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Dynamic separator is an equipment having a rotor and static vanes and is used to separate solids from gas-solids flow based on size. Particle separation in a dynamic separator happens due to complex interchanges between multiple forces exerted in the separation zone. Currently, there is only limited knowledge concerning the working principles of separation. This paper aims to systematically study a dynamic separator using numerical models to get insights into particle separation.

The Lagrangian–Eulerian formulation is used to simulate gas-solid flow. Multiple frames of reference using stage interpolation are used to account for rotation. Periodic symmetry in the equipment is exploited to create a simplified numerical model. The predictions from the numerical model are compared against available experimental data.

The numerical results indicate that only when particle collision is included, the separation efficiency trend from the experiment is matched by numerical predictions. Further, it is shown that at the same range of rotor speeds where numerical results predict increased separation efficiency, the solid pressure due to particle collision also reaches its maximum value. The gas flow and particle behavior in the separator are explained in detail.

The importance of particle collision in separation is interesting because traditionally, particle separation is assumed to be influenced by three forces, namely, centrifugal force, drag force and gravity. The numerical results, however, point to the contribution by particle collision, in addition to the above three forces.

In the paper a field model of superconductor matrix separator is shortly presented. It allows to determine the electromagnetic induction voltage value in magnet winding during matrix removing out of the field. The case of matrix removing taking place with various as well as constant velocity will is regarded. The last concept allowed to determine optimum velocity function regarding minimal removing matrix time satisfying the condition of superconductor winding stable work.

In the field of applied chemical process engineering, a great number of fundamentally different unit operations is known. In practice, they frequently overlap and sometimes also influence each other. One of these unit operations is dispersing, which means the uniform distribution of solid particles in a liquid phase. Dispersing technology is by no means a new development. In the early days and also in some special cases today, the term ‘dispersing’ stands for an additional process of communication of solid particles carried out at the same time as the process of distribution in the liquid phase. For this reason, dispersing is sometimes erroneously considered to be synonymous with the term ‘milling’ or ‘grinding.’

During the surface treatment of metals, pollutants occur in the pickling plants. Mainly three harmful substances are produced: sulphuric acid corrosives, hydrochloric acid corrosives and mixed acid corrosives. Different processes have been developed to eliminate or at least reduce these pollutants. An interesting and effective method is offered by Keramchemie of Siershahn, West Germany.

ABM Chemicals Ltd is exhibiting its range of photosensitisers for uv curing including the Glocure benzoin ethers. These highly cost effective materials ensure maximum utilisation of uv energy for the polymerisation process.

The purpose of this study is the 16-fold recycling process effect of VZH159 nickel alloy powder on its features and characteristics of the printed material obtained by selective laser melting (SLM). Chemical composition, content of gas impurities, powder grading, pore volume fraction and surface morphology of powder particles, structure and properties of SLM material, surface roughness and deviations from specified geometry of the test samples were investigated.

The experiment’s method procedure presumes the use of only recycled powder without adding any virgin powder at each build cycle. To avoid powder sloughing because of incomplete filling of the build space, a print area delimiter was used. For all manufactured samples, hot isostatic pressing was carried out in an ASEA Quintus-16 facility. Heat treatment was carried out in air furnaces. Structure investigations were carried out on a Leica DMIRM metallographic complex. Microstructure studies were carried out on a Verios 460 scanning electron microscope with X-ray microanalysis.

With the number of recycling stages, an increase in oxygen content is observed in the powder, which leads to an increment for oxides in the printed material. The 16-fold recycling does not have a significant effect on the features of the powder itself and the printed material if the build space is filled with manufacturing parts by no more than 20%.

The creep rupture strength of the SLM material, which appears to be a sensitive characteristic to the quality of the applied powder, does not change in the printed material after all stages of powder recycling as well.

Instrumentation to be shown will include: The Brookfield Helipath stand may be used with a suitable Brookfield viscometer fitted with a T‐bar spindle, the Helipath stand permits viscosity measurement of materials i.e. pastes, putty, creams, gelating, wax, resins and inks. The Stand incorporates a synchronous motor which automatically lowers or raises the viscometer enabling its rotating shearing element to describe a helical path through the sample.

