining permeability, based on measuring the pressure pepper generated by the sample being analyzed by

into a sealed chamber and having an internal hermetic cavity with a pressure sensor installed in it.

Calibration known method does not provide sufficient accuracy of measurement.

The circuit of the invention is improving the accuracy of the analysis.

It is achieved by increasing the pressure in the rep-i bladder at a constant speed, measuring the pressure in the sample cavity continuously, and finding the desired characteristics from the data obtained.

Claims (3)

The method consists in the following. On the outer surface of the sample in the form of shary. plates, cylinders, in which the side surfaces or end sides of the gas are insulated, a pressure sensor is installed. The same sensor is introduced into the sample at a known distance from the outer surface. Then the sample is placed into an airtight chamber, pressure is equalized over its cross section, after which the pressure in the chamber is changed at a constant rate and the difference in pressure is measured at the surface and inside the sample at the places of laying and sensors. According to the data obtained from the ratio:. -iH-i-Jjl HLR -Re) determine the coefficient of permeability (m / h) of the test material, where B is the rate of change of pressure in the chamber, kgf cm-hour. C is the distance from the sample surface to axis of symmetry: for a plate - half the thickness for a cylinder and a ball - radius g - distance from the axis of symmetry of the sample to the installation site, pressure sensor inside it, m G - sample shape factor: for plate G 2, for cylinder G 4, for the ball Рц - Pg - having established the pressure difference according to pressure sensors on the surface and inside the image tsa, kgf / cm. Based on the known value of the filtration coefficient of potential permeability dp of the material porosity L, the density of the material is used to calculate the value of the coef- fient of the size of the material being tested using the formula: -.-- -f- KG; L "s (rrrsv, h". L gI - m. H.kgch: / cm where Sr - ko9f4 "tsentnt specific gas of the bone material, in the dry content of the material:. density changes (Cmtrucky fluid pressure-dependent; for air Kg "1.21. Example. I am determined by filtering characteristics; - coefficient of permeability and filtration potential of conductivity with respect to the air of the plate and silicate concrete. D 3). Initial data: plate thickness from the surface to the plane of symmetry To 0.1 m; density of silicate concrete pd 185O; porosity of silicate concrete P 0, 2; coefficient K 1.21. Pressure sensors were installed on the surface and inside the plate, at a depth of 0.09 m, from the surface or, counting from the Symmetry plane, O , O1 m {; € R - 0.09 0.01 m). Claims The method for determining the permeability and filtration potential of the conductivity of particulate materials is based on measuring the pressure differential generated by the pressure chamber and having an internal cavity, It has a pressure sensor that differs in that with spruce Accelerating -toznostl analysis "uobto with constant velocity is increased pressure in a sealed chamber and is continuously measured by the pressure change in the sample cavity and the obtained data is determined by the desired characteristics -r. Sources of information, privaggiee into account when examining: 1.Zkova A.I. and others. Instruments and methods for determining the permeability of building materials. Successes of building physics in the USSR. M., 1967, p. 255. 2.Patent NDP # 63288, cl. G 01 N 33/38, 1971. 3. The patent of England No. 1313093, cl. G 15 G4, 1973.