Strömungsturbulenz und Verbrennung

Turbulent flow and combustion . Flame-generated turbulence was long a topic of lively discussion. Since the hot gases arising on combustion are much more viscous than, e.g. cold air and cold natural gas, the Reynolds number of a flow system is more likely to fall. Indeed, combustion is observed to promote laminar flow at low Reynolds numbers. The concept of “flame-generated” turbulence was imprecisely defined; a predominant thought was concerned with the turbulence-reinforcing effect of combustion in an existing field of turbulent flow. Some authors doubted whether such an effect is possible. Meanwhile, it has been established that combustion can affect turbulent exchange in various ways, as demonstrated in this paper.     

Verhalten der freien Fettsäuren nach tierexperimenteller Verbrennung

Behaviour of Free Fatty Acids After Burning in Animal Experiments The pattern of free fatty acids in the serum of rats after 20% burning was determined in order to elucidate the severe changes resulting from the shock after burning. Gas chromatographic analysis was carried out after 1/2, 1, 6, 24, 48 and 72 hours following burning trauma. For comparison the fatty acid pattern of a control group of unburned animals was examined. Gas chromatographic analysis showed following characteristic changes: 1. An increase of palmitic, stearic, palmitoleic, oleic, linoleic and linolenic acids after 6 hours following burning. 2. A constant level of palmitic acid even after 72 hours. 3. A slight decline of palmitoleic and oleic acids after 48 and 72 hours. 4. An increase of the polyunsaturated linoleic and linolenic acids till 24 hours after burning and a subsequent large decrease. The function of fatty acids, especially linoleic and linolenic acids, as constituents of membranes is of great importance. They determine essentially the membrane permeability. Moreover, the polyunsaturated fatty acids are precursors of prostaglandins, whose role in burning is little investigated. The characteristic change of polyunsaturated fatty acids suggests a relationship with membrane damage, increased thrombocyte aggregation and alterations of lung surfactant. Their steep decline might be caused by autoxidation due to lack of antioxidants, degradation during conversion to energy and incorporation into lipoproteins and membranes. The significance of free fatty acids in catabolism of the cell in severe trauma is unquestionable.     

Prozeßführung und Verfahrenstechnik zur schadstoffarmen Verbrennung von Abfällen

Process control and engineering of essentially pollutant-free combustion of wastes. The avoidance, reduction, and utilization of wastes are recognized as exploitable strategies. In spite of these measures, in the future wastes remain which still require treatment. Combustion is possible way substantially converting complex chemical compounds in an environmentally compatible manner. The present paper deals in a general manner with the possibilities of influencing combustion control (primary measures) for wastes in order to obtain minimum levels of pollutants. A difference is made between gaseous, liquid, or powdered wastes and those comprising mixtures of coarse, pasty, and liquid components. The paper deals with mixing mechanisms, temperature control, burn out, pollutant limitation, and the resulting fundamental possibilities of process control and engineering.