Influence of the parameters of deforming cutting on the features of the resulting slotted filter structures

OBRABOTKAMETALLOV Том 23 № 4 2021 TECHNOLOGY In most cases, when the fi lter element becomes dirty, it is necessary to stop the fi ltration process to replace it [2], which requires signi fi cant costs. The most promising are regenerable fi lter designs, which provide the possibility of cleaning it by the countercurrent fl ow of the fi lter medium [4]. The slotted structure of the fi lter in such designs is preferable since it provides both a relatively low hydraulic resistance and a high ef fi ciency of back fl ow cleaning [5]. Counter fl ow cleaning is carried out without disassembling the fi lter and increases the service life of the fi lter element by 20 or more times [6]. Among the slot fi lters, the most common are prefabricated elements and those obtained by mechanical or physical and technical processing [7, 8]. On the basis of the wire, meshes are obtained, including those with non-square cells, as well as spring and wire-frame fi lter elements. Belt and plate fi lters also belong to prefabricated elements and are not characterized by high manufacturability and productivity of their production. In terms of a set of operational parameters, the most promising are wire-frame meshes with the ability to obtain slotted gaps from 20 μ m, however, the high cost limits their widespread use [9]. Mechanical methods for obtaining through slots are based on milling the pipe wall with disc mills and pressure treatment methods. A wide range of slotted grids is obtained by pressure treatment, both by punching slots and by the method of simultaneous punching and drawing [10]. A promising direction in the manufacture of slotted fi lter partitions is the use of laser and electrical discharge piercing or wire processing [11, 12]. As a blank, sheets or pipes of various pro fi les can be used. The limitation of use is the high cost of equipment and relatively low productivity. The listed methods of obtaining metal slotted fi ltering partitions have limitations either on the minimum width of the slots obtained or on the productivity of their production, which affects the limitation of the operational characteristics and the high cost of their manufacture. In this paper, the preparation of fi lter structures by the deforming cutting ( DC ) method is considered. Deforming cutting is a patented type of blade cutting using a special tool [13] and is based on undercut- ting and plastic deformation of undercut layers with the formation of a macrorelief in the form of ribbing (Fig. 1). The peculiarities of this method are wastelessness, as well as the possibility of obtaining narrow (up to tens of micrometers) inter fi n gaps with a depth of gaps of up to a few millimeters. Earlier, the possibility of obtaining fi ltering titanium meshes by the DC method from thin sheet blanks was considered, with a minimum size of fi ltering slots obtained from 20 μ m with the possibility of increas- ing the size of the cell by stretching to a few millimeters [14]. Also, earlier, a research was carried out to study the process of obtaining slotted structures by the DC method on polymer pipes, in which the expediency of using the method for obtaining adjustable slotted Fig. 1. Scheme of pipe fi nning by the DR method ( a ) and the tool for its implementation ( b ): 1 – cutting edge; 2 – deforming edge; 3 – front surface; 4 and 5 – main back and auxiliary back surfaces