scholarly journals Features of heating technology at induction thermal processing with external electromagnetic field

2020 ◽  
Vol 65 (1) ◽  
pp. 54-61
Author(s):  
I. I. Vegera ◽  
A. V. Zizika ◽  
P. Y. Tsykunou ◽  
V. M. Yakovich
Keyword(s):  
Electromagnetic Field ◽  
Magnetic Circuit ◽  
Heating Temperature ◽  
Hardened Layer ◽  
Temperature Fields ◽  
Effect Of Temperature ◽  
Design Stage ◽  
Rigid Base ◽  
Total Width ◽  
Flat Part

According to the data of performed calculations and modeling of the hardening process, a design of inductors with magnetic cores for hardening long flat parts has been developed. At the design stage of this type of inductors, it was necessary to find out the degree of influence of the magnetic circuit design on the distribution of the temperature field during heating. To do this, we simulated electromagnetic and temperature fields to assess the concentration of the electromagnetic field at different heights of the “legs” of the inductor. As a result, a significant effect of the length of the “legs” of the magnetic circuit on the intensity of heating and the operability of the system as a whole was established. It is noted that insufficient height of the “leg” leads to a significant decrease in the field concentration, which leads to insufficient heating temperature and uneven distribution of heat zones in the heated part. In turn, an increase in the height of the “legs” leads to a narrowing of the heat release zone in the part compared to the total width of the coil and magnetic circuit. With a significant lengthening of the “legs”, the cooling circuit of the inductor will not be able to remove heat from the magnetic circuit obtained from the part, which will lead to the destruction of the magnetic circuit. The developed design of a two-turn single-circuit inductor and the general methodology made it possible to obtain a high-quality hardened layer with a depth of up to 3 mm with the formation of a martensitic structure of the required hardness on a planar-type flat part without significant energy loss. The part was machined by fixing it on a rigid base to compensate for the effect of temperature changes in linear dimensions. To obtain a uniform gap between the part and the inductor, a special pressure roller was used. The resulting structure of the hardened layer adequately meets the stated requirements for the part. The results of the research were used to develop a flat part of the “guide” type for lifting equipment (for example, a guide for the movement of the traction chain) and were introduced into production.

scholarly journals Influence of Rectifiers on Permanent Magnet Wind Generator Electromagnetic and Temperature Fields

2016 ◽  
Vol 10 (1) ◽  
pp. 205-219
Author(s):  
Qiu Hongbo ◽  
Dong Yu ◽  
Yang Cunxiang
Keyword(s):  
Electromagnetic Field ◽  
Temperature Field ◽  
Permanent Magnet ◽  
Core Loss ◽  
Harmonic Distortion ◽  
Temperature Fields ◽  
Stator Core ◽  
Current Harmonics ◽  
Copper Loss ◽  
Wind Generator

Power rectifiers are very necessary in the wind power generation systems since they are the necessary channels that link the generator and power gird together. However, they have some effects on the permanent magnet wind generator due to their work on fast on-off transitions. Taking an 8kW 2000r/min wind-driven permanent magnet generator as an example, the system model and external circuit were established. Firstly, based on the field-circuit coupling calculation method, the voltage and current harmonics have been studied respectively when the generator was connected to rectifier loads and pure resistance loads, so did the total harmonic distortion. The mechanism of harmonic impacted by rectifiers was revealed. Secondly, combined the harmonic electromagnetic field theory, the stator core loss, armature winding copper loss and rotor eddy loss were analyzed when the generator connected different loads. Furthermore, according to the definition of nonlinear circuits PF, the numerical analysis method was adopted to calculate the power factor when the generator connected two loads respectively. The change mechanism of PF impacted by rectifiers has been revealed. In addition, the temperature field model has been established and the generator temperature was also analyzed. The temperature distributions were obtained when the wind generator was connected to different loads. Then, the relationship between losses and temperature was combined, the change rules of permanent magnet temperature by the eddy current loss were studied under different load. At last, it can prove that the rectifiers have influences on both electromagnetic field and temperature field through comparing the simulation results with experimental test data.

