Wirbelschicht-Prozesse für die Chemieund Hütten-Industrie,die Energieumwandlung und den Umweltschutz

Fluidized bed processes for the chemical and metallurgical industries, energy conversion, and pollution control . This article presents a review of, and selection criteria for, gas/solids reactors with the aid of examples of industrially operating fluidized bed processes. The choice of optimum reactor design with regard to flow and reaction conditions, heat and mass transfer, grain size, and retention time of solids and gas is considered. In conclusion, various processes are described in terms of several process flowsheets.     

Die Darstellung von Gelen als stationäre Phase für die Gelchromatographie

The influence of the mode of synthesis on the characteristics of crosslinked polymers is examined for crosslinked copolymers of ethylvinylbenzol/divinylbenzol and vinylacetate/divinyladipate. Homogeneously crosslinked gels are mostly suited for separation of oligomers; polymers are able to be separated by use of heterogeneously crosslinked gels. It is demonstrated that in case of a heterogeneously crosslinking polymerization the heterogenity of the copolymers with decreasing solvatizing ability of the inert component is increasing; this leads simultaneously to an increase of the excluded molecular weight.     

Sojaproteinpräparate als Antispritzmittel für Margarine

Soy Protein Preparations as Antispattering Agents for Margarine It was found that soy protein concentrates obtained by successive extraction of ground soybeans with hexane and ethanol or with hexane alone, grinding to a particle size less than 100 μ and subsequent leaching with diluted acids at pH 4.5, are good antispattering agents. If the process is preceded by a debittering treatment of the beans with steam, products having very neutral taste are obtained. Addition of 0.2% of these concentrates to fully deaerated margarine containing 5% milk and 0.15% each of mono- plus diglycerides and lecithin, prevents spattering completely. Half-fat margarine does not spatter inspite of its high water content, if 0.1% of the concentrate is added. A disadvantage is the infection of soy protein concentrates with resistent fungus, which necessitates sterilization of the proteins at 85% C in acidic medium.     

Die Adsorptionsmittel als Helfer für den Umweltschutz und technische Testmethoden

Adsorbents as Aid in Environmental Protection and Technical Test Methods Practically all impurities from air and water can be removed by adsorbents upto a concentration which is no longer harmful. A special adsorbent can be employed for each field of application. Adsorbents are classified into hydrophobic (activated charcoal) and hydrophilic (silica gel, alumina gel, molecular sieves, active bentonites) types. Activated charcoal is primarily used for the removal of substances which are insoluble or sparingly soluble in water, whereas the inorganic adsorbents are employed for the removal of water-soluble substances and gases. Combinations of the two are often suitable. The adsorbed substances can be recovered or destroyed in concentrated form by steaming the adsorbents or by regenerating the latter with a hot gas (cooling during circulation).     

Verfahrensingenieure für das 21. Jahrhundert – Herausforderungen für die Hochschulausbildung

Chemical Engineers for the 21st Century – A Challenge to University Education The education of chemical engineers at the dawn of the 21st Century faces enormous challenges. The number of new students has dropped significantly since early 1990s. Globalisation is having an effect on the working environment of the engineering profession and changing the job market for process engineers whose activities now extend far beyond the chemical industry. As a result, universities and engineering schools now face increasing competition for students and scientific staff and for retention of degree programs and departments. This article throws light on the current situation of the universities, changes in working environment and conditions, and the demands placed on future chemical engineers and their education. Whatever changes may occur, e.g. through the introduction of Bachelor and Master degrees, the characteristic and proven profiles of engineering school and university training must be maintained while enhancing the conditions for good graduates.     

Ein Stoffdaten-Informationssystem für die Chemische Technik

A physical property data bank for chemical engineering . DETHERM , a data bank for physical property data of chemical compounds and mixtures as required by chemical engineers is described, which allows the retrieval of literature data, the algebraic manipulation of retrieved data, data calculations and estimations, data analysis, and connection with data processing systems. In the data bank both numerical and non-numerical data are stored, data and substances being labeled by ?tags”? which characterize the kind of stored data and substances.     

Ionenaustauscher als beispiel für reaktionsfähige hochpolymere

The resin-based ion exchange materials used nowadays are insoluble polyelectrolytes. Synthetic processes allow a large variety of modifications of the ion exchange substance itself as well as of the functional groups. It is thus possible to offer tailormade special resins for many different uses. Beside resins which are resistant at elevated temperatures or in oxidizing media, the introduction of the macroporous matrix has proved to be a special success. It leads to more resistant products and makes it possible to use appropriately designed ion exchange resins for general adsorption purposes as well, similar to activated carbon. The range of application of ion exchange resins is rapidly increasing as new resins are being offered and improved process engineering is being developed. The most important fields are water conditioning, detoxification of waste waters, recovery of valuable inorganic and organic substances, as well as use in chemical processes. These versatile products will in future be used in these fields to a greater extent and new applications will certainly be found.     

Kompensationsspannung als zusätzliches Beurteilungskriterium für PAN-Precursorfasern

Fibres made from poly(acrylonitrile-co-methylacrylate-co-itaconic acid) were stretched under different conditions. The overall degree of orientation as well as the degree of orientation and amount of the paracrystalline regions were evaluated; mechanical properties were investigated. The correlation between the values obtained and the so-called compensation tension of the fibres leads to the conclusion that the latter is a measure for the inner tension of the fibres and renders possible improvements in preparation and processing of the fibres.     

Verbrennungstechnik für den Umweltschutz

Combustion engineering for environmental protection. Use of combustion as a means of environmentally sound disposal of gaseous, liquid, and solid industrial production residues places new demands on combustion engineering, depending upon the properties of the residues. High temperature process engineering has the task of ensuring reliable disposal while satisfying legal requirements concerning the quality of combustion. Combustion engineering as a means of residue disposal raises many questions of a scientific and practical nature, which will all have to be answered.     

Rohrfertigung für den Reparaturbereich

Pipe fabrication for the repair sector. The paper discusses the changes in pipe fabrication that have taken place in recent years. These enable repair work to be carried out more efficiently, without thereby impairing the flexibility and speed of operation that are essential to maintenance work. A prerequisite for this is that work on the pipes be transferred to workshops. Only here is it possible for manual operations, such as manual welding, to be reduced to a minimum and be replaced by mechanized or semi-mechanized welding methods. The use of modern machines for bending the pipes is more economic than the welding in of pipe bends. Necking out of the pipes by mechanical means or the use of mechanically pre-fabricated connections permit optimum preparation of the weld seam for branch fittings. Any additional work on the pipes, where this is necessary, is carried out at workplaces specially designed for the purpose.