Liquid dispersion and gas absorption in a multi-stage high-speed disperser

Gas absorption in a centrifugal reactor: hydrodynamics

Monodisperse Electrosprays of Low Electric Conductivity Liquids in the Cone-Jet Mode

Investigation by laser Doppler velocimetry of the effects of liquid flow rates and feed positions on the flow patterns induced in a stirred tank by an axial-flow impeller

Rotating packed bed has been a device of wide application and is mainly used for process intensification of the mass transfer of gas-liquid processes in chemical and processing industries. It substantially reduces the size of the separation and distillation towers by replacing gravitational force with a much higher centrifugal force. However, the work related to its uses in thermal systems for heat transfer enhancement is still absent in open literature. This technology can also be used in heat transfer systems replacing cooling towers with rotating packed bed for reducing their size and enhancing the heat transfer rates. In the present work, the effect of rate of liquid flow on the characteristics of drop in air side pressure of counter-current flow RPB with a continuous multiphase air-water system has been experimentally investigated. The pressure drop was observed at different operating parameters which include rate of gas flow, rotor speed and rate of liquid flow. The experimental results have been reported for the drop in pressure of both dry and irrigated bed. In case of irrigated bed, the drop in pressure was substantially lesser in comparison to dry bed for most of the observations with a maximum reduction of 18.25% at a particular operating condition. The results obtained can further be used for the optimization of operating parameters.KeywordsRotating packed bedPressure dropGas flowrateLiquid flowrateRotational speed

The paper shows the effect of volumetric flow rate of liquid and diameters of solid particles in the sedimentation tank for the water contaminated with sediment and oil substances on the effectiveness of the tank. The effect of liquid flow rate on liquid damming has been studied. It has been shown that the liquid damming in the tank increases with increasing a volumetric flow rate of liquid at the inlet. The determined value of the loss coefficient is 3.06. The effectiveness of sedimentation tank for heavy fraction increases with the diameter of solid particles. It has been shown that an increase in the liquid flow rate reduces the effectiveness of the tank, both for the heavy and the light fractions. The vortex sedimentation tank of the proposed construction allows for the simultaneous removal of the heavy and light fractions from water and their partial separation.

During the flight, water flows under the action of shear force to form the overflow liquid film and freezes to form overflow ice. Overflow ice will change the aerodynamic shape of the aircraft and affect the safety and stability. In this paper, the three-dimensional structure of the liquid film in airflow was measured transiently with the digital image projection technology. The effects of different flat wall roughnesses, airflow velocities, and liquid film flow rates on the flow characteristics of the liquid film were analyzed. The experimental results show that the lower the wall roughness, the more pronounced the liquid film contraction toward the central axis. When the liquid flow rate drops to 0.228 l/min, the continuous liquid film transforms into rivulets on the surface of a large contact angle or low roughness. The average thickness of the liquid film on the flat is greater than that on the rough flat at low airflow velocity and low liquid flow rate, but smaller than that on the rough flat at high airflow velocity and high liquid flow rate. The wave near the inlet has an obvious acceleration process, and after reaching the peak speed, it gradually decreases and stabilizes near a certain value. The smoother the surface, the faster the acceleration of the wave at the inlet, and the greater the final stable wave speed.

The nature of the hydrodynamic flow of water down an inclined plane in the presence of static gas is discussed. The effects of liquid flow rates and angles of inclination of the plane on the film thickness and ripple inception are recorded. The ripples differ in number and character from those usually associated with liquid flow on a vertical wall Mass transfer of carbon dioxide into a water film on an inclined plane is determined more accurately than hitherto by introduction of modifications to the apparatus and the use of novel methods for determining end-effects. This makes possible more meaningful comparisions between experimental results and model theory. Penetration concentration profiles in the falling liquid film are presented

Dry catalyst impregnation in a double cone blender: A computational and experimental analysis

In this present work, a two-dimensional column with width of 30 cm., thickness of 1.5 cm., and height of 113 cm was employed to investigate the hydrodynamics of Three-Phase Fluidized Bed (TPFB) system. From the experiments, it was found that both superficial liquid and gas velocities affect the behavior of gas bubbles and solid particles in the system. The effect of liquid flow rate was more significant than that of gas flow rate. From image processing analysis, the bubble size decreased when the superficial velocity of either liquid or gas phase increased. Within yeast suspension system, an increase in yeast concentration gave rise to the smaller bubble size. Using ultrasonic transmission, it was found that the larger particle could lead to the less signal transmitted through the bed to the receiver. The relationship between solid holdup and amplitude ratio was found to be exponential. An increase in superficial gas velocity resulted a decrease in the amplitude ratio which represented the higher solid holdup. Ultrasonic transmission technique was mainly applied for investigating distribution of solid particle in the bed while visualization technique with digital image processing was employed to measure bubble size distribution which is used for determining the local gas holdup.

