Determination of the Mean Specific Power Input in Stirred Vessels with Suspensions

1992 ◽  
pp. 107-115 ◽  
Author(s):  
R. K. Geisler ◽  
C. Buurman ◽  
A. B. Mersmann
Keyword(s):  
Power Input ◽  
Specific Power ◽  
Stirred Vessels ◽  
Specific Power Input ◽  
The Mean

The Experiment Study on the Void Fraction in PPG Solution

2012 ◽  
Vol 455-456 ◽  
pp. 815-819
Author(s):  
Qian Qiao Chen ◽  
Qin Zhong ◽  
Li Qi ◽  
Qun Qun Cheng ◽  
Lu Wang ◽  
...  
Keyword(s):  
Gas Phase ◽  
Scale Up ◽  
Power Input ◽  
Gas Holdup ◽  
Specific Power ◽  
Experiment Study ◽  
Operation Parameter ◽  
Polymerization Reactor ◽  
Specific Power Input ◽  
Polyether Polyol

Using the three-layer impellers with big size diameter in an unbaffled elliptic bottom stirred tank，the gas holdup (ε) was studied in the systems of air-polyether polyol (PPG). The results indicate that the gas holdup in the air-PPG system is higher, it increase with the superficial gas phase velocity (Vs) and specific power input (Pm) increase, and decrease as the temperature increase. The influence is severely when the temperature is below 100°C, and is weak above 100 °C.The conclusions give reference for choosing the operation parameter and designing and scale-up of PPG polymerization reactor.

A Comparison of Mechanical and Energetic Estimates of Flight Cost for Hovering Sphinx Moths

1981 ◽  
Vol 91 (1) ◽  
pp. 117-129 ◽  
Author(s):  
TIMOTHY M. CASEY
Keyword(s):  
Body Mass ◽  
Power Output ◽  
Power Input ◽  
Flight Mechanics ◽  
Mechanical Power ◽  
Specific Power ◽  
Power Requirement ◽  
Power Cost ◽  
Mechanical Power Output ◽  
Specific Power Input

Mechanical power output, based on measured power input, is compared with calculated values for aerodynamic and inertial power output in sphinx moths ranging from 350 to 3400 mg. Aerodynamic power output, calculated from momentum and blade-element aerodynamic theories, scales with the 1.08 power of body mass, amounting to about 40% of the mechanical power output of large moths to about 15% in the smallest individuals. Calculated value for the inertial power cost of hovering represents a larger fraction of the mechanical power output than the aerodynamic cost in all moths, with the value increasing as body mass decreases. Independent estimates of inertial power output based on metabolic data are similar to those obtained from calculations of the moment of inertia for the wings. These data suggest that inertial power output represents the largest power requirement for hovering sphinx moths, and that elastic torques do not significantly reduce the mechanical power output. Higher mass-specific power input of small sphinx moths appears to be the result of greater mass-specific inertial power requirements. Estimates of flight cost based on morphology and flight mechanics of sphinx moths yield values for mechanical power output which are similar to values estimated from their flight metabolism.

scholarly journals Studies on oxygen mass transfer in stirred bioreactors 2: Suspensions of bacteria, yeasts and fungis

2003 ◽  
Vol 57 (6) ◽  
pp. 276-287 ◽  
Author(s):  
Anca-Irina Galaction ◽  
Corneliu Oniscu ◽  
Dan Cascaval
Keyword(s):  
Mass Transfer ◽  
Mass Transfer Rate ◽  
Power Input ◽  
Specific Power ◽  
Oxygen Mass Transfer ◽  
Stirred Bioreactor ◽  
Operating Variables ◽  
Surface Aeration ◽  
Velocity Surface ◽  
Specific Power Input

The aim of these experiments is to study the oxygen mass transfer rate by means of the mass transfer coefficient, for a stirred bioreactor and different fermentation broths, using a large domain of operating variables. For quantifying the effects of the considered factors (concentration and morphology of the biomass, specific power input, superficial air velocity surface aeration) on k\a, the experiments were carried out for non-respirating biomass suspensions of Propionibacterium shermanii Saccharomyces cerevisiae and Penicillium chrysogenum, mycelial aggregates (pellets) and free mycelia morphological structures.

scholarly journals Build Strategy and Impact Strength of SLM Produced Maraging Steel (1.2709)

