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  1. 11 Archives of Foundry
  2. 11 Archiwum Odlewnictwa
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  5. 8 Prace Naukowe Instytutu Technologii Maszyn i Automatyzacji Politechniki Wrocławskiej. Konferencje
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  1. 66 Jezierski J.
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1
Content available remote Model matematyczny współczynnika przenikania ciepła ściany osłonowej z oknem z uwzględnieniem powierzchni elementów składowych
Jezierski J., Borowska J.
Izolacje
|
2018
|
R. 23, nr 1
50--54
PL
W artykule zaprezentowano podejście do opracowania modelu matematycznego współczynnika przenikania ciepła ściany osłonowej z oknem, wykonanym z PVC w budynku mieszkalnym, w zależności od udziałów pól powierzchni elementów składowych (odcinków ściany pełnej, ramy okiennej i powierzchni szklonej). Przy realizacji eksperymentu obliczeniowego zastosowano lokalne planowanie sympleksowe w warunkach ograniczenia zakresu zmienności wybranych czynników. Analiza wykonana została na podstawie opracowanego deterministycznego modelu matematycznego opisującego tą zależność. Oszacowano efekty wpływu badanych czynników. Informacja może być przydatna dla naukowców, producentów i konsumentów stolarki okiennej.
EN
The article presents an approach to the development of a mathematical model of heat transfer coefficient for a curtain wall with a PVC window in a residential building, depending on the specific proportions of component surface areas (solid wall sections, window frames and glazed surfaces). In the course of implementation of the computational experiment, local simplex planning was used in the conditions of limited range of variability of selected factors. The analysis was made on the basis of the complete deterministic mathematical model describing this relationship. The effects of the studied factors were estimated. The information can be useful for scientists, producers and consumers of window joinery.
2
Generacja termoelektryczna w przemyśle i w domu
Jezierski J., Jabłczyńska J., Kalbarczyk K., Janczylik M., Rusowicz A.
Chłodnictwo : organ Naczelnej Organizacji Technicznej
|
2018
|
R. 53, nr 3
30--38
PL
W pracy opisano podstawy fizyczne procesu generacji energii elektrycznej za pomocą ogniw Peltiera przy wykorzystaniu efektu Seebeck’a. Omówino wady i zalety generatorów termoelektrycznych (TEG) oraz ich zastosowania, zarówno komercyjnie dostępne, jak i te będące w fazie badań. W części projektowej przedstawiono koncepcję zastosowania modułów TEG jako źródła energii wykorzystywanej do celów oświetleniowych w budynkach przemysłowych oraz domach jednorodzinnych. Idea opiera się na wykorzystaniu ciepła pochodzącego z nagrzewania się powierzchni dachów podczas intensywnego oddziaływania promieniowania słonecznego. Przeprowadzono analizę zapotrzebowania na energię elektryczną, możliwości generacji oraz ekonomiczną.
EN
In this paper we introduce basic principles of the Seebeck effect phenomenon, which induce power generation in Peltier modules. The benefits and weaknesses of thermoelectric generators are described as well as commercial applications and those still in development. In the project section there’s our main conception of TEG usage presented, which bases on the idea of utilization heat from roof’s surface that is heated by the Sun radiation. TEG is then powering a LED lightening system. The analysis of electric power demand, feasible power generation and economic results are also included.
3
Content available Heat Treatment of the SiMo Iron Castings - Case Study in the Automotive Foundry
Cygan B., Stawarz M., Jezierski J.
Archives of Foundry Engineering
|
2018
|
Vol. 18, iss. 4
103--109
EN
Silicon – molybdenum cast iron commonly called SiMo due to its unique properties has becoming more and more interesting engineering material. The history and development of this alloy is relatively long but, due to the significant difficulties during the manufacturing process resulting in the lower final quality than expected, it has not been applied to often in practice. The biggest challenge is its brittleness as a result of the carbides precipitations. During last few years, thanks to the many important researches made and the general foundry technology development, the interest in SiMo iron has been rapidly growing, especially for the castings for heavy duty applications like corrosion, high temperature and wear abrasion resistant parts. In the article the heat treatment attempts to improve the microstructure of SiMo castings has been presented. The goal was to destroy or at least to refine and uniformly distribute the carbides precipitations to improve mechanical properties of the exhaust manifold castings for the cars. The experiments were carried out for the alloy contains approx. 4% Si, 1% Mo and 3.2%C. The range of the research included: hardness measuring, standard mechanical properties and microstructure for as-cast state and after that the subsequent heat treatment process with another properties check. The result of the heat treatment was the elimination of pearlite from the metal matrix. Moreover, the changes of the carbide molybdenum – rich phase morphology were observed. The dispersion of the carbides precipitations in the carbides area was observed. The experiments proved the possibility to control the microstructure and the mechanical properties of the SiMo castings by means of heat treatment but only to some extent.