Characterization of Melting and Solidification Phenomena in Electromagnetic Punching of Aluminum Tubes

2012 ◽  
Vol 134 (1) ◽  
Author(s):  
De Waele Wim ◽  
Faes Koen ◽  
Van Haver Wim
Keyword(s):  
Plastic Deformation ◽  
Energy Levels ◽  
High Energy ◽  
Effect Of Temperature ◽  
Fracture Mechanisms ◽  
Time Interval ◽  
Short Time Interval ◽  
Total Width ◽  
Premature Failure ◽  
Charging Energy

Electromagnetic punching of tubular products is considered to be a promising innovative perforating process. The required punching energy decreases when using high velocities. Also, less tools are required when compared to conventional mechanical punching. However, the increase in punching speed can involve new strain and fracture mechanisms which are characteristic of the dynamic loading. In high energy rate forming processes the effect of temperature versus time gradient on the material properties becomes important due to the heat accumulated from plastic deformation and friction. The deformation induced heating will promote strain localization in it, possibly degrade its formability and cause premature failure in the regions of high localized strain. The feasibility of the electromagnetic pulse forming process for punching holes in aluminum cylindrical specimens has been investigated on an experimental trial-and-error basis. Experiments were performed using a Pulsar system (model 50/25) with a maximum charging energy of 50 kJ and a discharge circuit frequency of 14 kHz. Microscopic and metallographic inspection of the punched workpieces, together with hardness measurements, was performed to critically evaluate the quality of the cuts. It was observed that damage occurred at part of the edge of the punched hole during some of the perforation experiments. It was evidenced that in most workpieces, especially those performed at higher charging energy levels, a considerably high temperature must have been reached in the regions near the punched hole. The aluminum in this region was assumed to have melted and resolidified. These assumptions were affirmed by the following observations. Microscopic-size precipitates present in the unaffected base metal microstructure, had completely dissolved in that region; shrinkage cavities and dendrite rich regions were clearly visible. Next to this region, a heat affected zone was present where the grain boundaries had partially melted and precipitates partially disappeared. Considerably high temperatures, in the order of 520 to 660 °C, were reached in the regions around the punched holes, leading to melting and resolidification of the material. The total width of the thermally affected regions appeared to be larger at higher energy levels. The combination of heat generated by ohmic heating and by plastic deformation in a very short time interval is the most probable cause of the high peak temperatures that have occurred during the electromagnetic punching process.

scholarly journals Sealing Performance Analysis of an End Fitting for Marine Unbonded Flexible Pipes Based on Hydraulic-Thermal Finite Element Modeling

Energies ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 2198 ◽  
Author(s):  
Liping Tang ◽  
Wei He ◽  
Xiaohua Zhu ◽  
Yunlai Zhou
Keyword(s):  
Finite Element ◽  
Fluid Pressure ◽  
Temperature Fields ◽  
Effect Of Temperature ◽  
Fe Model ◽  
Element Analysis ◽  
Sealing Capacity ◽  
Sealing Performance ◽  
Metal Seal ◽  
Essential Components

End fittings are essential components in marine flexible pipe systems, performing the two main functions of connecting and sealing. To investigate the sealing principle and the influence of the temperature on the sealing performance, a hydraulic-thermal finite element (FE) model for the end fitting sealing structure was developed. The sealing mechanism of the end fitting was revealed by simulating the sealing behavior under the pressure penetration criteria. To investigate the effect of temperature, the sealing behavior of the sealing ring under different temperature fields was analyzed and discussed. The results showed that the contact pressure of path 1 (i.e., metal-to-polymer seal) was 31.7 MPa, which was much lower than that of path 2 (metal-to-metal seal) at 195.6 MPa. It was indicated that the sealing capacities were different for the two leak paths, and that the sealing performance of the metal-to-polymer interface had more complicated characteristics. Results also showed that the finite element analysis can be used in conjunction with pressure penetration criteria to evaluate the sealing capacity. According to the model, when the fluid pressures are 20 and 30 MPa, no leakage occurs in the sealing structure, while the sealing structure fails at the fluid pressure of 40 MPa. In addition, it was shown that temperature plays a significant role in the thermal deformation of a sealing structure under a temperature field and that an appropriately high temperature can increase the sealing capacity.

