Tavbay Khankelov’s research while affiliated with Tashkent State University of Law and other places

The article is devoted to solving a complex problem, including the issues of selecting the optimal set of machines and the technological scheme for implementing the sorting and crushing of municipal solid waste at transfer and recycling stations, and the justification of the key parameters of crushing and sorting machines, considering properties of waste. When examining the main parameters, the input and output characteristics of machines are considered in the developed technological scheme. When determining the properties of waste, 12 administrative districts of the territory of Tashkent were used as objects for cluster sampling. Through an in-depth study of the process of sorting and crushing municipal solid waste, based on the developed technological scheme, the type and design of the crushing machine were determined. Based on the methods of regression analysis and mathematical statistics, a series of multifactor experiments were conducted on the main parameters of a hammer crusher. In addition, considering the properties of waste, the main parameters of the drum screen were determined, in particular, the diameter of the grid opening. The developed optimal set of machines with substantiated rational parameters will make it possible to maximally prepare the components of municipal solid waste for use in the form of secondary raw materials.

The article is devoted to determining the main parameters of the working body (an implement) of the machine for distributing chemical and mineral materials (sand) ensuring high-quality performance of works. Based on the ranking of forces acting on a sand grain located on the surface of the machine implement and eliminating forces that do not significantly affect its movement, differential equations of a particle motion are obtained. Based on the solution to the differential equation, the following parameters were obtained: the flight range of the grain, the time of movement of the grain on the disk, and the angle of its dumping. In addition, issues related to the requirements for such machines are considered. The methodology developed makes it possible to significantly reduce the time and money spent and the costs of calculating the main parameters and arrange a rational design of the machine for distributing chemical and mineral materials.

The article is dedicated to the selection of the optimal set of machines for sorting and crushing municipal solid waste based on its properties and accumulation rates. Considering the properties of waste and technologies for its collection, a new technological scheme for processing municipal solid waste was developed and, based on this scheme, the optimal set of machines was selected. In addition, the research conducted to determine the fractional composition of the waste made it possible to substantiate the diameter of holes in the drum screen mesh. Based on the analysis of the morphological composition of the waste at the end of the technological chain, the type of crusher design was determined and the main parameters of the hammer crusher were substantiated in connection with the technological processing. The optimal set of machines will make it possible to process the components of municipal solid waste for use in the form of secondary raw materials with the least material and time costs.

A large number of studies are aimed at increasing the energy efficiency of grinding processes of various solid materials, while maintaining the values of other important indicators, such as material consumption, productivity, etc. Based on this trend, a new method for physically modeling the process of grinding municipal solid waste (MSW) was proposed for the first time. Existing physical modeling techniques are designed for homogeneous and isotropic materials (for example, soil, crushed stone, snow, coal, etc.). The strength properties of solid waste vary widely due to the significant heterogeneity of their components. Consequently, when crushing solid waste, traditional crusher designs have low efficiency in terms of energy intensity, material intensity and product quality. The purpose of this work is to develop a new technique for physical modeling of the grinding process, based on the main principles of similarity theory and modeling, considering the properties of waste heterogeneity. As a result of the research, a block diagram of the physical modeling methodology for the interaction of the working bodies of impact crushing machines with solid waste was developed. A list of tasks for the modeling process and similarity criteria have been determined based on the development of rheological models of the “working body - municipal solid waste” system and the laws of mechanics that characterize the waste grinding process. Based on the developed similarity criteria, scale equations for the grinding process are substantiated and formulas are derived for determining the expected parameters of the original based on the parameters measured on the model. The developed methodology makes it possible to create a crusher design with improved energy efficiency indicators with the least material and labor costs.

The problem of an approximate solution to hydrodynamic problems is the consideration of pressure. To exclude it from the equations, the transition to "non-primitive variables" (vortex and velocity vector divergence) is made. In this case, there are difficulties in the algorithmization of new equations for solving the inverse problem of hydrodynamics and a lot of internal iterative calculations. The object of this study includes equations in "non-primitive" variables. The research methods are based on the transformation without simplifications and assumptions of hydrodynamic equations into a form containing "non-primitive" variables and the demonstration of the possibilities of solving the equations. The GAMS programming language was used for approximate solutions for the first time. The aim of this paper is to demonstrate the possibility of solving the full equations in "non-primitive" variables for various conditions. The results showed the possibility of considering the compressibility of the medium when solving the inverse problem of hydrodynamics; the identity of solutions of the proposed system of equations and equations using the potential; and the possibility of using optimizing programming languages for hydrodynamics problems. The scientific novelty of this research consists of solving the full equations of hydrodynamics with the use of "non-primitive" variables but without the use of the current function.

The article deals with the theoretical substantiation of the process of sorting elastic components of waste. The experience of foreign countries shows that the use of waste, their segregation into useful components used as secondary raw materials at enterprises, allows not only to extract financial benefits from waste but also to clean up the environment. The aim of the study is to theoretically substantiate the process of sorting elastic components of waste from the rest of the mass. The theoretical and empirical methods were used in the study, in particular: a review and analysis of the literature sources, logical and system analysis, the main provisions of the theory of impact. The regulatory legal framework in the field of waste management in the Republic of Uzbekistan has undergone significant changes. There appeared laws, resolutions and decrees of the President, projects aimed at solving the problem of waste separate collection. The existing technology for the processing of solid municipal waste (SMW) in the Republic of Uzbekistan, in particular, in the city of Tashkent, does not allow the mechanized extraction of valuable components from the composition of SMW. In this regard, an analysis of the existing designs of sorting devices was conducted and a prototype was selected for the development of the design of a sorting device. A significant difference in the values of the rebound lengths of elastic components of waste from non-“elastic” ones was theoretically determined and experimentally confirmed.

The existing technology for processing solid household waste (MSW) at waste transfer stations in the city of Tashkent does not allow obtaining high-quality raw materials for compost production. In this regard, a crushing and screening complex has been developed to produce compost with low energy and material consumption. The carried out theoretical and experimental studies made it possible to determine that the rotor blades should be installed along the rotor line with an angle equal to zero degrees. To overcome the resistance arising between the bottom of the crusher and the lower surface of the rotor, several holes with a diameter of 12 mm are drilled on the bottom of the crusher in the radial direction. It was found that the rotational speed of the electric motor of the crusher, as well as the sorting device, is 1500 min-1, the angle of impact of organic waste on the rotor blades of the sorting device is approximately 45 degrees. The use of a crushing and screening complex made it possible to effectively grind and extract ballast inclusions from the composition of crushed organic waste by 85-90 percent.

Cone crushers of various sizes and modifications are used widely for rock processing now. The most widespread are crushers of the KDM and KMDT types. Depending on the types and modifications, crushers are used in various industries: crushing abrasive, extra strong rocks and building materials, in the production of cement and other materials in the construction industry; for crushing rocks in the mining industry.