Water‐borne coatings Increasing use of water‐borne emulsion coatings for original equipment manufacturers (OEM) and product finishes is requiring greater efficiency in coalescing‐aid solvents, an Eastman Chemical Co. representative said at a recent Chicago Society for Coatings Technology meeting. Eastman's Ronald K. Litton said emulsions designed for OEM and industrial applications have higher glass transition temperatures than emulsions used in architectural paints. That requires higher levels of coalescing aid to achieve good film formation. As a result, coalescing‐aid efficiency with a given emulsion system is a key factor, both from environmental (lower‐volatile organic compound (VOC)) and economic standpoints. Several properties should be examined when a coalescing aid is selected for water‐borne emulsion industrial coatings. The formulator should consider the evaporation rate and solubility parameter of the coalescing aid, along with its distribution pattern in a specific emulsion system. Those properties are important in defining the efficiency of a coalescing aid in terms of its ability to lower the minimum film‐forming temperature (MFFT) of an emulsion system. The coalescing aids also must be hydrolytically stable to provide minimum loss of efficiency due to ageing, Litton said. He showed several charts designed to assist formulators in the selection of optimum coalescing aids for emulsion systems. At the same conference, James T.K. Woo of The Glidden Co. discussed the grafting of high‐molecular‐weight epoxy resins with styrene‐methacrylic acid monomers, producing a water‐reducible copolymer. Grafting takes place at the aliphatic carbons of the epoxy resin, according to carbon‐13 NMR spectroscopy. The study was a follow‐up to a paper presented 14 years ago. Woo said recent research indicates that five grafting “peaks” were identified on a 400 megacycle carbon‐13 nuclear magnetic resonance spectroscopy instrument. The paper provided several theoretical calculation on grafting. Three of the graft peaks resulted from grafting at the secondary methylene carbons ‐CH2‐ and two resulted from grafting at the tertiary carbon ‐CH‐. The ratio of grafting at ‐CH2‐ to ‐CH‐appears to be 2.7:1 — lower than the 4:1 ratio of protons present on the aliphatic carbons that are susceptible to hydrogen abstraction leading to grafting. That indicates that the tertiary hydrogen is somwhat more susceptible to grafting than the methylene hydrogens, he said.

The purpose of this paper is to propose an effective methodology for the industrial design of tangential inlet cyclone separators that is based on the fully three-dimensional (3D) simulation of the flow field within the cyclone coupled with an effective genetic algorithm.

The proposed fully 3D computational fluid dynamics (CFD) model makes use of the Reynold stress model for the accurate prediction of turbulence, while the particle trajectories are simulated using the one-way coupling discrete phase, which is a model particularly effective in case of low concentration of dust. To validate the CFD model, the numerical predictions are compared with experimental data available in the scientific literature. Eight design parameters were chosen, with the two objectives being the minimization of the pressure drop and the maximization of the collection efficiency.

The optimization procedure allows the determination of the Pareto Front, which represents the set of the best geometries and can be instrumental in taking an optimal decision in the presence of such a trade-off between the two conflicting objectives. The comparison among the individuals belonging to the Pareto Front with a more standard cyclone geometry shows that such a CFD global search is very effective.

The proposed procedure is tested for specific values of the operating conditions; however, it has general validity and can be used in place of typical procedures based on empirical models or engineers’ experience for the industrial design of tangential inlet cyclone separators with low solid loading.

Such an optimization process has never been proposed before for the design of cyclone separators; it has been developed with the aim of being both highly accurate and compatible with the industrial design time.

There is a growing need for safety analysis of chemical processes. Risk analysis techniques capable of evaluating dangerous transient conditions together with the reliability of the protective systems need to be devised. Analyses a flash separator used for the raw separation of a naphtha stream into its volatile and liquid constituents from the point of view of its safe operation by the use of the DYLAM methodology. Details a newly developed dynamic simulator of the transient behaviour of the separation operation. This simulator, coupled with the DYLAM algorithm, depicts at any moment the behaviour of the process stream in the drum and highlights the time thresholds which, if exceeded, may result in an accident owing to an uncontrolled evolution of the operation.