Improved Agitators Applied to High Viscosity Fluids in Concentrated Juices

2003 ◽  
Author(s):  
E. Souza ◽  
A. C. Leal ◽  
F. L. Torsani ◽  
I. R. Hory
Keyword(s):  
Axial Flow ◽  
Internal Surface ◽  
High Viscosity ◽  
Viscous Fluids ◽  
Process Time ◽  
Standard Process ◽  
Internal Surface Area ◽  
Innovative Solution ◽  
The Cost ◽  
New System

The main objective of this work was to investigate a new agitation system, which would improve the standard process for concentrated juice after evaporation. The commonly used agitators for this kind of application were analyzed, including anchor agitators with tangential flow and pitched-blade agitators with axial flow. A pilot unit was installed “in company.” The results of the pilot test were scaled-up to an industrial size agitator with pitched-blade impellers. Three impellers, each with four blades at a 45° angle, were mounted on an off-center shaft. Better results were obtained in all the aspects analyzed. Process time was reduced by a factor often, power consumption was reduced by a factor of five, without air incorporation into the product. The new system had less internal surface area to be cleaned than the old system with an anchor impeller. Additionally, the new equipment was only one-fourth the cost of a similar installation with an anchor impeller. This innovative solution demonstrates the practical substitution of pitched-blade impellers for an anchor impeller in viscous fluids. Paper published with permission.

scholarly journals Porous Silicon Optical Devices: Recent Advances in Biosensing Applications

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1336
Author(s):  
Rosalba Moretta ◽  
Luca De Stefano ◽  
Monica Terracciano ◽  
Ilaria Rea
Keyword(s):  
Porous Silicon ◽  
Internal Surface ◽  
Cost Effective ◽  
Porous Matrix ◽  
Optical Biosensors ◽  
Internal Surface Area ◽  
Research Fields ◽  
Transduction Mechanisms ◽  
Index Changes ◽  
The Cost

This review summarizes the leading advancements in porous silicon (PSi) optical-biosensors, achieved over the past five years. The cost-effective fabrication process, the high internal surface area, the tunable pore size, and the photonic properties made the PSi an appealing transducing substrate for biosensing purposes, with applications in different research fields. Different optical PSi biosensors are reviewed and classified into four classes, based on the different biorecognition elements immobilized on the surface of the transducing material. The PL signal modulation and the effective refractive index changes of the porous matrix are the main optical transduction mechanisms discussed herein. The approaches that are commonly employed to chemically stabilize and functionalize the PSi surface are described.

What catalysis needs from the electron microscopist

1988 ◽  
Vol 46 ◽  
pp. 694-695
Author(s):  
Alexis T. Bell
Keyword(s):  
Active Sites ◽  
Heterogeneous Catalysts ◽  
Catalyst Deactivation ◽  
Surface Composition ◽  
Internal Surface ◽  
Active Phase ◽  
Atomic Scale ◽  
Metal Catalyst ◽  
Internal Surface Area ◽  
Porous Support

Heterogeneous catalysts, used in industry for the production of fuels and chemicals, are microporous solids characterized by a high internal surface area. The catalyticly active sites may occur at the surface of the bulk solid or of small crystallites deposited on a porous support. An example of the former case would be a zeolite, and of the latter, a supported metal catalyst. Since the activity and selectivity of a catalyst are known to be a function of surface composition and structure, it is highly desirable to characterize catalyst surfaces with atomic scale resolution. Where the active phase is dispersed on a support, it is also important to know the dispersion of the deposited phase, as well as its structural and compositional uniformity, the latter characteristics being particularly important in the case of multicomponent catalysts. Knowledge of the pore size and shape is also important, since these can influence the transport of reactants and products through a catalyst and the dynamics of catalyst deactivation.

scholarly journals Heat-Up Performance of Catalyst Carriers—A Parameter Study and Thermodynamic Analysis

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 964
Author(s):  
Thomas Steiner ◽  
Daniel Neurauter ◽  
Peer Moewius ◽  
Christoph Pfeifer ◽  
Verena Schallhart ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Surface Area ◽  
Internal Surface ◽  
Installation Space ◽  
Parameter Study ◽  
Thin Wall ◽  
Primary Role ◽  
Internal Surface Area

This study investigates geometric parameters of commercially available or recently published models of catalyst substrates for passenger vehicles and provides a numerical evaluation of their influence on heat-up behavior. Parameters considered to have a significant impact on the thermal economy of a monolith are: internal surface area, heat transfer coefficient, and mass of the converter, as well as its heat capacity. During simulation experiments, it could be determined that the primary role is played by the mass of the monolith and its internal surface area, while the heat transfer coefficient only has a secondary role. Furthermore, an optimization loop was implemented, whereby the internal surface area of a commonly used substrate was chosen as a reference. The lengths of the thin wall and high cell density monoliths investigated were adapted consecutively to obtain the reference internal surface area. The results obtained by this optimization process contribute to improving the heat-up performance while simultaneously reducing the valuable installation space required.