4
Content available Theoretical and Practical Aspects of Pneumatic Powder Injection into Liquid Alloys with a Non-Submerged Lance
Jezierski J., Janerka K., Stawarz M.
Archives of Metallurgy and Materials
|
2014
|
Vol. 59, iss. 2
731--734
EN
The method of powder injection into molten metal has been widely known since tens of years and successfully utilized in various metallurgical processes. The most common is a solution with injection lance submerged under the liquid alloy surface, because it is easier apart from some of disadvantages of this approach. In this paper the authors’ complex experiments on the pneumatic injection process with non-submerged lance have been presented. The new approach on jet cone angle importance and its influence on the efficiency of the injection process has been shown. The issue of the effective jet radius that was proposed by former scientists as well as computer modelling and injection experiments recorded with high speed camera have been presented. The final comparison of the typical injection lance and developed by authors new lance with flange was presented, too. The benefits of use of a new one for the treatment of small liquid alloy volume (e.g. inoculation or alloys addition introduction) have been pointed.
PL
Technologia wdmuchiwania proszków do ciekłego metalu jest znana od kilkudziesięciu lat i z powodzeniem stosowana w różnorodnych procesach metalurgicznych i odlewniczych. Zdecydowanie najczęściej stosowane jest rozwiązanie z użyciem lancy zanurzonej pod lustro obrabianego stopu, jako łatwiejsze choć nie pozbawione wielu istotnych wad. W pracy zaprezentowano zakończone kompleksowe badania autorów nad procesem wdmuchiwania proszków bez zanurzania lancy w kąpieli. Przedstawiono nowe spojrzenie na tzw. „kąt stożka rozejścia strumienia” i jego wpływ na skuteczność procesu, przeanalizowano zagadnienie tzw. „skutecznego promienia strumienia” proponowanego przez wcześniejszych badaczy oraz opisano wyniki badań symulacyjnych oraz eksperymentów wdmuchiwania, zarejestrowanych z użyciem kamery do szybkich zdjęć. Podjęto się także ostatecznego porównania rozwiązań lancy zwykłej i opracowanej przez autorów tzw. „lancy kołnierzowej” wskazując na zalety tej drugiej, jako narzędzia do obróbki niewielkich objętości ciekłych stopów np. w procesach wprowadzania żelazostopów czy też modyfikacji.
5
Content available Melting of Grey Cast Iron Based on Steel Scrap Using Silicon Carbide
Stojczew A., Janerka K., Jezierski J., Szajnar J., Pawlyta M.
Archives of Foundry Engineering
|
2014
|
Vol. 14, iss. 3
77--82
EN
The paper presents the issue of synthetic cast iron production in the electric induction furnace exclusively on the steel scrap base. Silicon carbide and synthetic graphite were used as carburizers. The carburizers were introduced with solid charge or added on the liquid metal surface. The chemical analysis of the produced cast iron, the carburization efficiency and microstructure features were presented in the paper. It was stated that ferrosilicon can be replaced by silicon carbide during the synthetic cast iron melting process. However, due to its chemical composition (30% C and 70% Si) which causes significant silicon content in iron increase, the carbon deficit can be partly compensated by the carburizer introduction. Moreover it was shown that the best carbon and silicon assimilation rate is obtained where the silicon carbide is being introduced together with solid charge. When it is thrown onto liquid alloy surface the efficiency of the process is almost two times less and the melting process lasts dozen minutes long. The microstructure of the cast iron produced with the silicon carbide shows more bulky graphite flakes than inside the microstructure of cast iron produced on the pig iron base.
6
Content available The Lean Manufacturing tools in Polish foundries
Jezierski J., Janerka K.
