Czasopismo Techniczne z. 6. Mechanika z. 5-M

Czasopismo Techniczne z. 6. Mechanika z. 5-M

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Collection items (27)


Ethylen production via oxidative coupling of methane (OCM) – investigation of alternative separation processes

Stünkel, Steffen, Repke, Jens-Uwe, Wozny, Günter
Article
2008
One of the most promising opportunities, for the researcher to find alternative methods to ensure the supply with raw materials for the chemical industry, therefore is the activation of methane by oxidative coupling of methane (OCM). With the help of unifying concepts in catalysis technology more benefit for the yield of ethylene production will be expected. The reaction product of the OCM process has to purified and separated. Therefore, data from the literature for the reaction products of oxidative coupling of methane were taken and used to simulate the purification and separation with the commercial tool CHEMCAD. Feasibility study was done to find the most valuable way to reach the aim of the process: most purified ethylene as a product.

Phosphorus recovery by induced map-precipitation

Heinzmann, Bernd, Kraume, Matthias, Stumpf, Daniel, Gros, Samuel
Article
2008
Different air flow rates were tested in a 1-L batch and a 45-L pilot reactor to optimize the parameters for MAP precipitation for phosphorus recovery in a large-scale plant. The pilot reactor was designed as an airlift reactor and the required pH values for precipitating MAP were reached by stripping CO2 of a model solution. The result was the same for all flow rates: about 85–90% of phosphorus was recovered as MAP at steady state. Hence it is promising, that the process for an optimized precipitation of MAP can been successful scaled up.

Application of model-based failure detection and identification to industrial production processes

Wozny, Günter, Arellano-Garcia, Harvey, Schubert, Udo
Article
2008
In this work, new prospects for current process control in the chemical process industry with application of model based predictive methods are presented. The data from a research cooperation work with the Evonik Degussa GmbH at Hanau-Wolfang, Germany let authors work out the models for failure detection and identification besides the basic regulatory control. The data derived from existing controllers, which make use of the predictive functional control method, is an attempt to define lower limits for model quality that is necessary to fulfill the secondary task satisfactory.

Drop breakage models for liquid–liquid dispersions in turbulent flows – comparison

Podgórska, Wioletta
Article
2008
In the paper four models of drop breakage in turbulent flow were compared. Breakage models were included to the population balance equation to predict transient drop size distributions. Predicted distributions were compared with experimental data. It was shown that models that take into account the effect of the system scale on breakage (multifractal model and model based on the division of impeller region into isotropic turbulent region and nonisotropic turbulent region) predict drop sizes most properly.

Wpływ nieustalonych warunków procesu na konstrukcję mikrobiologicznego bioreaktora membranowego

Noworyta, Andrzej
Article
2008
W artykule przedstawiono możliwość wykorzystania płukania zwrotnego w bioreaktorze membranowym do usuwania z powierzchni membrany biofilmu utworzonego z komórek mikroorganizmów. Zaproponowano sposób utrzymywania stałej objętości układu reakcyjnego oraz wyprowadzania nadmiaru cieczy stosowanej jako medium płuczące. Wykorzystano naturalną zdolność układu do samoregulacji do utrzymywania stężeń w przedziale wartości pozwalającym na traktowanie warunków panujących w procesie jako pseudo stacjonarne.

Rhelogical behavior of high-concentrated fine-grained suspension

Moravec, Jiří, Rieger, František
Article
2008
The high-concentrated and fine-grained suspensions are often met in different industries. The rheological behavior of these suspensions is different from behavior of suspensions with low concentration of solid phase or with bigger particles. The behavior of the suspensions is frequently described as viscoplastic. In this paper, newly proposed combined Bingham model is used for description of rheological behavior of chalk suspension in wide range of shear rates. The change in rheological behavior with change of solid phase concentration is determined on the basis of model parameters change. The effect of flow enhancing substance on the behavior of suspension is also shown.

Measurement techniques for drop size distributions in stirred and fast coalescing liquid–liquid systems

Maaß, Sebastian, Horn, Stefan, Kraume, Matthias
Article
2008
Complete models in stirred tanks for the drop size distribution as a function of power-input, material and process parameters are rare and relatively inaccurate. Furthermore industrial applications, like e.g. suspension polymerization processes, require a distinct average drop diameter and a small standard deviation of the distribution. An overview is given for already existing measurement technique: sound, laser and photo based techniques. The Lasentec FBRM® [22], which gives online, and in-situ information and an in house developed endoscope technique [21] will be discussed in detail. It is clearly shown, that the laser based method gives only qualitatively good but fast results for the tested system toluene/water. The quantitatively accurate experimental results of the endoscope technique gave a good base for testing and developing numerical models for even transient behavior of drop size distributions.

Badania i numeryczna symulacja warunków pracy zawieszenia rurociągów przemysłowych

Łopata, Stanisław, Gargula, Marek
Article
2008
Zawieszenia przewodów instalacji energetycznych stanowią jeden z licznych rodzajów mostków termicznych powodujących zazwyczaj trudne do określenia straty ciepła. W artykule przedstawiono wyniki badań rozkładu temperatury dla zawieszenia pionowego rurociągu parowego. Badania wykonano kamerą termograficzną, a do modelowania numerycznego wykorzystano programy GAMBIT i FLUENT. Uzyskane rezultaty badań i obliczeń numerycznych są wstępnym etapem prac, których celem jest ocena wielkości strat ciepła generowanych przez różnorodne mostki termiczne rurociągów energetycznych i przemysłowych. Wskazują one, że wymienione wyżej narzędzia mogą być wykorzystane do identyfikacji warunków pracy tych elementów, uwzględniając np. oddziaływanie otaczającego je środowiska.

Support for plant design with a modular concept

Lühe, Christian, Wozny, Günter
Article
2008
Cost estimation of various project variants (process-synthesis) and the subsequent quotation demands accurate, rapid and inexpensive estimating. Modularization and the use of parametric models correspond to these requirements. Kept together by a knowledge management system a framework with following characteristics is provided: estimating relies on historical data (accessible through mapping technology) and it is consistent and repeatable.

Modelowanie numeryczne RANS i URANS przepływu burzliwego typu ciecz–ciecz w mieszalniku Kenics

Jaworski, Zdzisław, Murasiewicz, Halina
Article
2008
Przedstawiono wyniki modelowania przepływu burzliwego dwufazowego typu ciecz–ciecz w mieszalniku statycznym z dziesięcioma wkładkami Kenics. W badaniach numerycznych wykorzystano technikę RANS i URANS dla liczby Reynoldsa, Re równej 10 000. W modelowaniu CFD przepływu dwóch płynów newtonowskich zastosowano podejście pseudohomogeniczne. Porównano wyniki symulacji uzyskanych dla metody RANS i URANS i sformułowano wnioski.