A Predictive Model To Determine the Effects of Temperature, Sodium Pyrophosphate, and Sodium Chloride on Thermal Inactivation of Starved Listeria monocytogenes in Pork Slurry

2003 ◽  
Vol 66 (7) ◽  
pp. 1216-1221 ◽  
Author(s):  
M. A. LIHONO ◽  
A. F. MENDONCA ◽  
J. S. DICKSON ◽  
P. M. DIXON
Keyword(s):  
Listeria Monocytogenes ◽  
Predictive Model ◽  
Thermal Inactivation ◽  
Heating Temperature ◽  
Sodium Pyrophosphate ◽  
Effect Of Temperature ◽  
Destructive Effect ◽  
Processed Meats ◽  
Natural Logarithm ◽  
D Values

The effects and interactions of 27 combinations of heating temperature (57.5 to 62.5°C), sodium pyrophosphate (SPP) level (0 to 0.5%, wt/vol), and salt (NaCl) level (0 to 6%, wt/vol) on the thermal inactivation of starved Listeria monocytogenes ATCC 19116 in pork slurry were investigated. A split-split plot experimental design was used to compare all 27 combinations. L. monocytogenes survivors were enumerated on tryptic soy agar supplemented with 0.6% yeast extract. The natural logarithm (loge) of the means of decimal reduction times (D-values) were modeled as a function of temperature, SPP level, and NaCl level. Increasing concentrations of SPP or NaCl protected starved L. monocytogenes from the destructive effect of heat. For example, D-values for the pathogen at 57.5°C in pork slurry with 0, 3, and 6% NaCl were 2.79, 7.75, and 14.59 min, respectively. All three variables interacted to affect the thermal inactivation of L. monocytogenes. A mathematical model describing the combined effect of temperature, SPP level, and NaCl level on the thermal inactivation of starved L. monocytogenes was developed. There was strong correlation (R2 = 0.97) between loge D-values predicted by the model and those observed experimentally. The model can predict D-values for any combination of variables that falls within the range of those tested. This predictive model can be used to assist food processors in designing thermal processes that include an adequate margin of safety for the control of L. monocytogenes in processed meats.

scholarly journals Additional heat loss of jamb in enclosing structures

2021 ◽  
Vol 263 ◽  
pp. 03017
Author(s):  
Maria Samsonova ◽  
Elvira Semenova ◽  
Christina Kotova ◽  
Leonid Salogub
Keyword(s):  
Heat Flux ◽  
Energy Efficiency ◽  
Heat Loss ◽  
Energy Efficient ◽  
Residential Buildings ◽  
Temperature Fields ◽  
Design Stage ◽  
Design Solution ◽  
Additional Heat ◽  
Aerated Concrete

One of the urgent problems today is to increase the energy efficiency of civil buildings. There is a need at the design stage to choose structures and design solutions that will compensate for the increasing consumption of energy resources in civil engineering. This article compares different building envelopes used in the construction of residential buildings: a volumetric block and a wall made of aerated concrete blocks. To determine the most energy efficient design solution construction is compared in different climatic regions. One of the most vulnerable places of a wall, from the point of view of energy efficiency, is a window jamb. In this article, an analysis is carried out to determine the construction with the lowest heat loss window jambs. Using the ELCUT software temperature fields and additional heat flux densities are calculated. According to the calculation, the proportion of heat loss due to window slope from heat loss according to the surface of the structure was determined. The heat flux density of the homogeneous section of the wall of the volume block is 1.28 times higher on average than in the aerated concrete wall. Regardless of the climatic conditions, the junction of the window jamb in buildings made of insulated panels of volumetric blocks is more energy efficient than the same junction in a building with aerated concrete walls.

scholarly journals PENGARUH SUHU DAN PENAMBAHAN BAHAN ABRASIVE KULIT ARI BIJI KAKAO TERHADAP KARAKTERISTIK KRIM BODY SCRUB

2019 ◽  
Vol 7 (3) ◽  
pp. 417
Author(s):  
Anak Agung Gede Rai Giri Natha ◽  
A.A.P. Agung Suryawan Wiranatha ◽  
Sri Mulyani
Keyword(s):  
Phenolic Compounds ◽  
Heating Temperature ◽  
Block Design ◽  
Characteristic Temperature ◽  
Effect Of Temperature ◽  
Total Phenolic ◽  
Total Phenolic Compounds ◽  
Cocoa Beans ◽  
Randomized Block Design

