The Experts below are selected from a list of 48 Experts worldwide ranked by ideXlab platform

S Schindler - One of the best experts on this subject based on the ideXlab platform.

  • on the design of the tubesheet and the tubesheet to shell junction of a fixed tubesheet heat exchanger
    International Journal of Pressure Vessels and Piping, 2006
    Co-Authors: K Behseta, S Schindler
    Abstract:

    Abstract For the (mechanical) design of an existing fixed tubesheet heat exchanger, a C2-Hydrogenation reactor in a petrochemical plant, various code solutions are compared with each other and with a Finite Element solution based on the Direct Route in Design by Analysis (EN 13445-3, Annex B). The codes and standards used in the investigation are ASME Section VIII, Division 1 and EN 13445-3, Clause 13 and Annex J. The ASME VIII/2 and TEMA codes are not appropriate for this design. The ASME VIII/1 and EN 13445-3 Clause 13 approaches are similar. Differences in Maximum Permissible Pressures result partly from different nominal design stresses. The modern EN 13445-3 Annex J approach, being based on limit analysis theory, leads to very different, much more efficient results. The Direct Route in Design by Analysis confirms the EN 13445-3 Annex J results, but gives, at the same time, clear insight into the behaviour of the whole structure and the various Maximum Permissible Pressure limiting details.

  • on the design of the tubesheet and the tubesheet to shell junction of a fixed tubesheet heat exchanger
    ASME 2006 International Mechanical Engineering Congress and Exposition, 2006
    Co-Authors: K Behseta, S Schindler
    Abstract:

    On the hand of the (mechanical) design of an existing, very large, extreme fixed tubesheet heat exchanger, a C2-Hydrogenation reactor in a petrochemical plant, various code solutions are compared, with each other and with a Finite Element solution based on the Direct Route in Design by Analysis (EN 13445-3, Annex B). The codes and standards used in the investigation are ASME Section VIII, Division 1 (and 2), (TEMA), and EN 13445-3, Clause 13 and Annex J. ASME VIII/2, and TEMA are not appropriate for this design. ASME VII/1 and EN 13445-3 Clause 13 approaches are similar. Differences in Maximum Permissible Pressures result partly from different nominal design stresses. The modern EN 13445-3 Annex J approach, being based on limit analysis theory, leads to very different, much more efficient results. The Direct Route in Design by Analysis confirms the EN 13445-3 Annex J results, but gives, at the same time, clear insight into the behaviour of the whole structure and the various Maximum Permissible Pressure limiting details.© 2006 ASME

K Behseta - One of the best experts on this subject based on the ideXlab platform.

  • on the design of the tubesheet and the tubesheet to shell junction of a fixed tubesheet heat exchanger
    International Journal of Pressure Vessels and Piping, 2006
    Co-Authors: K Behseta, S Schindler
    Abstract:

    Abstract For the (mechanical) design of an existing fixed tubesheet heat exchanger, a C2-Hydrogenation reactor in a petrochemical plant, various code solutions are compared with each other and with a Finite Element solution based on the Direct Route in Design by Analysis (EN 13445-3, Annex B). The codes and standards used in the investigation are ASME Section VIII, Division 1 and EN 13445-3, Clause 13 and Annex J. The ASME VIII/2 and TEMA codes are not appropriate for this design. The ASME VIII/1 and EN 13445-3 Clause 13 approaches are similar. Differences in Maximum Permissible Pressures result partly from different nominal design stresses. The modern EN 13445-3 Annex J approach, being based on limit analysis theory, leads to very different, much more efficient results. The Direct Route in Design by Analysis confirms the EN 13445-3 Annex J results, but gives, at the same time, clear insight into the behaviour of the whole structure and the various Maximum Permissible Pressure limiting details.

  • on the design of the tubesheet and the tubesheet to shell junction of a fixed tubesheet heat exchanger
    ASME 2006 International Mechanical Engineering Congress and Exposition, 2006
    Co-Authors: K Behseta, S Schindler
    Abstract:

    On the hand of the (mechanical) design of an existing, very large, extreme fixed tubesheet heat exchanger, a C2-Hydrogenation reactor in a petrochemical plant, various code solutions are compared, with each other and with a Finite Element solution based on the Direct Route in Design by Analysis (EN 13445-3, Annex B). The codes and standards used in the investigation are ASME Section VIII, Division 1 (and 2), (TEMA), and EN 13445-3, Clause 13 and Annex J. ASME VIII/2, and TEMA are not appropriate for this design. ASME VII/1 and EN 13445-3 Clause 13 approaches are similar. Differences in Maximum Permissible Pressures result partly from different nominal design stresses. The modern EN 13445-3 Annex J approach, being based on limit analysis theory, leads to very different, much more efficient results. The Direct Route in Design by Analysis confirms the EN 13445-3 Annex J results, but gives, at the same time, clear insight into the behaviour of the whole structure and the various Maximum Permissible Pressure limiting details.© 2006 ASME

Sharad Kumar Gupta - One of the best experts on this subject based on the ideXlab platform.

