Analysis of Thermal Gradients during Cyclic Thermal Loading under High Heating Rates

2008 ◽  
pp. 312-312-13
Author(s):  
EE Affeldt ◽  
J Hammer ◽  
U Huber ◽  
H Lundblad
Keyword(s):  
Thermal Loading ◽  
Thermal Gradients ◽  
Heating Rates ◽  
Cyclic Thermal Loading ◽  
High Heating

Comparing fast inductive tempering and conventional tempering: Effects on microstructure and mechanical properties

2018 ◽  
Vol 115 (4) ◽  
pp. 407 ◽  
Author(s):  
Annika Eggbauer Vieweg ◽  
Gerald Ressel ◽  
Peter Raninger ◽  
Petri Prevedel ◽  
Stefan Marsoner ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Impact Energy ◽  
Charpy Impact ◽  
Heat Treating ◽  
Processing Route ◽  
High Heating Rate ◽  
Heating Rates ◽  
High Heating ◽  
Tempering Treatment ◽  
Carbide Distribution

Induction heating processes are of rising interest within the heat treating industry. Using inductive tempering, a lot of production time can be saved compared to a conventional tempering treatment. However, it is not completely understood how fast inductive processes influence the quenched and tempered microstructure and the corresponding mechanical properties. The aim of this work is to highlight differences between inductive and conventional tempering processes and to suggest a possible processing route which results in optimized microstructures, as well as desirable mechanical properties. Therefore, the present work evaluates the influencing factors of high heating rates to tempering temperatures on the microstructure as well as hardness and Charpy impact energy. To this end, after quenching a 50CrMo4 steel three different induction tempering processes are carried out and the resulting properties are subsequently compared to a conventional tempering process. The results indicate that notch impact energy raises with increasing heating rates to tempering when realizing the same hardness of the samples. The positive effect of high heating rate on toughness is traced back to smaller carbide sizes, as well as smaller carbide spacing and more uniform carbide distribution over the sample.

Effect of low and high heating rates on reaction path of Ni(V)/Al multilayer

2017 ◽  
Vol 193 ◽  
pp. 244-252 ◽  
Author(s):  
Łukasz Maj ◽  
Jerzy Morgiel ◽  
Maciej Szlezynger ◽  
Piotr Bała ◽  
Grzegorz Cios
Keyword(s):  
Reaction Path ◽  
Heating Rates ◽  
High Heating

A FUNDAMENTAL STUDY ON THE COMBUSTION CHARACTERISTICS OF MUNICIPAL WASTE PLASTICS UNDER HIGH HEATING RATES

1995 ◽  
Author(s):  
Θωμαή Παναγιώτου
Keyword(s):  
Combustion Characteristics ◽  
Municipal Waste ◽  
Waste Plastics ◽  
Heating Rates ◽  
Fundamental Study ◽  
High Heating

