scholarly journals WAYS TO IMPROVE INDUCTION CRUCIBLE FURNARES

2019 ◽  
Vol 62 (2) ◽  
pp. 97-102
Author(s):  
G. E. Levshin
Keyword(s):  
Cylindrical Shell ◽  
Electromagnetic Scattering ◽  
Magnetic Circuit ◽  
Single Layer ◽  
Significant Part ◽  
Crucible Wall ◽  
Closed Cavity ◽  
Magnetic Circuits ◽  
Crucible Furnace ◽  
Induction Crucible Furnaces

Analysis of the main drawbacks caused by increased walls thickness of a lined crucible, presence of tubular copper single-layer inductor cooled from inside with standard water and absence or presence of core I-shaped magnetic circuits arranged around it forming a discrete ferromagnetic screen, was made for modern induction crucible furnaces. The first drawback is that a significant part of working electromagnetic flow Fwork is not used for effective heating, since it passes along the non-conductive lining of crucible, and not along the cage. Therefore, only 38.5  –  57.0  % of the flow Fwork is effectively used. The second drawback is increased cost and complexity of manufacturing of inductor coils from a special copper tube, which vibrate at twice the frequency, creating noise and weakening design of the furnace. Such inductors are characterized by reduced electrical efficiency and increased cost of preparation and cooling of conditioned water in systems that occupy an area several times greater than the area of furnace itself. The third drawback leads to the fact that a significant part of electromagnetic scattering flow of the Fconsupt does not participate in heating of charge and melt, but heats conductive elements of furnace, including surrounding magnetic inductor. Irrational use of total flow F, created by inductor, reduces its efficiency to almost 19  –  30  %, and the power factor cosφ to 0.03  –  0.10 and increases energy consumption. To reduce or eliminate disadvantages, three ways of improving these furnaces are proposed and justified: reducing thickness of crucible wall with its simultaneous hardening by installing a cylindrical shell between the crucible and the inductor, surrounding the inductor with an annular magnetic circuit and using a single or multiwire inductor instead of a tubular one. Combination of cylindrical shell, annular magnetic circuit, as well as the upper and lower plates of the furnace frame can form an annular closed cavity to accommodate wire inductor and circulating refrigerant, cooling the inductor and the magnetic circuit. As a result of the study, new design of induction crucible furnace with wire inductor and ring-type magnetic circuit developed at AltSTU is proposed, substantiated and patented. Based on experimental determination of effectiveness of the proposed structural elements, conclusion is made about the prospects for further research.

scholarly journals Vibration analysis of a sandwich cylindrical shell in hygrothermal environment

2021 ◽  
Vol 10 (1) ◽  
pp. 414-430
Author(s):  
Chunwei Zhang ◽  
Qiao Jin ◽  
Yansheng Song ◽  
Jingli Wang ◽  
Li Sun ◽  
...  
Keyword(s):  
Cylindrical Shell ◽  
Natural Frequency ◽  
Equations Of Motion ◽  
Single Layer ◽  
Functionally Graded ◽  
Sandwich Shell ◽  
Continuous Change ◽  
Multilayered Structures ◽  
Cylindrical Sandwich Shell ◽  
Vibrational Behavior

Abstract The sandwich structures are three- or multilayered structures such that their mechanical properties are better than each single layer. In the current research, a three-layered cylindrical shell including a functionally graded porous core and two reinforced nanocomposite face sheets resting on the Pasternak foundation is used as model to provide a comprehensive understanding of vibrational behavior of such structures. The core is made of limestone, while the epoxy is utilized as the top and bottom layers’ matrix phase and also it is reinforced by the graphene nanoplatelets (GNPs). The pattern of the GNPs dispersion and the pores distribution play a crucial role at the continuous change of the layers’ properties. The sinusoidal shear deformation shells theory and the Hamilton’s principle are employed to derive the equations of motion for the mentioned cylindrical sandwich shell. Ultimately, the impacts of the model’s geometry, foundation moduli, mode number, and deviatory radius on the vibrational behavior are investigated and discussed. It is revealed that the natural frequency and rotation angle of the sandwich shell are directly related. Moreover, mid-radius to thickness ratio enhancement results in the natural frequency reduction. The results of this study can be helpful for the future investigations in such a broad context. Furthermore, for the pipe factories current study can be effective at their designing procedure.

