Extremal temperature fields induced during the heat treatment of cylinders formed from reinforced composition materials

1982 ◽  
Vol 17 (5) ◽  
pp. 579-585
Author(s):  
Yu. A. Afanas'ev
Keyword(s):  
Heat Treatment ◽  
Temperature Fields ◽  
Composition Materials ◽  
Extremal Temperature

Development of Capillary Tube Production Technology

2019 ◽  
Vol 946 ◽  
pp. 362-367 ◽  
Author(s):  
Boris Yur'ev ◽  
Vyacheslav Dudko
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Electric Furnace ◽  
Capillary Tube ◽  
Surface Condition ◽  
Temperature Fields ◽  
Flow Diagram ◽  
Protective Atmosphere ◽  
Pure Hydrogen ◽  
Capillary Tubes

A manufacturing process was developed using an electric through-type furnace for capillary tubes used for single-use injection syringes. The process flow diagram consisting of a number of sequential steps and tube heat treatment conditions in protective atmosphere of pure hydrogen providing also for the tube purging with inert gas were considered. The electric furnace installed capacity and heating element dimensions were found as a result of the thermotechnical calculations. Industry research was carried out with a view to optimize the annealing process of capillary tubes in the electric furnace. A choice of material for the muffle fabrication was justified. Temperature fields inside the muffles were evaluated. The optimal flow of protective gas and the maximum allowable flow of purging gas in the form of nitrogen and argon were determined. Mechanical properties were studied for tubes (stocks), welded at the medical goods fabrication plant in Tumen and fabricated at the Pervouralsky Novotrubny Plant. Test data were obtained for optimal rates of tube movement in the furnace, allowing production of capillary tubes, acceptable for medical needle fabrication after annealing. It was demonstrated that capillary tube heat treatment, ensuring the required condition of both outside and inside surfaces, as well as required mechanical properties, is possible with the use of nitrogen as protective (instead of hydrogen) and purging gases. At that probability of better tube surface condition significantly grows.

Modeling of Temperature Cycles Induced by Pico- and Nanosecond Laser Pulses in Zinc Oxide and Molybdenum Thin Films

2015 ◽  
Vol 138 (3) ◽  
Author(s):  
D. Scorticati ◽  
G. R. B. E. Römer ◽  
A. J. Huis in't Veld ◽  
D. F. de Lange
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Zinc Oxide ◽  
Pulse Repetition Frequency ◽  
Laser Pulses ◽  
Temperature Fields ◽  
Nanosecond Laser ◽  
Pulsed Lasers ◽  
Temperature Cycles ◽  
Nanosecond Laser Pulses

The aim of this paper is to study the benefits of applying ultrashort pulsed lasers over nanosecond pulsed lasers for selective (i.e., superficial) heat treatment of materials in general and for selective heat treatment of thin films in particular. To this end, a background of the physics that govern the absorption of light and subsequent diffusion of heat in semiconductor and metallic materials is provided, when exposed to picosecond or nanosecond laser pulses, with a fluence below the ablation threshold. A numerical model was implemented using a commercial finite-element modeling package, to simulate the temperature fields in thin films induced by laser pulses. The results of the simulations provide insight in the temperature cycles and corresponding timescales, as function of the processing parameters, such as fluence, pulse duration, pulse repetition frequency, and laser wavelength. Numerical simulations were run for thin films of molybdenum (Mo) and zinc oxide (ZnO) on a glass substrate, which are materials commonly adopted as (back and front) electrodes in thin film solar cells.

scholarly journals Discrete Optimization of Software-Controlled Modes of Heat Treatment of Concrete Products in Heat-Technological Facilities

2019 ◽  
Vol 62 (3) ◽  
pp. 280-292
Author(s):  
A. M. Niyakovskii ◽  
V. N. Romaniuk ◽  
Yu. V. Yatskevich ◽  
A. N. Chichko
Keyword(s):  
Heat Treatment ◽  
Heat Supply ◽  
Time Lag ◽  
Hydration Process ◽  
Temperature Fields ◽  
Maximum Speed ◽  
Functional Dependencies ◽  
Industrial Facilities ◽  
Degree Of Hydration ◽  
Concrete Hydration

