The measure of volumetric flow rate is utilized to calculate sampling volume and airborne concentration in integrated air sampling. Consequently, calibration of the sampling train to verify volumetric flow rate is critical. The relation between sampler pressure drop and volumetric flow rate was studied in support of using the former rather than the latter for the calibration of sampling trains. Four types of respirable cyclones, two filter brands with membrane samples of the same and different lots of production, and two personal pump types were considered as components of the sampling trains under consideration. Volumetric flow rate and pressure drop were measured under controlled conditions in a cylindrical jar designed for these determinations. For all the configurations considered, the relation between sampler pressure drop and standard volumetric flow rate was linear. Intra-sample selection of cyclones of the same type and pump type did not create significant differences in sampler pressure drop. Filter selection, regardless of brand or production lot, did create linear response functions that had statistically different slopes and intercepts. When grouped by cyclone type and filter brand, the sampler pressure drop at the flow rate recommended by the cyclone’ s manufacturers showed variability that was not normally distributed. The recommended central tendency estimate of pressure drop is the median value, with point estimates that should be specific to a cyclone type / filter brand combination.

This paper presents a steady state one-dimensional two-fluid model for gas-solid two-phase flow in a vertical riser. The model is solved using conservative variable approach for the gas phase, and fourth order Runge-Kutta method is used for the solid phase. The model predictions for pressure drop are compared with available experimental data and with Eulerian-Lagrangian predictions, and a good agreement is obtained. The results indicate that the pressure drop increases as the solid mass flow rate, particle size, and particles density increase. In addition, the model predictions for minimum pressure drop velocity are compared with experimental data from literature and the mean percentage error. MPE for minimum pressure drop velocity is-9. 89%. It is found that the minimum pressure drop velocity increases as the solid mass flow, particle size and particle density increase, and decreases as the system total pressure increases.

KATAPAK-S is a type of structured catalytic packing, which is used in reactive distillation processes. The dry pressure drop characteristic (the pressure drop in the absence of liquid flow) is of significant importance for the investigation of process hydrodynamics. In this paper, the dry pressure drop within the catalyst packed channels of KATAPAK-S has been investigated using Computational Fluid Dynamics (CFD).Results of the CFD simulations were validated using experimental pressure drop data and empirical correlations. The CFD results showed an excellent agreement with theoretical and experimental data.

Although two-phase flow is frequently encountered in various locations of the process plants, there is no a generally accepted and verified twophase flow model that may be used to size lines for such conditions. An obvious example is condensate water return lines. The API method used in this study is based on the homogeneous equilibrium flow assumption, that is, equal velocity and equal temperature in both liquid and vapor phases. Moreover, DIERS method was used to verify and clarify the HEM approach to calculating the pressure drop in twophase regimes. The objective of this study is to introduce a solution for process lines design during different flashing scenarios. Applying API method, this study can find the two-phase line pressure drop and upstream pressure, while, by using DIERS method, one could realize that for a specified length of pipe how much two-phase flow could pass through when the pressure drop is just the same as that in the API model.

In this study pressure drop of R-134a refrigerator under convective boiling conditions in horizontal flattened tubes was investigated. Round copper tubes with outer diameter of 9.52 mm are flattened into oblong shape with different internal height of 6.6 mm, 5.5 mm, 3.8 mm, and 2.8 mm. The experimental set-up used is a well-instrumented vapor compression refrigeration cycle. It includes three evaporators named pre-evaporator, test evaporator, and after evaporator. The results show that pressure drop increases as the tube profile is flattened. The obtained experimental data are compared with the results of existing correlations for estimation of pressure drop inside flattened tubes. In worst condition, the maximum boiling flow pressure drop is increased to 600% for the horizontal flattened tube relative to the round tube values. Also, a correlation is developed to predict the boiling flow pressure drop inside flattened tubes. This correlation predicts the experimental results within an error band of ±20%.

Static Mixers (SM), also generally known as inline mixers, form a newly developing industry trend. They have no moving parts, hence have lower energy consumption, lower installation cost, and very low maintenance cost, and are thus an attractive alternative to conventional agitators. Modifications were made to the design to reduce pressure drop and increase the mixing intensity across the mixer and increase the application of inline mixers in the industries. Three hybrid geometries (different combinations of Kenics and LPD) of static mixers were constructed and simulated using Computational Fluid Dynamics (CFD) tools. Kenics is an excellent radial mixing device, and Low-Pressure Drop (LPD) is an excellent axial mixing device. The key design parameter to modify LPD was the slope angle of elliptical plates which affects the mixer performance. Different slope angles from 90º to 120º were simulated. Kenics was modified for different aspect ratios, and the edge of Kenics was curved. Pressure drop, thermal, and Discrete Phase Model (DPM) analysis were performed on these three different classifications of hybrid geometries. The most promising geometry to emerge based on the low-pressure drop and good mixing efficiency was the curved edge Kenics. Keen-sighted these results, further analysis was performed on curved edge Kenics after the modification of the blend radius. It was concluded that for a lower Reynold number, the curved edge with a higher blend radius dominates all other mixers. Result validation was done by comparing the trends and sensitivity of process variables with the established results and standards.