Mathematical Model of Vacuum‐Oscillating Drying of Lumber

A mathematical model of heat and mass transfer in vacuumoscillating drying of lumber in which the drying process is made up of alternating stages of warming up and vacuum treatment has been developed. At the stage of warming up, it has been proposed to use a superheated steam to intensify heat and masstransfer processes and to relax stresses occurring at the stage of vacuum treatment.     

The influence of the internal structure and dispersity to structural–mechanical properties of oil systems

Some oils and oil products are dispersed systems with composite internal organization. The dynamical model of dispersed particle, named complex structural unit (CSU), with complicated internal structure is suggested. A nucleus surrounded by solvate shell contains high-molecular mass components of different natures. Sizes of nuclei and solvate shells change in accordance with the magnitude of external influence. An optimal correlation between parameters of CSU and the value of external factor can be fixed for every technological process. The results of determination of the dispersity degree in oil systems are presented. Connection of nonmonotonous extremal dependence macroscopic parameters (viscosity, stability, etc.) and microscopic ones (particle sizes) with external influence value changing is shown. These regularities are basic for the intensification of technological processes. Technology is tested in practice with good results. For managing structural–mechanical properties, the addition of heavy residue, containing significant amount of resin–asphaltene substances (RAS), has been chosen together with thermal treatment and regulation of speed of cooling. Speed of cooling determines sizes and number of interacting particles. Connections between particles could be realized through the solvate shells formed from RAS or directly with each other. Finally, the structure of coalescence or condensation type is formed. These kinds of structures differ in their structural–mechanical properties. Such oil compositions are basis for specific products, which are used in mining industry for dust depressing and preventing adherence of granular materials to the walls of transportation equipment. The optimal combination of influencing of external factors gives an opportunity to include bigger amount of heavy residues for decreasing the cost.     

Developing the technology for producing highly concentrated iso-butylene

The technology used at Russian plants for the recovery of polymerization-grade iso-butylene is based on synthesizing tert-butanol through the hydration of iso-butylene incorporated into raw hydrocarbon fractions with the subsequent separation and decomposition of tert-butanol. The hydration of iso-butylene is performed in reactive extraction reactors with countercurrent initial reagents on a molded sulfocationite catalyst. In this paper, a version of the process performed in a flow reactor at near-stoichiometric ratios of reagents is proposed in the context of modernizing the existing technology. The dependence of iso-butylene conversion and the amount of by-products (dimers, sec-butanol) on the type of hydrocarbon feedstock and the process parameters is studied. The iso-butane-iso-butylene fraction (IIF) and the butylene-iso-butylene fraction (BIF) are used as feedstocks. It is shown that iso-butylene conversion is lower for the BIF feedstock, and the concentration of by-products is higher than for the IIF feedstock. A tert-butanol synthesis flowsheet is proposed that includes flow and reactive extraction reactors and allows us to increase the capacity of an existing plant with a simultaneous reduction in the process’s overall energy consumption due to the production of a highly concentrated tert-butanol solution at the outlet of the flow reactor, and to obtain iso-butylene with a purity of no less than 99.99 wt %.     

Normal Mode Spectra of Hierarchical Ensembles of Interconnected Oscillators

Technical Physics Letters - A family of normal mode spectra of hierarchically organized ensembles of identical interconnected oscillators with different topology of the organization is constructed....     

Safe corrosion inhibitor for treating cooling water on heat power engineering plants

Heat power engineering (HPE) consumes significant volumes of water. There are, therefore, problems associated with corrosion, biological fouling, salt deposits, and sludge formation on functional surfaces of heat power equipment. One of the effective ways to solve these problems is the use of inhibitory protection. The development of new Russian import-substituting environmentally friendly inhibitors is very relevant. This work describes experimental results on the OPC-800 inhibitor (TU 2415-092-00206 457-2013), which was produced at Karpov Chemical Plant and designed to remove mineral deposits, scale, and biological fouling from the surfaces of water-rotation node systems on HPE objects. This reagent is successfully used as an effective corrosion inhibitor in the water recycling systems of Tatarstan petrochemical enterprises. To save fresh make-up water, the circulating system is operated in a no-blow mode, which is characterized by high evaporation and salt content coefficients. It was experimentally found that corrosion rate upon treatment of recycled water with the OPC-800 inhibitor is 0.08–0.10 mm/year. HPE mainly uses inhibitors based on oxyethylidene diphosphonic (OEDPA) and nitrilotrimethylphosphonic (NTMPA) acids. The comparative characteristic of inhibition efficiency for OPC-800 and OEDF-Zn-U2 is given. The results obtained indicate that OPC-800 can be used as an inhibitor for treatment of cooling water in HPE plants. In this case, it is necessary to take into account the features of water rotation of a thermal power plant.     

Service of mullite-corundum refractories in the center portion of the roof of high-power electric arc furnaces

Conclusions Type MKS domestic mullite-corundum parts to Technical Standard 14-8-140-75 have been introduced for the center portion of the water cooled roof of high-power arc steel melting furnaces at Belorussian Metallurgical Plant. The length of the roof campaign reached 180–220 heats without intermediate repairs, which is 25% longer than the life of imported refractories.The design of the center portion of the roof without a hole for charging of loose materials provides with the forms and dimensions of the parts used a symmetric lining and uniform distribution in it of the thermomechanical loads, which provides uniform wear of the lining and eliminates deformation of it during service of furnaces.On the basis of investigation of samples of the imported and domestic mullite-corundum roof parts after service it was established that wear of the lining occurs by fusion as the result of interaction of the refractories with the melting dust at 1660–1710°C.Different relative rates of chemical transformation and fusion of the mineral phases of the refractories were revealed. Mullite interacts with the melting reactants and fuses most intensely. In connection with this its content in mullite-corundum roof parts must not exceed 15–20%.Translated from Ogneupory, No. 1, pp. 56–60, January, 1987.     

A system of phase synchronization of a spin-transfer nano-oscillator

We have studied the dynamics of a filterless phase-synchronization system (PSS) of a spin-transfer nano-oscillator (STNO) generating microwave oscillations in a broad range of frequencies under the effect of direct current and external magnetic field. Bifurcations in the system caused by a change in the frequency detuning of synchronized oscillations are considered. Bands of phase locking and synchronism are determined. The existence of a phase-locking band in the filterless PSS of STNOs basically distinguishes these oscillators from other types of microwave generators.     

State Primary Standard of the Unit of Liquid Mass Flow Rate

The pressing current problems of increasing the level of the metrological service of instruments for measuring liquid mass flow rate are presented. The action principle, metrological characteristics, results of investigations of the State primary standard of the unit of liquid mass flow rate, and the verification scheme regulating the order of transferring the size of the unit to working measurement standards are presented.