In the article the technique of an assessment of modes of operation of the heat engineering equipment used for heat treatment of concrete products in the conditions of programcontrolled heat supply according to the pattern of “heating – isothermal influence – cooling” has been developed. The method is based on the numerical solution of a non-stationary heat equation supplemented by equations describing the hydration process of a concrete product; also, it includes a system of initial and boundary conditions for its spatial structure. The method makes it possible to create tabulated functions of temperature and the degree of hydration of the time of heat treatment in any point of a 3D-product. The mathematical tools for calculating the functional dependencies of concrete hydration equipment with software-heated environment are presented. Numerical calculations of the concrete hydration process in the formwork are performed with respect to the symmetrical object. Based on the calculation of the temperature gradient across the minimal cross section of the product, a numerical analysis of the functions modeling heat supply mode depending on the processing time of a concrete product has been fulfilled. It is demonstrated that the maximum speed of the hydration process in a concrete product hardening is achieved at the maximum of time lag of isothermal cure. Additionally, with an increase in the duration of the product heating, the value of the maximum hydration rate decreases. It is concluded that the method of assessing the mode of heat treatment of concrete products being developed makes it possible to determine parameters for the calculation of the minimal useful heat required for the heat treatment of concrete products with spatially distributed parameters. The proposed method is applicable to calculate the temperature fields and the extent of hydration in the products of any geometric shape and volume in a software-controlled heating environment of industrial facilities for the accelerated hydration of concrete, and also affords the possibility of preliminary calibration prior to the assignment of relevant heat supply modes to the products being processed.

Modeling of Macro-Physical Parameters of Foam Glass under Exposure of Cyclic Thermal Effects

2019 ◽  
Vol 974 ◽  
pp. 464-470 ◽  
Author(s):  
S.V. Fedosov ◽  
M.O. Bakanov ◽  
S.N. Nikishov
Keyword(s):  
Heat Treatment ◽  
Raw Materials ◽  
Foam Glass ◽  
Glass Production ◽  
Raw Material ◽  
Temperature Fields ◽  
Material Surface ◽  
Heating Process ◽  
Physical Parameters ◽  
Entire Volume

The process of the raw materials mixture heat treatment in the foam glass production is of great importance in the formation of the finished product thermal characteristics. Selection of optimal temperature regimes at the stages when the process of glass particles melting is activated and thermal decomposition of the gasifier occurs is of particular importance. Otherwise, a situation when the gasifier has decomposed by mass on the layers close to the material surface at that the reaction has not been initiated at the raw materials mixture center may emerge. The problem can be solved by the uniform heating throughout the raw materials mixture entire volume. The fact that excessive heating can entail additional financial costs for manufacturers’ energy resources and as a result the cost of the material can be increased and affect its competitiveness among thermal insulation materials should be taken into account. A method for calculating temperature fields allowing to simulate the thermophysical heating process in the center of the material under study on the basis of its surface temperature indicators has been presented in the paper. Such an approach may make calculation of the rational time intervals for the raw material mixture heat treatment prior to the foaming stages and partially optimization of the production process possible.

Simulation and Control of Distortion of Hydro Turbine Blade Steel Casting in Heat Treatment Process

2012 ◽  
Vol 706-709 ◽  
pp. 1580-1585
Author(s):  
Hai Liang Yu ◽  
Jin Wu Kang ◽  
Tian You Huang
Keyword(s):  
Heat Treatment ◽  
Treatment Process ◽  
Temperature Fields ◽  
Air Cooling ◽  
Heat Treatment Process ◽  
Element Simulation ◽  
Forced Air ◽  
Blade Casting ◽  
And Control ◽  
Good Agreement

Blades are key part of hydro turbines, which often distorts during heat treatment process for their special structures. In this paper, thermal fluid finite element simulation of the forced air cooling process of a blade casting was carried out under a variety of distances between fans and blades, air speeds, groups of fans and circumstance temperatures. The temperature fields of blade castings were obtained. A novel parameter, temperature difference between surfaces of castings along thickness direction, was proposed to analyze the distortion of blade castings. The distortion behavior of blade castings with martensitic stainless steel were discussed, which is in good agreement with distortion regularity of the experimental ones. The temperature differences between blade casting surfaces are always greater than zero, resulting in distortion which could be divided into three stages. Finally, we focused on discussing the control methods of distortion behavior of blade castings which could be operated in actual production.

