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EN
The article presents the role of the ceramic layered moulds used in the investment casting method with new (certified) and recycled material from ceramic moulds (CM) after casting process. The materials that were obtained are mainly aluminosilicates and SiO2. The investigation of changes in the quality of ceramic moulds (including the recycled ceramic material) includes the chemical composition of the ceramics as recovered ceramic material, changes in the particle size of the layered covering material, the gas permeability during the pouring of liquid metal, and the creation of the porosity are presented. Than the thermophysical parameters and dimensional accuracy of the casting manufactured in the new ceramic layered shell moulds were analysed. Additionally the global cost savings and improved ecological conditions in the foundry and its surroundings was estimated.
2
Content available remote Charakterytyka osadu czynnego i ścieków z oczyszczalni ścieków w Zgierzu
PL
Przeprowadzono badania osadu czynnego i ścieków z oczyszczalni ścieków w Zgierzu. Wykazano, że analizowanym okresie osad czynny charakteryzował się dużą bioróżnorodnością. Wyznaczone wartości indeksu biotycznego osadu pozwoliły zaklasyfikować go w większości przypadków do I klasy jakości. Wyznaczone wartości indeksu objętościowego osadu pozwoliły zaklasyfikować go z kolei do osadu o bardzo dobrych właściwościach sedymentacyjnych. O braku spuchnięcia osadu świadczy też niska lub średnia liczebność bakterii nitkowatych. Ścieki dopływające do oczyszczalni charakteryzują się dużą zmiennością składu. Należą one do grupy ścieków średnio i wolno rozkładalnych (BZT5/ChZT wynosi średnio około 0,4). Analizy zmian stężenia azotu i fosforu ogólnego w ściekach pozwoliły określić skuteczność usuwania tych pierwiastków na bardzo dobrą.
EN
Conducted studies of activated sludge and wastewater from the wastewater treatment plant in Zgierz. It has been demonstrated that the analyzed period, sludge characterized by a high biodiversity. The determined value of the sludge biotic index allowed to classify it in most cases the quality class. The determined value of the sludge volume index made it possible to classify it in turn to sludge with very good sedimentation. The lack of swelling sludge also provides low or average number of filamentous bacteria. Sewage flowing into the treatment plant are highly volatile composition. They belong to a group of sewage medium and slowly degradable (BOD5/COD is an average of about 0,4). Analysis of changes in the concentration of nitrogen and phosphorus in wastewater allowed to determine the effectiveness of the removal of these biogens very good.
PL
Rozporządzenie Ministra Infrastruktury z dnia 2 września 2004 r. [1] ma już ponad 10 lat. Od tamtej pory w zakresie jakości przygotowywania specyfikacji technicznych wykonania i odbioru robót budowlanych zmieniło się bardzo dużo, jednakże z punktu widzenia producenta prefabrykatów mostowych nadal wiele zapisów musi zostać poprawionych.
EN
The Regulation of the Minister of Infrastructure of 2 September 2004 [1] has been in force for more than 10 years. Since then, much has changed in terms of the quality of the development of technical specifications for the completion and acceptance of construction works, but from the point of view of a manufacturer of bridge prefabricated elements still many provisions should be revised. The main issues are the lack of detailed adaptation of the specifications to a specific task, referring to non-binding norms or combining the so-called ‘old standards’ with harmonized standards. Sometimes, the authors of the specification expose their ignorance of the production process, certification rules, and currently available building materials. The lack of proper specificity and groundless regulations negatively affect the entire construction process by increasing the laboriousness of a contractor and a manufacturer and generating unnecessary additional costs (e.g. of additional concrete tests). It is hoped that each subsequent year of the Regulation’ duration will have a positive impact on the content of STWiOR (Specifications for Work Completion and Acceptance).