Archives of Metallurgy and Materials
|
2013
|
Vol. 58, iss. 3
937--940
EN
The concept of Lean Manufacturing (or Lean Production) is widely present in the quality management systems of the best factories. Foundry plants in Poland have continuously been implementing modern management tools; however, the experiences of the authors show that the usage of lean tools is at a lower level in domestic foundries than in similar plants abroad. This was the reason why a survey was prepared and over 300 foundry plants were questioned regarding the application of Lean Manufacturing tools. The questions (20 in total) asked if and what tools are implemented in the plant and what benefits have been achieved, or why lean tools have not been implemented in a particular plant. The answers were thoroughly analysed and the results show that, among others, only 29% of all foundries use lean tools, and the main reason why most of them do not is that these tools are not understood well enough.
PL
Koncepcja Lean Manufacturing (lub Lean Production) obecna jest szeroko w systemach zarządzania wiodących zakładów przemysłowych. W odlewnictwie, w tym polskim, również widoczny jest stały postęp we wdrażaniu nowoczesnych narzędzi zarządzania. Jednak doświadczenia autorów wskazują, że w aspekcie zastosowania narzędzi lean, polskie odlewnie odstają jednak od zagranicznych. Te spostrzeżenia były powodem podjęcia badań, ankietowych skierowanych do krajowych odlewni (ponad 300). Pytania (łącznie 20) dotyczyły głównie zagadnień, czy i jakie narzędzia lean są wykorzystywane w zakładzie, jakie są korzyści z ich stosowania lub też dlaczego takich narzędzi nie wdrożono. Odpowiedzi zostały starannie przeanalizowane a wyniki wskazują między innymi, że zaledwie 29% odlewni stosuje jakiekolwiek narzędzia lean a najczęstszym powodem ich niestosowania jest niewystarczające zrozumienie.
7
Content available remote Quality and properties of the cast iron produced on the steel scrap base
Janerka K., Jezierski J., Szajnar J.
Archives of Materials Science and Engineering
|
2012
|
Vol. 53, nr 2
92-101
EN
Purpose: The goal of the article is to show the issue of the cast iron melting on the steel scrap base only (with no pig iron in charge). The particular interest was focused on the charging material chemical composition influence on the particular elements content in produced cast iron and its quality, too. Design/methodology/approach: The grey cast iron melting on the steel scrap base and recarburizers (anthracite, natural and synthetic graphite, petroleum coke) was conducted to achieve the goals of the experiments. The chemical composition, mechanical properties and microstructure was tested for each melt. Melting was conducted in inductive furnace of 20kg capacity. Findings: The experiments drawn to the conclusions that cast iron melted on the steel scrap base contains less impurities (sulfur and phosphorus) than this melted on the pig iron base. During the results further analysis the relationship between carburizer grade and both mechanical properties and microstructure of the produced cast iron was proved (microstructure heredity). Research limitations/implications: To finally prove the hypothesis regarding the microstructure heredity given in the article, further researches should be carried out with the anthracite use as a carburizer. Practical implications: The results achieved suggest that when anthracite is used as a carburizer it is possible to increase mechanical properties with no necessity of changing other process parameters. Regarding the fact that the anthracite is relatively cheap carburizer it may cause in consequence less expensive production along with the cast iron quality parameters increase. Originality/value: The issue of the materials microstructure heredity is not widely described in the literature and the experiments results presented in the article allow to create the hypothesis that this phenomenon is present in the metal alloys.
8
Content available Wytapianie żeliwa szarego i sferoidalnego bez surówki
Janerka K., Jezierski J., Szajnar J., Bartocha D.
Archives of Foundry Engineering
|
2012
|
Vol. 12, iss. 1s
81--86
PL
Przedstawione w artykule zagadnienia w sposób pośredni, ale bardzo znaczący dotykają problematyki ochrony środowiska. Obejmują one tematykę wytwarzania żeliwa szarego i sferoidalnego wyłącznie na bazie złomu stalowego. Eliminacja lub ograniczenie surówki we wsadzie to korzyści zarówno ekonomiczne jak i ekologiczne. W artykule omówiono podstawowe zagadnienia związane z metodą prowadzenia procesu nawęglania w piecach elektrycznych. Przedstawiono jak wpływa rodzaj materiału nawęglającego na skład chemiczny, strukturę i własności wytopionego żeliwa. Wskazano również czynniki ograniczające produkcję żeliwa sferoidalnego na bazie złomu stalowego.
