Wyniki wyszukiwania - BazTech

1

Określenie możliwości intensyfikacji produkcji miedzi katodowej w HM Głogów II

Kopyto Dorota, Baranek Wit, Piątek Jędrzej, Leszczyńska-Sejda Katarzyna, Wierzbicki Łukasz J., Cwolek Beata, Krawiec Grzegorz

Rudy i Metale Nieżelazne Recykling

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2019

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R. 64, nr 4

3--11

PL

W artykule przedstawiono wyniki badań procesu elektrorafinacji miedzi z zastosowaniem podwyższonej gęstości prądu i przy zmniejszonym rozstawie elektrod. Badania obejmowały również ustalenie optymalnych dawek stosowanych inhibitorów organicznych, a także określenie natężenia i kierunku przepływu elektrolitu przez wanny elektrolityczne, które umożliwiłyby produkcję katod miedzianych o jakości zgodnej z założonymi normami.

EN

Research results of copper electrorefining process at increased current density and reduced electrodes spacing are presented in this article. Research work included also establishment of other process parameters, i.e. organic inhibitors dosage, current intensity and flow direction of electrolyte through electrolysers, which will allow copper cathodes production of required quality according to standards.

2

Membrane gas separation module with pulsed retentate for low-permeable component recovery

Battalov Stanislav V., Trubyanov Maxim M., Puzanov Egor S., Sazanova Tatyana S., Drozdov Pavel N, Vorotyntsev Ilya V.

Chemical and Process Engineering

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2019

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Vol. 40, nr 1

57–-65

EN

The paper presents the experimentalstudy of a novel unsteady-statemembrane gas separation approachfor recovery of a slow-permeant component in the membrane module with periodical retentate with-drawals. The case study consisted in the separation of binary test mixtures based on the fast-permeantmain component (N2O, C2H2) and the slow-permeant impurity (1% vol. of N2)using a radial counter-current membrane module. The novel semi-batch withdrawal technique was shown to intensify theseparation process and provide up to 40% increase in separation efficiency compared to a steady-stateoperation of the same productivity.

3

Review on hierarchically microstructured monolithic reactors for high yield continuous production of fine chemicals

Mrowiec-Białoń J., Ciemięga A., Maresz K., Szymańska K., Pudło W., Jarzębski A. B.

Chemical and Process Engineering

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2018

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Vol. 39, nr 4

367–-375

EN

Preparation and properties of hierarchically structured porous silica monoliths have been discussed from the viewpoint of their application as continuous microreactors for liquid-phase synthesis of fine chemical in multi kilogram scales. The results of recent topical papers published by two research teams of Institute of Chemical Engineering Polish Academy of Sciences (ICE) and Department of Chemical Engineering and Process Design, Chemical Faculty, Silesian University of Technology (SUT) have been analyzed to specify the governing traits of microreactors. It was concluded that even enhancement factor of 100 in activity, seen in enzyme catalyzed reactions, can be explained by a proportional reduction of its physical constraints, i.e. huge enhancement of external mass transfer and micromixing. It is induced by very chaotic flows of liquid in tens of thousands of waving connected channels of ca. 25–50 mm in diameter, present in the skeleton. The scale of enhancement in the caseof less active catalysts was smaller, but still large enough to consider the most practical applications.

4

Evaluation of the absorbing pervaporation technique for ammonia recovery after the haber process

Atlaskin A., Petukhov A. N., Yanbikov N. R., Salnikova M.E., Sergeeva M. S., Vorotyntsev V. M., Vorotyntsev I. V.

Chemical and Process Engineering

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2018

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Vol. 39, nr 3

323–-333

EN

A novel absorbing pervaporation hybrid technique has been evaluated experimentally for the recovery of ammonia from the gas mixture in a recycle loop of synthesis plants. This process of hybridization brings together the combination of energy-efficient membrane gas separation based on poly(dimethylsiloxane) poly(diphenylsilsesquioxane) with a high selective sorption technique where a water solution with polyethylene glycol 400 (PEG-400) was used as the liquid absorbent. Process efficiency was studied using the pure and mixed gases. The influence of PEG-400 content in aqueous solutions on process selectivity and separation efficiency was studied. The ammonia recovery efficiency evaluation of an absorbing pervaporation technique was performed and compared with the conventional membrane gas separation. It was shown that the absorbing pervaporation technique outperforms the conventional membrane method in the whole range of productivity, producing the ammonia with a purity of 99.93 vol.% using the PEG 80 wt.% solution. The proposed method may be considered as an attractive solution in the optimization of the Haber process.

5

Intensyfikacja procesu spiekania tworzyw ceramicznych – przegląd

Dziubak C.

