scholarly journals Droplet Impact Phenomena in Fluidized Bed Coating Process with a Wurster Insert

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
T. Havaić ◽  
A.-M. Đumbir ◽  
M. Gretić ◽  
G. Matijašić ◽  
K. Žižek
Keyword(s):  
Droplet Diameter ◽  
Droplet Breakup ◽  
Process Efficiency ◽  
Process Conditions ◽  
Coating Process ◽  
Deposition Mechanism ◽  
Consistency Results ◽  
Fluidized Bed Coating ◽  
Impact Phenomena ◽  
Mixture Film

The aim of this study is to determine favorable process conditions for the coating of placebo tablets. Tablets made of microcrystalline cellulose are coated with hydroxypropyl cellulose polymer and Advantia™ Prime polymeric mixture film in lab-scale fluid-bed environment with a Wurster tube. In order to determine favorable process conditions (concentration, Wurster tube position, inlet air temperature, and atomization pressure), evaluation factors expressing process efficiency were calculated. Stereomicroscopy analysis provided good results with respect to the coating layer adherence and consistency. Results showed that the increased number of the coating cycles contributes to the desired featureless film morphology, when sufficiently high temperature and pressure are applied, thus resulting in high intra- and intertablet uniformity. Additionally, this paper analyzes the coating process from a mechanistic perspective of the underlying phenomena occurring on a tablet surface. Provided diagrams can help efficiently in detecting proper conditions that will result in coated tablets with strictly defined aimed properties. Process and formulation properties synergically result in a preferential occurrence of a deposition mechanism for all experiments conducted. Moreover, collision is found as a prevalent impact regime for the coating process studied. Finally, our intention here is to correlate hydrodynamic conditions and droplet breakup occurrence with a droplet diameter.

scholarly journals Indicative Marker Microbiome Structures Deduced from the Taxonomic Inventory of 67 Full-Scale Anaerobic Digesters of 49 Agricultural Biogas Plants

2021 ◽  
Vol 9 (7) ◽  
pp. 1457
Author(s):  
Julia Hassa ◽  
Johanna Klang ◽  
Dirk Benndorf ◽  
Marcel Pohl ◽  
Benedikt Hülsemann ◽  
...  
Keyword(s):  
Stable Process ◽  
Process Condition ◽  
Full Scale ◽  
Process Models ◽  
Process Efficiency ◽  
Process Conditions ◽  
Rrna Gene ◽  
General Process ◽  
Specific Distribution ◽  
Biogas Plants

There are almost 9500 biogas plants in Germany, which are predominantly operated with energy crops and residues from livestock husbandry over the last two decades. In the future, biogas plants must be enabled to use a much broader range of input materials in a flexible and demand-oriented manner. Hence, the microbial communities will be exposed to frequently varying process conditions, while an overall stable process must be ensured. To accompany this transition, there is the need to better understand how biogas microbiomes respond to management measures and how these responses affect the process efficiency. Therefore, 67 microbiomes originating from 49 agricultural, full-scale biogas plants were taxonomically investigated by 16S rRNA gene amplicon sequencing. These microbiomes were separated into three distinct clusters and one group of outliers, which are characterized by a specific distribution of 253 indicative taxa and their relative abundances. These indicative taxa seem to be adapted to specific process conditions which result from a different biogas plant operation. Based on these results, it seems to be possible to deduce/assess the general process condition of a biogas digester based solely on the microbiome structure, in particular on the distribution of specific indicative taxa, and without knowing the corresponding operational and chemical process parameters. Perspectively, this could allow the development of detection systems and advanced process models considering the microbial diversity.

Monte Carlo simulations to determine coating uniformity in a Wurster fluidized bed coating process

2006 ◽  
Vol 166 (2) ◽  
pp. 81-90 ◽  
Author(s):  
KuZilati KuShaari ◽  
Preetanshu Pandey ◽  
Yongxin Song ◽  
Richard Turton
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Fluidized Bed ◽  
Coating Process ◽  
Fluidized Bed Coating ◽  
Coating Uniformity

scholarly journals A Review of the Chemistry of Anaerobic Digestion: Methods of Accelerating and Optimizing Process Efficiency

Processes ◽  
2019 ◽  
Vol 7 (8) ◽  
pp. 504 ◽  
Author(s):  
Anthony Anukam ◽  
Ali Mohammadi ◽  
Muhammad Naqvi ◽  
Karin Granström
Keyword(s):  
Anaerobic Digestion ◽  
Energy System ◽  
Process Efficiency ◽  
Process Conditions ◽  
Future Directions ◽  
Digestion Process ◽  
Process Chemistry ◽  
Depth Analysis ◽  
Sustainable Energy System ◽  
Digestion Methods

