Improving Saturation Efficiency with Implicit Relations

2019 ◽  
pp. 301-320 ◽  
Author(s):  
Shruti Biswal ◽  
Andrew S. Miner
Keyword(s):  
Saturation Efficiency

Saturation efficiency for 1550 nm photons with 2×2 amorphous Mo₈₀Si₂₀ superconducting nanowire at 22 K

2021 ◽  
Author(s):  
Labao Zhang ◽  
Feiyan Li ◽  
Hang Han ◽  
qi chen ◽  
biao zhang ◽  
...  
Keyword(s):  
Saturation Efficiency ◽  
Superconducting Nanowire

Experimental Evaluation of Evaporative Cooler Using Agro Materials

2015 ◽  
Vol 23 (04) ◽  
pp. 1550028 ◽  
Author(s):  
R. Ramkumar ◽  
M. Kesavan ◽  
A. Ragupathy
Keyword(s):  
Ambient Condition ◽  
Experimental Results ◽  
Test Results ◽  
Test Rig ◽  
Air Velocity ◽  
Different Types ◽  
Saturation Efficiency ◽  
Evaporative Cooler ◽  
Luffa Sponge ◽  
Efficiency Improve

The purpose of the study is to investigate the direct evaporate cooler in hot and humid regions with two different types of agro-based materials. In our experimental study, the locally available agro materials luffa (Sponge Gourd), zizanioides (Vetiver) were used with various thickness and the experimental results were compared with mathematical values. The operating parameters of pad thickness, air velocity, were changed and the performance of the cooler was analyzed. A test rig was designed and fabricated to collect experimental data. The performance of the evaporative cooler was evaluated based on the ambient condition. The analysis of the data indicated that cooling saturation efficiency improve with decrease of air velocity and higher pad thickness. It was shown that zizanioides-based pad with 160[Formula: see text]mm thickness has the higher performance (88%) at 4.5[Formula: see text]m/s air velocity in comparison with luffa pad materials. The experimental results of outlet air temperature and number of transfer units (NTU) were compared with mathematical model. The test results were within the limit of 15% and 10% to mathematical values.

Thermally Developing 3D Cross Flow Between Cross Corrugated Parallel Plates in Evaporative Coolers

2010 ◽  
Author(s):  
Ehsan Tavakoli ◽  
Reza Hosseini
Keyword(s):  
Pressure Drop ◽  
Flow Direction ◽  
Cross Flow ◽  
Navier Stokes ◽  
Parallel Plates ◽  
Main Emphasis ◽  
Saturation Efficiency ◽  
Finite Difference Discretization ◽  
Corrugated Plates ◽  
Energy Equations

The 3D cross flow between parallel corrugated plates with perpendicular directions of corrugation is numerically modeled as a laminar, incompressible, steady flow. The present work tries to investigate the thermally developing characteristics of the flow in this type of geometry, in the case of constant temperature on walls. The main emphasis is on introducing correlations for saturation efficiency and simply modeling the evaporation process within evaporative coolers with such geometries. The applied numerical method is the Chorin’s artificial incompressibility method and finite difference discretization is used to model the Navier-Stokes and energy equations in a structured mesh. The results show that saturation efficiency decreases with increase in Reynolds number. This also depends on the depth of evaporative media along the flow direction. Increasing the number of waves along the flow direction, results higher saturation efficiencies and also more pressure drop. For a specific saturation efficiency, the overall pressure drop decreases at higher amplitude to wavelength ratios. Also the overall pressure drop grows as the depth of the domain increases. The same trend is observed for experimental data of commercial evaporative pads.

A simplified method for assessing the saturation efficiency at full-scale dissolved air flotation plants

1998 ◽  
Vol 38 (6) ◽  
pp. 303-310 ◽  
Author(s):  
S. Steinbach ◽  
J. Haarhoff
Keyword(s):  
Full Scale ◽  
Dissolved Air Flotation ◽  
Atmospheric Air ◽  
Comprehensive Method ◽  
Simplified Method ◽  
Saturation Efficiency ◽  
Air Flotation ◽  
Saturation Systems ◽  
Measuring Unit ◽  
Dissolved Air

This paper proposes a simplified yet comprehensive method for measuring the efficiency of air saturation systems used in dissolved air flotation. It is based on a review of methods suggested by other researchers in this field, but several improvements to existing methods are made. A saturation air composition different than that of atmospheric air and incomplete precipitation in the measuring unit after pressure release are taken into consideration. The developed measurement and calculation procedure provide engineers and operators alike with an easy tool to assess the saturation efficiency of their system at full-scale DAF plants as well as at pilot and laboratory scale plants.

scholarly journals Anomalous transport in discrete arcs and simulation of double layers in a model auroral circuit