Surveillance Models of Large-Scale ESP With High Viscosity Fluids and Gas

2012 ◽  
Author(s):  
Lissett Barrios ◽  
Stuart Scott ◽  
Charles Deuel
Keyword(s):  
Large Scale ◽  
Two Phase Flow ◽  
Electrical Current ◽  
High Viscosity ◽  
Viscous Fluids ◽  
Phase Flow ◽  
Centrifugal Pumps ◽  
Operational Parameters ◽  
Two Phase ◽  
Operational Conditions

The paper reports on developmental research on the effects of viscosity and two phases, liquid–gas fluids on ESPs which are multi stage centrifugal pumps for deep bore holes. Multiphase viscous performance in a full-scale Electrical Submersible Pump (ESP) system at Shell’s Gasmer facility has been studied experimentally and theoretically. The main objectives is to predict the operational conditions that cause degradations for high viscosity fluids when operating in high Gas Liquid Radio (GLR) wells to support operation in Shell major Projects. The system studied was a 1025 series tandem WJE 1000. The test was performed using this configuration with ten or more pump stages moving fluids with viscosity from 2 to 200 cP at various speed, intake pressure and Gas Void Fractions (GVF). For safety considerations the injected gas was restricted to nitrogen or air. The ESP system is a central artificial lift method commonly used for medium to high flow rate wells. Multiphase flow and viscous fluids causes problems in pump applications. Viscous fluids and free gas inside an ESP can cause head degradation and gas locking. Substantial attempts have been made to model centrifugal pump performance under gas-liquid viscous applications, however due to the complexity this is still a uncertain problem. The determination of the two-phase flow performance in these harmful conditions in the ESP is fundamental aspects in the surveillance operation. The testing at Shell’s Gasmer facility revealed that the ESP system performed as theoretical over the range of single flowrates and light viscosity oils up to Gas Volume Fractions (GVF) around 25%. The developed correlations predict GVF at the pump intake based on the operational parameters. ESP performance degrades at viscosity higher than 100cp as compared to light oil applications, gas lock condition is observed at gas fraction higher than 45%. Pump flowrate can be obtained from electrical current and boost for all range of GVF and speed. The main technical contributions are the analysis of pump head degradation under two important variables, high viscosity and two-phase flow inside the ESP.

Paperometer: A Low-Cost Incentive Spirometer

2020 ◽  
Author(s):  
Shonit Nair Sharma ◽  
Devrina Chidambaram ◽  
Gianna Mizzi ◽  
Daniel Rosen ◽  
Kristin Slaughter ◽  
...  
Keyword(s):  
Lung Function ◽  
Medical Devices ◽  
Low Cost ◽  
Environmental Friendliness ◽  
Global Pandemic ◽  
Innovative Solution ◽  
Repeated Use ◽  
Functional Prototype ◽  
The Cost ◽  
Respiratory Rehabilitation

Abstract As a preemptive response to the widespread need for respiratory medical devices developing in the wake of the COVID-19 pandemic, we propose a low-cost incentive spirometer for respiratory rehabilitation in patients with reduced lung function. An incentive spirometer manufactured entirely out of recyclable material, termed “Paperometer,” aims to address the multifaced problem of medical device inaccessibility: high cost, lack of user- or environmental-friendliness, and unavailability to those who need them the most. Operating in accordance with governing physical formulae including Ohm’s law and the Hagen-Poiseuille equation, Paperometer is intended to improve the user’s lung function through repeated use of the device, which facilitates slow, deep breaths of air. Several prototypes were created based on a list of design criteria established through background research and stakeholder interviews. From four initial prototypes, all created predominantly from simple foldable geometries, one design was selected for further iteration. The most promising functional prototype was crafted from recyclable plastic and paper folded into various shapes including a box, tube, and pinwheel. The Paperometer concept stands as an innovative solution to reduce the cost and environmental burden of meeting the demand for medical devices. Once validated, the device may serve as an important tool in combating the ongoing global pandemic.

