Experimental Investigations of the Adsorption of NH3 on Silica Gel-Based Adsorbent

2005 ◽  
Author(s):  
Xiaolin Wang ◽  
Wolfgang Zimmermann ◽  
Kim Choon Ng ◽  
Lizhen Gao ◽  
Ju¨rgen U. Keller
Keyword(s):  
Adsorption Isotherm ◽  
Silica Gel ◽  
Working Condition ◽  
Experimental Results ◽  
Experimental Investigations ◽  
Promising Alternative ◽  
Weight Percentage ◽  
Heats Of Adsorption ◽  
Pure Silica ◽  
Gas Calorimeter

The silica gel-water working pair has been commonly used for commercial adsorption chillers due to the environmental benign refrigerant and low desorption temperature (less than 85°C). However, the application has been constrained due to the vacuum working condition and Ice point. This motivates researchers to investigate alternative working pairs. The silica gel-based adsorbents - ammonia working pairs have been found to be the most promising alternative. The isotherms and heats of adsorption of the working pair are essential to be investigated for designing the adsorption reactor and predicting the chiller performance. A novel sensor-gas calorimeter has been used to simultaneously measure the adsorption isotherm and heats of adsorption. The experimental results for adsorption of ammonia on the pure silica gel and silica gel treated with different weight percentage of calcium chlorine are presented.

scholarly journals A Multi-Mode Broadband Vibration Energy Harvester Composed of Symmetrically Distributed U-Shaped Cantilever Beams

Micromachines ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 203
Author(s):  
Xiaohua Huang ◽  
Cheng Zhang ◽  
Keren Dai
Keyword(s):  
Energy Harvester ◽  
Low Frequency ◽  
Experimental Results ◽  
Vibration Energy ◽  
Cantilever Beams ◽  
Resonant Frequencies ◽  
Promising Alternative ◽  
Piezoelectric Energy ◽  
Straight Beam ◽  
Resonance Frequencies

Using the piezoelectric effect to harvest energy from surrounding vibrations is a promising alternative solution for powering small electronic devices such as wireless sensors and portable devices. A conventional piezoelectric energy harvester (PEH) can only efficiently collect energy within a small range around the resonance frequency. To realize broadband vibration energy harvesting, the idea of multiple-degrees-of-freedom (DOF) PEH to realize multiple resonant frequencies within a certain range has been recently proposed and some preliminary research has validated its feasibility. Therefore, this paper proposed a multi-DOF wideband PEH based on the frequency interval shortening mechanism to realize five resonance frequencies close enough to each other. The PEH consists of five tip masses, two U-shaped cantilever beams and a straight beam, and tuning of the resonance frequencies is realized by specific parameter design. The electrical characteristics of the PEH are analyzed by simulation and experiment, validating that the PEH can effectively expand the operating bandwidth and collect vibration energy in the low frequency. Experimental results show that the PEH has five low-frequency resonant frequencies, which are 13, 15, 18, 21 and 24 Hz; under the action of 0.5 g acceleration, the maximum output power is 52.2, 49.4, 61.3, 39.2 and 32.1 μW, respectively. In view of the difference between the simulation and the experimental results, this paper conducted an error analysis and revealed that the material parameters and parasitic capacitance are important factors that affect the simulation results. Based on the analysis, the simulation is improved for better agreement with experiments.

Experiment Study of Small Composite Desiccant Wheel Based on Ceramic

2012 ◽  
Vol 614-615 ◽  
pp. 665-669
Author(s):  
Chun Xia Jia
Keyword(s):  
Silica Gel ◽  
Residential Building ◽  
Experimental Results ◽  
Moisture Removal ◽  
Experiment Study ◽  
Desiccant Wheel ◽  
Rotating Speed ◽  
Removal Capacity

Small composite desiccant wheels based on ceramic are designed and developed. The experiments test the influence of the rotating speed and wheel thickness on the dehumidification performance. Furthermore the dehumidification performance of the composite desiccant wheel is compared with the silica gel wheel. The experimental results show increasing the rotating speed of the desiccant wheel can improve the moisture removal capacity. Compared with the silica gel wheel, the moisture removal amounts of the thin composite desiccant wheel are about similar with that of the thick silica gel wheel. It is further indentified that the new composite desiccant wheel can reduce the size of the dehumidifier and has more potential for residential building field.