The heat transfer in a shear driven rivulet flow at isothermal conditions in a minichannel has been studied. The experiments were conducted using the setup, specially designed for the shear driven rivulet flow. The effect of liquid flow rate and substrate temperature on the width of the rivulet was studied experimentally using Laser induced fluorescence technique (LIF). The temperature distribution for different time moments of the rivulet surface was measured by the FLIR infrared (IR) camera. IR-measurements served to demonstrate that rivulet surface temperature is lower than substrate one due to liquid evaporation from the rivulet surface.

Microbubble usually has very small volume, and it is difficult to rise in the water, so it can be used to wrap ozone for sewage treatment. In the present study, the experiments of bubble formation in a mechanical microfluidic device are developed. The effect of liquid flow rate and gas pressure on bubble formation characteristic was obtained through experiments. By observing experimental phenomena, it can be concluded that bubble growth process can be divided into three stages, and the law of the detachment volume and formation frequency of microbubbles under single variable factor was investigated by the control variable method. The investigation of bubble formation characteristic can help to control bubble detachment volume and formation frequency precisely.

Understanding the hydrodynamic behavior of the H-Coal reactor is the main objective of this project. To that end, a literature search reviewed all information related to the fluid dynamics behavior of gas/liquid/solid systems. Concurrently, a cold flow model including a glass reactor 6'' in diameter and 20' high was constructed following practices established by HRI in their process development unit. The cold flow model is used to conduct experiments with gas and liquid slurries which at room temperature have similar properties to those of the H-Coal liquids at reactor conditions. The volume fraction occupied by gas/liquid slurries and catalyst particles is determined by several experimental techniques. The use of a mini computer for data collection and calculation has greatly accelerated the analysis and reporting of data. Data on nitrogen/water/HDS catalyst and coal char fines are presented in this report. Correlations identified in the literature search were utilized to analyze the data. From this analysis it became evident that the Richardson-Zaki correlation adequately describes the effect of liquid flow rate on catalyst expansion. The effect of coal char fines can be accounted for by the effect it has on the liquid viscosity. For the gas/slurry/catalyst and the water/nitrogen systems, a model developed by Darton and Harrison was used to analyze the data. Recognizing that the ultimate implementation of this work will require the development of a mathematical model, continuing emphasis will be placed on identifying the proper correlation describing the H-Coal reactor fluid dynamics. Since the major goal of this program is to be of use to the H-Coal project, the experimental runs will emphasize this objective throughout the rest of the program's life.

BACKGROUNDThe addition of a physical solvent to a traditional chemical absorbent has been shown to improve the absorption and desorption performance of the absorbent system. This type of novel absorbent system combining a single physical solvent with an amine solvent is a promising development in the industrial application of CO2 capture.RESULTSHybrid solutions composed of Monoethanolamine (MEA), a physical solvent, and H2O were comprehensively investigated using the rapid solvent screening apparatus and a VLE apparatus. The results show that 30 wt% MEA with 20 wt% Sulfolane and 50 wt% H2O achieved higher rich loading, strong cyclic CO2 capacity and the highest desorption rate over a wide range of CO2 loadings. Also, the mass transfer performance of CO2 absorption into the 30 wt% MEA and 20 wt% Sulfolane solution was investigated in a lab‐scale random packing column. The effects of liquid flow rate, liquid feed temperature, lean CO2 loading, inert gas flow rate and CO2 partial pressure on the mass transfer performance were evaluated in terms of volumetric overall mass transfer coefficient (KGav). Furthermore, a correlation was developed for CO2 absorption into MEA/Sulfolane solution in a random packing column using semi‐empirical models as functions.CONCLUSIONUnlike for amine solution alone, inert gas flow rate is an indispensable operating parameter in the MEA/Sulfolane system. A mass transfer correlation model was established and holds significance in studying the kinetics of CO2 absorption by a mixture of physical and chemical solvents and for the optimal design of Dixon‐ring random packing columns. © 2019 Society of Chemical Industry

Public education on 3-dimensional media

Experimental study of the SO2 removal efficiency and volumetric mass transfer coefficients in a pilot-scale multi-nozzle spray tower