EN
The problems presented in the article relate to the environmental protection issue in indirect but very significant way. They cover the issue of grey and ductile cast iron production exclusively on the steel scrap base. The pig iron limitation or even complete elimination from solid charge results both in economic and ecological benefits. The main topics related to carburization process in electric furnaces were presented in the article. The influence of the carburizer type on the chemical composition, microstructure and the properties of the produced cast iron were described. The limitations in ductile iron production on the steel scrap were indicated, too.
9
Content available Czynniki wpływające na wskaźniki procesu nawęglania
Janerka K., Szajnar J., Jezierski J., Bartocha D.
Archives of Foundry Engineering
|
2011
|
Vol. 11, iss. 3 spec.
89--96
PL
W artykule przedstawiono czynniki wpływające na uzyskiwane wskaźniki nawęglania (szybkość i efektywność) w procesie wytapiania żeliwa. Analiza obejmuje rodzaj nawęglacza (antracyt, grafit naturalny i grafit syntetyczny , koks naftowy ) oraz wielkość cząstek. Kolejne czynniki rozpatrywane w pracy to metoda nawęglania (wprowadzanie nawęglacza do stałego wsadu i na powierzchnię kąpieli metalowej) oraz parametry ciekłego metalu (temperatura i skład chemiczny ). Analizę przeprowadzono w oparciu o wykonane eksperymenty , wyniki obliczeń symulacji komputerowych oraz dane literaturowe.
EN
The article presents the factors affecting the carburizing rates obtained (rate and efficiency) during the process of melting cast iron. The analysis includes the recarburizer type (anthracite, natural and synthetic graphite, petroleum coke) and particle size. Further factors considered in work are the methods of recarburization (recarburizer introduction to a solid charge and on the surface of the metal bath) and the parameters of the melt (temperature and chemical composition). The analysis was based on experiments performed, the calculation results of computer simulations and literature data.
10
Content available remote The carburizer influence on the crystallization process and the microstructure of synthetic cast iron
Janerka K., Bartocha D., Szajnar J., Jezierski J.
Archives of Metallurgy and Materials
|
2010
|
Vol. 55, iss. 3
851-859
EN
The problems of synthetic cast iron production on the steel scrap and various carburizers (natural and synthetic graphite, petroleum coke, anthracite, cupola coke and charcoal) basis were presented in the paper. Until now the authors in their papers had analyzed mainly carbon assimilation by the liquid metal rate (recarburization efficiency) when these carburizers and various methods of recarburization were used [1,2,3,4]. The analysis covered the chemical composition and the properties of carburizers commonly used in foundries [5,6] and mechanical properties of the cast iron obtained on the steel scrap basis, too [2,7,8,9]. The computer modeling of heating and dissolution of carburizers’ particles inside liquid metal were carried out, too [10,11]. The crystallization process of the synthetic cast iron analysis and that produced on pig iron basis for comparison were presented. There was observed that the carburizers change the DTA (Derivative Thermal Analysis) curves in specific temperature ranges. The authors presented some experimental results in form of recorded DTA curves. The presented results show also carburizers microstructures and synthetic cast iron and made on pig iron basis structures, too. The problems given under consideration in the paper has a purpose of set up a discussion on "heredity of cast iron" – some charging materials properties transferred to cast iron. Does such an issue exist and if yes, in what extent it decides of melted alloys properties (synthetic cast iron in described example)?
PL
W artykule przedstawiono zagadnienia związane z wytwarzaniem żeliwa syntetycznego na bazie złomu stalowego i różnych rodzajów materiałów nawęglających (grafitu naturalnego i syntetycznego, koksu naftowego, antracytu, koksu odlewniczego i wegla drzewnego). Dotychczas autorzy w swoich publikacjach analizowali przede wszystkim stopień przyswojenia węgla przez ciekły metal (efektywnosc nawęglania) przy stosowaniu tych nawęglaczy i różnych metod nawęglania [1,2,3,4]. Analiza obejmowała również skład chemiczny i właśnosci najczęściej stosowanych w odlewnictwie nawęglaczy [5,6] oraz własności mechaniczne żeliwa wytopionego na bazie złomu stalowego [2,7,8,9]. Prowadzone są równiez symulacje komputerowe procesu nagrzewania i rozpuszczania cząstek nawęglaczy znajdujących się w ciekłym metalu [10,11]. W artykule przedstawiono analizę procesu krzepnięcia żeliwa syntetycznego i dla porównania żeliwa uzyskanego na bazie surówki. Zauważono, że materiały nawęglajace zmieniają przebieg krzywych Analizy Termiczno Derywacyjnej w pewnych zakresach temperatury. Autorzy przedstawili część uzyskanych wyników pomiarów w postaci zarejestrowanych krzywych ATD. Zaprezentowany materiał obejmuje również struktury materiałów nawęglających i struktury żeliwa syntetycznego oraz wytopionego na bazie surówki. Podjęta w artykule tematyka ma na celu wywołanie dyskusji o "dziedzicznosci" cech materiałów wsadowych przenoszonych do żeliwa. Czy takie zagadnienie istnieje i w jakim stopniu decyduje o własnościach wytopionych materiałów (w analizowanym przypadku żeliwa syntetycznego)?
