scholarly journals Effects of Operating Parameters on the Cut Size of Turbo Air Classifier for Particle Size Classification of SAC305 Lead-Free Solder Powder

Processes ◽  
2019 ◽  
Vol 7 (7) ◽  
pp. 427 ◽  
Author(s):  
Nipon Denmud ◽  
Kradsanai Baite ◽  
Thawatchai Plookphol ◽  
Somjai Janudom
Keyword(s):  
Feed Rate ◽  
Operating Parameters ◽  
Rotor Speed ◽  
Air Velocity ◽  
Inlet Velocity ◽  
Air Inlet ◽  
Multiple Variable ◽  
Air Classifier ◽  
Free Solder

In the present study, the effects of operating parameters, namely, rotor speed, feed rate, and inlet air velocity, on the cut diameter of a cage-type separator were studied. The design of experiments (DOE) method was used to investigate the relationship between the operating parameters and the cut size. The experimental results were statistically analyzed using MINITAB 16 software. Both the rotor speed and air inlet velocity had significant main effects on the cut size. The feed rate was also significant but had a weak effect with respect to the rotor speed and inlet air velocity effects. The cut size decreased with an increase in rotor speed and increased with an increase in air inlet velocity. However, the cut size slightly decreased with an increase in feed rate. An empirical multiple-variable linear model for predicting the cut size of the classification was created and presented. The results derived from the statistical analysis were in good agreement with those from the experiments, additionally extended from the DOE. The optimal conditions for classification of SAC305 powder with size range 25–40 μm were obtained when the turbo air classifier was operated at rotor speed 406 RPM, the feed rate 4 kg/h, and the air velocity 5 m/s. The smallest cut size of the classifier was about 27.8 μm.

The Study of a Classroom with Solar Chimney Hybrid Ventilation

2011 ◽  
Vol 243-249 ◽  
pp. 1755-1761
Author(s):  
Shu Hui Xu ◽  
Hai Guang Dong
Keyword(s):  
Natural Ventilation ◽  
Heat Sources ◽  
Solar Chimney ◽  
Air Velocity ◽  
Inlet Velocity ◽  
Air Inlet ◽  
Factors Influencing ◽  
Optimal Value ◽  
Temperature Efficiency ◽  
Hybrid Ventilation

In order to improve effect of hybrid ventilation, the paper discussed a solar chimney to enhance natural ventilation. Some factors influencing solar chimney hybrid ventilation in classroom, such as heat sources, air inlet arrangements, air velocity and solar radiation were studied by simulation and validated by experiments. The characteristics of temperature distribution and temperature efficiency in classroom were obtained and analyzed. A low position of air inlet in the room makes high temperature efficiency, the optimal value of the air inlet velocity is about 0.5 m/s. The research provides a better way to enhance hybrid ventilation by solar chimney.

scholarly journals PARAMETERS EFFECTING FORCED VORTEX FORMATION IN BLADE PASSAGEWAY OF DYNAMIC AIR CLASSIFIER

2017 ◽  
Vol 57 (5) ◽  
pp. 304 ◽  
Author(s):  
Martin Adamčík ◽  
Tomáš Svěrák ◽  
Peter Peciar
Keyword(s):  
Velocity Vector ◽  
Stokes Equations ◽  
Structural Parameters ◽  
Vortex Formation ◽  
Turbulence Models ◽  
Navier Stokes ◽  
Operating Parameters ◽  
Air Inlet ◽  
Vector Maps ◽  
Air Classifier

<p>Air classification of particulate materials is a method of classifying particles into coarse and fine fractions based on their size, density, or shape. Performance of the rotor air classifier is affected by operating parameters which include the classifier rotor speed, air inlet velocity and material feed rate. Effects of operating and structural parameters on turbulent flow field patterns inside of a dynamic air classifier are investigated. Increasing the computing power, together with new turbulence models and<br />approaches, to simulate complex fully turbulent problems by solving Navier-Stokes equations allows studying and capturing smaller flow structures and properties more accurately. Velocity vector maps for varying operating parameters are studied by means of numerical simulations. The experimental section includes a visualization of flow patterns and velocity vector maps in the rotor region by the use of the particle image velocimetry (PIV). Results are compared and discussed.</p>

Air Flow Analysis in Square Duct Bend

2014 ◽  
Vol 695 ◽  
pp. 622-626 ◽  
Author(s):  
Mohamad Nor Musa ◽  
Mohd Nurul Hafiz Mukhtar
Keyword(s):  
Reynolds Number ◽  
Pressure Drop ◽  
Cross Section ◽  
Air Flow ◽  
Flow Analysis ◽  
Maximum Velocity ◽  
Maximum Pressure ◽  
Air Velocity ◽  
Square Duct ◽  
Inlet Velocity

