Том 51, № 9-10 (2016)

Effective technical means (methods and devices) designed to produce reactoplastic nanomodified polymer composites that provide increased strength and service life for structures based on them were analyzed. It was shown that technical means using low-frequency ultrasound cavitation were effective. This was due to the difficulty of providing a uniform distribution of nanoparticles in the oligomer because of the tendency of the added nanoparticles to attract each other and the resulting adhesion and aggregation.

The method of statistical entropy analysis of small-scale LNG plants is developed on the basis of the first and second laws of thermodynamics. The analysis stages are shown and the main calculation relationships are given. Average statistical data are used in the calculations to indicate the ranges of possible variations of quantities, such as ambient temperature, under-recuperation in heat exchanger, heat influxes from the surroundings, efficiency of compressors and expanders, etc. The proposed method can be used to calculate the work required to compensate for the entropy produced in the core units of the plant and so to determine as early as in the design stage the most power consuming components for their updating or replacement.

The analysis of options for arranging an adsorber composed of several sections is given. The formulas for calculating the geometric parameters of individual adsorber elements were obtained for a specified diameter of the cooling nitrogen bath. The expenditure of refrigerant and energy required to regenerate the sorbent were defined for several constructional variants. The operating costs for a single adsorber cycle were calculated. The optimum regeneration temperature was determined at which the cost of purifying the mixture is minimal.

Current and future applications of the isotope ³H were described. Data about the supply and demand for this helium isotope were given. Sources of ³H were discussed. The possibility of extracting it from natural helium was evaluated.

If there were a list of endangered chemical elements, then helium would be one of the top ten most critical. Along with silver, zinc, and germanium, helium will practically be exhausted on the planet by the end of the XXIst century. Moreover, helium is the only gaseous element on the list. The unique physical and chemical properties of helium make it irreplaceable in scientific research, medicine, power engineering, aerospace, and defense sectors. Helium has a right to be considered mankind’s most important strategic resource.

As a result of the conducted investigations of equipment and technology, it has been shown that the application of flexible production systems on the basis of standard equipment modules is promising for obtaining a range of high-purity reagent-quality inorganic acids. Specialized equipment included in the equipment modules is considered for the achievement of the required quality of production.

The basic assumptions of a technique of optimal design of releasable hoop connections developed at Irkutsk-NIIkhimmash are considered. The technique is based on the use of the finite element method in combination with application methods of multidimensional optimization and makes it possible to design a hoop connection of minimal mass while simultaneously satisfying strength and air-tightness constraints. Through the use of the proposed technique and a computer program that is part of the COMPASS software system, we were able to introduce a number of releasable hood connections of standard sizes at the Chemical Plant of Angarsk Petrochemical Company of Rosneft as well as optimize the costs of maintenance and repair of the high-pressure equipment and reduce the rate of industrial accidents occurring in the course of repair operations.

This work is devoted to modeling of operation of low-capacity (0.5 W at 77 K) Stirling microcryogenic gas cooler (MCGC). A mathematical model of the cooler, a system of equations, and methods of solution of the equations system are given. The results of computational study of the operating conditions of the cooler are furnished. The design modifications for realizing heat removal from the MCGC compressor chamber cover are analyzed and calculated.

Wastewater from different stages and the average runoff in the production of cephalexin monohydrate were investigated. Comprehensive assessment of wastewater quality was proposed based on the definition of integral indicators of quality, which allows for the choice of treatment method at various stages of production and for reducing the anthropogenic load on the hydrosphere.

Reasons are studied for breakdown and failure of tubular coil elements (finned tubes) designed for heating a production medium with flue gas heat before entering reaction columns. An analysis of cases of abnormal and emergency situations shows that cases of finned tube damage and breakdown occur predominantly due to infringement of operating regimes, changes in material properties during operation, and irregularities of the tube manufacturing process.

The dependence of fracture toughness (stress intensity factor K_1c) for steels on their mechanical properties (yield strength and impact energy) taking account of the effect of temperature is considered. The nature of change in K_1c in the temperature range +20 to –40°C is demonstrated on the example of three steels.

A new concept of high-throughput turning of polymers was presented. The concept consisted of a combination of ordinary lathe treatment with simultaneous irradiation of the workpieces by nanosecond electromagnetic pulses. As a result, the material surface structure weakened, which was a prerequisite for increasing the cutting speed. The treatment method and a device for reducing it to practice were developed and protected by patents. Experimental data confirming the effectiveness of the proposed technical solutions were presented.