ΑΥΤΗ Η ΕΡΓΑΣΙΑ ΕΙΝΑΙ ΜΙΑ ΒΑΣΙΚΗ ΕΡΕΥΝΑ ΕΠΑΝΩ ΣΤΗΝ ΚΑΥΣΗ ΠΛΑΣΤΙΚΩΝ ΠΟΥ ΒΡΙΣΚΟΝΤΑΙ ΣΤΑ ΑΠΟΡΡΙΜΑΤΑ (ΠΟΛΥ-ΣΤΥΡΕΝΙΟ (PS), ΠΟΛΥ-ΕΘΥΛΕΝΙΟ (ΡΕ) ΚΑΙ PVC). ΣΦΑΙΡΙΚΑ ΣΩΜΑΤΙΔΙΑ ΠΛΑΣΤΙΚΩΝ ΙΣΟΥ ΜΕΓΕΘΟΥΣ ΔΗΜΙΟΥΡΓΗΘΗΚΑΝ ΣΤΟ ΕΡΓΑΣΤΗΡΙΟ ΚΑΙ ΚΑΗΚΑΝ ΕΝΑ, ΕΝΑ ΣΕ ΗΛΕΚΤΡΙΚΟ ΦΟΥΡΝΟ ΚΑΙ ΘΕΡΜΟΚΡΑΣΙΕΣ 1040 -1400 Κ. Η ΚΑΥΣΗ ΤΩΝ ΣΩΜΑΤΙΔΙΩΝ ΜΕΛΕΤΗΘΗΚΕ ΜΕ ΕΝΑ ΤΡΙΧΡΩΜΑΤΙΚΟ ΠΥΡΟΜΕΤΡΟ ΚΑΙ ΜΙΑ ΥΨΗΛΗΣ ΤΑΧΗΤΗΤΑΣ ΚΙΝΗΜΑΤΟΓΡΑΦΙΚΗ ΜΗΧΑΝΗ, ΩΣΤΕ ΝΑ ΣΥΛΛΕΧΘΟΥΝ ΟΙ ΕΞΗΣ ΠΛΗΡΟΦΟΡΙΕΣ: Α) Ο ΧΡΟΝΟΣ ΤΗΣ ΚΑΥΣΗΣ, Β) ΤΟ ΕΙΔΟΣ ΤΗΣ ΚΑΥΣΗΣ (ΟΜΟΙΟΓΕΝΗΣ Η ΕΤΕΡΟΓΕΝΗΣ), Γ) ΤΟ ΠΑΧΟΣ ΤΗΣ ΦΛΟΓΑΣ ΚΑΙ Δ) Η ΤΑΧΥΤΗΤΑ ΠΤΩΣΗΣ ΤΩΝ ΣΩΜΑΤΙΔΙΩΝ. ΟΙ ΠΛΗΡΟΦΟΡΙΕΣ ΑΥΤΕΣ ΧΡΗΣΙΜΟΠΟΙΗΘΗΚΑΝ ΓΙΑ ΤΟΝ ΥΠΟΛΟΓΙΣΜΟ ΤΗΣ ΣΤΙΓΜΙΑΙΑΣ ΠΕΡΙΕΚΤΙΚΟΤΗΤΑΣ ΤΗΣ ΦΛΟΓΑΣ ΣΕ ΑΙΘΑΛΗ ΚΑΙ ΤΗΣ ΠΡΩΤΕΥΟΥΣΑΣ ΦΥΣΙΚΗΣ ΚΑΙ ΧΗΜΙΚΗΣ ΔΙΕΡΓΑΣΙΑΣ ΚΑΤΑ ΤΗΝ ΚΑΥΣΗ ΤΩΝ ΣΩΜΑΤΙΔΙΩΝ. ΚΑΘΕ ΥΛΙΚΟ ΠΑΡΟΥΣΙΑΣΕ ΜΟΝΑΔΙΚΑ ΧΑΡΑΚΤΗΡΙΣΤΙΚΑ ΚΑΥΣΗΣ. ΟΙ ΦΛΟΓΕΣ ΤΩΝ PVC ΣΩΜΑΤΙΔΙΩΝ ΕΙΧΑΝ ΤΗΝ ΜΕΓΑΛΥΤΕΡΗ ΠΕΡΙΕΚΤΙΚΟΤΗΤΑ ΣΕ ΑΙΘΑΛΗ, ΕΝΩ ΤΩΝ ΡΕ ΤΗΝ ΜΙΚΡΟΤΕΡΗ. Η ΤΑΧΥΤΗΤΑ ΚΑΥΣΗΣ ΤΩΝ PS ΣΩΜΑΤΙΔΙΩΝ ΒΡΕΘΗΚΕ ΟΤΙ ΕΞΑΡΤΑΤΑΙ ΑΠΟ ΤΗΝ ΤΑΧΥΤΗΤΑ ΔΙΑΧΥΣΗΣ ΣΤΗΝ ΑΕΡΙΑ ΦΑΣΗ, ΕΝΩ ΤΩΝ ΡΕ ΑΠΟ ΤΗΝ ΤΑΧΥΤΗΤΑ ΠΥΡΟΛΥΣΗΣ ΤΩΝ ΣΩΜΑΤΙΔΙΩΝ. Η ΑΝΑΦΛΕΞΗ ΤΩΝ PVC ΣΩΜΑΤΙΔΙΩΝ ΕΜΠΟΔΙΣΤΗΚΕ ΑΠΟ ΤΗΝ ΥΠΑΡΞΗ ΤΗΣ ΧΛΩΡΙΝΗΣ ΠΟΥ ΔΙΕΦΥΓΕ ΑΡΧΙΚΑ. ΟΤΑΝ Η ΚΑΥΣΗ ΑΡΧΙΣΕ, ΔΗΜΙΟΥΡΓΗΘΗΚΕ ΜΙΑ ΠΑΧΙΑ ΚΑΙ ΠΡΟΑΝΑΜΙΓΜΕΝΗ ΦΛΟΓΑ ΓΥΡΩΑΠΟ ΤΟ ΣΩΜΑΤΙΔΙΟ.