  • mathematical modeling of co2 separation from gaseous mixture using a hollow fiber membrane module physical mechanism and influence of partial wetting
    Journal of Membrane Science, 2015
    Co-Authors: N Goyal, Shishir Suman, Sharad Kumar Gupta
    Abstract:

    The present study describes a steady-state phenomenological model for CO2 separation via reactive absorption into aqueous Diethanolamine (DEA) solution using a micro-porous Poly-propylene (PP) Hollow-Fiber Membrane Module (HFMM). The developed model is based on the fundamental mechanisms of molecular diffusion, bulk convection and liquid-phase chemical reaction, and simultaneously accounts for the consequences of ‘partial-wetting’ phenomenon. Furthermore, a physically-consistent wetting mechanism has been formulated assuming that the membrane pores may be modeled as a bundle of straight cylindrical capillaries with distinct radii (characterized by the membrane pore-size distribution) and equal lengths, while keeping in mind the various pore-scale micro-physical phenomena. Under the simplifying parameterizations of the Finite-Volume Method (FVM), the source-code for discretized equations was compiled and implemented using C++ Language for a co-current module operation with aqueous DEA solution flowing inside the fiber-lumen and CO2–N2 gaseous mixture passing through the shell-side. A Benchmarking Analysis revealed an excellent agreement between the model predictions and the experimental data reported in open-literature, thereby validating the current model formulation, and rendering it fundamentally relevant with respect to the wetting-phenomenon. In addition, the module performance in terms of CO2 flux, Overall Mass-Transfer Coefficient (MTC), and Removal-Efficiency, has been systematically analyzed pertaining to the physical influence of other operating variables such as absorbent concentration, hydrodynamics, Pressure, temperature, and membrane characteristics. From a modeling standpoint, it may be concluded that the present model successfully captures various observations vis-a-vis the process of CO2 separation using micro-porous HFMMs, reported previously in the literature. Moreover, for a given gas-phase hydrodynamics, the current set of results suggest the existence of a unique liquid-phase hydrodynamic regime, bounded by a minimum and a Maximum Permissible Pressure, under which the module can be effectively operated without any dispersive losses. Besides, the currently developed model has been demonstrated to explain the reduction in CO2 flux over time by allowing for morphological changes, including an enlargement in the average pore-size and a broadening of the pore-size distribution.

N Goyal - One of the best experts on this subject based on the ideXlab platform.

  • mathematical modeling of co2 separation from gaseous mixture using a hollow fiber membrane module physical mechanism and influence of partial wetting
    Journal of Membrane Science, 2015
    Co-Authors: N Goyal, Shishir Suman, Sharad Kumar Gupta
    Abstract:

    The present study describes a steady-state phenomenological model for CO2 separation via reactive absorption into aqueous Diethanolamine (DEA) solution using a micro-porous Poly-propylene (PP) Hollow-Fiber Membrane Module (HFMM). The developed model is based on the fundamental mechanisms of molecular diffusion, bulk convection and liquid-phase chemical reaction, and simultaneously accounts for the consequences of ‘partial-wetting’ phenomenon. Furthermore, a physically-consistent wetting mechanism has been formulated assuming that the membrane pores may be modeled as a bundle of straight cylindrical capillaries with distinct radii (characterized by the membrane pore-size distribution) and equal lengths, while keeping in mind the various pore-scale micro-physical phenomena. Under the simplifying parameterizations of the Finite-Volume Method (FVM), the source-code for discretized equations was compiled and implemented using C++ Language for a co-current module operation with aqueous DEA solution flowing inside the fiber-lumen and CO2–N2 gaseous mixture passing through the shell-side. A Benchmarking Analysis revealed an excellent agreement between the model predictions and the experimental data reported in open-literature, thereby validating the current model formulation, and rendering it fundamentally relevant with respect to the wetting-phenomenon. In addition, the module performance in terms of CO2 flux, Overall Mass-Transfer Coefficient (MTC), and Removal-Efficiency, has been systematically analyzed pertaining to the physical influence of other operating variables such as absorbent concentration, hydrodynamics, Pressure, temperature, and membrane characteristics. From a modeling standpoint, it may be concluded that the present model successfully captures various observations vis-a-vis the process of CO2 separation using micro-porous HFMMs, reported previously in the literature. Moreover, for a given gas-phase hydrodynamics, the current set of results suggest the existence of a unique liquid-phase hydrodynamic regime, bounded by a minimum and a Maximum Permissible Pressure, under which the module can be effectively operated without any dispersive losses. Besides, the currently developed model has been demonstrated to explain the reduction in CO2 flux over time by allowing for morphological changes, including an enlargement in the average pore-size and a broadening of the pore-size distribution.

Bologna I - One of the best experts on this subject based on the ideXlab platform.

  • Recent Innovations in Turbulent Mixing with Static Elements
    2020
    Co-Authors: Viale Risorgimento, Bologna I
    Abstract:

    Static Mixer consists of a number of stationary mixing elements inserted along the direction of flow in a pipe. Each mixing element allows to divide the flow and to recombine it in a geometric sequence. A lot of static mixers are now available, e.g. Sulzer SMV and SMI, Chemineer KM, the Kenics HEV. These products differ quite considerably and the construction have effects on the manufacturing costs and also on the costs for the inbuilt the mixers in a plant. These well known motionless mixers allow to obtain good performances but usually the mixing length necessary for obtaining the homogeneity is longer than 5-10 pipe diameters. Another important constrain is the Maximum Permissible Pressure loss in the operation. In the recent years, new products composed of a minimum number of elements, have been launched. These new products have a short inbuilt device length, they require a short mixing path and they have low Pressure drops. This review analyzes the behaviour of these new innovative static mixers.