Impingement/Effusion Cooling Wall Heat Transfer: Reduced Number of Impingement Jet Holes Relative to the Effusion Holes

2017 ◽  
Author(s):  
Abubakar M. El-Jummah ◽  
Ahmad Nazari ◽  
Gordon E. Andrews ◽  
John E. J. Staggs
Keyword(s):  
Heat Transfer ◽  
Internal Surface ◽  
Surface Flow ◽  
Electrical Heating ◽  
Wall Heat Transfer ◽  
Internal Wall ◽  
Suction Surface ◽  
Internal Surface Area ◽  
Impingement Jet ◽  
Effusion Hole

Internal wall heat transfer for impingement/effusion cooling was measured and predicted using conjugate heat transfer (CHT) computational fluid dynamics (CFD). The work was only concerned with the internal wall heat transfer and not with the effusion film cooling and there was no hot gas crossflow. Previous work had predicted impingement/effusion internal wall cooling with equal number of holes. The present work investigated a small number of impingement holes and a larger number of effusion holes. The aim was to see if the effusion holes acted as a suction surface to the impingement surface flow and thus enhanced the wall heat transfer. Hole ratios of 1/4, 1/9 and 1/25 were studied by varying the number of effusion holes for a fixed array of impingement holes and a fixed impingement gap, Z, of 8 mm. The Z/D for the impingement holes was 2.7. The impingement hole pitch, X, to diameter, D ratio X/D was 10.6 at a constant effusion hole X/D of 4.7 for all the configurations. The impingement holes were aligned on the midpoint of four effusion holes. The results were computed for a mass flux G from 0.1–0.94 kg/sm2bar for all n. This gave 26 separate CFD/CHT computations. Locally surface, X2, average heat transfer coefficient (HTC), hx, values were determined using the lumped capacitance method. Nimonic 75 metal walls with imbedded thermocouples were used to determine hx from the time constant in a transient cooling experiment following electrical heating to about 80°C. The CHT/CFD predictions showed good agreement with measured data and the highest number of effusion holes for the 1/25 hole ratio gave the highest h. However, comparison with the predicted and experimental results for equal number of impingement and effusion holes for the same Z, showed that there was little advantage of decreasing the number of impingement holes, apart from that of decreasing the Z/D significantly for the 1/15 hole ratio, which increased the heat transfer. The largest number of effusion holes had the highest heat transfer due to the greater internal surface area of the holes and their closer spacing. This was present irrespective of the number of impingement holes and there was no evidence of any benefit of the 25 effusion holes enhancing the single impingement jet heat transfer. For the lowest number of effusion hole there was predicted to be a small disadvantage of reducing the number of impingement jets.

scholarly journals Impact of Nanoparticle Consolidation on Charge Separation Efficiency in Anatase TiO2 Films

2021 ◽  
Vol 9 ◽  
Author(s):  
Karin Rettenmaier ◽  
Thomas Berger
Keyword(s):  
Thermal Annealing ◽  
Charge Separation ◽  
Separation Efficiency ◽  
Internal Surface ◽  
Processing Temperature ◽  
Cyclic Voltammograms ◽  
Internal Surface Area ◽  
Deep Traps ◽  
Charge Separation Efficiency ◽  
The Impact

Mesoporous films and electrodes were prepared from aqueous slurries of isolated anatase TiO2 nanoparticles. The resulting layers were annealed in air at temperatures 100°C ≤ T ≤ 450°C upon preservation of internal surface area, crystallite size and particle size. The impact of processing temperature on charge separation efficiency in nanoparticle electrodes was tracked via photocurrent measurements in the presence of methanol as a hole acceptor. Thermal annealing leads to an increase of the saturated photocurrent and thus of the charge separation efficiency at positive potentials. Furthermore, a shift of capacitive peaks in the cyclic voltammograms of the nanoparticle electrodes points to the modification of the energy of deep traps. Population of these traps triggers recombination possibly due to the action of local electrostatic fields attracting photogenerated holes. Consequently, photocurrents saturate at potentials, at which deep traps are mostly depopulated. Charge separation efficiency was furthermore investigated for nanoparticle films and was tracked via the decomposition of hydrogen peroxide. Our observations evidence an increase of charge separation efficiency upon thermal annealing. The effect of particle consolidation, which we associate with minute atomic rearrangements at particle/particle contacts, is attributed to the energetic modification of deep traps and corresponding modifications of charge transport and recombination, respectively.