A Mathematical Model of a Modified Voice Coil Energy Harvester

2011 ◽  
Author(s):  
Alireza Hekmati ◽  
Siamak Arzanpour
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Flux Density ◽  
Peak Power ◽  
Magnetic Field Intensity ◽  
Magnetic Circuit ◽  
Magnetic Flux Density ◽  
Magnetic Conductor ◽  
Magnetic Circuits ◽  
The Magnetic Field

This paper presents a mathematical modeling of a modified voice coil generator, which consists of a moving coil within a fixed magnetic circuit. The simulation has been done with Comsol Multiphysics software, which is a powerful tool to demonstrate the pattern of magnetic field and calculate the induced current in the coil. In our simulations, the magnetic circuit consists of the magnetic conductor and the air gap. In this analysis, the magnetic flux density and the magnetic field intensity are calculated. Moreover, through calculation of the total reluctance of the magnetic circuit and employing the ohm’s law for magnetic circuits, the effect of the length and cross section of the total circuit on the magnetic flux are investigated. Finally, a pattern for the magnetic flux density are demonstrated and the simulation result indicates that the magnetic field is well concentrated on the coil area, therefore this prototype can capture and convert most of the kinetic energy to electricity. A prototype has been fabricated and tested on the shaker. The experimental results indicate that this setup is able to produce the maximum voltage of 0.326 V and the peak power equal to 2.605 mW in 35 Hz frequency and 1 mm peak to peak amplitude.

Nonlinear Buckling Analysis of Long-Span Suspended Latticed Intersected Cylindrical Shell

2014 ◽  
Vol 919-921 ◽  
pp. 169-176 ◽  
Author(s):  
Ming Liang Zhu ◽  
Yan Sun
Keyword(s):  
Cylindrical Shell ◽  
Bearing Capacity ◽  
Single Layer ◽  
Ultimate Bearing Capacity ◽  
Buckling Analysis ◽  
Nonlinear Buckling ◽  
Long Span ◽  
The Stability ◽  
Nonlinear Buckling Analysis ◽  
Material Nonlinear

The Suspended Latticed Intersected Cylindrical Shell (SLICS) is a new structural system, composed by the single layer Latticed Intersected Cylindrical Shell (LICS) and the prestressed cable-strut system. Mechanical properties of this structure were investigated through nonlinear buckling analysis by the consistent imperfect buckling analysis method, compared with the single layer LICS. Structure parameters including prestress level, member section, length of bar, rise-span ratio, obliquity were analyzed. And the effect of material nonlinearity on the stability was studied. Results show that the ultimate bearing capacity of the SLICS is improved as the introduction of prestress. However the prestress level has a limited impact on the ultimate bearing capacity. And the material nonlinear is very important to the stability of the SLICS.

scholarly journals Experiment, Optimization, and Design of Electromagnetic Track Brake for High-Speed Railways System

2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Chun Xiang ◽  
Jun-Cheng Wang ◽  
Yu-Feng Gu ◽  
Shi-Jin Zhang ◽  
Shi-An Chen
Keyword(s):  
High Speed ◽  
Copper Wire ◽  
Final Height ◽  
Three Dimensional ◽  
Single Layer ◽  
Longitudinal Axis ◽  
Iron Core ◽  
Railway Systems ◽  
Magnetic Circuits ◽  
Final Design

To enhance braking force and control convenience of high-speed railway systems, this paper proposes a new electromagnetic track brake, and the corresponding design, optimization, and experimental test are implemented. The proposed track brake is longitudinal-axis magnetic circuits excited by multiple coils electromagnets, and the pole shoes are extending outward. A preliminary design of an electromagnetic track brake is developed, including iron core height, iron core width, iron core gap, excitation ampere-turn, coil arrangement form, coil thickness, and preliminary height of single-layer coil. The electromagnet number and pole shoe gap are optimized through three-dimensional electromagnetic simulation comparisons. The final design of the electromagnetic track brake is determined, including iron core length, copper wire diameter, coil turn, and final height of single-layer coil. Experimental verification of electromagnetic attractive force is performed through prototype tests, and the newly developed electromagnetic track brake can enhance electromagnetic braking deceleration by 39%.

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