scholarly journals Boundary Layers on Rough Compressor Blades

1972 ◽  
Author(s):  
K. Bammert ◽  
R. Milsch
Keyword(s):  
Boundary Layer ◽  
Friction Coefficient ◽  
Boundary Layers ◽  
Axial Flow ◽  
Experimental Results ◽  
Experimental Investigations ◽  
Compressor Blades ◽  
Turbulent Transition ◽  
Good Reproduction ◽  
Compressor Efficiency

Blades of axial flow compressors are often roughened by corrosion or erosion. There is only scant information about the influence of this roughening on the boundary layers of the blades and thereby on the compressor efficiency. To obtain detailed information for calculating the efficiency drop due to the roughness, experimental investigations with an enlarged cascade have been executed. The results enabled to develop new formulas for a modified friction coefficient in the laminar region and for the laminar-turbulent transition and the separation points of the boundary layer. Thus, together with the Truckenbrodt theory, it was possible, to get a good reproduction of the experimental results.

Experimental Investigations of the Machinability of Titanium Alloy TC4 with Different Hydrogen Contents

2011 ◽  
Vol 418-420 ◽  
pp. 1307-1311
Author(s):  
Jun Hu ◽  
Yong Jie Bao ◽  
Hang Gao ◽  
Ke Xin Wang
Keyword(s):  
Surface Roughness ◽  
Titanium Alloy ◽  
Cutting Force ◽  
Hydrogen Content ◽  
Experimental Results ◽  
Cutting Conditions ◽  
Experimental Investigations ◽  
Cutting Condition ◽  
The Given

The experiments were carried out in the paper to investigate the effect of adding hydrogen in titanium alloy TC4 on its machinability. The hydrogen contents selected were 0, 0.25%, 0.49%, 0.63%, 0.89% and 1.32%, respectively. Experiments with varing hydrogen contents and cutting conditions concurrently. Experimental results showed that the cutting force of the titanium alloy can be obviously reduced and the surface roughness can be improved by adding appropriate hydrogen in the material. In the given cutting condition, the titanium alloy TC4 with 0.49% hydrogen content showed better machinability.

Experimental Investigation on the Suppression Device of VIV of a Flexible Riser

2014 ◽  
Author(s):  
Yun Gao ◽  
Shixiao Fu ◽  
Leijian Song ◽  
Tao Peng ◽  
Runpei Lei
Keyword(s):  
Fatigue Damage ◽  
Experimental Results ◽  
Experimental Investigations ◽  
Flexible Riser ◽  
Excited Mode ◽  
Response Characteristics ◽  
Helical Strakes ◽  
Uniform Current ◽  
Viv Suppression ◽  
Synchronization Regime

Experimental investigations were conducted on a flexible riser with and without helical strakes. A uniform current was obtained by towing a riser model in a tank, and the vortex-induced vibration (VIV) suppression of strakes with different heights and pitches was studied. The results of the bare riser show that the characteristics of the synchronization of the VIV for a flexible riser have many orders, and the excited mode jumps from one to another abruptly. During the high order synchronization regime, the VIV response decreases with the increased order of the synchronization. The experimental results also indicate that the response characteristics of a bare riser can be quite distinct from those of a riser with helical strakes, and the suppression performance depends on the geometry of the helical strakes. The fatigue damage in the CF direction is of the same order as that in the IL direction for the bare riser. However, for the riser fitted with helical strakes, the fatigue damage in the CF direction is much smaller than that in the IL direction. The experimental results also confirmed that strake height has a greater influence on the VIV response than the strake pitch, and the drag exerted on the riser increases with strake pitch and height.

EXPERIMENTAL INVESTIGATIONS ON THE INFLUENCE OF TiC/GRAPHITE REINFORCEMENT IN WEAR BEHAVIOR OF Al 6061HYBRID COMPOSITES

2019 ◽  
Vol 26 (04) ◽  
pp. 1850173 ◽  
Author(s):  
S. JEYAPRAKASAM ◽  
R. VENKATACHALAM ◽  
C. VELMURUGAN
Keyword(s):  
Hybrid Composites ◽  
Wear Behavior ◽  
Research Work ◽  
Testing Machine ◽  
Wear Testing ◽  
Experimental Investigations ◽  
Sem Images ◽  
Weight Percentage ◽  
Casting Technique ◽  
Graphite Particles

