Projektiranje i uvećanje mjerila biokemijskih reaktora s višestrukim miješalima

Mechanically agitated gas-liquid contactors are frequently used in the chemical, food and biochemical industries as fermenters and as hydrogenation or chlorination reactors. However wide is the usage of such vessels, their design is not based on chemical engineering data, but is still rather empirical. Thus, it is highly desirable to have a tool for the rational design of agitated gas-liquid contactors that is based on fundamental chemical engineering parameters that are transferable to other systems and operating conditions. Focusing on liquid film-controlled processes and using the data from fermenters of different scales, we develop kLa correlations that are suitable for scale-up. First, we discuss how to determine the proper experimental kLa values, which are not distorted by other equipment parameters as is the gas residence time. We demonstrate the possible kLa distortion on the pilot-plant experimental data by comparing the results obtained by two different experimental techniques. Further, we present physically correct kLa data for fully non-coalescent (sodium sulphate solution) batch. The data are presented both for laboratory and pilot-plant fermenters. We identify the process parameters, the values of which are dependent on the vessel scale when operated under the same power input per volume, and, using these parameters, we develop common kLa correlations suitable to describe the data for various scales of the vessel. The correlations developed reduce the uncertainty in predicting the volume of industrial scale fermenters from almost 1/2 to 1/4 of their total volume, thereby enabling significant reductions in both the initial costs, and operating costs.Uređaji za mehaničko miješanje sustava kapljevina-plin često se upotrebljavaju u kemijskoj, prehrambenoj i biokemijskoj industriji kao fermentori i kao reaktori za hiodrogeniranje i kloriranje. No u širokoj primjeni takvih reaktora njihov se dizajn ne temelji na kemijsko-inženjerskim podatcima te je još uvijek prilično empirijski. Dakle, vrlo je poželjno imati alat za racionalno projektiranje/dizajn uređaja za mehaničko miješanje sustava kapljevina-plin koji se temelji na fundamentalnim kemijsko-inženjerskim parametrima koji su prenosivi i na druge sustave i druge radne uvjete. Usredotočivši se na procese kontrolirane tekućim filmom i primjenjujući podatke iz fermentera različitih mjerila, razvijene su korelacije kLa koje su pogodne za uvećanje mjerila. Najprije se govori o načinu kako utvrditi odgovarajuće eksperimentalne vrijednosti kLa koje nisu narušene drugim parametrima kao to je to vrijeme zadržavanja plina. Pokazuje se moguća distorzija eksperimentalnih podataka kLa poluindustrijskih postrojenja usporedbom rezultata koji su dobiveni dvjema različitim eksperimentalnim tehnikama. Nadalje, prikazuju se fizički ispravni podatci kLa za smjesu (otopinu natrijeva sulfata) u potpunosti bez koalescencije (spajanja). Podatci su prikazani i za laboratorij i za fermentore poluindustrijskih postrojenja. Utvrđuju se procesni parametri vrijednosti koje su ovisne o mjerilu reaktorske posude, kada djeluju pod istom ulaznom snagom po jedinici obujma i primjenom ovih parametara razvijaju se uobičajene korelacije kLa prikladne za opisivanje podataka za različita mjerila reaktorske posude. Razvijene korelacije smanjuju nesigurnost u predviđanju obujma fermentora industrijskih razmjera s gotovo 1/ 2 do 1 / 4 od svog ukupnog obujma i time omogućuju znatno smanjenje početnih operativnih trokova.</p

Progress in design and experimental activities for the development of an advanced breeding blanket

There is no doubt about the interest of achieving as fast as possible the capability to build and operate high performance reactors that finally allow fusion competing in the electricity market. An advanced breeding blanket based on the Dual Coolant Lithium Lead concept with single module segment architecture, designed for the European DEMO, is certainly aligned with such objective. This work describes some recent outcomes of the efforts carried out in the framework of the Prospective R&D Work Package in EUROfusion to develop this line. The evolution of the design has been guided by strategies aimed to achieve an equilibrium between tritium breeding & shielding requirements and mechanical integrity. To enhance the thermodynamic cycle efficiency and reduce the recirculation power by minimizing pressure losses in both the breeding zone and the first wall have been complementary guidelines. Specific models have been created to characterize phenomena like heat transfer and tritium permeation in the breeder channels. The experimental activities, which in general have produced promising results, have consisted in the characterization of different ceramic materials (carbides and oxides) in terms of functional properties at high temperature (as-received and irradiated/implanted samples) and compatibility with PbLi

The Design and Scale-Up of Multiple-Impeller Fermenters for Liquid Film Controlled Processes

Mechanically agitated gas-liquid contactors are frequently used in the chemical, food and biochemical industries as fermenters and as hydrogenation or chlorination reactors. However wide is the usage of such vessels, their design is not based on chemical engineering data, but is still rather empirical. Thus, it is highly desirable to have a tool for the rational design of agitated gas-liquid contactors that is based on fundamental chemical engineering parameters that are transferable to other systems and operating conditions. Focusing on liquid film-controlled processes and using the data from fermenters of different scales, we develop kLa correlations that are suitable for scale-up. First, we discuss how to determine the proper experimental kLa values, which are not distorted by other equipment parameters as is the gas residence time. We demonstrate the possible kLa distortion on the pilot-plant experimental data by comparing the results obtained by two different experimental techniques. Further, we present physically correct kLa data for fully non-coalescent (sodium sulphate solution) batch. The data are presented both for laboratory and pilot-plant fermenters. We identify the process parameters, the values of which are dependent on the vessel scale when operated under the same power input per volume, and, using these parameters, we develop common kLa correlations suitable to describe the data for various scales of the vessel. The correlations developed reduce the uncertainty in predicting the volume of industrial scale fermenters from almost 1/2 to 1/4 of their total volume, thereby enabling significant reductions in both the initial costs, and operating costs.<br

Porphyrinogens in Urine in Various Types of Porphyrias

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