Prace Instytutu Ceramiki i Materiałów Budowlanych

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2017

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R. 10, nr 30

7--56

PL

Dążenie do wytwarzania w procesie spiekania wysokojakościowych tworzyw i wyrobów ceramicznych w relatywnie niskiej temperaturze wymusza stosowanie dodatków aktywizujących. Małe ilości tych nieorganicznych dodatków nazywanych: aktywatorami, mineralizatorami, modyfikatorami mają wpływ na przebieg procesu spiekania, niekiedy powodują obniżenie temperatury, a poprzez modyfikację lub kształtowanie mikrostruktury decydują o parametrach jakościowych tworzywa. W procesie technologicznym występują również dodatki organiczne (spoiwa, plastyfikatory) mające niebezpośredni wpływ na efektywność spiekania. Przedstawione przykłady różnych dodatków aktywizujących wskazują, że jeden i ten sam związek może pełnić różne funkcje w zależności od składu chemicznego spiekanego zestawu surowcowego, zastosowanej temperatury i rodzaju procesu (konsolidacja, spiekanie reakcyjne, swobodne, ciśnieniowe). Świadczy to, że zastosowany w artykule podział na: aktywatory, mineralizatory i modyfikatory nie jest jednoznaczny i dotyczy jedynie pewnej grupy związków. Poza przytoczonymi, sprawdzonymi przykładami, dodatki aktywizujące należy dobierać ilościowo i jakościowo odpowiednio do rodzaju spiekanego zestawu surowcowego i oczekiwanej, zakładanej efektywności procesu.

EN

The pursuit of manufacturing high quality material and ceramic products in sintering process at relatively low temperatures requires the use of activating additives. Small amounts of these non-organic additives, called activators, mineralizers and modifiers have influence on the sintering process, sometimes resulting in lowering the temperature, and by modifying or shaping the microstructure they determine the quality parameters of the material. The technological process involves also the use of organic additives (binders, plasticizers) that have indirect impact on sintering efficiency. Presented examples of various activating additives indicate that one and the same compound can perform different functions, depending on the chemical composition of sintered raw material set, the temperature used and the process characteristics (consolidation, reaction sintering, free, and pressure). This proves that the division into activators, mineralizers and modifiers used in the publication is not unequivocal and relates only to certain group of compounds. In addition to the tried and tested examples as cited above, the activating additives should be selected quantitatively and qualitatively, according to the type of sintered raw material set and desired process efficiency.

6

Influence of Steam Reforming Catalyst Geometry on the Performance of Tubular Reformer – Simulation Calculations

Franczyk E., Gołębiowski A., Borowiecki T., Kowalik P., Wróbel W.

Chemical and Process Engineering

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2015

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Vol. 36, nr 2

239--250

EN

A proper selection of steam reforming catalyst geometry has a direct effect on the efficiency and economy of hydrogen production from natural gas and is a very important technological and engineering issue in terms of process optimisation. This paper determines the influence of widely used seven-hole grain diameter (ranging from 11 to 21 mm), h/d (height/diameter) ratio of catalyst grain and Sh/St (hole surface/total cylinder surface in cross-section) ratio (ranging from 0.13 to 0.37) on the gas load of catalyst bed, gas flow resistance, maximum wall temperature and the risk of catalyst coking. Calculations were based on the one-dimensional pseudo-homogeneous model of a steam reforming tubular reactor, with catalyst parameters derived from our investigations. The process analysis shows that it is advantageous, along the whole reformer tube length, to apply catalyst forms of h/d = 1 ratio, relatively large dimensions, possibly high bed porosity and Sh/St ≈ 0.30-0.37 ratio. It enables a considerable process intensification and the processing of more natural gas at the same flow resistance, despite lower bed activity, without catalyst coking risk. Alternatively, plant pressure drop can be reduced maintaining the same gas load, which translates directly into diminishing the operating costs as a result of lowering power consumption for gas compression.

7

Computational Fluid Dynamics and Experimental Studies of a New Mixing Element in a Static Mixer as a Heat Exchanger

Konopacki M., Kordas M., Fijałkowski K., Rakoczy R.

Chemical and Process Engineering

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2015

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Vol. 36, nr 1

59--72

EN

The main aim of this work is to study the thermal efficiency of a new type of a static mixer and to analyse the flow and temperature patterns and heat transfer efficiency. The measurements were carried out for the static mixer equipped with a new mixing insert. The heat transfer enhancement was determined by measuring the temperature profiles on each side of the heating pipe as well as the temperature field inside the static mixer. All experiments were carried out with varying operating parameters for four liquids: water, glycerol, transformer oil and an aqueous solution of molasses. Numerical CFD simulations were carried out using the two-equation turbulence k-ω model, provided by ANSYS Workbench 14.5 software. The proposed CFD model was validated by comparing the predicted numerical results against experimental thermal database obtained from the investigations. Local and global convective heat transfer coefficients and Nusselt numbers were detrmined. The relationship between heat transfer process and hydrodynamics in the static mixer was also presented. Moreover, a comparison of the thermal performance between the tested static mixer and a conventional empty tube was carried out. The relative enhancement of heat transfer was characterised by the rate of relative heat transfer intensification.