The aims of this study were: 1) to determine the effect of temperature and the addition of abrasive ingredients on the epidermis of cocoa beans to the characteristics of body scrub creams, and  2) to obtain temperature and the addition of abrasive ingredients to the epidermis of cocoa beans to produce the best characteristic body scrub cream, and 3)  how the quality of body scrub cream changes during storage. The experimental design used in this study was a factorial randomized block design, which consisted of 2 factors. The first factor was the heating temperature which consists of two levels, namely temperature of 65 °C and 75 °C. The second factor was the addition of abrasive materials which consists of three levels namely 3 percent, 6 percent and 9 percent. All treatments were grouped into 3 groups to obtain 18 experimental units. The data obtained were analyzed by variance and  the Duncan test. The best result of body scrub cream is the treatment of heating temperature 65°C and the addition of powder epidermis of cocoa beans 9 percent  with the characteristics of pH 5.53, viscosity of 36,627 cp, content of phenolic compounds 21.631 mg GAE/g, aroma 5.85 and passions 5.55. pH, viscosity and total phenolic compounds are stable up to 6 weeks of storage. Keywords : epidermis of cocoa beans, body scrub, characteristic, temperature, addition of abrasives

scholarly journals Low-temperature induction heating of flat metal objects in a traveling electromagnetic field

2022 ◽  
Vol 1211 (1) ◽  
pp. 012015
Author(s):  
A N Kachanov ◽  
Y S Stepanov ◽  
N A Kachanov ◽  
V A Chernyshov ◽  
D A Korenkov
Keyword(s):  
Electromagnetic Field ◽  
Low Temperature ◽  
Edge Effect ◽  
Induction Heating ◽  
Eddy Currents ◽  
Magnetic Circuit ◽  
Heating System ◽  
Open Circuit ◽  
Longitudinal Edge ◽  
Temperature Induction

Abstract The article discusses possible options for a low-temperature induction heating system (LTIHS) of flat metal products in a traveling electromagnetic field. The problem of calculating eddy currents, active and reactive powers induced in a heated flat object, as well as electromagnetic forces acting on the object moving it in a given direction, is posed and solved. A mathematical model has been developed that takes into account the dependence of the influence on the main parameters of the electromagnetic field of the following factors: geometric dimensions of the air gap between the poles of the magnetic circuit and the heated flat body; the longitudinal edge effect caused by the open circuit of the magnetic circuit of the inductor, as well as the transverse edge effect associated with the appearance of the longitudinal components of eddy currents in a heated flat object. The solution of particular problems of LTIHS in one- and two-dimensional formulation allows them to be simplified and to perform calculations for various design variants of induction heating devices with a traveling electromagnetic field, using a one-dimensional model that explicitly takes into account the features of electromagnetic processes in the systems under study.

scholarly journals A REVIEW: EFFECT OF TEMPERATURE TO ANTIOXIDANT ACTIVITY AND HCN LEVEL IN CASSAVA (MANIHOT ESCULENTA CRANTZ) LEAVES

2021 ◽  
Author(s):  
Zainal Abidin ◽  
Asriani Suhaenah ◽  
Maya Sari
Keyword(s):  
Antioxidant Activity ◽  
Peer Review ◽  
Manihot Esculenta ◽  
Heating Temperature ◽  
Persea Americana ◽  
Effect Of Temperature ◽  
Antioxidant Compounds ◽  
Manihot Esculenta Crantz ◽  
Cassava Leaves ◽  
Dry Heating

Cassava Leaves (Manihot esculenta Crantz) is one of the food resources that many people consume as vegetables in some regions. People believe that it has natural antioxidant compounds such as phenolic and flavonoids.  Also,  it  contains  HCN  elements  known  as  toxic  compounds. However, HCN levels can be reduced by dry heating and boiling. Phenolic and flavonoids are not resistant to heating and are easily oxidized. This article aim to assess the effect of temperature to antioxidant activity and the decrease of HCN level of cassava leaves. The pretreatment  heating  by oven (dry heating) and cooking (boiling heating) greatly affects to the antioxidant activity and  the reduction of cyanide acid (HCN) level in cassava leaves. This article may be useful for any one or any researcher to determine pretreatment heating temperature and heating method  to process prepare cassava leaves.                        Peer Review History: Received 6 November  2020; Revised 25 Decembe; Accepted 4 January, Available online 15 January 2021 UJPR follows the most transparent and toughest ‘Advanced OPEN peer review’ system. The identity of the authors and, reviewers will be known to each other. This transparent process will help to eradicate any possible malicious/purposeful interference by any person (publishing staff, reviewer, editor, author, etc) during peer review. As a result of this unique system, all reviewers will get their due recognition and respect, once their names are published in the papers. We expect that, by publishing peer review reports with published papers, will be helpful to many authors for drafting their article according to the specifications. Auhors will remove any error of their article and they will improve their article(s) according to the previous reports displayed with published article(s). The main purpose of it is ‘to improve the quality of a candidate manuscript’. Our reviewers check the ‘strength and weakness of a manuscript honestly’. There will increase in the perfection, and transparency. Received file:                           Comments of reviewer(s):         Average Peer review marks at initial stage: 5.0/10 Average Peer review marks at publication stage: 7.5/10 Reviewer(s) detail: Ahmad Najib, Universitas Muslim Indonesia, Makassar, Indonesia, [email protected] Dr. Marwa A. A. Fayed, University of Sadat City, Egypt, [email protected] Prof. Dr. Ali Gamal Ahmed Al-kaf, Sana'a university, Yemen, [email protected] Similar Articles: PHYTOCHEMICAL INVESTIGATION AND EVALUATION OF ANTIOXIDANT AND THROMBOLYTIC PROPERTIES OF LEAVE EXTRACTS OF GARDENIA CORONARIA BUCH-HAM PHYTOCHEMICAL SCREENING AND IN VITRO ANTIOXIDANT AND ANTI-DIABETIC POTENTIALS OF PERSEA AMERICANA MILL. (LAURACEAE) FRUIT EXTRACT