scholarly journals Development of Energy-Efficient Modes of Installations for Heat Treatment of Concrete Products Using Numerical Calculation Methods

2021 ◽  
Vol 20 (3) ◽  
pp. 195-206
Author(s):  
V. N. Romaniuk ◽  
A. M. Niyakovskii ◽  
A. N. Chichko ◽  
Yu. V. Yatskevich
Keyword(s):  
Heat Treatment ◽  
Energy Consumption ◽  
Energy Saving ◽  
Thermal Energy ◽  
Spatial Configuration ◽  
Temperature Fields ◽  
Cement Clinker ◽  
Hydration Reaction ◽  
Isothermal Exposure ◽  
Component Structure

Production of concrete and reinforced concrete products in the conditions of the Republic of Belarus and in the countries with similar climatic conditions requires heat treatment in heat-technological installations in order to achieve the desired strength of the products at the appointed time, which consumes a great amount of thermal energy.  In this case, the purpose of equipment operating  modes is associated with a number of difficulties when it comes to new products of complex spatial configuration and structure. The optimality criteria of such modes are, as a rule, the duration and temperature limits of processing, providing the required strength with minimal energy consumption. In the conditions of serial production in the case of structurally simple objects, the assignment of heat treatment modes is carried out empirically. As the analysis shows, the modes obtained in this way do not meet the above criteria, especially from the standpoint of energy saving. The paper, using a mathematical model previously developed by the authors, proposes dependencies for calculating the optimal modes of heat treatment of concrete products that are distinguished by a complex spatial shape and multi-component structure. The method is based on three-dimensional transfer equations, taking into account internal sources of heat release due to the ongoing hydration reaction of the active components of the cement clinker, and the boundary conditions corresponding to the structure of the processed product, as well as the type of heat technology device for accelerated hydration. Equations are proposed for calculating the amount of heat energy supplied to the processed product providing a given strength at a specified time. On the example of a manufactured industrial concrete product and for the conditions of an actually used device for accelerated hydration, a comparison has been made between two limiting modes of heat treatment: with isothermal exposure and in its absence. As a result of the performed calculations, the dependences of energy consumption, temperature fields and the degree of hydration in the product for both modes have been obtained and an energy-saving mode of heat treatment corresponding to the case under consideration has been developed. It is shown that the used numerical method allows to solve problems of this type and to achieve thermal energy savings.

scholarly journals Induction Heating of Gear Wheels in Consecutive Contour Hardening Process

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3885
Author(s):  
Jerzy Barglik ◽  
Adrian Smagór ◽  
Albert Smalcerz ◽  
Debela Geneti Desisa
Keyword(s):  
Heat Treatment ◽  
Induction Heating ◽  
Temperature Fields ◽  
High Tech ◽  
Total Efficiency ◽  
Critical Temperatures ◽  
Hardening Process ◽  
Conventional Heat Treatment ◽  
Non Linear ◽  
Gear Wheels

Induction contour hardening of gear wheels belongs to effective heat treatment technologies especially recommended for high-tech applications in machinery, automotive and aerospace industries. In comparison with long term, energy consuming conventional heat treatment (carburizing and consequent quenching), its main positive features are characterized by high total efficiency, short duration and relatively low energy consumption. However, modeling of the process is relatively complicated. The numerical model should contain both multi-physic and non-linear formulation of the problem. The paper concentrates on the modeling of rapid induction heating being the first stage of the contour induction hardening process which is the time consuming part of the computations. It is taken into consideration that critical temperatures and consequently the hardening temperature are dependent on the velocity of the induction heating. Numerical modeling of coupled non-linear electromagnetic and temperature fields are shortly presented. Investigations are provided for gear wheels made of a special quality steel AISI 300M. In order to evaluate the accuracy of the proposed approach, exemplary computations of the full induction contour hardening process are provided. The exemplary results are compared with the measurements and a satisfactory accordance between them is achieved.

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