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.

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.

Fly Ash-Desulfurization Gypsum Mortar and Concrete Part I: Mix Proportions and Hydration

2011 ◽  
Vol 250-253 ◽  
pp. 809-816
Author(s):  
Yu Chen ◽  
Ying Li Gao
Keyword(s):  
Fly Ash ◽  
Flue Gas ◽  
Hydration Process ◽  
Cement Stone ◽  
Composite Binder ◽  
Strength Concrete ◽  
Concrete Hydration ◽  
Concrete Part ◽  
Flue Gas Desulphurization

Fly ash (FA) and flue gas desulphurization gypsum (FGD) were blended in proportion into a new composite binder added with cement, lime and some modifiers. In the paper, the mix proportions of composite binder with low-quality FA and FGD were studied. FA-FGD more than 80% with FA:FGD 3:2 was suggested for mortar, plastering and slurry while FA:FGD 2:1 and FA-FGD 30~40% was recommended for middle-strength concrete. Hydration process of typical mixtures of FA-FGD paste was investigated through SEM and XRD tests. The conclusion could be made that FA showed much improved pozzolana activity especially at early ages due to the existence of FGD as an ideal sulfate activator, which also crystallized later to strengthen the hardened paste. The microstructure of hydrated FA-FGD paste was more excellent than that of neat cement stone or one blended with the same percentage of pure FA.

scholarly journals Features of heat treatment of grain in dryers of the contact type

2019 ◽  
Vol 126 ◽  
pp. 00045
Author(s):  
Sergey Sutyagin ◽  
Andrey Pavlushin ◽  
Petr Ageyev
Keyword(s):  
Heat Treatment ◽  
Energy Saving ◽  
Agricultural Production ◽  
Heat Supply ◽  
Contact Method ◽  
Thermal Impact ◽  
Drying Process ◽  
Contact Type ◽  
Grain Drying

The main types of use of thermal impact on grain used in agricultural production are analyzed. The perspective patented design of energy–saving installation for grain drying is offered. The installation uses a contact method of heat supply to the processed product. The results of studies on the optimization of the main parameters of the grain drying process are presented.

An experimental study on the concrete hydration process using Fabry–Perot fiber optic temperature sensors

Measurement ◽  
2012 ◽  
Vol 45 (5) ◽  
pp. 1077-1082 ◽  
Author(s):  
Xiaotian Zou ◽  
Alice Chao ◽  
Ye Tian ◽  
Nan Wu ◽  
Hongtao Zhang ◽  
...  
Keyword(s):  
Experimental Study ◽  
Fiber Optic ◽  
Temperature Sensors ◽  
Hydration Process ◽  
Fabry Perot ◽  
Concrete Hydration ◽  
Fiber Optic Temperature

INTELLIGENT APPROACH FOR DIAGNOSIS ELECTRICAL EQUIPMENT OF INDUSTRIAL FACILITIES

2019 ◽  
pp. 37-45 ◽  
Author(s):  
A. E. Kolodenkova ◽  
S. S. Vereshchagina
Keyword(s):  
Functional Model ◽  
Cognitive Model ◽  
Electrical Equipment ◽  
Production Model ◽  
Functional Dependencies ◽  
Actual Problem ◽  
Industrial Facilities ◽  
New Formulation ◽  
High Level ◽  
Intelligent Approach

This paper is devoted to actual problem of ensuring of trouble-free functioning and a high level of fault tolerance of industrial facilities’ electrical equipment (EE) by diagnosing them during their operation. However, when diagnosing equipment, a number of challenges arise related to the following problems: a large number of monitored parameters, the presence of not only statistical information but the values of linguistic variables that are used by staff on duty, insufficient and incomplete input information. Proposed approach to diagnosing EE based on a composition of fuzzy cognitive model with a fuzzy vertices, links and fuzzy-functional cognitive model with functional links for generating intermediate information, and as well as fuzzy-production model of an upper level for taking final diagnostics decisions. The proposed approach is based on the functional model of EE diagnosing in IDEF0 notation which reflects the sequence of all necessary functions related to the diagnosing and provides the identification of the key data flows and a more comprehensive understanding of the process. The paper also provides a formulation of the fuzzy-set method that is based on the construction of functional dependencies formed in clear mapped set “the occurrence frequency of for equipment's dangerous situation”. This method’s novelty lies in the new formulation of the problem in accordance with the latest scientific achievements and its solution that was not previously considered in the well known sources of literature. The suggested method is allows to calculating the predicted values of controlled parameters of EE in case of statistic and fuzzy source data. The proposed approach to the EE diagnosis at industrial objects makes it possible to improve the accurate and complete EE diagnosis through the knowledge of the staff on duty, thereby resulting in timely repair and maintenance.

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.

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