The anaerobic digestion technology has been in existence for centuries and its underlying theory established for decades. It is considered a useful technology for the generation of renewable energy, and provides means to alleviate problems associated with low access to energy. However, a great deal of current research is targeted towards the optimization of this technology under diverse digestion process conditions. This review presents an in-depth analysis of the chemistry of anaerobic digestion and discusses how process chemistry can be used to optimize system performance through identification of methods that can accelerate syntrophic interactions of different microorganisms for improved methanogenic reactions. Recent advances in addition to old research are discussed in order to offer a general but comprehensive synopsis of accumulated knowledge in the theory of anaerobic digestion, as well as an overview of previous research and future directions and opportunities of the AD technology. Achieving a sustainable energy system requires comprehensive reforms in not just economic, social and policy aspects, but also in all technical aspects, which represents one of the most crucial future investments for anaerobic digestion systems.

Numerical Analysis on Droplet Deformation and Breakup in High Gravity Field

2014 ◽  
Vol 624 ◽  
pp. 276-279 ◽  
Author(s):  
Jian Dong Li ◽  
Dian Jun Zuo ◽  
Yu Ting Zhang
Keyword(s):  
Gravity Field ◽  
Droplet Diameter ◽  
Droplet Breakup ◽  
Test Method ◽  
High Gravity ◽  
Droplet Deformation ◽  
Geotechnical Centrifuge ◽  
G Value ◽  
High Gravity Field ◽  
Breakup Time

Research slope stability under rainfall condition in geotechnical centrifuge is an ideal test method, however, the influence of high centrifugal force field produced by running geotechnical centrifuge cannot be neglected. Droplet deformation and breakup under different gravity and of different diameters were studied with VOF method, the results shows that the process of droplet deformation and breakup is similar under condition of different g-value and diameters, droplet breakup in a very short time in high gravity field, and with the increase of g-value, the breakup time of droplet became shorter, with the increase of droplet diameter, the breakup time of droplet became longer under same gravity acceleration. Studies in this paper have important significance in developing geotechnical centrifuge artificial rainfall equipment.

Improvements in the process efficiency and bond strength when friction surfacing stainless steel onto aluminium substrates

2017 ◽  
Vol 233 (4) ◽  
pp. 687-698 ◽  
Author(s):  
Michael JR Stegmüller ◽  
Richard J Grant ◽  
Paul Schindele
Keyword(s):  
Mixed Mode ◽  
Detrimental Effect ◽  
Process Efficiency ◽  
Inductive Heating ◽  
Coating Process ◽  
Bonding Mechanism ◽  
Mechanical Interlocking ◽  
Bonding Area ◽  
High Shear Strength ◽  
Mode Failure

Friction surfaced specimens produced by the application of inductive heating and utilising a flash-reducing tool were compared with those obtained through the classical approach. It was found that the use of inductive heating resulted in an increased consumption of the coating material; however, the push-off strength could be more than doubled when compared with the classical process with high shear strength values of up to 111 MPa. The application of the flash-reducing tool reduced the flash to less than 0.05% of the material deposited as a coating and manifested itself in the form of small chips. High push-off strength values of up to 135 MPa were observed, accompanied by an increased coating thickness, coating width and bonding area. Temperature measurements with thermocouples taken during the coating process showed that the melting temperature of the aluminium substrate was reached at the substrate–coating interface. Mixed mode failure was evident at the fractured surfaces of the push-off test specimens and mechanical interlocking appears to be a main bonding mechanism. The presence of cavities were shown to have a detrimental effect on the bonding integrity, but could be reduced in size and number by the application of the flash-reducing tool.

Development and Modeling of Melt Electrohydrodynamic-Jet Printing of Phase-Change Inks for High-Resolution Additive Manufacturing

2014 ◽  
Vol 136 (6) ◽  
Author(s):  
Chuang Wei ◽  
Jingyan Dong
Keyword(s):  
Surface Tension ◽  
Additive Manufacturing ◽  
High Resolution ◽  
Phase Change ◽  
Electrostatic Force ◽  
Droplet Diameter ◽  
Scaling Law ◽  
Process Conditions ◽  
Drop On Demand ◽  
Jet Printing

