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  • Author: Vladislav Sviatskii x
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Abstract

This paper presents the technology of production of synthetic fibrous materials from PET-raw by vertical blowing method. Fibre production by vertical blowing method is accompanied by complex and specific phenomena; therefore, development of new progressive technologies, high-performance machines and units for producing such materials is impossible without process modelling, which can significantly reduce the number of natural tests, cost and designing time and select optimal operating modes. Molten material motion in the melting unit of the hydrostatic type is determined by means of Poiseuille formula. Furthermore, the paper has proven that the melting unit has the greatest impact on process productivity by means of outlet radius and the pressure change of compressed air acting on the molten material surface. Increase in the height of the molten material column in the main cylindrical chamber of melting unit also leads to an increase in process productivity.

Abstract

This paper presents the technology of production of synthetic fibrous materials from PET-row by vertical blowing method. The formation of fibers from the melt of thermoplastics by vertical blowing method is accompanied by complex and specific phenomena, so creation of new progressive technologies, high-performance machines and units for producing such materials is impossible without process modeling, which can significantly reduce the number of natural tests, cost and development time and choose optimal operating modes. The motion of the molten material in the melting unit of the hydrostatic type is determined from the Poiseuille formula. Also in the article proved that the greatest impact on process productivity is made by the melting unit, exactly by outlet radius and the pressure change of compressed air, acting on the molten material surface. The increase in the height of the molten material column in the main cylindrical chamber of melting unit also leads to increase of process productivity.

Abstract

The first part of the paper concerns the natural deposition conditions of the 325/1 seam in the “W” coal mine, in the 102 longwall mining panel. It also presents the most important technical conditions regarding the exploitation at this longwall. To characterize the methane hazard in the longwall area, the parameters of ventilation and total methane concentrations as well as the volumetric flowrate of methane captured by the methane removal system, have been presented graphically. A significant part of the methane flow in the longwall area was released to the air flowing to the longwall. The most significant part of the article is the presentation and analysis of the results of prognoses of mean methane concentrations at the exhaust of the longwall area. The accuracy of the prognoses of methane concentration was verified using two methods: while not considering the release of methane to the air flowing to the longwall and while considering the total flowrate of methane to the ventilation air in the area of the 102 longwall. The method of forecast presented in the article has so far been checked for a 5-day and 6-day work day, as well as for walls operating in a non-regular mode. The article refers to the wall operating in a continuous mode, which required adaptation of the proposed method to this mode. The application of the one-day forecast proposed in the article allows for undertaking temporary methane prevention measures enabling safe use of the wall.