Vol 23, No 1 (2022)

An analysis is made of the traditional and advanced electrolytic technology for producing metallic aluminum from the point of view of environmental friendliness of production. A brief description is given of the use of Soderberg anode cells and pre-baked anodes combined by a common carbon anode material oxidized into gaseous oxide and carbon dioxide during aluminum reduction. In order to reduce (eliminate) the carbon footprint, the concept of an inert anode is proposed, the material of which does not enter into the aluminum reduction reaction, and therefore is not consumed (almost), while the release of oxygen in the status of the final gaseous “waste” is allowed. The basis for the development is an electrolytic cell with a self-baking Soderberg anode of the S-8BM type, which characterizes the oldest technology and has a large geography of representation in Russia. As a result of comparing the operating conditions and technological possibilities for obtaining anodes of similar sizes from composite and ceramic materials (cermets) when replacing the carbon anode array, it was decided to use the classic copper-nickel alloy CuNi44Mn1, which has a minimum iron content (reducing the grade of aluminum) and characterized by thermal stability at electrolysis temperature. Based on the electrical characteristics of the basic process and taking into account the recommendations of “RUSAL Laboratory” specialists, the dimensions of the metal inert anode are determined and recommendations are given for the reconstruction of the above-mentioned electrolyzer when switching to a new aluminum production technology.

This paper investigates the construction of hydrodynamic surfaces, which are defined by algebraic equations and describe the theoretical hull of a vessel. A technique for automation of generating hydrodynamic surfaces is proposed. This technique allows to create a vast variety of hull shapes, for which Lame curves with variable exponents are used as surface generator lines. The surface is constructed by a family of curves in one of the three mutually perpendicular planes, which permits to obtain three algebraically different, but geometrically identical surfaces. This paper introduces parametric equations for each of the three surfaces, generated by families of sections, buttocks and waterlines in the form of Lame curves. The algorithm of modelling a submarine hull with different fore and aft bodies and a parallel middle body by a closed surface is demonstrated and the modelling results are illustrated. The presented technique may be effectively applied at the early stages of ship design when choosing the optimal hull shape, for which a number of surfaces need to be considered.

It is known that during long-term operation of crank machines for cold sheet stamping, which consists in cyclic loading of the structure with mechanical stresses, fatigue degradation of the metal occurs, leading to the occurrence and growth of cracks. Nevertheless, the main trend of modern Russian approaches to modernizing the park of forging and pressing machines is the desire to preserve large metal-consuming parts of stamping presses when replacing the control system and hydraulic and/or pneumatic components of additional actuators. Practice has shown that such approach is economically and technologically justified. For countries that do not have the capacity to manufacture stamping machines of their own brands, there is a need to purchase equipment abroad (including Russia), usually for economic reasons in the secondary market after a long period of operation. In this case, competent pre-sale preparation is required in order to avoid emergencies and equipment failures after its installation at the purchasing enterprise. Ensuring the durability of crank stamping machines after a period of long-term operation is an urgent task, both for the industry of developing countries and for the Russian one. Using the example of a powerful crank stamping press, during the pre-sale preparation of which cracks in the slider were revealed, a way to eliminate the causes of cracking during its further operation is shown.

This work is devoted to the results of experimental studies on the impact of wave loading on a buried pipeline. Currently, there is an active development of large deposits located on the shelf and the northern rivers (Ob Bay, Yenisei), from where delivery to the places of consumption should be made. The most convenient type of transportation is the pipeline. Its route often crosses water areas, the size of which can reach five kilometres or more. Such dimensions allow the occurrence of a wave load acting on the pipeline. The issue of pipeline stability is especially relevant for designers in order to avoid accidents during operation. Nowadays, the regulatory documentation does not address this issue. Only the force of Archimedes is considered, without taking into account the wave action. The causes and process of moving the pipe up in the ground are difficult to theoretically analyze, therefore, it is mainly studied by empirical methods. In this work, the dependence between the wave load and the buoyancy force is established experimentally. The series of experiments was conducted with changing wave parameters and pipeline depth. This article will be useful for submarine pipeline designers.