This paper present new result for experimental analysis of air flow velocity and pressure distributions between two ducts bend: (1) 90° duct bend with a single turning vane having 0.03m radius and (2) 90° duct bend with double turning vane, in 0.06 × 0.06 m duct cross section. The experiment used five different Reynolds numbers chosen between the ranges 1 ×104 and 6×104. Each experiment has four point measurements: (1) point 1 and point 2 at cross section A-A and (2) point 3 and point 4 at cross section B-B. The first experimental study used single turning vane radius 0.03m with inlet air velocity from 2.5m/s to 12.2m/s. And for the second experiment that used square turning vane with 0.03m radius. In experiment 2, the inlet air velocity also start from 2.5m/s to 12.2m/s. From analysis results, the pressure drop in experiment 1 is higher than experiment 2. As example the maximum pressure drop at 7.5m/s inlet air velocity between point 1 and 3 was found to be 71.6203 Pa in experiment 1 as compared to 61.8093 Pa in experiment 2. The velocity after duct bend is greater when using double turning vane compare used single turning vane as maximum velocity at point 3 in experiment 2 compare to velocity at point 3 in experiment 1 that is 55.677× 10-4 m/s and 54.221× 10-4 m/s. The velocity at duct wall is equal to zero. When increase the value of Reynolds number or inlet velocity, the maximum velocity and total pressure also increase. For example in experiment 1 at point 1, the velocity is 48.785 × 10-4 m/s at Reynolds number 1 ×104 and velocity 65.115×10-4 m/s at Reynolds number 12.2 ×104 . Velocity flow in duct section are lower than inlet velocity. In experiment 1, the inlet velocity is 2.5m/s meanwhile the maximum velocity in the duct section at point 2 is 73.075×10-4 m/s that is much more lower than inlet velocity.

PERFORMANCE ASSESSMENT OF A SOLID DESICCANT AIR DEHUMIDIFIER

2016 ◽  
Vol 78 (8-4) ◽  
Author(s):  
Nazri Kamsah ◽  
Haslinda Mohamed Kamar ◽  
Muhammad Imran Wan Khairuzzaman ◽  
M. Idrus Alhamid ◽  
Fazila Mohd Zawawi
Keyword(s):  
Removal Rate ◽  
Operating Parameters ◽  
Inlet Temperature ◽  
Moisture Removal ◽  
Desiccant Wheel ◽  
Air Inlet ◽  
Low Humidity ◽  
Experimental Rig ◽  
Humidity Environment

The presence of moisture in the air along with temperature has a long term and devastating effect on man and material. One way to create a low humidity environment is by using a solid desiccant wheel system. In the present work, an experimental analysis has been carried out under steady-state conditions to investigate the effects of different operating parameters on a solid desiccant wheel system performances. An experimental rig consists of an FFB300 air dehumidifier system was constructed. A parametric investigation was carried out to examine the effects of the reactivation air inlet temperature and process air outlet velocity on the thermal effectiveness, dehumidification efficiency, and moisture removal rate of the desiccant wheel system. The analysis shows that both thermal effectiveness and dehumidification efficiency decrease with the increase of the reactivation air inlet temperature, by 2.5 % and 43 %, respectively. Likewise, when the process air outlet velocity increases both performances criteria reduce by 10 % and 28 %, respectively. The moisture removal rate increases significantly by 30 % as the reactivation air inlet temperature increases. However, the process air outlet velocity has no significant effect on the moisture removal rate. 

scholarly journals Effect of Biodegradable Binder Properties and Operating Conditions on Growth of Urea Particles in a Fluidized Bed Granulator

Materials ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2320 ◽  
Author(s):  
Ehsan Zhalehrajabi ◽  
Kok Keong Lau ◽  
Ku Zilati Ku Shaari ◽  
Seyed Mojib Zahraee ◽  
Seyed Hadi Seyedin ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Air Temperature ◽  
Scale Up ◽  
Cost Effective ◽  
Stokes Number ◽  
Operating Conditions ◽  
Air Velocity ◽  
Air Inlet ◽  
Lower Temperature ◽  
Penetration Time

Granulation is an important step during the production of urea granules. Most of the commercial binders used for granulation are toxic and non-biodegradable. In this study, a fully biodegradable and cost-effective starch-based binder is used for urea granulation in a fluidized bed granulator. The effect of binder properties such as viscosity, surface tension, contact angle, penetration time, and liquid bridge bonding force on granulation performance is studied. In addition, the effect of fluidized bed process parameters such as fluidizing air inlet velocity, air temperature, weight of primary urea particles, binder spray rate, and binder concentration is also evaluated using response surface methodology. Based on the results, binder with higher concentration demonstrates higher viscosity and higher penetration time that potentially enhance the granulation performance. The viscous Stokes number for binder with higher concentration is lower than critical Stokes number that increases coalescence rate. Higher viscosity and lower restitution coefficient of urea particles result in elastic losses and subsequent successful coalescence. Statistical analysis indicate that air velocity, air temperature, and weight of primary urea particles have major effects on granulation performance. Higher air velocity increases probability of collision, whereby lower temperature prevents binder to be dried up prior to collision. Findings of this study can be useful for process scale-up and industrial application.

