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EN
The thermal reclamation process as a utilisation method of spent moulding and core sands is more costly than other reclamation methods, but in the majority of cases it simultaneously provides the best cleaning of mineral matrices from organic binders. Thus, the application of the thermal analysis methods (TG-DSC), by determining the temperature range within which a degradation followed by a destruction of bounded organic binders in moulding sands, can contribute to the optimisation of the thermal reclamation process and to the limiting its realisation costs. The thermal analysis results of furan resin, one of the most often applied binder in foundry practice, are presented in the hereby paper. The influence of the heating rate of the sample - placed in the thermal analyser - on its degradation and destruction process under oxygen-free (argon) and oxygen (air) conditions, were compared. The recorded TG and DSC curves were used for analysing these processes as the temperature as well as the time function. The obtained results were analysed with regard to determining the required temperature of the thermal reclamation of the investigated organic binder. The usefulness of the developed methodology was found out, however under conditions of meeting several essential requirements concerning the repeatability of performed analyses.
EN
The results of investigations concerning the influence of the applied sand matrix (fresh sand, reclaim) on the properties of moulding sands used for production of large dimensional castings (ingot moulds, ladles), are presented in the hereby paper. The performed investigations were aimed at determining the influence of various reclamation methods of spent moulding sands on the quality of the obtained reclaimed material. Moulding sands were prepared on the fresh quartz matrix as well as on sand matrices obtained after various reclamation methods. The selected moulding sand parameters were tested (strength, permeability, grindability, ignition losses, pH reactions). It can be stated, on the basis of the performed investigations, that the kind of the applied moulding sand matrix is of an essential meaning from the point of view of creating conditions minimising formation of large amounts of gases and their directional migration in a casting mould.
EN
In this article, there were presented results of research on influence of reclamation process on the ecological quality of reclaim sand with furan resin used in nonferrous foundry. The quality of reclaimed sand is mainly define by two group of chemical substances from elution of reclaimed sand: Dissolves Organic Carbon (DOC) and Total Dissolves Solids (TDS). Reclaimed sand used in test was prepared in experimental thermal reclaimer and mechanical vibration reclaimer REGMAS installed in Faculty of Foundry Engineering at University of Science and Technology in Krakow. The reference point is molding sand shaking out and crumble in jaw crusher. Test of elution was made in acreditation laboratory in Center For Research and Environmental Control in Katowice up to the standard with Dissolves Organic Carbon (DOC) - PN-EN 1484:1999; Total Dissolves Solids (TDS) - PN-EN 15216:2010. The standard for elution test is PN-EN 12457- 4:2006. Except that we were made loss of ignition test, to check how many resin was rest on sand grains.
EN
The results of investigations of thermal reclamation of spent moulding sands originating from an aluminum alloy foundry plant are presented in this paper. Spent sands were crushed by using two methods. Mechanical fragmentation of spent sand chunks was realized in the vibratory reclaimer REGMAS. The crushing process in the mechanical device was performed either with or without additional crushing-grinding elements. The reclaimed material obtained in this way was subjected to thermal reclamations at two different temperatures. It was found that a significant binder gathering on grain surfaces favors its spontaneous burning, even in the case when a temperature lower than required for the efficient thermal reclamation of furan binders is applied in the thermal reclaimer. The burning process, initiated by gas burners in the reclaimer chamber, generates favorable conditions for self-burning (at a determined amount of organic binders on grain surfaces). This process is spontaneously sustained and decreases the demand for gas. However, due to the significant amount of binder, this process is longer than in the case of reclaiming moulding sand prepared with fresh components.
EN
In this article, there were presented the results of research on combined mechanical and thermal regeneration of waste moulding sand with furfuryl resin originated from one of national foundries manufacturing aluminium alloys castings. Attempts of mechanical reclamation were led on the REGMAS reclaimer enabling to realize preliminary and primary reclamation with use of two modes of mechanical interactions on waste moulding sand. In the first attempt the reclaimer worked without any additional regenerating elements, and as the second solution, the reclaimer operated with additional crushing and abrasive elements to increase the result of primary reclamation. Thermal reclamation was led in the prototypic thermal reclaimer, enabling to fully control the process of grain matrix recovery. As a result of completed investigations the small efficiency of mechanical reclamation was determined. However, use of combined regeneration allowed for obtaining grain matrix of high purity. Thermal regeneration was conducted in prototypic thermal reclaimer. Evaluation of reclaim (reclaimed material) quality was carried out in the way of iginition losses and grain-size analysis, surface morphology and also by executing of strength testing of moulding sand prepared on obtained grain matrix for the particular reclamation operations.
