Vol 54, No 5-6 (2018)

A method is proposed for calculating the inhomogeneity coefficient in the workspace of a drum-belt mixer of bulk components with brush elements in a three-stage batch mixing method with non-uniform proportioning. The method is based on a stochastic model of the motion of rarefied particle flows following interaction with flexible elements fixed along a helical line on the surface of the mixer drums. The principal coefficients affecting the quality of a bulk mixture are analyzed in the form of combined structural and regime complexes of parameters of the mixer and the characteristics of the physical and mechanical state of the mixed media are analyzed. The results obtained can be used to develop an engineering technique for calculating the parameters of a new drum-belt mixer of friable components.

The possibility of enhancing heat exchanger efficiency by applying capillary-porous coatings onto the surface of a heating element using gas-thermal spray techniques is explored. Aluminum oxide porous coating was applied by electric-arc metallization using AMC wire of 1.6 mm diameter as the coating material. Aluminum oxide coatings were applied by spraying filamentous material with a Top–Jet gun.

A description of a new design of an electrical dehydrator intended for dehydration and desalting of crude oil before primary processing is described. A distinctive feature of the design is the delivery conduit which is designed to enable preliminary electrophysical treatment of an oil emulsion by means of nanosecond electromagnetic pulse.

Three main types of cryothermal vacuum units for testing spacecraft products at liquid-helium temperature are considered. Methods for heat removal from test objects depending on their geometric and thermophysical properties are presented. The designs of the different thermal vacuum chambers are discussed considering the thermophysical processes occurring in them. The operating efficiency of the thermal vacuum chambers and their advantages and disadvantages are estimated based on an analysis of heat-transfer processes.

Specimens of steels 30KhGSA, 38KhS and 40Kh, strengthened by plasma hardening, are tested under dry friction conditions in a disk-on-block system. Good wear resistance of hardened steels is established for alloy systems Cr–Mn–Si (30KhGSA) and Cr–Si (38KhS). The wear resistance of single-component system 40Kh is less by a half. This can be explained by the higher carbon equivalent of 30KhGSA steel. Blocks in contact wear to the least with hardened steel 38KHS discs.

The process of continuous two-stage feeding of carbon nanomaterials of the “Taunit” series and catalysts for their production was studied. It is established that a two-stage continuous feeding technology allows to provide accuracy almost equal to the accuracy of batch feeding.

Effective use of low-temperature exhaust heat in the direct thermodynamic cycle with water and alternative working fluids is proposed. The calculations are performed for a compressor station and a gas turbine plant and the most optimal fluid for the direct cycle is selected.

A classification of the bubble caps of the contact plates of mass-transfer columnar apparatuses is proposed. The most characteristic designs of bubble caps that have been developed by domestic and foreign designers and inventors are considered.

The possibility of obtaining bimetallic steel castings by the lost foam casting method is demonstrated, in which an insert of special steel is placed in an expanded polystyrene mold. Bottom casting is used. With the optimum choice of the casting temperature, fusion of the steels is guaranteed and there is no warping of flat inserts. Stages of bimetallic casting formation are considered and the parameters affecting filling of the mold and ensuring the production of a finished casting are determined. It is shown that the heat treatment of objects with air cooling provides hardness of 20–46 HRC for steel of 20X13 with different tempering conditions. The technology is recommended for parts of the locking assembly of pipeline fittings and other products where a combination of local special properties and workability is required.

A mathematical model for membrane extraction of high-purity hydrogen from methane steam-conversion products that takes into account hydrogen outflow through a palladium membrane (V-1 alloy) and chemical reactions among components of the starting gas mixture in the presence of a carbon monoxide conversion catalyst is presented. A practical example shows that the presented model describes adequately and rather accurately the main parameters of the model membrane reformer with the carbonmonoxide catalyst and allows the optimal technological regimes to be selected.

A mathematical model of the working processes of a hybrid displacement piston power machine with profiled groove seal is proposed. Calculation of the working processes in the compressor section in the presence of a liquid film under the piston and a “pump” course in the pump section and a piston seal is presented. The working processes for a hybrid displacement piston power machine with a smooth groove seal and with a profiled groove seal is calculated and the influence of a profiled groove seal on the working processes and the dynamics of the layer of liquid over the piston is demonstrated.

Promising designs of overrunning mechanisms able to increase the reliability and competitiveness of machines and mechanisms in the oil and gas industry are considered.

Corrosion resistance of 09G2S steel in a moving model environment of formation water of the Kharyaga oilfield and in a moist hydrogen sulfide-containing atmosphere that simulate the chemical composition of the technological environment in petroleum gas preparation and drying is investigated. Introduction of inhibitors Olazol Т2P, Olazol 26501, Telaz and IKB2–2 into the model environments reduces the corrosion rate of the investigated steel from 3.34 to 0.37 g/(m²·hr). In a moist hydrogen sulfide-containing atmosphere, coating of steel surface in inhibitor film increases the time to appearance of corrosion damage. After 30 days of testing, the surface of steel without an inhibitor film is entirely covered in corrosion products, and under the inhibitor film the corrosion damage area is much smaller. The obtained results indicate that effective protection of steel of petroleum gas preparation and drying equipment is possible using the studied inhibitors.

The characteristics of the granular polymer material plasticization process in a plasticizer shear flow are studied. A mathematical model of the process, which fully conforms to the modern concepts of the plasticization mechanism and allows determination of the key process parameters, particularly the plasticization time, under intense shear impact on the polymer granules, is proposed. This model provides the possibility of performing technological calculations even at the stage of designing mixing equipment for preparation of highly viscous polymer solutions.

The design and metrological characteristics of an acoustic high-volume volumetric flow meter of gaseous and liquid substances (Reynolds number greater than 10,000) are considered. The device has a simple design and is characterized by high measurement precision and high rate of performance.

Computational experiment was carried out using a neural network model that makes it possible to extract new knowledge from experimental data. Certain features and regularities of the heat exchange of chlorobenzene in an electric field have been identified.