scholarly journals Coating of Pharmaceutical Particles by Spouted Bed with a Draft Tube. Relationship between Coating Efficiency and Operating Conditions.

2000 ◽  
Vol 37 (8) ◽  
pp. 572-579 ◽  
Author(s):  
Shinji ANDO ◽  
Tooru MAKI ◽  
Taku MIZUTANI ◽  
Norikazu NAMIKI ◽  
Hitoshi EMI ◽  
...  
Keyword(s):  
Draft Tube ◽  
Operating Conditions ◽  
Spouted Bed ◽  
Coating Efficiency

CFD-DEM simulation of particle coating process coupled with chemical reaction flow model

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Meng Chen ◽  
Zhao Chen ◽  
Yaping Tang ◽  
Malin Liu
Keyword(s):  
Chemical Reaction ◽  
Concentration Distribution ◽  
Coupling Model ◽  
Operating Conditions ◽  
Experimental Result ◽  
Coating Process ◽  
Spouted Bed ◽  
Desorption Process ◽  
Particle Coating ◽  
Coating Efficiency

Abstract Particle coating process, one of the main methods to improve the particle properties, is widely used in industrial production and pharmaceutical industry. For the scale up and optimization of this process, a mechanistic and detailed study is needed or numerical simulation as an alternative way. Decomposition of substances usually involves multiple chemical reactions and produces multiple substances in the actual chemical reaction. In the study, a chemical reaction flow (CRF) model has been established based on kinetic mechanism of elementary reaction, the theory of molecular thermodynamics and the sweep theory. It was established with the comprehensive consideration of the decomposition of substances, deposition process, adhesion process, desorption process, hydrogen inhibition, and clearance effect. Then the CFD-DEM model was coupled with CRF model to simulate particle coating process by FB-CVD method, and the CFD-DEM-CRF coupling model was implemented in the software Fluent-EDEM with their user definition function (UDF) and application programming interface (API). The coating process in the spouted bed was analyzed in detail and the coating behavior under different conditions were compared at the aspects of CVD rate, coating efficiency, particle concentration distribution, particle mixing index and gas concentration distribution. It is found that the average CVD rate is 6.06 × 10−4 mg/s when the inlet gas velocity is 11 m/s and bed temperature is 1273 K, and simulation result agrees with the experimental result well. Average CVD rate and coating efficiency increase with temperature increasing, but decrease acutely with mass fraction of injected hydrogen increasing. The CFD-DEM-CRF coupling model can be developed as a basic model for investigating particle coating process in detail and depth and can provide some guidance for the operating conditions and parameters design of the spouted bed in the real coating process.

scholarly journals Drying of solutions and suspensions in the modified spouted bed with draft tube

2002 ◽  
Vol 6 (2) ◽  
pp. 47-70 ◽  
Author(s):  
Zorana Arsenijevic ◽  
Zeljko Grbavcic ◽  
Radmila Garic-Grulovic
Keyword(s):  
Draft Tube ◽  
Pure Water ◽  
Inorganic Compound ◽  
Operating Conditions ◽  
Rate Equations ◽  
Spouted Bed ◽  
Two Phase ◽  
Inert Particles ◽  
Polyethylene Particles ◽  
Drying Model

A modified spouted bed dryer with inert particles was used for drying of solutions and suspensions. The effects of the operating conditions on dryer throughput and product quality were investigated. Experiments were performed in a cylindrical column 215 mm in diameter and 1150 mm in height with a draft tube 70 mm in diameter and 900 mm length. The bed was made of polyethylene particles 3.3 mm in diameter and of density of 921 kg/m3. The pesticide Cineb, inorganic compound calcium carbonate, organic compound calcium stearate, and pure water were used as feeding materials. A drying model using the continuity and momentum equations for turbulent accelerating two-phase flow and conventional rate equations is proposed and discussed. The work is relevant for estimating dryer performance.

scholarly journals Minimum spoutable gas flow rate in side-outlet spouted bed with inner draft-tube.

