Microwave Setup Design for Continuous Fine‐Chemicals Synthesis

A feasibility study in state‐of‐the‐art multi‐ and monomode microwave cavities was conducted to outline important functionalities necessary in a microwave setup for continuous fine‐chemicals synthesis. For multimode operation, the heating efficiency depends on the position as well as on the volume distribution of the load. For monomode operation, the heating efficiency does not depend on the axial position and has a maximum with respect to the load diameter. Based on this study, a microwave setup consisting of four cavities was designed and constructed. The setup provided a defined microwave field pattern and allowed focusing of the microwave power. A near‐uniform distribution of microwave energy in all four cavities of the setup was achieved at reduced grid to applicator losses.     

Einsatzgrenzen von T‐Stücken mit Abzweigen gleichen Durchmessers

Limitations of Tees with Branches of Equal Diameter Welded and necked‐out tees are frequently used in pressure vessel and piping design. Standard calculations based on the Kellog method are merely applicable for pressure loading. Supplementary forces and moments are excluded in this case. The application of numerical methods of structural analysis is extremely helpful in this situation. However, detailed modelling of the geometry is quite complicated and standard models of the cylinder‐cylinder intersection type cannot be used. Special models of the welded and necked‐out design variants have to be generated and parametrized in order to be applicable for different nominal sizes. Tees as structural components have to be considered under various aspects with respect to their mechanical behaviour. The following investigation proposes methods for design under static and cyclic loading conditions based on detailed FE analyses. The results reveal a considerable potential of tees which has to be proved by analysis.     

Untersuchung des binären Diffusionskoeffizienten in Argon/Neon‐Gemischen mittels einer Loschmidt‐Zelle kombiniert mit holografischer Interferometrie

Binary diffusion coefficients D_ij were determined for mixtures of argon and neon over the entire composition range using a Loschmidt cell at 293.15 – 333.15 K and 1 – 10 bar. Before the measurements, the different pure gases were added into the two half‐cells of the Loschmidt cell. After connecting both half‐cells, the change in partial molar density, or rather in the refractive index has been detected simultaneously as a function of position and time within each half‐cell using holographic interferometry. The binary diffusion coefficients obtained for the upper half‐cell show systematic deviations from literature data. In contrast, the data measured in the lower half‐cell are in excellent agreement with literature. Within the measurement uncertainty, the product of the molar density of the mixture and D_ij is not affected by the pressure.