EN
The results of investigations of spent moulding sands taken from the mould at various distances from the surface of the produced casting, are presented in the paper. The casting mould was made with an application of the cooling system of the metal core in order to increase the cooling rate of the ladle casting. As temperature measurements in the mould indicated the heat flow from the metal did not create conditions for the complete burning of a moulding sand. The analysis was performed to find out changes of spent moulding sands caused by degradation and destruction processes of organic binders. Conditions occurring in the casting mould were discussed on the bases of testing: ignition losses, dusts contents, pH reactions and the surface morphology of the moulding sand samples. Factors limiting the effective mould degassing were pointed out. Operations, possible for realisation, which can limit the reasons of a periodical occurrence of increased amounts of casting defects due to changing gas evolution rates being the result of the technological process, were also indicated.
EN
The results of investigations of spent moulding sands taken from the mould in which the metal core cooling system - to increase the cooling rate of the ladle casting - was applied, are presented in the hereby paper. The changes of the spent moulding sand at the casting external side being the result of degradation and destruction processes of organic binder, were analysed in this publication. Since the reclaimed material, obtained as a result of the mechanical reclamation of spent sands of the same type, is used as a grain matrix of the moulding sand, the amount of a binder left from the previous technological cycle is essential for the sound castings production. On the bases of investigations of the thermal analysis, ignition losses, dusts contents and pH values of the samples taken from the spent sand the conditions under which the process of gases displacing in the casting mould was realised as well as factors limiting the efficient mould degassing - were considered in this study. The possible reason of a periodical occurrence of an increased number of casting defects due to changing gas volume emission, being the reason of the realised technological process, was indicated.
8
EN
The thermal analysis results of the selected group of binders and the thermal reclamation of one spent moulding sand with organic binder, are presented in the paper. The reclaiming process of the quartz matrix was performed on the basis of the own method of selecting the reclamation temperature. Taking into account thermogravimetric (TG) analysis results of the binder, the temperature range - required for performing the efficient reclamation of spent moulding sand containing this binder - was indicated. In order to confirm the assumptions, the thermal reclamation operations were carried out at a temperature similar to the determined on the TG basis and - for comparisons - at lower and higher temperatures. During the reclamation operation the reclaim samples were taken for the loss on ignition testing, aimed at the determination of the process efficiency. Temperature in the reclaimer chamber and gas consumptions were also recorded. On the bases of the thermal analyses, loss on ignition, gas consumption and temperatures of the reclaimed moulding sand bed the recommendations for the realisation of the thermal reclamation were given. These recommendations will allow a better, than currently available, process control in an aspect of decreasing the pyrolysis effect and limiting the emission of substances harmful for the environment.
PL
W publikacji przedstawiono wyniki badań analizy termicznej wybranej grupy spoiw i regeneracji termicznej jednej zużytej masy ze spoiwem organicznym. Proces odzysku osnowy kwarcowej przeprowadzono w oparciu o sformułowany własny sposób doboru temperatury regeneracji. Na podstawie zrealizowanych badań analizy termograwimetrycznej (TG) spoiwa wskazano zakres temperatury, wymaganej do przeprowadzenia skutecznej regeneracji termicznej masy zużytej z jego udziałem. W celu potwierdzania przyjętych założeń wykonano zabiegi regeneracji termicznej w temperaturze zbliżonej do wyznaczonej na podstawie TG oraz dla porównania w niższej i wyższej temperaturze. W trakcie trwania zabiegu regeneracji pobierano próbki regeneratu do badania strat prażenia, w celu określenia skuteczności działania procesu. Podczas regeneracji rejestrowano temperaturę w komorze regeneratora oraz zużycie gazu. Na podstawie zestawienia analiz termicznych, strat prażenia, zużycia gazu oraz temperatury złoża regenerowanej masy podano wytyczne do realizacji regeneracji termicznej, w warunkach pełniejszej niż dotychczas kontroli procesu w aspekcie zmniejszenia zjawiska pirolizy i emisji związków szkodliwych do otoczenia.
