The production of facing brick by plasma treatment combined with technological operations of softening roasting and spray-coating of decorative material based on technogenic raw material is examined. A unified nomenclature of quality indicators for wall (facing) ceramic is developed.In housing construction, a great deal of importance is now placed on the exterior finishing of buildings and the longevity and quality of the facing materials and their architectural expressivity. Plasma treatment of the facing surface of structural materials is one of the most effective treatments, since it conserves resources and energy. Plasma technology is ecologically clean because it uses argon gas to form the plasma. The high plasma temperatures (7000 -10,000 K) greatly intensify the processes leading to the formation and accumulation of a glass phase in the surface layers of the ceramic being treated, including the facing surface of structural materials. As a result, the treatment time is shorter than for conventional technology.The present article presents the results of investigations of glazing on wall ceramic using powders based on raw material from technogenic deposits. Wastes from enrichment of KMA iron quartz, from claydite production, and from the production of ceramic sanitary ware were used for glazing. The chemical composition of the waste is presented in Table 1.A number of investigations have shown that powders with grain size 10 -250 mm are optimal for plasma spraying [1,2]. We used the 60 -250 mm fraction of KMA wastes for plasma spraying. Other production wastes were first milled in ball mills with uralite balls and sieved in sieves with cell sizes corresponding to plasma spraying technology.The UPU-8M serially produced plasmatron was used for plasma treatment. The operational parameters of the plasmatron were as follows: working voltage 30 -32 V and current strength 350 -450 A. Argon serves as the plasma form the gas; its flow rate was 2.5 m 3 /h at pressure 0.25 MPa. The flow rate of the water cooling the GN-5r plasma burner was 10 -12 liters/min. The Saha equation was use to calculate the temperature of the plasma flame [3]. The calculations show that the mass-average temperature of the plasma flame with current strength 350 -450 A and argon flow rate 2.5 m 3 /h is 7800 -8600 K.
Introduction. Asphalt concrete is the most common material for arranging road pavement layers. The significant advantages of asphalt concrete include high performance characteristics, relatively high technical indicators, suitability for regeneration, etc. At the same time, asphalt concrete also has disadvantages, one of which is the significant dependence of strength and deformation characteristics on ambient temperature. Problem statement. Currently, there are no clear criteria for the selection of bitumen in Ukraine that would take into account the conditions of asphalt concrete in the design of pavement structure, but the first steps are already being taken in this direction. The purpose of this work was to practically determine the required properties of bitumen in accordance with the previously proposed algorithms. Objective. Practical determination of the required properties of bitumen in accordance with the previously proposed algorithms. Materials and methods. Analysis of the algorithm for determining the required properties of bitumen, climatic conditions of asphalt concrete and calculation of the required bitumen grade when designing a pavement structure. Results. Suggestions for improving the algorithm for selecting bitumen when designing a pavement structure are provided. An analysis of the climatic conditions of asphalt concrete operation and the calculation of the required bitumen grade according to performance indicators when designing a pavement structure for a conditional road section were performed. A system for selecting bitumen by penetration classification based on established performance indicators is proposed. Conclusions. The proposed algorithm for determining the required bitumen grade when designing a pavement structure can be used to determine the bitumen grade both by performance and penetration classification.