1981 ◽  
Vol 14 (6) ◽  
pp. 462-466 ◽  
Author(s):  
HIROTSUGU HATTORI ◽  
KAZUYUKI TANAKA ◽  
KUNIHIKO TAKEDA
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Draft Tube ◽  
Gas Flow Rate ◽  
Spouted Bed ◽  
Side Outlet

Cycle time in draft tube conical spouted bed dryer for sludge from paper industry

2013 ◽  
Vol 100 ◽  
pp. 413-420 ◽  
Author(s):  
María J. San José ◽  
Sonia Alvarez ◽  
Francisco J. Peñas ◽  
Iris García
Keyword(s):  
Cycle Time ◽  
Draft Tube ◽  
Paper Industry ◽  
Spouted Bed

Drying of Agricultural Grains in a Multiple Porous Draft Tube Spouted Bed

2017 ◽  
Vol 204 (8) ◽  
pp. 942-950 ◽  
Author(s):  
S. Rajashekhara ◽  
D. V. R. Murthy
Keyword(s):  
Draft Tube ◽  
Spouted Bed

Modelling batch drying of sand in a draft-tube conical spouted bed

2011 ◽  
Vol 89 (10) ◽  
pp. 2054-2062 ◽  
Author(s):  
Martin Olazar ◽  
Gartzen Lopez ◽  
Haritz Altzibar ◽  
Javier Bilbao
Keyword(s):  
Draft Tube ◽  
Spouted Bed

Drying of Porous Solid Particles in Various-Shaped Spouted Bed with a Draft-Tube

2001 ◽  
Vol 34 (12) ◽  
pp. 1549-1552 ◽  
Author(s):  
HIROTSUGU HATTORI ◽  
TAKAYUKI MORIMOTO ◽  
MASAHIRO YAMAGUCHI ◽  
TOMOMI ONEZAWA ◽  
CHIKAO ARAI
Keyword(s):  
Draft Tube ◽  
Solid Particles ◽  
Porous Solid ◽  
Spouted Bed

Hydraulic Instability Onset Detection in Kaplan Turbines by Monitoring Shaft Vibrations

2012 ◽  
Author(s):  
P. Pennacchi ◽  
P. Borghesani ◽  
S. Chatterton ◽  
A. Vania
Keyword(s):  
Experimental Test ◽  
Turbine Unit ◽  
Swirling Flow ◽  
Draft Tube ◽  
Operating Conditions ◽  
Low Flow ◽  
Operating Life ◽  
Vortex Rope ◽  
Power Load ◽  
Helical Vortex

Design of hydraulic turbines has often to deal with hydraulic instability. It is well-known that Francis and Kaplan types present hydraulic instability in their design power range. Even if modern CFD tools may help to define these dangerous operating conditions and optimize runner design, hydraulic instabilities may fortuitously arise during the turbine life and should be timely detected in order to assure a long-lasting operating life. In a previous paper, the authors have considered the phenomenon of helical vortex rope, which happens at low flow rates when a swirling flow, in the draft tube conical inlet, occupies a large portion of the inlet. In this condition, a strong helical vortex rope appears. The vortex rope causes mechanical effects on the runner, on the whole turbine and on the draft tube, which may eventually produce severe damages on the turbine unit and whose most evident symptoms are vibrations. The authors have already shown that vibration analysis is suitable for detecting vortex rope onset, thanks to an experimental test campaign performed during the commissioning of a 23 MW Kaplan hydraulic turbine unit. In this paper, the authors propose a sophisticated data driven approach to detect vortex rope onset at different power load, based on the analysis of the vibration signals in the order domain and introducing the so-called “residual order spectrogram”, i.e. an order-rotation representation of the vibration signal. Some experimental test runs are presented and the possibility to detect instability onset, especially in real-time, is discussed.

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