PL
W publikacji przedstawiono wyniki badań, których celem było określenie wpływu wybranych parametrów pracy doświadczalnego regeneratora termicznego na skuteczność jego działania. Efektywność pracy urządzenia przeprowadzono analizując wpływ: temperatury pracy, temperatury powietrza fluidyzacji, stopnia nagrzania komory regeneratora termicznego oraz sposobu mieszania złoża. Badania wykonano na stanowisku doświadczalnym zainstalowanym w hali maszyn odlewniczych Wydziału Odlewnictwa AGH. Ocenę wpływu poszczególnych parametrów dokonano na podstawie badania strat prażenia pozyskanego regeneratu. Wykonano także badania wytrzymałości na zginanie kształtek z masy rdzeniowej w uniwersalnej maszynie do wykonywania próbek testowych i małych rdzeni w technologii hot-box (LUT).
EN
The publication presents the results of a study aimed at determining the effect of selected parameters of the experimental thermal regenerator on its effectiveness. Efficiency of operation was carried out by analysing the effect of: operating temperature, fluidizing air temperature, heat degree in regenerator chamber and method of mixing fluidized bed. The research was conducted at the experimental station installed in the machine hall of the Faculty of Foundry Engineering AGH UST. Assessment of the impact of individual parameters was based on loss on ignition of achieved reclaims. Studies of bending strength of the core sands prepared with reclaim in hot-box technology are also presented.
EN
The publication presents the results of thermal examinations conducted to determine of the thermal degradation of the polymeric binder (BioCo2) in the moulding sand. Thermal degradation process was identified using literature data on the decomposition of the polymers materials and based on own research (TG-DSC, MIR-DRS). In order to determine the degradation temperature and the thermal effects of transformations occurring when the moulding sand were heated, two methods were used: the thermogravimetry (TG) and differential scanning calorimetry (DSC). In this paper the spectroscopic studies (MIR-DRS) were also performed in order to elucidate structural changes occurring in the BioCo2 binder under an influence of heating. Temperature spectra were made for the moulding sand sample in the temperature range: 25-400oC (operation range of the temperature attachment of the IR spectrometer). The heating process was performed in a continuous way, and the spectra were recorded at a given temperature. On the bases of the performed thermal analysis of the moulding sand the temperature range required for the efficient thermal reclamation was indicated.
EN
The results of the thermal reclamation investigations of the spent moulding sand with the Ekotec 35 binder, are presented in the paper. The reclamation process of the quartz matrix was carried out on the basis of the author's own method of selecting the reclamation temperature. On the bases of the performed thermo-gravimetric analysis of the binder the temperature range required for the efficient thermal reclamation was indicated. In order to confirm the assumption the thermal reclamations were performed at a temperature determined by the TG and - for comparisons - at a lower and higher temperature. During the reclamation process samples of the reclaim were taken for testing ignition losses in order to determine the process efficiency. The correctness of the assumed method of selecting the temperature range of the thermal reclamation of spent moulding sand with the Ekotec 35 binder was confirmed.
PL
Celem przeprowadzonych badań było określenie możliwości regeneracji mieszaniny zużytych mas rdzeniowych pochodzących z procesów warm-box i technologii piasków otaczanych (Croninga), z dodatkiem zużytej masy klasycznej z bentonitem. Ze względu na rodzaj badanych mas zużytych poddano je regeneracji kombinowanej termiczno-mechanicznej, z wykorzystaniem stanowisk doświadczalnych zainstalowanych w Hali Maszyn Odlewniczych Wydziału Odlewnictwa AGH. Efekt regeneracji określany był poprzez badanie straty prażenia uzyskanego regeneratu, morfologii powierzchni ziaren oraz wytrzymałości na zginanie próbek mas formierskich, wykonanych z masy na osnowie regeneratu zagęszczanej metodą nadmuchiwania na stanowisku doświadczalnym PS-1 w technologii warm-box, po czasie odstawania próbek wynoszącym 1h.
EN
The aim of the study was to determine the possibility of reclamation of used core sands mixtures originated from the processes of warm-box and croning with the addition of the classical sand with bentonite. Due to the nature of studied sands combined thermal and mechanical regeneration was performed, with the use of experimental stands installed at the Foundry Engineering Faculty of AGH University of Science and Technology. The effects of reclamatiom process were determined by studying the loss on ignition of the reclaim, as well as the particle surface morphology and a bending strength of samples prepared according to warm-box core molding sands technology, performed using the laboratory PS-1 blower.