4
PL
Przedstawiono sposób oczyszczania kwasu fumarowego otrzymanego w procesie biokonwersji odpadowego glicerolu, za pomocą grzybów z gatunku Rhizopus oryzae. Głównymi problemami podczas izolacji kwasu to zróżnicowany skład brzeczki oraz jej niestabilność. Wykorzystując niską rozpuszczalność kwasu fumarowego oraz adsorpcję na sorbentach z grupy modyfikowanych krzemionek, otrzymano kwas fumarowy o czystości 97–99,9%, z wydajnością 80–95%.
EN
Fumaric acid from bioconversion of glycerol was sepd. from the wort by its acidification with HCl, adsorption of impurities on a modified SiO2 and crystn. from EtOH/H2O mixts. The sepn. yield was 80–95%, product purity 97–99.9%.
EN
The study investigated the properties of selected certified mixtures used to make wax patterns for the production of precision castings for the aerospace industry. In addition, an assessment of the recycled mixtures consisting of certified wax materials recovered during autoclaving was carried out. Hardness was tested via a proposed method based on penetration, creep related deformation, bending strength and linear contraction. The hardness was studied on laboratory specimens and patterns made with the use of injection molding equipment. For these patterns, linear contraction was estimated at variable pressure and for different temperature injection parameters. Deformations connected with creep and resistance were evaluated on cylindrical specimens. Differences in creep resistance in relation to the hardness were observed depending on the type of pattern mixtures. Recycled mixture has a greater resistance and smaller linear contraction than certified mixtures used for making sprue, raisers and other parts of filler system.
PL
W pracy zbadano właściwości wybranych mieszanek modelowych atestowanych stosowanych do wykonywania modeli wytapianych przy produkcji odlewów precyzyjnych dla przemysłu lotniczego. Dodatkowo badaniom poddano masę z recyklingu składająca się z odzyskanych w procesie autoklawizacji mieszanek woskowych atestowanych. Zaproponowano badania twardości metodą penetracji, odkształceń związanych z pełzaniem, wytrzymałości na zginanie oraz skurczu liniowego. Twardość badano na próbkach laboratoryjnych oraz na modelach wykonanych na wtryskarce przemysłowej. Dla tych modeli oszacowano skurcz liniowy przy zmiennych parametrach ciśnienia i temperatury wytrysku. Odkształcenia związane z pełzaniem i wytrzymałość badano na modelach walcowych. Obserwuje się różnice odporności na pełzanie w odniesieniu do twardości w zależności od rodzaju mieszanki modelowej. Masa z recyklingu ma większą odporność i mniejszy skurcz liniowy niż masa atestowana stosowana na układy wlewowe.
EN
Results of analysis presented in this paper were based on analysis of casts made especially for this research purpose and related to actual cast – industrial. The evaluation of the dimensional accuracy of casts was made in relation to the pressure of the liquid metal with consideration of the ceramic mould temperature. Ceramic moulds used in these analyses were made from crystalline quartz with an aqueous colloidal silica binder containing polymers (KK), and ethyl silicate (KE).
PL
Przed wybudowaniem oczyszczalni, ścieki komunalne i przemysłowe z terenu miasta Zgierza odprowadzane były bezpośrednio do rzeki Bzury i w znaczący sposób wpływały na zanieczyszczenie wód Wisły i Bałtyku. Stopień zagrożenia ekologicznego był na tyle poważny, że Zgierz oraz Zakłady Produkcji Barwników „Boruta” zostały uznane przez Konferencję Krajów Nadbałtyckich (Helsinki 93) za jedno z najpoważniejszych źródeł zanieczyszczeń Bałtyku, tzw. „hot spots”.
EN
This research presents comprehensive assessment of the precision castings quality made in the Replicast CS process. The evaluation was made based on quality of the surface layer, shape errors and the accuracy of the linear dimensions. Studies were carried out on the modern equipment, among other things a Zeiss Calypso measuring machine and profilometer were used. Obtained results allowed comparing lost wax process models and Replicast CS process.