scholarly journals Thermal Performance of Tropical Atrium

2013 ◽  
Vol 12 (1) ◽  
pp. 34-40 ◽  
Author(s):  
Mohammad Baharvand ◽  
Mohd Hamdan Bin Ahmad ◽  
Tabassom Safikhan ◽  
Sayyed Mohammad Mahdi Mirmomtaz
Keyword(s):  
Energy Demand ◽  
Building Energy ◽  
Air Velocity ◽  
Humid Climate ◽  
Air Inlet ◽  
Architectural Feature ◽  
Common Problems ◽  
Hot And Humid Climate ◽  
Lower Temperature ◽  
Tropical Climates

Abstract Atrium is a popular architectural feature utilized widely by building designers and owners to bring various benefits such as adequate daylight, circulation spaces and surfaces for landscape applications. But atrium problems in tropical climates such as excessive daylight, glare and high temperature, which lead to increase building energy demand, have been reported. To avoid and reduce these unpleasant features, a side-lit atrium has been suggested. Although researchers proposed side-lit atrium to prevent common problems of atria, the lack of precedent research on this issue compels these authors to study atrium performance in hot and humid climate. So the research aims to examine two different atrium roof form types in terms of temperature and ventilation impacts in hot and humid climate of Malaysia using DesignBuilder as a simulation program. The results indicate lower temperature of side-lit model with better airflow pattern in comparison with top-lit model while the top-lit model provides higher air velocity at the air inlet and outlet.

Numerical Simulation Study of a New Type Solar Collector Wall System

2013 ◽  
Vol 860-863 ◽  
pp. 98-102
Author(s):  
Shu Hui Xu ◽  
Feng Jiao Zhang ◽  
Jian Kai Wang ◽  
Chang Liu
Keyword(s):  
Numerical Simulation ◽  
Velocity Field ◽  
Simulation Study ◽  
Solar Collector ◽  
Collection Efficiency ◽  
Inlet Velocity ◽  
Air Inlet ◽  
New Type ◽  
Collecting Efficiency ◽  
Wall System

In this paper, a new kind of solar collector wall system was designed. Numerical simulation for the orifice plate solar collector wall was carried out to analyze the change of the distributions of the temperature and velocity and the heat collecting efficiency under the conditions of different air inlet velocity. The results shows that the temperature stratification decreases with the increase of the inlet velocity, and the velocity field stratification enhances with the increase of the inlet velocity, and the collection efficiency first increases then decreases with the constantly increasing inlet velocity, and the collection efficiency is the highest when the inlet velocity is 2.5 m/s, up to 81.34%.

Critical rotating speed of rotor cup in an air suction open-end spinning machine

2016 ◽  
Vol 87 (13) ◽  
pp. 1593-1603 ◽  
Author(s):  
Meina Xiao ◽  
Hua-Shu Dou ◽  
Chuanyu Wu
Keyword(s):  
Flow Structure ◽  
Critical Speed ◽  
Stokes Equations ◽  
Flow Behavior ◽  
Three Dimensional ◽  
Rotor Speed ◽  
Pressure Balance ◽  
Rotating Speed ◽  
Air Inlet ◽  
Transfer Channel

Simulation of three-dimensional turbulent flow in a rotor spinning machine is carried out, and the flow structure and behavior in the rotor cup are analyzed. The governing equations are the steady three-dimensional Navier–Stokes equations and the Spalart–Allmaras turbulence model. The results show that the rotating speed has great influence on the flow behavior in the rotor cup. It is found that there is a critical speed of the rotor cup beyond which the pressure and velocity on the slip surface is not changed anymore regardless of the magnitude of the rotating speed. When the rotating speed is larger than this critical speed, the flow structure becomes unstable with the increasing of the rotating speed. The mechanism of this phenomenon is that the airflow in the rotor groove passes about 180 degrees from two sides along the rotor wall and a pressure balance is achieved. When the rotating speed is larger than the critical speed, the balance will break down. When the rotor speed is low, the flow characteristic in the air-inlet plane is mainly determined by the high-speed airflow at the outlet of the transfer channel. However, when the rotor speed is higher than the critical speed of n = 80,000 r/min, the flow behavior is mainly determined by the rotating rotor. In the meridian plane perpendicular to the air-inlet plane, the flow behavior is mainly determined by the rotor speed. The rotating speed of the rotor has little effect on the flow characteristics in the transfer channel.

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