Перспективы развития энергосберегающих способов дробления хрупких материалов

Crushing machines are part of the charge departments of blastfurnace and steelmaking shops of metallurgical enterprises. One of the main indicator of the crushing process is its energy efficiency. It is determined by the mass of crushed material when consuming a unit of electricity. The article considers various methods of crushing brittle materials and the design of crushing machines for their implementation. The analysis of the crushers has shown that impact crushers are the most energyefficient. However, due to a significant drawback (the yield of a suitable product is very small), they are practically not used in the metallurgical industry, in which high requirements are imposed on the finished product fractional composition. In the metallurgical industry, compression crushers are widely used with approximately the same specific energy intensity, that is, with the same energy consumption for the destruction of a unit volume of material of equal strength. Compression fracture is the most energy intensive crushing method known. In singleroll crushers, a piece of material is fed into the gap between a roll and a solid, stationary plate. During the operation a complex stress state is generated in the destructed material. Compressive forces act on a piece of crushed material, causing normal compressive stresses in it, and an internal torque, causing shear stresses. This is achieved by the reduction in energy on crushing by 20 - 30 % in comparison with crushers operating in compression (all other things are equal). The authors describe the design of a crusher, in which the destruction of the processed material occurs due to the forces acting on the crushed piece in one plane towards each other. In this case, only shear stresses arise in the processed piece. The use of crushers, in which the destruction of the processed material occurs due to generation of only tangential stresses in a piece, can reduce the energy consumption per unit of finished product by almost a half. The design of such crushers is a promising direction in the development of machines intended for crushing. © 2021 National University of Science and Technology MISIS. All rights reserved

Prospects for Energy-Saving Methods of Crushing Brittle Materials

Crushing machines are part of the charge departments of blast-furnace and steel-making shops of metallurgical enterprises. One of the main indicator of the crushing process is its energy efficiency. It is determined by the mass of crushed material when consuming a unit of electricity. The article considers various methods of crushing brittle materials and the design of crushing machines for their implementation. The analysis of the crushers has shown that impact crushers are the most energy-efficient. However, due to a significant drawback (the yield of a suitable product is very small), they are practically not used in the metallurgical industry, in which high requirements are imposed on the finished product fractional composition. In the metallurgical industry, compression crushers are widely used with approximately the same specific energy intensity, that is, with the same energy consumption for the destruction of a unit volume of material of equal strength. Compression fracture is the most energy-intensive crushing method known. In single-roll crushers, a piece of material is fed into the gap between a roll and a solid, stationary plate. During the operation, a complex stress state is generated in the destructed material. Compressive forces act on a piece of crushed material, causing normal compressive stresses in it, as well as an internal torque causing shear stresses. This is achieved by the reduction in energy on crushing by 20–30% in comparison with crushers operating in compression (all other things are equal). The authors describe the design of a crusher, in which the destruction of the processed material occurs due to the forces acting on the crushed piece in one plane towards each other. In this case, only shear stresses arise in the processed piece. The use of crushers, in which the destruction of the processed material occurs due to generation of only tangential stresses in a piece, can reduce the energy consumption per unit of finished product by almost a half. The design of such crushers is a promising direction in the development of machines intended for crushing. © 2021, Allerton Press, Inc

The Dipole Magnet Design for the ALICE DiMuon Arm Spectrometer

An essential part of the DiMuon Arm Spectrometer of the ALICE experiment is a conventional Dipole Magnet of about 890 tons which provides the bending power to measure the momenta of muons. The JINR engineering design of the Dipole Magnet, technical characteristics and description of the proposed manufacturing procedure are presented. The proposed Coil fabrication technique is based on winding of flat pancakes, which are subsequently bent on cylindrical mandrels. The pancakes are then stacked and cured with prepreg insulation. The method is demonstrated on hand of the prototype II, which consists of a pancake made with full-size aluminium conductor. Some details of electromagnetic and mechanical calculations are described. The results of measuring of mechanical and electrical characteristics of materials related to the coil composite structure are discussed

Challenges in QCD matter physics - The Compressed Baryonic Matter experiment at FAIR

Substantial experimental and theoretical efforts worldwide are devoted to explore the phase diagram of strongly interacting matter. At LHC and top RHIC energies, QCD matter is studied at very high temperatures and nearly vanishing net-baryon densities. There is evidence that a Quark-Gluon-Plasma (QGP) was created at experiments at RHIC and LHC. The transition from the QGP back to the hadron gas is found to be a smooth cross over. For larger net-baryon densities and lower temperatures, it is expected that the QCD phase diagram exhibits a rich structure, such as a first-order phase transition between hadronic and partonic matter which terminates in a critical point, or exotic phases like quarkyonic matter. The discovery of these landmarks would be a breakthrough in our understanding of the strong interaction and is therefore in the focus of various high-energy heavy-ion research programs. The Compressed Baryonic Matter (CBM) experiment at FAIR will play a unique role in the exploration of the QCD phase diagram in the region of high net-baryon densities, because it is designed to run at unprecedented interaction rates. High-rate operation is the key prerequisite for high-precision measurements of multi-differential observables and of rare diagnostic probes which are sensitive to the dense phase of the nuclear fireball. The goal of the CBM experiment at SIS100 (sqrt(s_NN) = 2.7 - 4.9 GeV) is to discover fundamental properties of QCD matter: the phase structure at large baryon-chemical potentials (mu_B > 500 MeV), effects of chiral symmetry, and the equation-of-state at high density as it is expected to occur in the core of neutron stars. In this article, we review the motivation for and the physics programme of CBM, including activities before the start of data taking in 2022, in the context of the worldwide efforts to explore high-density QCD matter.Comment: 15 pages, 11 figures. Published in European Physical Journal

PENGARUH PENAMBAHAN CACAHAN LIMBAH PLASTIK JENIS HIGH DENSITY POLYETHYLENE (HDPE) PADA

Waste is a very complex problem in urban area. Plastic waste is increasing every year. Kupang with population of 291,794 people generate waste reaches 926 m3/day. Organic waste to 700 m3 and inorganic waste about 226 m3. Concrete is planned by strength quality 25 MPa. Based on the analysis in this study obtained that concrete flexural strength value increased due to the addition of HDPE plastic shredded into the concrete, with chopped levels are added to the concrete at 0%, 0.50% and 0.90% .0,70%. Flexural strength value of normal concrete without the addition of shredded plastic (0%) is 4.12 MPa, flexural strength of concrete with the addition of shredded plastic 0.50% is 4.30 MPa increased 4.37% from normal concrete flexural strength, flexural strength of concrete with the addition of shredded plastics 0.70% is 4.21 MPa increased 2.19% from the normal concrete flexural strength and flexural strength of concrete with the addition of shredded plastic 0.90% is 3.94 MPa decreased 3.64% of flexural strength normal concrete

CONCEPTUAL DESIGN OF A 240 MeV SUPERFERRIC SEPARATED ORBIT CYCLOTRON *

Abstract A conceptual design of the Separated Orbit Cyclotron (SOC) for the proton energy of 240 MeV based on the use of superferric magnets (dipoles and quadrupoles) is presented. Superconducting RF cavities are used as well. The beam intensity is determined by, but not limited to the 500µA available from the IBA "Cyclone-30" cyclotron to be used as the 30MeV injector. The electrical power draw of the helium refrigerator is 250kW