1987 ◽  
Vol 5 (2) ◽  
pp. 381-391 ◽  
Author(s):  
Robert A. Smith
Keyword(s):  
Transmission Line ◽  
Double Layer ◽  
Anomalous Transport ◽  
Double Layers ◽  
Lower Hybrid ◽  
Double Layer Potential ◽  
Layer Potential ◽  
Variable Resistor ◽  
Potential Structure ◽  
Saturation Efficiency

The evolution and long-time stability of a double layer in a discrete auroral arc requires that the parallel current in the arc, which may be considered uniform at the source, be diverted within the arc to charge the flanks of the U-shaped double-layer potential structure. A simple model is presented in which this current re-distribution is effected by anomalous transport based on electrosatic lower hybrid waves driven by the flank structure itself. This process provides the limiting constraint on the double-layer potential. The flank charging may be represented as that of a nonlinear transmission line. A simplified model circuit, in which the transmission line is represented by a nonlinear impedance in parallel with a variable resistor, is incorporated in a 1-d simulation model to give the current density at the DL boundaries. Results are presented for the scaling of the DL potential as a function of the width of the arc and the saturation efficiency of the lower hybrid instability mechanism.

Performance Study of Cooling Pads

2013 ◽  
Vol 664 ◽  
pp. 931-935 ◽  
Author(s):  
Banyat Niyomvas ◽  
Bunjerd Potakarat
Keyword(s):  
Water Flow ◽  
Cotton Fabric ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Performance Study ◽  
Saturation Efficiency ◽  
Evaporative Cooler

The efficiency of an evaporative cooler on different cooling pads have been studied. Two type of cooling pads made of a curtain fabric and a raw cotton fabric were comparatively studied. The effect of blower speeds at 725, 1015 and 1450 RPM and water flow rate of 26.9 liters per minute were investigated. The results showed that an average of the different temperature between inlet and outlet were 2.9 oC and 1.7 oC for a curtain fabric and a raw cotton fabric, respectively. Saturation efficiency of the cooling pads made of a curtain fabric was in the ranges of 46.3 to 61.3% or represents an average of 54.8%, and 29.7 to 39.2% or represents an average of 33.2% for a raw cotton fabric.

scholarly journals PENGURANGAN KADAR H2S DARI BIOGAS LIMBAH CAIR RUMAH SAKIT DENGAN METODE ADSORPSI

Konversi ◽  
2013 ◽  
Vol 2 (1) ◽  
pp. 1
Author(s):  
Alwathan Alwathan ◽  
Mustafa Mustafa ◽  
Ramli Thahir
Keyword(s):  
Activated Carbon ◽  
Residence Time ◽  
Carbon Adsorbent ◽  
Mesh Size ◽  
Freundlich Isotherm ◽  
Packing Material ◽  
The Third ◽  
Carbon Burnout ◽  
Saturation Efficiency ◽  
Materials Used

Biogas sebelum digunakan harus dimurnikan terlebih dahulu dari kandungan asam sulfida (H2S) yang meskipun jumlahnya kecil namun menimbulkan kerugian karena menimbulkan korosi pada logam  atau apabila dibakar akan membentuk SO2 atau SO3 yang dikenal dengan SOx yang menyebabkan terjadinya hujan asam. Tujuan dari penelitian ini adalah mencari waktu jenuh adsorben dalam menjerap H2S, mengetahui kemampuan adsorben karbon aktif dalam menyerap dan mencari konstanta persamaan adsorpsi isotherm Freundlich pada variasi ukuran karbon aktif  yang digunakan dalam menghitung waktu tinggal adsorpsi. Bahan yang digunakan adalah sludge dari hasil pengolahan limbah cair rumah sakit. Metode yang dilakukan dalam penelitian ini yaitu mengukur kandungan H2S  dalam biogas sebelum melalui adsorber disusun secara seri ukuran tinggi kolom 70 cm, diameter ½ inch, tinggi isian 64 cm bahan isian karbon aktif dengan ukuran 4, 7, 10, 12, 14 mesh kecepatan biogas 0.5 liter/menit diperoleh  hasil karbon aktif paling cepat mengalami kejenuhan ukuran 4 mesh yaitu 60 menit, H2S yang terjerap 202.42  unit  dari effisiensi kejenuhan 9.76% sedangkan waktu jenuh paling lama 90 menit ukuran karbon aktif  14 mesh H2S yang terjerap 368.65 unit effisiensi kejenuhan 9.79%. Karbon aktif yang optimal digunakan yaitu 12 mesh waktu jenuh 80 menit, effisiensi kejenuhan 9.82% dengan waktu tinggal 127.927 detik sedangkan waktu tinggal paling singkat terjadi pada ukuran adsorben 4 mesh, yaitu waktu tinggal  73.855 detik. Keywords: limbah, biogas, adsorpsi, asam sulfida, karbon aktif Biogas is purified before being used in from the acid content of sulfide (H2S), although the numbers are small, but the resulting loss due to corrode metal or when burned to form SO2 or SO3, known as SOx that cause acid rain. The purpose of this study to find time in the saturated adsorbent adsorb H2S,  the ability of the activated carbon adsorbent adsorb adsorption equation and find the constants in the Freundlich isotherm variations in the size of activated carbon for in calculating the residence time of adsorption. The materials used are the sludge from the hospital wastewater treatment. The method was performed in this study for  measure the content of H2S in the biogas before passed  through to the third adsorber column 70 cm height, ½ inch diameter, 64 cm high filling packing material of activated carbon with a size of 4, 7, 10, 12, 14 mesh velocity biogas 0 , 5 litre. / min obtained results most rapidly activated carbon burnout mesh size of 4 is 60 minutes, H2S is adsorption 202.42 mg of 9.76% while the efficiency of saturation saturation time exceeding 90 minutes 14 mesh size activated carbon is adsorption H2S 368.65 mg 9.79% saturation efficiency. Optimal use of activated carbon which is 12 mesh saturated 80-minute time, efficiency saturated 9.82% with a residence time of 127.927 seconds while the shortest residence time occurs on the mesh size of adsorbent 4, the residence time of 73.855 seconds. Keywords: waste , biogas, adsorption, acid sulfide, activated carbon

