SU1388743A1 - Method of taking samples - Google Patents

Abstract

The invention relates to methods for sampling material from surface layers and can be used in the technical fields related to the analysis of dust samples, contaminants and sediments on the surfaces of such products as gas and hydraulic lines, heat exchangers, etc. The aim of the invention is to take samples from layers on the surfaces of solids. The method of sampling from the surface layer is to disperse the surface layer, hold the dust particles and then separate the samples. In this case, the dispersion is carried out in a magnetic field by ferromagnetic granules, which are electrostatically charged before dispersion. Before separating the dust sample, the powder mass of the granules is demagnetized and de-electrified. Composite granules containing ferromagnetic and organic components are used as ferromagnetic granules. In a ratio, vol.%: Ferromagnetic component 40-95; organic component 5-60. Ebonite can be used as an organic component. 3 hp f-ly, 1 ill., 1 tab. "(L

Description

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The invention relates to methods for sampling material from surface layers and can be used in many technical fields, for example, for sampling for the analysis of dust, pollution and precipitation on surfaces of various products. including gas and hydraulic lines, heat exchangers and other structures.

The aim of the invention is to take samples from layers on the surfaces of solids.

The drawing shows the implementation of the method of sampling.

The elements of the permanent magnets 2 of alternating polarity are placed at the end of the housing 1 of the device. Ferromagnetic granules 3 are located between the ends of the magnets and the product. Case 1 receives a rotation around the axis (rotational drive not shown) and leads to the surface of product 4 before contact with it of ferromagnetic granules 3, Granules

2

composite particles by mixing the initial powders, heating the mixture to soften the organic component, pressing the mixture into briquettes, followed by cooling and grinding into granules.

Example. Sampling of the exhaust gases of an automobile engine on the surface of a glass plate was made.

The conditions for sampling were as follows: case diameter with magnetic elements 80 mm; the number of revolutions of the body is 5,200 rpm, the gap between the end of the body and the surface of the plates is 1.0 mm; plate size 60x100 mm-, granularity of granules 315/100 microns; the volume of the dose of granules 5 components of the granules: ferromagnetic - alloy Fe - A1 (8%), organic - ebonite; plate processing time 20 s. The efficiency of sampling was evaluated by the ratio (a,%) of the difference between the mass of ferromag0

3, rotating together with the body, pressing abrasive granules after and until they fall to the surface of the product 4, pro sampling the difference between the mass

the dispersion of the surface layer is worn out and electrified as a result of friction. The separated dust particles of the surface material are attracted and held by the granules 3. After the housing 1 stops, the granules 3 together with the dust particles of the sample are demagnetized in an AC solenoid, electrified by mixing in a grounded mixer and separated from the granules 3 by separation. .

To enhance the attractive, non-magnetic dispersive dust particles to the granules last before the dispersion process, electrostatic charge is reported, for example, by rubbing the granules on synthetic fabric glued onto a rigid dielectric base,

When implementing the method using composite granules, which. contain ferromagnetic and organic components. The ferromagnetic component is a granule of a ferromagnetic ferroalloy designed to hold the granules in a magnetic field. The organic component may be a polymer, an oligomer or a low molecular weight substance, such as ebonite, and is intended to impart an electrostatic charge to the composite granule. Make

plates before and after sampling. Be-, the guise of a shows how many percent of the mass of the dust-like particles dispersed from the surface of the plates are drawn and the ferromagnetic granules retained. Satisfy the requirement of a-60%. The results obtained are given in the table.

55

 - sampling with electrification

granules before the process. surface coating. Analysis of the results shows that the introduction of an organic component in the amount of 5-60% into the composition of the granules significantly increases the efficiency and quality of sampling. When the amount of the organic component is less than 5%, the granules have an insufficient charge of static electricity and sampling is ineffective. When the content of the organic component is more than 60% (and the corresponding content of the ferromagnetic component is less than 40%), the granules have low magnetic properties, are poorly maintained by the magnetic field and do not provide effective sampling.

The best results on the efficiency and quality of sampling and surface cleaning were obtained in experiment 6, before which the granules were subjected to electrification.

The application of the proposed invention is expedient in many fields of technology for sampling from layers on surfaces of various structures.

Claims (4)

1. Method of sampling from the surface layer, including dispersion five 0 five the surface layer, the collection of particles, followed by the separation of the test substance, characterized in that, in order to take samples from the layers on the surfaces of solids, the dispersion of the surface layer is carried out in a magnetic field by ferromagnetic granules, and before the test substance is removed granules with a dispersed surface layer are demagnetized and de-electrified. 2. Method POP1, characterized in that an electrostatic charge is given to ferromagnetic granules prior to dispersion of the surface layer. 3. Method according to Claims 1 and 2, that is, in that, as ferromagnetic granules, composite granules are used that contain ferromagnetic and organic components, selected in a ratio,% by volume: Ferromagnetic component 40-95 Organic component 60-5 4. The method according to claims 1 to 3, about tl and h a - y and with the fact that, for example, ebonite is used as an organic component.