This paper presents the development and modeling a high-resolution electrohydrodynamic-jet (EHD-jet) printing process using phase-change ink (i.e., wax), which is capable of producing sub-10 μm footprints (sub-10 fL in volume) for super-resolution additive manufacturing. In this study, we successfully apply EHD-jet printing for phase-change ink (wax), which is widely used as modeling and supporting material for additive manufacturing, to achieve micron-scale features. The resolution for single droplet on substrate is around 5 μm with the thickness in the range of 1–2 μm, which provides great potential in both high-resolution 3D printing and 2D drop-on-demand microfabrication. The droplet formation in EHD printing is modeled by finite element analysis (FEA). Two important forces in EHD printing, electrostatic force and surface tension force, are modeled separately by FEA. The droplet size is obtained by balancing the electrostatic force and surface tension of the pending droplets around meniscus apex. Furthermore, to predict the droplet dimension at different process conditions, a dimensionless scaling law is identified to describe the relationship between dimensionless droplet diameter and modified nondimensional electrical bond number. Finally, the droplets in-flight velocity and impact characteristics (e.g., Reynolds number and Weber number) are modeled using the results from FEA analysis.

scholarly journals Numerical Study on the Efficiency of Biomass and Municipal Waste Fixed-Bed Co-Gasification

2019 ◽  
Vol 114 ◽  
pp. 06006 ◽  
Author(s):  
Igor G. Donskoy
Keyword(s):  
Sewage Sludge ◽  
Energy Production ◽  
Numerical Study ◽  
Fixed Bed ◽  
Electric Energy ◽  
Process Efficiency ◽  
Small Scale ◽  
Process Conditions ◽  
Stoichiometric Ratio ◽  
Process Characteristics

The utilization of combustible waste, such as sewage sludge, can be combined with energy production for small-scale consumers. One of the ways of such utilization can be gasification, which makes it possible to obtain a combustible gas suitable for thermal and electric energy production. The aim of this study is to estimate the efficiency of sewage sludge co-conversion with woody biomass using mathematical model that allows to investigate process characteristics under different process conditions (air stoichiometric ratio, fuel mixture composition, initial moisture of sewage sludge). Dependencies of gasification process characteristics are evaluated and compared with published experimental data. Fixed-bed downdraft process is investigated related to using of wood and sewage sludge mixtures. New results are obtained considering process efficiency dependence on input fuel composition, method is proposed to estimate acceptable fuel mixtures based on agglomeration and efficiency requirements.

Full scale experience of two stage thermophilic/mesophilic sludge digestion

1997 ◽  
Vol 36 (6-7) ◽  
pp. 449-456 ◽  
Author(s):  
Jürgen Oles ◽  
Norbert Dichtl ◽  
Hans-hermann Niehoff
Keyword(s):  
Degradation Process ◽  
Pilot Scale ◽  
Full Scale ◽  
Process Efficiency ◽  
Anaerobic Sludge ◽  
Process Conditions ◽  
Two Stage ◽  
Operational Conditions ◽  
Digestion Process ◽  
General Goals

The general goals of anaerobic sludge stabilisation are degradation of organic substances, reduction of solids, decrease of pathogenic bacterias, improvement of dewatering capabilities and production of biogas. The anaerobic degradation process can be divided in several steps with different optimum operational conditions. This gives the possibility to design treatment plants as a two-stage process, optimizing the process conditions in each step and thereby leading to an overall increase in process efficiency. Research results in lab scale and pilot scale have shown that a two-stage digestion process with a high loaded first thermophilic (50-55°C) stage and a second stage under mesophilic (35-37°C) conditions with sufficient retention time will lead to the best results. After giving a short summary of the development of the two-stage thermophilic/mesophilic digestion process the paper will present full scale experiences with this system in Germany.

Studies in Optimization of Aqueous Film Coating Parameters

2009 ◽  
Vol 2 (3) ◽  
pp. 621-626
Author(s):  
Navin Sheth ◽  
Sunny Shah ◽  
Arti Potdar ◽  
Anand Shah
Keyword(s):  
Process Parameters ◽  
Film Coating ◽  
Solid Content ◽  
Process Efficiency ◽  
Coating Process ◽  
Trial And Error ◽  
Rotating Speed ◽  
Coating Uniformity ◽  
Trial And Error Method ◽  
Error Method

The purpose of this research was to study the aqueous-based film coating of tablets utilizing a laboratory-scale side-vented perforated pan-coating apparatus. The process parameters of potential importance with respect to the final film quality were evaluated by using trial and error method. Tablets were evaluated for coating uniformity (mg), coating process efficiency (%), surface roughness, and %LOD (loss on drying). Spray rate and inlet air temperature both affect the all characteristic of coated tablets. Rotating speed of pan mainly affect the coating uniformity of tablets. % Solid content affects the surface of coated tablets and also creates a problem in spray flow. The process parameters relevant to a side-vented perforated pan coating process can be identified and, consequently, optimized.

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