scholarly journals A review of common natural ventilation and evaporative cooling systems for Greenhouses and the Nigerian reality

2021 ◽  
Vol 46 (3) ◽  
pp. 1-22
Author(s):  
C.E. Ikechukwu-Edeh ◽  
M.C. Ndukwu ◽  
I.E. Ahaneku
Keyword(s):  
Natural Ventilation ◽  
Cooling System ◽  
Local Development ◽  
Evaporative Cooling ◽  
Cooling Systems ◽  
Saturation Efficiency ◽  
Evaporative Cooling System ◽  
The Common ◽  
Ventilation Method ◽  
Cooling Methods

Greenhouses simulate the "desired" environment for successful growth and development of plants. They, by design, achieve this desired environment by supplying the necessary climatic inputs needed by the plants to strive and at the same time exclude factors impeding the growth of plants, hence it is called a controlled environment. One of the common and most desired attribute of the greenhouse is its ability to provide effective cooling to the plants. This paper reviewed, extensively, the concept of evaporative cooling as applied in greenhouses. Factors like Vapor Pressure deficit (VPD), Relative Humidity, Ambient Temperature were also discussed with regards to its effects on the efficiency of the evaporative cooling system. The efficiencies of the Fan and Pad System and the Fog systems were reviewed and compared with their consequent dependence on factors like nozzle spacing, nozzle length, saturation efficiency of pad material etc. The Natural Ventilation method was also reviewed as a "stand alone " greenhouse cooling method and as an augmentation to other cooling systems. Factors like rate of air exchange, total area of vents, wind speed, vent opening angles etc. were also discussed in line with their effects on the effectiveness of the Natural ventilation method. The Nigerian Perspective on Greenhouses and its Cooling methods was also discussed with reference to local development of evaporative coolers as well as its importation, its affordability, management, availability and appliance to the Nigerian farming culture.

scholarly journals Experimental Investigation of the Potential of a New Fabric-Based Evaporative Cooling Pad

2020 ◽  
Vol 12 (17) ◽  
pp. 7070 ◽  
Author(s):  
Eloy Velasco-Gómez ◽  
Ana Tejero-González ◽  
Javier Jorge-Rico ◽  
F. Javier Rey-Martínez
Keyword(s):  
Pressure Drop ◽  
Cooling System ◽  
Evaporative Cooling ◽  
Specific Humidity ◽  
Pressure Drops ◽  
Direct Evaporative Cooling ◽  
Saturation Efficiency ◽  
Evaporative Cooling System ◽  
Factorial Design Of Experiments ◽  
Full Factorial

Direct evaporative coolers are energy-efficient, economic solutions to supplying cooling demand for space conditioning. Since their potential strongly depends on air hygrothermal conditions, they are traditionally used in dry and hot climates, though they can be used in many applications and climates. This work proposes a new direct evaporative cooling system with a fabric-based pad. Its design enables maximum wetted surface with minimum pressure drop. Its performance has been experimentally characterized in terms of saturation efficiency, air humidification, pressure drop, and level of particles, based on a full factorial Design of Experiments. Factors studied are air dry bulb temperature, specific humidity, and airflow. Saturation efficiencies obtained for a 25 cm pad are above the values achieved by other alternative evaporative cooling (EC) pads proposed in the literature, with lower pressure drops.

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