EN
While analyzing shape accuracy of ferroalloy precision castings in terms of ceramic moulds physical anisotropy, low-alloy steel castings ("cover") and cast iron ("plate") were included. The basic parameters in addition to the product linear shape accuracy are flatness deviations, especially due to the expanded flat surface which is cast plate. For mentioned castings surface micro-geometry analysis was also carried, favoring surface load capacity tp50 for Rmax = 50%. Surface load capacity tp50 obtained for the cast cover was compared with machined product, and casting plate surface was compared with wear part of the conveyor belt. The results were referred to anisotropy of ceramic moulds physical properties, which was evaluated by studying ceramic moulds samples in computer tomography equipment Metrotom 800.
EN
Presentation of various disposable patterns variants in order to obtain accuracy in investment casting with particular focus on hard waxes. The analysis covered disposable patterns based on hard waxes, paraffin-stearic blends with addition of polyethylene wax and high density polystyrene.
EN
The article presents an analysis of the applicability of the Replicast CS process as an alternative to the investment casting process, considered in terms of the dimensional accuracy of castings. Ceramic shell moulds were based on the Ekosil binder and a wide range of ceramic materials, such as crystalline quartz, fused silica, aluminosilicates and zirconium silicate. The linear dimensions were measured with a Zeiss UMC 550 machine that allowed reducing to minimum the measurement uncertainty.
EN
The article compares the energy intensity of ductile iron precision castings manufacturing process with the 0.5% C steel locking mechanism element made with forging die. During the analysis variations of manufacturing processes were taken into account and also additional comparison of energy intensity connected with the machining of the steel blank was made. The influence of the manufacturing processes on the environment was evaluated.
PL
W artykule porównano energochłonność wytwarzania odlewu precyzyjnego wykonanego z żeliwa sferoidalnego z odkuwką matrycową dla widełek mechanizmu blokującego ze staliwa 0,5 % C. Uwzględniono różne warianty procesów wytwarzania oraz porównano je z energochłonnością wyrobu otrzymanego z półfabrykatu hutniczego otrzymanego metodą obróbki skrawaniem. Oceniono wpływ procesów wytwarzania na środowisko.
EN
The paper analyzes the structure of the ceramic mould, which include discussion about its structure creation. The results of research relate to the strength of the ceramic mould and its thermophysical properties. Structural anisotropy was found and its influence on the mould surface morphology depending on its position with respect to the sprue in the assembly set. The paper also presents evaluation of microgeometry of patterns, ceramic mould and casts produced in a joint production process. Last part includes the results of the fractal dimension measurements of ceramic mould cross-sections. The analysis was based on the mould porosity. For the analyzed structures the percentage of pores and linear fractal dimension was determined, using the line counting dimension method (LCD), which is a modification of box counting dimension method (BCD).
EN
A complex activated sludge model implemented in BioWin software has been implemented to assure its predictability and improve the effectiveness of biological wastewater treatment in the full-scale plant in Poland. The influence of temperature and sludge retention time (SRT) on the quality of the effluent was also studied. The calibration was successfully performed according to the Good Modelling Practice Unified (GMP) protocol. Five parameters at a steady state and ten under dynamic conditions were calibrated. It occurred that in the studied wastewater treatment plant SRT should be kept at the low level sufficient to sustain nitrification.
EN
In the opinion of metrologists, technologists and trybologists surface microgeometry is one of the most important factors affecting the performance characteristics of the machine parts (resistance to wear, sliding and lubricating properties, durability and tightness of joints, fatigue strength, corrosion resistance, etc.). The analysis was made of the ceramic mould elements structure influence on the microgeometry of steel castings surface and their dimensional accuracy. To assess the structure of the ceramic mould previous studies made with usage of computer tomography where used, those studies highlight the ceramic mould structure anisotropy and its properties.