Élimination des hydrures métalliques des déchets gazeux d'un réacteur LP-MOVPE pour la croissance de composés (In, Ga) (As, P)

1993 ◽  
Vol 71 (7-8) ◽  
pp. 307-315 ◽  
Author(s):  
P. Cova ◽  
R. A. Masut ◽  
R. Lacoursière ◽  
A. Bensaada ◽  
C. A. Tran ◽  
...  
Keyword(s):  
Epitaxial Growth ◽  
Transit Time ◽  
Vapour Phase ◽  
Reaction Chamber ◽  
Vapour Phase Epitaxy ◽  
Toxic Gases ◽  
Gas Molecules ◽  
Chemical Products ◽  
The Cost ◽  
New System

We have realized a new system for treating gaseous wastes from a metallorganic vapour phase epitaxy (MOVPE) reactor used for the low pressure epitaxial growth of intrinsic and doped semiconducting crystals in the InGaAsP family. The system is based on a series of 5 successive phases of destruction: dilution, combustion pyrolysis, condensation and filtering. The design minimizes the cost remarkably and optimizes the incineration of toxic gases. After the combustion of 138 m3 of H2 and the incineration of 276 L of phosphine, we observe that the reaction chamber does not show any corrosion nor any deposit of chemical products, which are daily eliminated together with the water produced during the combustion. For the maximum phosphine concentration that has been used (7340 ppm), no phosphine concentration has been detected in the output with a detecting system having a sensitivity of 0.001 ppm. For the total fluxes entering the reaction chamber (10–25 L/min), the transit time (1s) of gas molecules does not limit the efficiency of conversion of toxic gases. This is important if one wishes to adapt this system to a MOVPE production reaction using a higher flux of phosphine.[Journal translation]

Wireless Heartrate Monitoring Along Prioritized Alert Notification Using Mobile Techniques

2020 ◽  
pp. 230-243
Author(s):  
Rajasekaran Rajkumar
Keyword(s):  
Information System ◽  
Quality Of Service ◽  
Cost Effective ◽  
Efficient Solutions ◽  
Essential Information ◽  
Hospital Database ◽  
Clinical Records ◽  
The Cost ◽  
New System

The increasing number of problems that need to be addressed in the hospital sector calls for innovation in this field. It brings us the need to find cost-effective and memory-efficient solutions to handle the vast data and sector it into essential information to operate on the patient. There used to be many systems to manage clinical records which are fixed at a place. It is quite complicated to get the information and make this data available at a patient's bedside. This leads to a considerable amount of wasted time in moving to those storage PCs and also the cost afforded is comparatively high. A computer system that controls and accomplishes all the data in the hospital database to provide effective healthcare is called hospital information system (HIS). The introduction of HIS made billing and inventor easier for the staff. This paper discusses diverse methods that improve the cost, demands of HIS, and provide techniques to function efficiently using wireless networks. Also, the paper gives a comparative study on different aspects such as cost, quality of service, transportation, and security. A new system is proposed by combining the wireless healthcare system along prioritized alert notification.

Adoption of a New Online Travel Management System for FED-AK

2010 ◽  
Vol 12 (1) ◽  
pp. 1-16 ◽  
Author(s):  
Aundrea Kell ◽  
Shari Pierre ◽  
Bogdan Hoanca
Keyword(s):  
Transaction Costs ◽  
Management System ◽  
Government Agency ◽  
Lessons Learned ◽  
Online Help ◽  
Extensive Training ◽  
Employee Resistance ◽  
The Cost ◽  
Online Travel ◽  
New System

This case describes the implementation of an online travel management system at FED-AK, the Alaska office of a U.S. government agency. The previous system was intended to accomplish the same functionality, but due to employee resistance, it was used only as a forms generator in conjunction with a paper- and mail-based process. The new system is integrated, which compels employees to use all the functionality provided. It also incorporates many lessons learned from the old system—in particular, extensive training and online help functions. The system is expected to significantly reduce the cost of travel by minimizing errors, enforcing policies, and reducing transaction costs. The system will also lead to faster reimbursement of employee travel expenses.

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