Introduction. Asphalt concrete is the most common material for paving layers of roads. Significant advantages of asphalt concrete include high operational characteristics, relatively high technical values, suitability for regeneration and more. At the same time, asphalt concrete has its drawbacks, one of which is the significant dependence of strength and deformation characteristics fronm the ambient temperature. The essential role in the temperature properties of asphalt concrete is played by bitumen, the quality of which is currently evaluated by standard indicators in accordance with the penetration system. The properties of bitumen can be more accurately and objectively evaluated by rheological indicators (viscosity and cohesion) or by operational ones, which are determined depending on the climatic conditions of asphalt concrete layers. Therefore, there is a need to analyze the climatic conditions of asphalt concrete in the pavement structure. Problem statement. Today in Ukraine a penetration system uses for evaluation of bitumen properties that determines the type of bitumen and the corresponding characteristics. About 30 years ago, the United States developed a system for evaluation of bitumen operational characteristics, which combines climatic conditions and transport loadings. This approach allows to choose bitumen for assigned designing combination of high and low temperatures. Evaluation of the appropriate climatic conditions of asphalt concrete in Ukraine will allow to develop zoning on the basis of which it is possible to make the optimal choice of bitumen, which would increase the durability of asphalt concrete and pavement structure in general. Purpose. Creation of bitumen selection system during designing of pavement structure, considering the ambient temperature, transport loadings, traffic intensity, level of reliability and location of asphalt concrete in the pavement structure. Materials and methods. Collection of climatic data regarding ambient temperature according to the data of meteorological stations located in regional centers of Ukraine for the period from 2005 till 2020 and determination of the needed operational properties of bitumen. Results. The zoning of the territory of Ukraine according to the climatic conditions of asphalt concrete considering the ambient temperature, transport loadings, traffic intensity, level of reliability and location of asphalt concrete in the pavement structure is developed. Conclusions. Development and introduction of zoning of the territory of Ukraine according to the operational conditions of asphalt concrete and bitumen selection system according to operational indicators will prevent the formation of destruction in the form of plastic deformations, cracks and low-temperature cracks and thus will increase the durability of asphalt concrete. Keywords: asphalt concrete, bitumen, binding layer, operational properties, pavement structure, pavement layer, upper layer of foundation.
The increasingly stringent demands on the quality of the products of gas-processing plants and reduction of the discharge of deleterious wastes into the environment make it absolutely necessary to improve the technology of gas processing and enhance the effectiveness of the technological equipment. The task of good preparation of natural gas, of stratal water, and of gas condensate in particularly topical at the Astrakhan Gas Processing Plant (AGPP) because the gas supplied to it has a very complex composition, is aggressive and ecologically dangerous. The technical and economic indices of the technological installations including the costs of repairs were therefore analyzed. The results of the analysis were the basis for working out suggestions for the reconstruction of these installations.Installation U171 for the Separation of Stratal Gas. The installation U171 is intended for the separation and scrubbing of gas supplied to the plant from the wells. Each of the four separation lines ensures gas-liquid separation of the untreated gas and compensation of fluctuations of the flow rate caused by pulsating plugs of gas condensate. The installation contains buffer and separation tanks and other equipment. After separation in the buffer tank the gas and liquid (condensate, stratal water) are throttled from 7 to 6.2 MPa and are delivered to the separation tank which acts as three-phase separator operating on the gravitational principle. Practice during the entire period of operation of the plant showed that the installation did not attain the planned regime. Deviations of the productivity from the specified one have a considerable effect on the hydrodynamic flow regime of the biphase mixture in the gas-condensate pipes. Thus the project envisages the speeds of the biphase mixture in the gas-condensate pipes corresponding to the speed of the stream in annularly disperse regime. But when the speed of the stream drops below the minimal level, the regime changes to plug flow which complicates the process of separation. Constant fluctuations of the flow rate bring about failure of the level and flow-rate regulators.Gas after separation contains a large amount of undesirable admixtures which greatly impair the indices of operation of the subsequent equipment, viz., the installations ensuring desulfurization of the gas U172. Condensate often gets into the aqueous phase and passes along the entire technological chain, and water gets into the condensate. Investigations showed that the separation of emulsions can be improved solely by improving the design of separating devices or by adding a demulsifier to the mixture. The costs of repair work on the installation U171 increase practically every year (by a factor of 2.1 in 1991, by a factor of 4.8 in 1995) because of the frequent clogging of filters and failure of control instruments and of the stop and control fittings.Installation U165 for Filtering Water and Incineration of Industrial Wastes. The installation U165 ensures degassing of water upon pressure decrease, filtering o...
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