Studies on changes in the temperature field and recrystallization properties of glass fiber reinforced polypropylene composite strip winding process

2020 ◽  
pp. 095440622097059
Author(s):  
Jiazhong Xu ◽  
Tianyu Fu ◽  
Zhao Hui
Keyword(s):  
Mechanical Properties ◽  
Glass Fiber ◽  
Heating Temperature ◽  
Heating Time ◽  
Temperature Fields ◽  
Fiber Reinforced ◽  
Composite Ring ◽  
Glass Fiber Reinforced ◽  
The Press ◽  
Temperature Heating

The glass fiber reinforced polypropylene (GF/PP) composite ring specimens were fabricated based on the composites prepreg tape winding process. The heated winding process was simulated by ANSYS software to obtain the temperature distribution of the wound layer of the specimen. At the same time, the temperature of the wound layer was collected and stored using a temperature-controlled recorder. The temperature fields between the wound layers were found to be different significantly, and the temperature measured through experiments was generally below the simulation results, where it is especially noticeable in the fusion zone. After the recrystallization of GF/PP specimen, the maximum shear strength that the specimen can withstand was improved. The response surface method was used to test and analyze the influence of recrystallization on the mechanical properties of the specimen, Obtain optimized process parameters, heating temperature of 91 °C, pressure of the press roller is 106 N, heating time of 13 min, the highest sample obtained is 28.67Mpa. The experimental results show that the influence of recrystallization parameters on the mechanical properties of the composite specimens (from large to small) are: heating temperature, heating time, and the roller pressure.

scholarly journals Influence of Real-Time Heating on Mechanical Behaviours of Rocks

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Bin Gu ◽  
Zhijun Wan ◽  
Yuan Zhang ◽  
Yangsheng Ma ◽  
Xiaodong Bernard Xu
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Real Time ◽  
Heating Temperature ◽  
Thermal Cracking ◽  
Effect Of Temperature ◽  
Rock Engineering ◽  
Mechanical Behaviours ◽  
Theoretical And Numerical Analysis ◽  
Rock Mechanical Properties

The rock mechanical properties under the effect of high temperature present a great significance on underground rock engineering. In this paper, the mechanical properties of sandstones, marbles, and granites under real-time heating were investigated with a servo-controlled compression apparatus. The results show that mechanical behaviours of all the three types of rocks are influenced by real-time heating to different degrees. Due to thermal cracking, the uniaxial compressive strengths decrease as the heating temperature rises from room temperature to 400°C. Above 400°C, the sandstone exhibits a significant increase in UCS because of the sintering reaction. The sintering enlarges the contact area and friction between crystal grains in the sandstone, which strengthens the bearing capacity. For marbles, the UCS continues to decrease from 400°C to 600°C due to thermal cracking. However, the carbonate in the marble begins to decompose after 600°C. The generated particles would fill the cracks in the marble and increase the strength. For granites, their UCS presents a sharp decline after 400°C because of thermal cracking. For all rock elastic modulus, they present a decreasing trend, and this indicates that the rock’s ability to resist deformation gradually weakens under the effect of temperature. In general, rock mechanical behaviours under real-time heating differ from those in normal situations, and use of the parameters presented here is important for underground rock engineering related to high temperature and can improve the precision in theoretical and numerical analysis.

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