Application of numerical simulation in the design of wire-mesh mist eliminator
Previous design of wire-mesh mist eliminator relies on enormous experiments and consumes a lot. In this paper, its pressure drop is simulated by numerical simulation, and non-simplified three-dimensional calculation model is established. After calculated under the flow velocity of 3-10m/s and compared it with the experimental data, the results show that the numerical simulation result achieves a very high precision. Meanwhile, the influence of different wire diameter and space between wire-mesh layers on the pressure drop of mist eliminators is studied and the proper space between wire-mesh layers within the scope of wire-diameter is 0.6mm–0.8mm. Two types of model were verified through the model experiment and the experimental error is less than 4%, which can be a theoretical guidance for designing mesh filter.
Design of complex wire‐mesh mist eliminators
Knitted wire-mesh mist eliminators have widespread application in many industrial plants. Despite their extensive use, the open literature regarding them is really limited. Some experimental data and mechanistic models have been published for common knitted wire-mesh mist eliminators formed from a single metal pad. This type of mist eliminator can be used in most distillation and absorption columns, but because of the poor removal efficiency, cannot be used in operations involving acid mist, fine fog resulting from liquid condensation from a saturated vapor, oil mist from compressed gases, and natural-gas dehydration applications. Moreover, other possible problems may arise when the separator is fed with high liquid and gas flow rates, because these conditions can induce flooding in the mist eliminator. In both of these cases, common wire-mesh mist eliminators do not perform satisfactorily, and therefore complex wire-mesh mist eliminators have to be installed to improve separation efficiency or to increase allowable liquid loadings while avoiding flooding phenomena. This article presents a mechanistic model based on a set of new experimental data obtained by investigating performance of commercial complex eliminators.
Die Beschreibung der Partikelabscheidung durch Trägheitskräfte mit Hilfe einer dimensionsanalytisch abgeleiteten Kennzahl
Description of particle precipitation by inertial forces by means of a group derived by dimensional analysis. The fractional degree of precipitation depends upon many operating parameters: these can be attributed to three independent dimensionless groups: the Stokes, the Reynolds, and the Euler number. On the basis of extensive experimental material, dimensional analysis shows that, for sufficiently large Reynolds numbers and in a large range of the Euler number, the inertial precipitation depends upon a single dimensionless group, the precipitation parameter ΨA. It can be regarded as the ratio of two energies, viz. a characteristic precipitation energy, expressed as the product of the inertial energy of the particle and the pressure drop coefficient of the precipitators, and a frictional energy dissipated in the boundary surface of the impact body. Thus inertial precipitation is transformed from a complicated flow problem into an energetic problem in which pressure drop plays a major role. Simple approximation formulae can be given for the fractional degree of precipitation and the limiting droplet size for all types of separators.