This research work focuses about fabrication and investigation on the influence of Titanium Carbide (TiC)-graphite particles reinforcement in wear behavior of Aluminium Matrix Composites (AMC). The stir casting technique was used to fabricate AMC reinforced with various weight percentage of TiC and graphite particles. Wear tests were conducted by using pin-on-disc wear testing machine. The hardness of the hybrid composites were recorded on the test specimen. The worn out surfaces of composites were analyzed using Scanning Electron Microscope (SEM). Results reveal that the presence of TiC and graphite particles improved the wear resistance. The wear of composite is primarily due to delamination and abrasion. The graphite particles serve as the solid lubricant on the wear of composite. The hardness of composite is improved with the decrease in weight percentage of graphite. SEM images reveal that the reinforcement particles in the matrix are homogeneously distributed. Also, worn-out surfaces of the composite were studied to observe wear track and wear mechanisms like plowing grooves, crack or cutting, and fragmentation.

Notizen: The Heats of Adsorption of the Trichloroethanes on Porous Alumina

1975 ◽  
Vol 30 (4) ◽  
pp. 567 ◽  
Author(s):  
T. D. Tribbeck
Keyword(s):  
Silica Gel ◽  
Porous Alumina ◽  
Heat Of Adsorption ◽  
Heats Of Adsorption

Abstract The trichloroethanes undergo rapid dehydrochlorination in the presence of porous transitional aluminas, at temperatures as low as 80 °C. Attempts to measure their heats of adsorption on these solids above 80 °C are therefore unsuccessful. Silica gel is an inactive dehydrochlorination catalyst, and the heat of adsorption of 1,1,2-trichloroethane measured for this material is reported.

Heterogeneous Interactions of Methylamines on porous Adsorbents Part II. Interactions on Silica–Alumina and Silica Gel Surfaces of Di- and Tri-methylamine in the Region of their Boiling Points

1972 ◽  
Vol 50 (15) ◽  
pp. 2451-2456 ◽  
Author(s):  
W. G. Cook ◽  
R. A. Ross
Keyword(s):  
Silica Gel ◽  
Surface Coverage ◽  
Adsorbed Layer ◽  
Silica Gels ◽  
Heats Of Adsorption ◽  
Boiling Points ◽  
Silica Alumina ◽  
Desorption Isotherms ◽  
Adsorption Desorption ◽  
Heterogeneous Interactions

The adsorption of di- and tri-methylamine has been studied at 280 and 276°K, respectively, on a range of silica gels and on silica–alumina. Adsorption–desorption isotherms and isothermal calorimetric heats of adsorption were measured. Heats of adsorption for di-methylamine on silica gel varied from 29.0 kcal/mol at θ = 0.05 to 12.0 kcal/mol at monolayer completion, while for silica–alumina the heats fell from 31.4 to 9.0 kcal/mol between these same values of surface coverage. For tri-methylamine on silica gel, heats fell from 21.0, θ = 0.05, to 10.3 kcal/mol, θ = 1.00, while heats of 21.4 and 9.9 kcal/mol, respectively, were found at these same surface coverages on silica–alumina. The values of the heats of adsorption are discussed in terms of interactions in the adsorbed layer which are believed to be influenced by the pore sizes in the adsorbent and by the basicity of the amine molecules.

Identification of Critical Net Positive Suction Head From Noise and Vibration in a Radial Flow Pump for Different Leading Edge Profiles of the Vane

2013 ◽  
Vol 135 (12) ◽  
Author(s):  
S. Christopher ◽  
S. Kumaraswamy
Keyword(s):  
Radial Flow ◽  
Leading Edge ◽  
Open Circuit ◽  
Experimental Results ◽  
Experimental Investigations ◽  
Flow Rates ◽  
Noise And Vibration ◽  
Operating Condition ◽  
Radial Flow Pump ◽  
Flow Pump

Experimental investigations concerning cavitation in radial flow pump for three different leading edge profiles of the vane were carried out in an open circuit system. The operating condition of the radial flow pump under cavitating case was understood by measurement of noise and vibration along with the pump parameters for various speeds and flow rates. The outcome of the experimental results revealed that the noise and vibration were better predictors of inception and development of cavitation. Further observation inferred from critical net positive suction head (NPSH) curve of 3% head drop and critical NPSH value of noise and vibration are presented.

Sign in / Sign up

Export Citation Format

Share Document