8

Intensification of Mass Exchange in Physico-Chemical Processing of Fibrous Materials in a Liquid Medium

Kucharski A., Świątek J., Wrocławski Z.

Fibres & Textiles in Eastern Europe

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2003

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Vol. 11, no. 3 (42)

15--20

EN

Physico-chemical processing is very often used in the textile and paper industries, and in the industry of high-energy materials based on nitrocellulose. Mass exchange in these processes depends on the specific features of the form and structure of the parent substance (reactant). Notwithstanding the differences among the reagents used in the above-mentioned industries, the mass exchanging processes are similar. As liquids acting therein, we have dyes and bleaching agents used as solutions in chemical processing of fibres, acids and inorganic alkali in paper manufacturing, and nitric acid with compounds which form hydrates in the nitration process of cellulose. In general, in all these processes the motion of mass takes place together with chemical reactions of an additive or exchange character. The problems of mass exchange are analysed in this article from the point of view of the designers and constructors of machines and apparatuses which must perform the processes mentioned above. This analysis is based on the characteristic criteria of similarity between quantities, considering the geometric, energetic, and dynamic conditions which determine the process intensity. It has been proved that, according to the present state of knowledge and technique, the laminar liquid wall-surface layer which surrounds the fibrous parent substance acts as the main resistance for mass motion. It is possible to decrease this layer by several times (even over 30 times), and by this means significantly intensify the process. A process intensification criterion is presented.

PL

Obróbka fizyko-chemiczna materiałów włóknistych jest dość powszechna w przemyśle włókienniczym, papierniczym i materiałów wysokoenergetycznych, opartych na nitrocelulozie. Wymiana masy w tych procesach jest uwarunkowana szczególnymi cechami postaci substratu. Mimo różnicy reagentów procesy są podobne: w chemicznej obróbce włókna - barwniki i środki wybielające w roztworach; w produkcji papieru - kwasy i ługi nieorganiczne; w procesie nitracji celulozy - kwas azotowy ze związkami tworzącymi hydraty. Ruch masy w omawianych procesach odbywa się z reguły z równoczesną reakcją chemiczną (addytywną lub wymienną). Zagadnienie poddano analizie ze stanowiska projektantów i konstruktorów maszyn i aparatów wykonujących proces, opierając się na związkach liczb znamiennych, biorąc pod uwagę warunki natury geometrycznej, energetycznej i dynamicznej, które determinują intensywność procesu. Wykazano, że przy obecnym stanie wiedzy i techniki o procesie wymiany masy, główny opór dla ruchu masy stanowi laminarna warstwa przyścienna płynu, otaczająca substrat włóknisty. Odpowiednim rozwiązaniem konstrukcyjnym można tę warstwę przyścienną wielokrotnie (ponad 30-krotnie) zmniejszyć i ewidentnie zintensyfikować proces. Podano kryterium intensyfikacji procesu.

9

Intensification of mass transfer in wet textile processes by power ultrasound

Moholkar V. S., Nierstrasz V. A., Warmoeskerken M. M. C. G.

Autex Research Journal

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2003

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Vol. 3, no. 3

129--138

EN

In industrial textile pre-treatment and finishing processes, mass transfer and mass transport are often rate-limiting. As a result, these processes require a relatively long residence time, large amounts of water and chemicals, and are also energy-consuming. In most of these processes, diffusion and convection in the inter-yarn and intra-yarn pores of the fabric are the limiting mass transport mechanisms. Intensification of mass transport, preferentially in the intra yarn pores, is key to the improvement of the efficiency of wet textile processes. Power ultrasound is a promising technique for accelerating mass transport in textile materials. In this paper, the intensification of mass transfer in textiles under the influence of ultrasound on the basis of a total system approach is described. EMPA 101-test fabric was selected as a model for the cleaning process. This study focuses on two aspects, the mechanism of the ultrasound-assisted cleaning process and the effect of the presence of the cloth on the ultraso und wave field generated in a bath. It has been found that the dissolved gas content in the system plays a dominant role in the cleaning process. The cleaning effects observed are explained by two different mechanisms: small-amplitude acoustic bubble oscillations and micro-jets (resulting from the collapse of acoustic bubbles in the boundary layer between the fabric and the bulk fluid) that give rise to convective mass transfer in the intra-yarn pores. It has also been observed that the overall power consumption of the system varies with the position of the fabric in the acoustic field. This variation is explained on the basis of a model involving the specific flow resistance of the fabric and the physical properties of the standing waves.