scholarly journals The Role of Residence Time Distribution in the Continuous Steady-State Mixed Suspension Mixed Product Removal Crystallization of Glycine

2018 ◽  
Vol 19 (1) ◽  
pp. 66-80 ◽  
Author(s):  
Iyke I. Onyemelukwe ◽  
Anna R. Parsons ◽  
Helen P. Wheatcroft ◽  
Amy Robertson ◽  
Zoltan K. Nagy ◽  
...  
Keyword(s):  
Steady State ◽  
Residence Time ◽  
Time Distribution ◽  
Residence Time Distribution ◽  
Mixed Product ◽  
Product Removal ◽  
Mixed Suspension

scholarly journals Hydraulic Characteristics, Residence Time Distribution, and Flow Field of Electrochemical Descaling Reactor Using CFD

Processes ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1896
Author(s):  
Bolin Hu ◽  
Xiaoqiang Zhang ◽  
Zhaofeng Wang ◽  
Zixian Wang ◽  
Yuanfan Ji
Keyword(s):  
Steady State ◽  
Energy Consumption ◽  
Flow Field ◽  
Residence Time ◽  
Time Distribution ◽  
Residence Time Distribution ◽  
Short Circuit ◽  
Hydraulic Characteristics ◽  
Plate Height ◽  
Plate Spacing

This paper uses computational fluid dynamics (CFD) to simulate flow field distribution inside an electrochemical descaling reactor in three dimensions. First, the reactor flow field was obtained by steady-state simulation, and the grid independence was verified. Then, the steady state of the flow field was judged to ensure the accuracy of the simulation results. Transient simulations were performed on the basis of steady-state simulations, and residence time distribution (RTD) curves were obtained by a pulse-tracing method. The effects of plate height and plate spacing on reactor hydraulic characteristics (flow state and backmixing) were investigated using RTD curves, and the results showed that increasing the plate height and decreasing the plate spacing could make the flow more similar to the plug flow and reduce the degree of backmixing in the reactor. The flow field details provided by CFD were used to analyze the reactor flow field and were further verified to obtain the distribution patterns of dead and short circuit zones. Meanwhile, information regarding pressure drops was extracted for different working conditions (490, 560, and 630 mm for pole plate height and 172.6, 129.45, and 103.56 mm for pole plate spacing), and the results showed that increasing the pole plate height and decreasing the pole plate spacing led to an increased drop in pressure. In this case, a larger pressure drop means higher energy consumption. However, increasing the pole plate height had a smaller effect on energy consumption than decreasing the pole plate spacing.

scholarly journals The Change of Liquid Steel Flow Control System in the Tundish – Modelling Research/ Zmiana Systemu Kontroli Przepływu Ciekłej Stali W Kadzi Pośredniej – Badania Modelowe

2014 ◽  
Vol 59 (4) ◽  
pp. 1433-1440 ◽  
Author(s):  
J. Pieprzyca ◽  
T. Merder ◽  
M. Saternus ◽  
H. Kania
Keyword(s):  
Control System ◽  
Flow Control ◽  
Residence Time ◽  
Liquid Steel ◽  
Time Distribution ◽  
Residence Time Distribution ◽  
Flow Regulation ◽  
Flow Control System ◽  
Steel Flow

Abstract The article presents the results of research concerning the change of liquid steel flow and mixing in the T-type tundish. It has been installed in one of polish steel plants. Continuously changing market conditions have forced the change in the range of cast strand. As a consequence the new control system of liquid steel flow had to be applied. Up to now a baffle with notch has played the role of steel flow regulation. It was placed between the inlet and channel zones of a tundish. However such solution was not satisfactory. Therefore, a new flow control equipment was designed - baffles and different constructional variants of turbulence inhibitors. To estimate the efficiency of their functioning and in the same time their influence on the tundish work, modelling research was carried out. The research was also complemented by numerical simulations. The article presents results of such research as well as experimentally and numerically determined RTD curves of mixing (Residence Time Distribution).

Kinetics of secondary nucleation with attrition and the mean size of product crystals from the continuous stirred crystalliser

1981 ◽  
Vol 46 (1) ◽  
pp. 79-85 ◽  
Author(s):  
Jaroslav Nývlt
Keyword(s):  
Experimental Data ◽  
Kinetic Equation ◽  
Residence Time ◽  
Secondary Nucleation ◽  
Mixed Product ◽  
Product Removal ◽  
Mixed Suspension ◽  
Mean Size ◽  
The Mean ◽  
Kinetics Of

A form of kinetic equation of nucleation has been proposed expressing also the mechanism of attrition of crystals. In limiting cases this equation expresses the secondary nucleation due to attrition or caused by other mechanisms while both limit expressions are quite different. The resulting relation enables correlation of experimental data also in the case when it is not possible to neglect any of the mentioned phenomena. Relation has been derived for the mean size of product crystals from the MSMPR (mixed suspension, mixed product removal) crystalliser showing that in cases with the prevailing attrition of crystals it might be advantageous to operate at a larger crystalliser output i.e. with a shorter residence time of crystals in the unit.

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