2020 ◽  
Author(s):  
Anders E. W. Jarfors ◽  
Akash Chikke Gowda Hosapalya Shashidhar ◽  
Hrushi Kailash Yepur ◽  
Jacob Steggo ◽  
Nils-Eric Andersson ◽  
...  
Keyword(s):  
Impact Strength ◽  
Maraging Steel ◽  
Fracture Behaviour ◽  
Power Input ◽  
Impact Testing ◽  
Specific Power ◽  
Powder Bed ◽  
Scan Speed ◽  
Specific Power Input ◽  
The Impact

The current paper aims to study the impact properties of additively manufactured Maraging steel (1.2709) using laser powder bed fusion (PBF-L) processing. The specimens were manufactured using 3Dsystems ProX 300 equipment under constant specific power input, or Andrew Number. The interactions between the build strategy and parameters, such as Hatch spacing and Scan speed was, and the impact strength and fracture were investigated. The Impact energy anisotropy was also investigated parallel and perpendicular to the build direction. Instrumented impact testing was performed, and the fractography supported that the fusion zone geometry dictated the fracture behaviour. The influence from gaseous elements such as Nitrogen, Oxygen and Hydrogen was found insignificant at the levels found in the printed material.

scholarly journals Build Strategy and Impact Strength of SLM Produced Maraging Steel (1.2709)

Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 51
Author(s):  
Anders E. W. Jarfors ◽  
Akash Chikke Gowda Hosapalya Shashidhar ◽  
Hrushi Kailash Yepur ◽  
Jacob Steggo ◽  
Nils-Eric Andersson ◽  
...  
Keyword(s):  
Impact Strength ◽  
Maraging Steel ◽  
Fracture Behavior ◽  
Power Input ◽  
Impact Testing ◽  
Specific Power ◽  
Powder Bed ◽  
Scan Speed ◽  
Specific Power Input ◽  
The Impact

The current paper aimed to study the impact properties of additively manufactured maraging steel (1.2709) using laser powder bed fusion (PBF-L) processing. The specimens were fabricated using 3D Systems ProX 300 equipment under constant specific power input, or Andrew number. The interactions between the build strategy and parameters such as hatch spacing and scan speed was, and the impact strength and fracture were investigated. The impact energy anisotropy was also investigated in parallel and perpendicular to the build direction. Instrumented impact testing was performed, and the fractography supported that the fusion zone geometry dictated the fracture behavior. The influence from gaseous elements such as nitrogen, oxygen, and hydrogen was found insignificant at the levels found in the printed material.

scholarly journals Perspective Design of Algae Photobioreactor for Greenhouses—A Comparative Study

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1338
Author(s):  
Kateřina Sukačová ◽  
Pavel Lošák ◽  
Vladimír Brummer ◽  
Vítězslav Máša ◽  
Daniel Vícha ◽  
...  
Keyword(s):  
Chlorella Pyrenoidosa ◽  
Power Input ◽  
Pilot Scale ◽  
Sustainable Production ◽  
Specific Power ◽  
Energetic Efficiency ◽  
Flat Panel ◽  
Tubular Photobioreactor ◽  
Specific Power Input ◽  
Negative Balance

The continued growth and evolving lifestyles of the human population require the urgent development of sustainable production in all its aspects. Microalgae have the potential of the sustainable production of various commodities; however, the energetic requirements of algae cultivation still largely contribute to the overall negative balance of many operation plants. Here, we evaluate energetic efficiency of biomass and lipids production by Chlorella pyrenoidosa in multi-tubular, helical-tubular, and flat-panel airlift pilot scale photobioreactors, placed in an indoor environment of greenhouse laboratory in Central Europe. Our results show that the main energy consumption was related to the maintenance of constant light intensity in the flat-panel photobioreactor and the culture circulation in the helical-tubular photobioreactor. The specific power input ranged between 0.79 W L−1 in the multi-tubular photobioreactor and 6.8 W L−1 in the flat-panel photobioreactor. The construction of multi-tubular photobioreactor allowed for the lowest energy requirements but also predetermined the highest temperature sensitivity and led to a significant reduction of Chlorella productivity in extraordinary warm summers 2018 and 2019. To meet the requirements of sustainable yearlong microalgal production in the context of global change, further development towards hybrid microalgal cultivation systems, combining the advantages of open and closed systems, can be expected.

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