11
Content available remote Wytwarzanie żeliwa syntetycznego w aspekcie mniejszej uciążliwości dla środowiska
Janerka K., Szajnar J., Bartocha D., Jezierski J.
Archives of Foundry Engineering
|
2010
|
Vol. 10, iss. 2 spec.
77--82
PL
W artykule przedstawiono zagadnienia produkcji żeliwa syntetycznego, wytwarzanego na bazie złomu stalowego. Wprowadzenie większej ilości złomu stalowego jako surowca wtórnego do wytopu jest niewątpliwie korzystne z punktu widzenia ochrony środowiska. Zmniejszenie udziału lub eliminacja surówki ze wsadu pozwala również na ograniczenie emisji zanieczyszczeń, które powstają przy jej produkcji. Problemem przy wytwarzaniu żeliwa syntetycznego jest uzyskanie odpowiedniej zawartości węgla w żeliwie. Dlatego w artykule przedstawiono metody nawęglania i materiały nawęglające stosowane w odlewnictwie. Analiza obejmuje również zagadnienia emisji zanieczyszczeń przy produkcji surówki, koksu wielkopiecowego i nawęglaczy.
EN
The issues of synthetic cast iron production on the steel scrap basis were presented in the paper. The steel scrap volume increase in solid charge is undoubtedly beneficial from the environmental point of view because it is a waste material. The pig iron amount decrease or even its complete elimination from the solid charge allows the pollution from its production decrease. However, when the synthetic cast iron is produced the problem of proper carbon content appears. Therefore in the paper the recarburization methods and carburizers used in foundry industry were presented. The analysis covers some issues of pollution in pig iron production process, blast-furnace coke and carburizers.
12
Content available remote The properties and structure of the carburizers
Janerka K., Jezierski J., Pawlyta M.
Archives of Foundry Engineering
|
2010
|
Vol. 10, iss. 1
67-74
EN
The results of examinations of the carburizers for foundry industry were presented in the article. The commonly used carburizers were selected for the experiments (anthracite, natural and synthetic graphite, petroleum coke of various grades), cupola coke and charcoal as well. The experiments consist of bulk and standard density, screen analysis (on the basis of it the equivalent diameter was calculated) and the microstructure of the carburizers measurements. The chemical composition and basic properties of carburizers were described too.
13
Content available remote Określenie głębokości osadzania żeber radiatora za pomocą symulacji numerycznej
Jezierski J., Kowalik M., Trzepieciński T.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
2009
|
z. 77 [269]
19-25
PL
W pracy zaprezentowano wyniki badań doświadczalnych oraz symulacji numerycznej procesu osadzania żebra radiatora. Do symulacji numerycznej użyto pakietu Msc MARC/Mentat 2005. Porównano zastosowaną technologię osadzania żeber w płycie radiatora poprzez wgłębianie stempli na krawędziach frezowanego kanału z wynikami symulacji numerycznej. Miarą jakości złącza jest powierzchnia przylegania żebra w złączu z powierzchnią rowka w płycie radiatora. W celu sprawdzenia tego parametru przecięto radiator i wykonano zgłady do zdjęć metalograficznych.
EN
In this paper the results of experimental researches and numerical simulation of the heat sink fin fixed were presented. The Msc MARC/Mentat 2005 package was used to numerical simulation. The aim of the article is to compare application mount technology of fins in heat sink plate with the results of numerical simulation. The measure of the joint qualities is the adherent surface of the fin in joint with the groove surface in heat sink plate. To verify this parameter the heat sink was cross-cutted and the metallographic specimen were performed.