PL
Podstawowe znaczenie dla charakterystyki polimeru ma określenie takich jego parametrów, jak: temperatura destrukcji, zeszklenia, topnienia, określonych ubytków masy czy przemian polimorfi cznych, które to decydują często o jakości produktu i jego zastosowaniu. Badaniom analizy termicznej (TG-DSC) poddano próbkę spoiwa polimerowego. Badania te miały na celu określenie zmian, jakie mogą zachodzić w masie odlewniczej w warunkach kontaktu z ciekłym metalem.
EN
To characterise a polymer, it is of fundamental importance to determine its parameters, like the temperatures of destruction, vitrification, melting point, specific mass losses or polymorphic transformations, which frequently determine the quality of the product and its applications. Thermal analyses (TG-DSC) of the sample of a polymer binder were conducted. These examinations were also aimed at identifying the changes that can take place in the casting paste when it comes into contact with liquid metal.
PL
Zagospodarowanie zużytych mas formierskich i rdzeniowych wytwarzanych w przemyśle odlewniczym jest aktualnie coraz większym problemem, głównie ze względów ekologicznych. Dlatego celowe wydaje się poszukiwanie metod zmierzających do minimalizacji nakładów na jego realizację.
EN
Management of spent moulding and core sands produced in the foundry industry becomes currently more and more difficult problem, mainly due to ecological reasons. Therefore searching for methods leading to the minimisation of expenditures for its realisation, seems appropriate.
EN
For the practical and functional reasons the investigation of the thermal decomposition process is of an essential meaning in relation to the thermal stabilisation of materials and obtaining for them the desired thermal properties. On the other side, thermal tests are carried out in order to identify degradation mechanisms, which is important in the environment protection context, including materials reuse. The cycle of investigations in which thermal TG-DTA methods were applied as supplementary ones for the works on the optimisation of the thermal reclamation process is presented in the hereby paper. The thermal reclamation process as a utilisation method of spent moulding and core sands is more costly than other reclamation methods, but in the majority of cases it simultaneously provides the best cleaning of mineral matrices from organic binders. Thus, the application of the thermal analysis methods (TG-DTA), by determining the temperature range within which a degradation followed by a destruction of bounded organic binders in moulding sands, can contribute to the optimisation of the thermal reclamation process and to the limiting its realisation costs.
PL
Ze względów praktycznych i użytkowych zbadanie procesu degradacji termicznej ma podstawowe znaczenie w odniesieniu do problemu procesu stabilizowania termicznego materiałów i otrzymywania dla nich pożądanych właściwości termicznych. Z drugiej strony badania termiczne prowadzi się w celu rozpoznania mechanizmów ich degradacji, co ma też znaczenie w kontekście ochrony środowiska, w tym ich powtórnego wykorzystania materiałowego. W publikacji przedstawiono cykl badań, w którym zastosowano metody termiczne (TG-DTA) w uzupełnieniu do prowadzonych prac nad optymalizacją procesu regeneracji termicznej. Proces regeneracji termicznej jako sposób utylizacji zużytych mas formierskich i rdzeniowych w stosunku do innych rodzajów regeneracji zużytych mas jest bardziej kosztowny, ale jednocześnie dający w większości przypadków najlepsze oczyszczenie osnowy mineralnej ze spoiw organicznych. Stąd zastosowanie metod analizy termicznej (TG-DTA), poprzez określenie zakresu temperatury, w którym dochodzi do degradacji, a następnie destrukcji związanych spoiw organicznych w masie, może przyczynić się do optymalizacji procesu regeneracji termicznej i zmniejszenia kosztów jego realizacji.
EN
The results of the thermal reclamation investigations of the spent moulding sand with the polymer BioCo2 binder, are presented in the paper. The reclamation process of the quartz matrix was carried out on the basis of the author's own method of selecting the reclamation temperature. On the bases of the performed thermo-gravimetric analysis of the binder the temperature range required for the efficient thermal reclamation was indicated. In order to confirm the assumption the thermal reclamations were performed at a temperature determined by the TG and - for comparisons - at a lower and higher temperature. During the reclamation process samples of the reclaim were taken for testing ignition losses in order to determine the process efficiency. The correctness of the assumed method of selecting the temperature range of the thermal reclamation of spent moulding sand with the polymer BioCo2 binder was confirmed.