PTFE–Al2O3 reactive interaction at high heating rates

2014 ◽  
Vol 119 (1) ◽  
pp. 245-251 ◽  
Author(s):  
M. A. Hobosyan ◽  
Kh. G. Kirakosyan ◽  
S. L. Kharatyan ◽  
K. S. Martirosyan
Keyword(s):  
Heating Rates ◽  
High Heating ◽  
Reactive Interaction

Approximate method for the analysis of components undergoing ratchetting and failure

1998 ◽  
Vol 33 (1) ◽  
pp. 55-65 ◽  
Author(s):  
J Lin ◽  
F P E Dunne ◽  
D R Hayhurst
Keyword(s):  
Approximate Method ◽  
Mechanical Loading ◽  
Thermal Loading ◽  
Cyclic Plasticity ◽  
Processing Unit ◽  
Computationally Efficient ◽  
Element Analysis ◽  
Cyclic Thermal Loading ◽  
Central Processing ◽  
Practical Design

An approximate method has been presented for the design analysis of engineering components subjected to combined cyclic thermal and mechanical loading. The method is based on the discretization of components using multibar modelling which enables the effects of stress redistribution to be included as creep and cyclic plasticity damage evolves. Cycle jumping methods have also been presented which extend previous methods to handle problems in which incremental plastic straining (ratchetting) occurs. Cycle jumping leads to considerable reductions in computer CPU (central processing unit) resources, and this has been shown for a range of loading conditions. The cycle jumping technique has been utilized to analyse the ratchetting behaviour of a multibar structure selected to model geometrical and thermomechanical effects typically encountered in practical design situations. The method has been used to predict the behaviour of a component when subjected to cyclic thermal loading, and the results compared with those obtained from detailed finite element analysis. The method is also used to analyse the same component when subjected to constant mechanical loading, in addition to cyclic thermal loading leading to ratchetting. The important features of the two analyses are then compared. In this way, the multibar modelling is shown to enable the computationally efficient analysis of engineering components.

Evolution of Gases from the Pyrolysis of Raw and Torrefied Biomass and from the Oxy-combustion of their Bio-Chars

2021 ◽  
pp. 1-30
Author(s):  
Xiaoxiao Meng ◽  
Wei Zhou ◽  
Emad Rokni ◽  
Xigang Yang ◽  
Yiannis Levendis
Keyword(s):  
Co2 Emissions ◽  
Carbon Capture ◽  
Heating Rates ◽  
Renewable Biomass ◽  
Carbon Capture And Utilization ◽  
Combustion Emissions ◽  
Torrefied Biomass ◽  
High Heating ◽  
Pyrolysis Of Biomass ◽  
N Compounds

Abstract The current research assessed the evolution of gases from pyrolysis of biomass and from subsequent combustion of bio-chars. Raw and torrefied biomass was pyrolyzed in nitrogen or carbon dioxide under high heating rates (104 K/s) and high temperatures (1450 K). Pyrolyzates gases were monitored for carbon, nitrogen and sulfur oxides. Subsequently, generated bio-chars were burned in both conventional (air) and simulated oxy-combustion (O2/CO2) gases. In principle, oxy-combustion of renewable biomass coupled with carbon capture and utilization/sequestration can help remove atmospheric CO2. Pyrolysis of biomass in CO2 generated lower char yields, lower SO2 and NO, and higher CO2, CO and HCN mole fractions, compared to pyrolysis in N2. HCN was the most prominent among all measured nitrogen-bearing gases (HCN, NH3, NO) from biomass pyrolysis. Compared to their combustion in air, bio-chars burned more effectively in 30%O2/79%CO2 and less effectively in 21%O2/79%CO2. Emissions of CO were the lowest in 21%O2/79%CO2. Emissions of HCN were the highest in air combustion, and decreased with increasing O2 mole fraction in oxy-combustion; emissions of NO were highest in 30%O2/79%CO2, and emissions of NO were dominant during bio-char oxy-combustion compared with other N-compounds. In oxy-combustion bio-chars released the lowest emissions of SO2. Finally, the emissions of CO, NO, HCN, and SO2 from combustion of DDGS bio-chars were higher than those from RH bio-chars, because of different physicochemical properties.

Comparison of the Slow Pyrolysis Behavior and Kinetics of Coal, Wood and Algae at High Heating Rates

2020 ◽  
Vol 29 (6) ◽  
pp. 3943-3955 ◽  
Author(s):  
Bothwell Nyoni ◽  
Sifundo Duma ◽  
Shaka V. Shabangu ◽  
Shanganyane P. Hlangothi
Keyword(s):  
Heating Rates ◽  
Slow Pyrolysis ◽  
Pyrolysis Behavior ◽  
High Heating ◽  
Kinetics Of
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