14
Content available remote Powder pneumatic injection as a tool for wastes utilization
Jezierski J., Janerka K.
Archives of Materials Science and Engineering
|
2009
|
Vol. 36, nr 2
118-124
EN
Purpose: Metallurgical process generates many solid, gaseous and liquid wastes. Nowadays when environmental protection is one of the most important problems and when pollution limits are very tight as well, problem of the metallurgical wastes is a strategic one. Design/methodology/approach: In present days the metallurgical and foundry plant have to utilize their own wastes, especially these which are the most dangerous and toxic or have to render harm of its and transfer to another industry branch for further utilization. Nowadays the issue of wastes management has the place both in industrial practice and scientific field too. The presented work is a result of such an approach, where a cooperation between scientific and industrial partners gives good economical and ecological results. Findings: One of the very efficient method of utilization of furnace dusts from any melting furnace or the finest fractions of charging materials is pneumatic powder injection directly into molten metal bath.The method is pretty easy and cost effective in various conditions and its flexibility allows to implement it in almost every foundry or metallurgical plant. Research limitations/implications: Further experiments should be carried out to solve some additional problems appearing during powder injection processes to make them more efficient in various technological conditions. Practical implications: Nowadays in Poland operate more than ten industrial stands for powdered carburizers injection, installation of furnace dust injection back to the melting furnace or pneumatic inoculation of alloys (mostly in cast iron foundries). Originality/value: The paper presents a few modern solutions for recycling and utilization of furnace dusts (in cupolas and EAF’s) and pneumatic carburization with use of powdered carburizers which are very often in form of grinded graphite electrodes wastes. All of the mentioned results and method had been developed in Department of Foundry and some of the designs had been previously patented.
15
Content available remote Montaż i analiza wymiarowa zespołu tłok-korbowód w silniku spalinowym
Jezierski J., Kowalik M., Siemiątkowski Z.
Technologia i Automatyzacja Montażu
|
2008
|
nr 3
28-30
EN
The volume of combustion chamber consists of head and cylinder space. The distribution of volumes in the cylinder depends on accuracy of dimensions, determined the production process and precision of the piston - rod connecting during assembling. In this paper presents analyses tolerance of the piston - rod connecting and it assembly. The scheme of aim dimensions was elaborated for calculation height of volumes in the cylinder space.
16
Content available remote Analiza tolerancji komory spalania w cylindrze w chwili wtrysku paliwa
Jezierski J., Kowalik M., Siemiątkowski Z.
Silniki Spalinowe
|
2007
|
R. 46, nr SC1
124-130
EN
Every contemporary internal combustion engine has been created in the result of work of many generations of design engineers and the need of perfecting the engines has stimulated the development of design, essembling and calculation methods. The volume V of the cylinder combustion chamber depends on toleranced dimensions of the crankshaft system elements, and also on the injection advance angle α. The geometrical analysis of crankshaft system, presented in this article, gives a basis for examining processes in individual cylinders. It also makes it possible to evaluate thermodynamics of the whole engine. If we have the function for the analysis of combustion chamber tolerances in individual cylinders, calculate volume of tolerances Tv is easy.
17
Analiza geometryczna układów korbowych w silnikach spalinowych
Jezierski J., Kowalik M., Siemiątkowski Z.
Przegląd Mechaniczny
|
2007
|
nr 9 supl.
24-26
PL
W pracy przedstawiono analizę wymiarów tolerowanych układu korbowego w silnikach spalinowych. Na podstawie tej analizy stwierdzono, że różnice objętości komór spalania w poszczególnych cylindrach są znaczące i mają wpływ na stopień sprężania. Wyniki tej analizy mogą być wykorzystane w konstruowaniu silników spalinowych wszystkich typów oraz w badaniach nad procesami spalania.
EN
The volume of the cylinder combustion chamber depends on toleranced dimension of the crankshaft system elements and also on the injection, advance anglea. The geometrical analysis of crankshaft presented in this article give basis for examining processes individual cylinders. If also makes it possible to evaluate thermodynamics of the whole engine. The results may be useful for constructions of the different engines.
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Content available remote Properties of cast iron modifying with use of new inoculants
Jezierski J., Bartocha D.
