International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

This article presents information about methods for evaluating the permeable materials based on metal powders mechanical and filtration properties. It describes methods for determining the permeability coefficient and local permeability coefficient, filtration fineness, and shear strength of powder materials, assessing the sintering quality of composite permeable materials containing fibers, and testing for strength under operating pressure differentials (up to 1 atm). The role of 3D-modeling in improving the efficiency of research is highlighted, enabling the rapid development and manufacture of fixtures for hermetically sealed specimens as their shape and size change.

This article presents information on modern methods for manufacturing long-length tubular porous powder filter elements, including hydrostatic and dry radial isostatic pressing, mold pressing, sintering of loosely formed powder in a mold, and roller deformation of flat porous sintered blanks. The advantages and disadvantages of these methods are described. Photos of typical products manufactured using these methods are presented.

Information is provided on the critical values of the ratio of the thickness of a filter element in the shape of a pipe to the radius of a cylindrical surface when it is manufactured by rolling a porous sheet blank sintered from tin-phosphorous bronze powder. An increase in the efficiency of using filter elements obtained in this way has been shown. Images of some of the developed filter products introduced into production are presented.

The article presents information on the regeneration of filter elements (filter components) made of tin-phosphorus bronze powders that were tested during polyethylene production in the unloading unit of the ethylene polymerization reactor for cleaning hydrocarbon compounds from polyethylene powder particles. It was found that during the testing period, the filter elements met the requirements specified in the equipment regulatory documents. After completing the tests, two thermal regeneration cycles were carried out: at LLC “Stavrolen” and at O.V. Roman Powder Metallurgy Institute. It was found that in the first case, the filter element throughput was restored to 67.5% of the initial value, and in the second case, to 97.2%, which indicates the multiple regeneration possibility of spent powder filter elements when used to clean hydrocarbon compounds from polyethylene powder particles.

The results of comparative studies of the structure and properties of two-layer filter materials based on finely dispersed nickel powder are presented, in which the substrates were formed using hollow spheres and carbamide as pore-forming agents. The properties of the layers forming the structures of these two-layer materials, as well as the composite biporous material properties consisting of a mixture of hollow spheres of finely dispersed nickel powder and finely dispersed nickel powder are studied. The prospects for using hollow spheres to create two-layer filter materials are shown.

The possibility of using hollow spheres to create highly porous materials (HPM) based on fine powders is shown. In the process of obtaining HPM, fine powder acts as a matrix, hollow spheres are used as a pore-forming agent. At the same time, in the initial state, hollow spheres are formed in the form of bead-shaped polystyrene granules (PSG) with a coated shell of fine aluminum oxide powder, followed by the removal of PSG during sintering. The shell prevents the integration of spherical voids into a single system of large pores, providing high purification fineness. It is confirmed that this technology provides an increase in throughput at a given fineness of purification.

A method for determining the local permeability of powder filtering materials (PFM) based on the measurement of gas-flows sequentially passing through the measuring head and different areas of the measured object (sample, product), and a device for its implementation are described. The device is characterised by simplicity of execution and can be used both in laboratory and production conditions. By the average value of localised flow rates the throughput capacity of the whole product can be estimated.

On the filter for fine air purification example the possibilities of additive technologies are shown, which allow to simplify and facilitate significantly the product development process, in particular, the filtering purpose. The results of 3-D modeling of the filter design, as well as 3-D modeling and 3-D printing of the tooling for studying the properties of filter elements to the filter and their structural elements (except for the filter layer) are given. The possibility of questions operative solution in case of adjustment necessity of tooling designs and filter elements at additive technologies application is noted.