SPECIAL-PURPOSE FILTER ELEMENTS BASED ON METALLIC POROUS MATERIALS FOR HIGH-QUALITY PURIFICATION OF COMPRESSED AIR AND GASES

Th e relevance of the work is determined by the need to provide a range of modern technological devices with eff ective fi lter elements designed for high-quality purifi cation of air and various gases. Filters ensure the reliable operation of a number of products for specifi c technical purposes, for example, in the production of throttle cryocoolers of IR devices. Th ey can be manufactured using microporous metal powder materials with an average hydraulic diameter of the pore channels of less than 15 mm. An important factor in the operation of fi lter elements is also their magnetic properties, namely, extremely low magnetization ability. Th e technology and methods for obtaining metal materials for transpiration purposes, with optimal physical and technical characteristics for manufacturing non-magnetic fi lter elements, have been worked out. Th e changes in the shape of powder particles and their magnetic properties during milling are analyzed. Besides, the optimal modes for obtaining the maximum amount of powder of the required size and the need for a preliminary annealing operation to restore the non-magnetic properties of the fi lter elements obtained are determined. Th e task of the work is to develop methods for manufacturing non-magnetic fi lter elements for high-quality purifi cation of air and gases from coarse domestic powder, thereby eliminating the need to import fi ne steel powder. Th e technology for the manufacture of fi lter elements, for fi ne purifi cation of air and gases, from coarse powders of domestic production, was worked out, it consists of the following operations: milling with a disperser and sieving of particles; annealing of the resulting powder in the vacuum to restore its non-magnetic properties and remove strain hardening; formation of blanks of fi lter elements; sintering of fi lter element; calibration. Th e results obtained in the work are important for the creation of highquality domestic equipment for the intended purpose.