PL
W artykule przedstawiono wyniki badań regeneracji zużytej masy rdzeniowej pochodzącej z procesu cold-box. Badaniom poddano masy zużyte składające się głównie z niedopuszczonych do produkcji uszkodzonych rdzeni. Rdzenie te, nie podlegały destrukcji termicznej w formie, stąd ich dalsza obróbka mająca na celu odzyskanie osnowy kwarcowej wymagała zastosowania specjalnych technik pozwalających na efektywne oczyszczenie ziaren piasku z otoczki zużytego materiału wiążącego. W tym celu stosowano kombinację regeneracji mechanicznej o narastającym czasie obróbki w połączeniu z regeneracją termiczną. Odzyskane regeneraty były następnie poddane badaniom mającym na celu określenie ich stopnia oczyszczenia. Spośród znanych metod oceny instrumentalnej regeneratu w badaniach określano wartości: straty prażenia, odczynu pH, składu ziarnowego (analiza sitowa). Jako sprawdzian jakości regeneratu zastosowano badanie wytrzymałości na zginanie mas rdzeniowych sporządzonych na zregenerowanej osnowie.
EN
The paper presents the results of the regeneration of the spent core sand from cold-box process. The study concerned the reclamation treatment of foundry cores which was not allowed to production process due to their not permissible defects. These cores as a compacted core sand which not been subjected to thermal destruction in the mould had fully preserved their previous characteristic eg. strength, shape and volume hardening. In this case regeneration aimed at recovering the quartz matrix requires the use of special techniques to clean the grains of sand from the used binding material. To solve this problem the special preparing of used cores were applied ensuring the proper grain size composition subjected to dedusting prior to reclamation treatment. Both the mechanical and mechanical-thermal methods of regeneration were tested during research. The recovered the quartz matrix was evalutated by following of well known instrumental tests: loss on ignition, pH value, sieve analysis, dust content. Furthermore reclaim was used to prepare core sand and to perform test bending strength tests.
EN
The investigation results of the thermal reclamation of spent core sands made in the hot-box technology are presented in the paper. Energy-consumption of the process was tested by recording the media consumption during the thermal treatment of the determined intensity. Gas demands in dependence of the reclamation process temperatures were compared. During the reclamation process the reclaimed material samples were taken to test ignition losses in order to determine the efficiency of the realised procedures. The influence of the reclamation temperature on the quality of the obtained reclaimed material was checked. The effects of the realised reclamation procedures of the same moulding sand at various temperatures were also assessed on the grounds of strength of moulding sands prepared on the bases of the obtained reclaims. It was found that the process energy-consumption can depend on the expected core sand parameters. The attention was drawn to the fact, that bearing of costs for the thermal reclamation - very often - does not correspond directly with the obtained effects. The thermal reclamation performed very intensively, which corresponds with the costs increase, is not always needed for obtaining the core sand of parameters comparable with the sand made of fresh components.
EN
The investigation results of the influence of the selected parameters of the thermal reclaimer operations on the temperature changes in the combustion chamber and the process energy consumption, are presented in the hereby paper. The analysis of the heat treatment was performed with the application of a fresh foundry sand, since it was assumed that the dominating energy part was used for the grain matrix heating and due to that, the energy used for burning small amounts of organic binder remained on sand grains could be omitted. Thermal treatment processes performed under various conditions were analysed from the point of view of a gas consumption and temperatures obtained in the experimental reclaimer. The recorded data allowed to point out the parameters having essential influence on the process of the quartz matrix heating in the combustion chamber as a gas consumption function.
PL
Proces regeneracji termicznej jest jednym ze sposobów utylizacji zużytych mas formierskich i rdzeniowych. W stosunku do innych rodzajów regeneracji zużytych mas jest to zabieg kosztowny, ale jednocześnie dający w większości przypadków najlepsze oczyszczenie osnowy (piasku kwarcowego) ze spoiw organicznych. Zastosowanie analizy termicznej w celu określenia zakresu temperatury, w którym dochodzi do degradacji, a następnie destrukcji związanych spoiw organicznych, może przyczynić się do optymalizacji procesu i zmniejszenia kosztów jego realizacji.
EN
The thermal reclamation process is one of the utilisation ways of spent moulding and core sands. This procedure, in relation to other kinds of reclamation, is rather costly, however simultaneously providing – in a majority of cases – the best purification of the matrix (high-silica sand) from organic binding materials. The application of the thermal analysis in order to determine the temperature range, within which a degradation followed by a decomposition of organic binders occurs, can contribute to the process optimisation and decreasing costs of its realisation.
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