Journal of Achievements in Materials and Manufacturing Engineering
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2007
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Vol. 22, nr 1
25-28
EN
Purpose: Modification of various alloys is a well known process for improvement its properties by changing of microstructure character. In foundry technology it is connected mostly to cast iron production where many inoculants is used for obtaining some results like grain refinement, graphite inclusions proper distribution etc. Those changes caused that produced alloy have a much better properties especially mechanical ones. Design/methodology/approach: In the paper were presented some results of the experiments made for checking quality of the two new on Polish foundry market complex inoculants. One of them is a "graphite" inoculant (about 50% C) and second is Ba-Ca combination based inoclulant. The experiments contained metallographic and quantitative metallographic analysis and wedge test bars analysis. Findings: These experiments proved a good quality of inoculants in the field of microstructure improvement (graphite size reduction) and a hard spot defects liquidation. Research limitations/implications: The next experiments are planned for checking the mechanical properties of the produced alloys. Practical implications: The inoculants being analysed are used in several Polish foundries now because of author's good results. Originality/value: There were the first experiments with these materials although the methods of investigations are not novel or original. The results have a very big importance not only from scientific but from practical point of view too.
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Content available remote Character of diphase stream force in powder injection technique
Jezierski J., Szajnar J.
Journal of Achievements in Materials and Manufacturing Engineering
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2007
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Vol. 20, nr 1-2
455-458
EN
Purpose: The method of pneumatic injection of powdered reagents into liquid alloys in some moment of melting process is known since many years. Mostly it is carrying out with use of submerged lance but in some cases that technique is difficult or impossible at all to use. This is the reason for making investigations in the filed of powders injection with non-submerged lance. Design/methodology/approach: The main experimental method was measurement and recording of time-changing diphase stream force value with use of dedicated laboratory stand. The recorded data made possible to show character of force in form of graphs and calulation of stream parameters. The last step was formulating of statistical equations joining all important parameters of the process. Findings: In the course of the work was found a diphase stream force character (especially interesting are start and end point of injection). The influence of main pneumatic parameters on the force value was analyzed too. Research limitations/implications: The future experiments will be conducted with use to Fluent 6.2 program for checking the results in computer simulations. The limitation is number of values being analyzed in experimental plan. Practical implications: The invented lance can be used for powders pneumatic injection but only for small its quantities (e.g. microalloying) because non-immersed lance should be used with low stream concentration. The usage of that lance can increase liquid alloy heat losses (not introducing carrier gas into liquid) and lance consumption (non-immersed in liquid bath). Originality/value: The problem of stream force in powder injection process is in Poland only analyzed by Department of Foundry and nobody (in author's opinion) was analyzed it with connection in powder injection. Originality of the researches is a computer recording and analyzing of the diphase stream force. The results should interest every who wants to learn more about pneumatic powder injection.
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Content available remote Relationship between stream forces and parameters of the powder injection into metal bath
Jezierski J., Szajnar J.
Archives of Materials Science and Engineering
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2007
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Vol. 28, nr 4
238-245
EN
Purpose: The pneumatic method of introduction of various powders into ladle or metallurgical furnaces is use because of its many advantages. There are no problems with use of injection lances in electric arc furnaces but in inductive furnaces or ladles, especially big ones the problem of metal flowing out of it may appear. This is the reason why the authors have maiden some experiments which results are presented in the article. Design/methodology/approach: The new lance with a flange was invented and used in powdered material injections experiments. The experimental plan was prepared that contain the most important parameters of pneumatic process. A statistical analysis was made to connect the results of the injection process with its parameters. Findings: The main conclusion is the influence of carrier gas pressure, lance inside diameter and mass concentration of diphase stream on the obtained results. The next one is that changing of the lance geometry could effectively improve the technological parameters of the process and that the new design of the injection lance is prepared properly. Research limitations/implications: The limitations of the results is that the experiments were only the "cold model" ones, without presence of molten metal. The only liquid medium used was water for experiments with stream distance measurement. The nest experiments are planned with injection of powder into laboratory induction furnaces for checking the obtained results. Practical implications: According to the authors, the new lance can be used for introducing a small quantity of the powdered material like modifiers or something like that. Originality/value: The approach to the problem of diphase stream forces and distance of stream in liquid is according to authors' knowledge a new one. The lance with flange proposed for those usage is not present in literature and is an originality too. The paper could be interesting for all interested in problems of melting processes improving.
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