scholarly journals Development of Couette-Taylor Crystallizer in Cooling Crystallization: Promotion of Size Distribution of L-lysine

2016 ◽  
Vol 54 (5) ◽  
pp. 643
Author(s):  
Huyen Thi Thanh Trinh ◽  
Tuan Anh Nguyen ◽  
Thao Thanh Phan ◽  
Quang Chau Khuu ◽  
Giang Truong Dang

The Couette-Taylor (CT) crystallizer was developed to promote the size distribution of L-Lysine crystal product in cooling crystallization. When using the CT crystallizer, the size distribution of crystal product was much narrower than that of the conventional Stirred tank (ST) crystallizer. Here, the coefficient size distribution (n) in CT crystallizer was quite large as 3.43, while it was only 2.17 in ST crystallizer at the same 360 rpm of agitation or rotation speed. This result indicated that the CT crystallizer was much more effective than the ST crystallizer in terms of the size distribution of L-lysine crystal products in cooling crystallization. The advantage of CT crystallizer over the ST crystallizer was explained in terms of the high energy dissipation of Taylor vortices flow, where it was 7.6 times higher than that of random fluid motion in conventional ST crystallizer. As such, the supersaturation profile in the CT crystallizer was much more homogeneous than that in the ST crystallizer, which resulted in promotion of size distribution L-lysine crystal product.

2016 ◽  
Vol 54 (5) ◽  
pp. 625 ◽  
Author(s):  
Huyen Thi Thanh Trinh ◽  
Tuan Anh Nguyen ◽  
Thao Thanh Phan ◽  
Quang Chau Khuu ◽  
Nhan Thi Hong Le ◽  
...  

The effect of Taylor vortices flow of Couette-Taylor (CT) crystallizer on the nucleation and reconstruction of L-glutamic acid was firstly investigated in cooling crystallization. Generally, L-glutamic acid has two kinds of polymorphic crystal including metastable α-form and stable β-form, where the α-form is initially crystallized and then slowly transformed into the β-form, which is called the phase transformation. The present study explored that there was a significant difference between CT and the conventional ST crystallizer as regards the nucleation and reconstruction of L-glutamic acid. Here, the phase transformation determined by the nucleation and reconstruction was 40h in ST crystallizer, yet it was only 20h as using the CT crystallizer, implying that the nucleation and reconstruction of L-glutamic acid was facilitated 2.0 times as using the Taylor vortices flow. The advantage of Taylor vortices flow in CT crystallizer over the random fluid motion in ST crystallizer with regard to the nucleation and reconstruction was explained in terms of the high energy dissipation of Taylor vortices flow.


2010 ◽  
Vol 163-167 ◽  
pp. 398-405
Author(s):  
San Sheng Dong ◽  
Zi Xue Lei ◽  
Jun Hai Zhao

Based on the pseudo-static test of 6 high-strength RC columns with central reinforcement skeletons, this paper studied their hysterisis performance, degradation of strength and rigidity, and energy dissipation capacity, with the affecting factors analyzed. The result shows that the central reinforcement skeletons can compensate for the low plasticity and brittle failure susceptibility of high-strength concrete so that all the specimens have stable strength, slow rigidity degradation and high energy dissipation capacity at later stage of loading; the larger the core areas the higher the strengths and ductility of the specimens, but slightly faster the degradation of strength and energy dissipation capacity as compared with the specimens with smaller core areas; the spacing of ties, longitudinal reinforcement ratio of core area both influence the strength degradation and energy dissipation capacity of the specimens, but they have little effect on their strengths.


2005 ◽  
Vol 21 (4) ◽  
pp. 1093-1112 ◽  
Author(s):  
Thomas T. C. Hsu ◽  
Mohamad Y. Mansour

A new Cyclic Softened Membrane Model (CSMM) was recently developed to predict the stiffness, ductility, and energy dissipation of reinforced concrete (RC) elements subjected to reversed cyclic shear. Using the nonlinear finite element analysis, we can integrate these responses of elements to predict the behavior of a whole structure, such as a low-rise shear wall, subjected to earthquake action. This study of CSMM summarizes systematically the effects of the two primary variables: the steel bar angle with respect to the direction of the applied principal stresses and the steel percentage. The results clearly show that RC structures under cyclic shear stresses could be designed to be very ductile, have large stiffness, and possess high energy-dissipation capacities (just like flexural-dominated elements), if the steel bars are properly oriented in the directions of principal stresses and if the steel percentages are kept within certain limits.


2020 ◽  
Vol 10 (22) ◽  
pp. 8264
Author(s):  
Sang-Woo Kim ◽  
Kil-Hee Kim

This study proposes a relatively simple steel damper with high energy dissipation capacity. Three types of steel dampers were evaluated for structural performance. The first damper with U-shape had two vertical members and a semicircular connecting member for energy dissipation. The second damper with an angled U-shape replaced the connecting member with a horizontal steel member. The last damper with D-shape had a horizontal member added to the U-shaped damper. All the dampers were designed with steel plates on both sides that transmitted external shear force to the energy-dissipating members. To evaluate the structural performance of the dampers, an in-plane cyclic shear force was applied to the specimens. The D-shaped damper showed ductile behavior with excellent energy dissipation capacity after yielding without decreasing in strength during cyclic load. In other words, the D-shaped specimen showed excellent performance, with about 3.5 times the strength of the U-shaped specimen and about 3.8 times the energy dissipation capacity due to the additional horizontal member. Furthermore, the efficient energy dissipation of the proposed D-shaped steel damper was confirmed from the finite element (FE) analytical and experimental results.


Author(s):  
Adnan S. Saeed ◽  
Mohammad A. AL-Shudeifat

Rotating and vibro-impact Nonlinear Energy Sinks (NESs) have been employed for rapid and passive Targeted Energy Transfer (TET). Both have been proven to be efficient, shown high energy dissipation and have been tested experimentally. A novel type of NES that combines the two principles of nonlinear TET, rotating inertial coupling and vibro-impact, is numerically investigated on a 2 degree of freedom physical system. Two configurations of the new promising NES are considered via changing the location of the impacts. The optimized parameters of both configurations proved that high amounts of energy can be transferred from the primary system to the new promising type of NESs passively and rapidly.


2013 ◽  
Vol 26 (8) ◽  
pp. 1248-1253 ◽  
Author(s):  
Xuchun Gui ◽  
Zhiping Zeng ◽  
Yuan Zhu ◽  
Hongbian Li ◽  
Zhiqiang Lin ◽  
...  

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