Development of technology for electron beam welding of impellers of centrifugal pumps for ships and offshore structures operated in the Arctic

Object and purpose of research. Centrifugal equipment is widely used in various sectors of industry. One of the main part of centrifugal equipment is the impeller. Application of impellers in shipbuilding is a promising field, in particular for fail-free operation in harsh Arctic environment. The purpose of this study is development of manufacturing processes for impellers involving electro-beam welding (EBW) without soldering alloys and final thermal treatment. Materials and methods. The main material chosen for the impeller is the high-strength cold-resistant steel 10ХН3МД. Main results. In the process of technology development, the impeller design was chosen. Welding conditions were optimized on mock-up samples modeling the T-joint of cover plate with vane. Sample tests and investigation were done. Conclusions were made regarding the follow-on work and EBW introduction. Conclusion. EBW technology for manufacturing of impellers was developed making it possible to fabricate impellers of high-strength cold resistant materials, including difficult-to-weld materials.

SOME TECHNOLOGICAL PARAMETERS OF VIBRATION CENTRIFUGAL EQUIPMENT AS A FACTOR IN CONTROL OF CONCRETE PROPERTIES

An increase in the volume of construction requires innovations in technological, structural and design solutions for reinforced concrete elements. As a result of the centrifugation method, variatropic concretes with different cross-sectional characteristics and structures made from them. Therefore, at the stages of calculation and design of building structures of a variatropic structure, an unreasonably large supply of bearing capacity is usually laid, leading to an impressive rise in the cost of promising building structures. It is proposed to combine centrifugation with vibration to increase the density and ensure a more uniform distribution of the components of the concrete mixture over the wall thickness of an annular section product, in particular columns. Vibration will be ensured through the use of clamps, which are put on the shafts of the installation. Within the framework of the proposed experimental setup for creating vibrocentrifuged samples of annular cross-section with a variatropic structure and a method for their manufacture, the technological parameters of vibration are identified, which have the most significant effect on the characteristics of vibrocentrifuged concrete. In the experiments, the following technological factors varied: the height of the technological protrusions of the clamps and the vibration mode. The problem of assessing the influence of these factors on the integral characteristics of concrete is investigated. The results of experimental studies of the influence of the considered technological factors on the integral characteristics of vibrocentrifuged concrete are presented. The results obtained show the feasibility of continuing the study of rational technological parameters of vibrocentrifugation to improve the characteristics of concrete and regulate its variatropy, which will allow the proposed method to be patented in the future and to design an improved vibrocentrifuged column with more fully utilized reserves of the bearing capacity of building structures.

Model of microprocessor centrifugal equipment for honey extraction

The paper presents a model of centrifugal equipment for extracting honey made around an ATmega 328 processor, with which the Arduino Uno module is equipped. The created model is functional, being tested, and the practical results obtained would allow the transition to prototype equipment. The created model is flexible, allowing to obtain flexible operating cycles, with variable speeds, soft settable, in both directions of rotation. The number of frames from which the bee honey can be extracted is variable depending on the juicer itself, which is driven by the motor

Performance Comparison Between Fast Fourier Transform-Based Segmentation, Feature Selection, and Fault Identification Algorithm and Neural Network for the Condition Monitoring of Centrifugal Equipment

This paper compares and evaluates the performance of two major feature selection and fault identification methods utilized for the condition monitoring (CM) of centrifugal equipment, namely fast Fourier transform (FFT)-based segmentation, feature selection, and fault identification (FS2FI) algorithm and neural network (NN). Multilayer perceptron (MLP) is the most commonly used NN model for fault pattern recognition. Feature selection and trending play an important role in pattern recognition and hence affect the performance of CM systems. The technical and developmental challenges of both methods were investigated experimentally on a Paxton industrial centrifugal air blower system with a rotational speed of 15,650 RPMs. Five different machine conditions were experimentally emulated in the laboratory. A low training-to-testing ratio of 50% was utilized to evaluate the performance of both methods. In order to maximize fault identification accuracy and minimize computing time and cost, a near-optimal NN configuration was identified. The results showed that both techniques operated with a fault identification accuracy of 100%. However, the FS2FI algorithm showed a number of advantages over NN. These advantages include the ease of implementation and a reduction of cost and time in development and computing, as it processed the data from the first trial in less than 6.2% of the time taken by the NN.

THE SOLIDIFICATION MICROSTRUCTURE OF BIOMEDICAL TITANIUM ALLOYS UNDER THE CENTRIFUGAL FORCE

Two biomedical alloys, Ti -39 Nb -5.1 Ta -7.1 Zr ( TNTZ1 ) and Ti -35.3 Nb -5.1 Ta -7.1 Zr ( TNTZ2 ) were melted using LZ5 type centrifugal equipment for casting titanium. The solidification microstructures of TNTZ1 and TNTZ2 alloys cast in graphite crucible without centrifugal force are mostly big arborescent crystal with dispersed porosity in it. After pouring into a graphite mould under centrifugal force, the lower part of ingot showed mostly arborescent crystals with few equiaxed crystals, while the upper part of ingot is basically spherical equiaxed crystals. The solidification defects, such as dispersed pores were very difficult to find. Nb is supposed to refine the arborescent crystals. X-ray diffraction (XRD) analysis showed Ti -phase and Nb -phase existing in the above two alloys. The content of Ti was found relatively low in crystal interior and relatively high in crystal boundary. The content of Nb/Zr was uniform in whole microstructure.