EN
Shape accuracy analysis of aluminum alloy castings was made in function of ceramic mould properties. Taken it to account was anisotropy of those properties, including influence of ceramic mould properties on the porosity of castings. Ceramic moulds strains, which occur in sintering phase, were evaluated with taking into account the design and production process.
EN
This research paper will present and analyze selected testing of wax patterns - bending strength test, test of resistance to creep and penetration hardness test. Evaluation of these tests will be carried out in terms of the shape accuracy of wax patterns. Additionally, statistical evaluation will be carried out of relationships between selected parameters of previously mentioned tests. Standard bending tests will be statistically evaluated and compared with two other test methods conducted on corresponding patterns. Particular attention will be given to creep resistance, which is a very useful test method for assessing changes in the shape of complex patterns in the function of time and temperature. At the same time an evaluation of hardness tests of wax patterns will be carried out with usage of appropriate samples or by direct examination of the production patterns.
EN
The paper presents the effect of suction pressure exerted on the liquid AlSi alloy when it is introduced into a ceramic mould made in the investment process and the results compared with data obtained on gravity poured castings. The study used special pattern sets and ceramic moulds made with the alternately applied soluble silicate binder and ethyl silicate. Additionally, self-supported moulds based entirely on the Ekosil binder were used. In the analysis of castings, the following parameters were examined: a linear dimensional accuracy, the state of surface microgeometry and the possibility of metal penetration into a complex ceramic mould, allowing also for the presence of capillary phenomena. In the process of casting with back-pressure, the pressure values of 500 hPa, 600 hPa and 700 hPa were applied in the chamber where the ceramic mould was located, with the temperature of the said mould kept at a level of 150±10ºC.
PL
Przedstawiono analizę możliwości wykorzystania w odlewnictwie gipsu odpadowego (syntetycznego) uzyskiwanego w procesie odsiarczania spalin w energetyce. Energetyka jest jednym z największych producentem SO2. W celu ochrony środowiska i obniżenia ilości zanieczyszczeń stosuje się odsiarczanie spalin metodą mokrą. W wyniku tego procesu powstaje gips odpadowy, który może być stosowany w praktyce. Przeprowadzono badania, w wyniku których określono sposoby przygotowania tego gipsu do wykonywania form odlewniczych. W artykule oceniono skład chemiczny, wytrzymałość i przepuszczalność form z uzyskanego gipsu syntetycznego, porównano je z właściwościami gipsu odlewniczego GoldStar XL oraz właściwościami form ceramicznych. Zbadano strukturę gipsów, wykonano badania na derywatografie oraz określono energochłonność procesu wytwarzania gipsu odpadowego w instalacji mokrego odsiarczania. Po analizie zebranych danych można stwierdzić, że gips syntetyczny może być używany jako materiał na formy odlewnicze. Nie obserwuje się znaczącego spadku najważniejszych właściwości, a z drugiej strony istnieje wiele dodatkowych korzyści, w tym niskie zużycie energii, obniżenie kosztów i zmniejszenie wpływu na środowisko.
EN
This article investigates possible use of waste gypsum (synthetic), recovered via flue-gas desulfurization from coal-fired electric power plants, in foundries. Energy sector, which in Eastern Europe is mostly composed from coal-fired electric power plants, is one of the largest producers of sulfur dioxide (SO2). In order to protect the environment and reduce the amount of pollution flue-gas desulfurization (FGD) is used to remove SO2 from exhaust flue gases of fossil-fuel power plants. As a result of this process gypsum waste is produced that can be used in practical applications. Strength and permeability tests have been made and also in-depth analysis of energy consumption of production process to investigate ways of preparing the synthetic gypsum for casting moulds application. This paper also assesses the chemical composition, strength and permeability of moulds made with synthetic gypsum, in comparison with moulds made with traditional GoldStar XL gypsum and with ceramic molds. Moreover examination of structure of synthetic gypsum, the investigations on derivatograph and calculations of energy consumption during production process of synthetic gypsum in wet flue-gas desulfurization were made.
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