Gas-liquid Stream Research Articles

Preliminary purification of the gas-liquid stream from hydrocarbon condensate, water and mechanical impurities

The paper discusses the process plan of the piston compressor package as well as the design of the gas separator. A technical proposal has been developed to improve the preliminary purification of the gas-liquid stream from hydrocarbon condensate, water and mechanical impurities. With the help of modern computer technologies, the design of the inlet device in the separator has been developed. The operation of the gas separator was simulated after the application developed by the devices. With the help of the program, the results of the study of the gas separator operation are presented.

Verification of the calculation modeling methods of the atomizing of a gas and gas-liquid stream from a pneumatic nozzle

The paper presents a verification of calculation modeling methods of atomizing of a gas and gas-liquid stream from a pneumatic nozzle based on the experimental data obtained in the IT SB RAS. Turbulent supersonic flow of compressible gas is considered here. Mathematical model includes description of gas phase motion based on the RANS (Reynolds Averaged Navier-Stokes) and URANS (Unsteady RANS) approach using two-parameter turbulence model k-ω SST and Reynolds Stress Model (RSM). The Lagrange method was used to model flow of water droplets. Dispersed phase is solved by tracking a large number of droplets through calculated flow field. Dispersed phase can exchange momentum, mass, and energy with fluid phase. Comparative analysis showed an acceptable qualitative and quantitative agreement between calculation and experiment, both for subsonic and supersonic flow.

Simulation of the turbulent structure of a flow and heat transfer in an ascending polydisperse bubble flow

We report on the results of numerical simulation of the turbulent structure of a flow in a vertical polydisperse gas—liquid stream in a tube. The mathematical model is based on the application of the Euler description taking into account the inverse effect of bubbles on the averaged characteristics and turbulence of the carrying phase. Turbulent characteristics of the liquid are calculated using the model of transfer of Reynolds stress tensor components. The variation of the number of bubbles is described using the model of average volume of a bubble taking into account their splitting, coalescence, and expansion upon a change in the gas temperature. The effect of the change in the volumetric consumption gas content, the initial temperature of the liquid, and its velocity on the structure of the flow and on the heat transfer in the two-phase flow is analyzed. The addition of the gas phase to the turbulent liquid causes an increase in the heat transfer by more than 2.5 times. Comparison of the results of simulation with experimental data shows that the approached developed here makes it possible to simulate bubble turbulent flows with heat exchange with the tube wall in a wide range of gas contents.

Nitrogen supported solvent evaporation using continuous-flow microfluidics

In this work we demonstrate a continuously operating microfluidic device for solvent removal and exchange for chemical syntheses by means of a supporting gas. The glass device consists of three sections: (i) three merging microchannels to create an annular gas–liquid stream; (ii) a serpentine channel with a heater underneath to allow efficient evaporation of the volatile solvent; (iii) a section with side capillaries to separate the liquid from the gas phase. We demonstrate the performance of the device for the removal of acetonitrile from an acetonitrile–water mixture. We achieved efficient removal of acetonitrile within a few seconds for flow rates of 20–30 μL min−1 and a nitrogen pressure of 1.2 bar. In three steps, acetonitrile was reduced from 50 wt% in the feed solution to 1 wt% in the final solution. We believe that the device can be easily applied to other solvent mixtures.

Experimental analysis of the separation efficiency of an orientation independent gas/liquid membrane separator

A membrane separator for orientation independent gas liquid separation in portable direct methanol fuel cell systems is presented in this paper. Its working principle is based on capillary forces using a combination of hydrophilic and hydrophobic materials with milli/micro structured channels. The efficiency of liquid recycling is studied experimentally with regard to the influence of system parameters and environmental parameters and to the separator’s orientation. In further experiments, the limits for a complete gas separation are detected with respect to the volume flow of the gas and the liquid phase. It is shown that the orientation has only a minor influence on the liquid recycling efficiency compared to other parameters. Significant for the loss of liquid in the separator is the temperature difference between the inlet of the gas liquid stream and the environment. Furthermore, geometry parameters affect the limitation for the separation efficiency as well as system parameters.

An extractive distillation technique for producing CO 2 enriched injection gas in enhanced oil recovery (EOR) fields

Sharp Separation of CO 2 (carbon dioxide) from CO 2-rich gases issuing from enhanced oil recovery (EOR) fields is investigated by different processing alternatives. A new extractive distillation technique without using an external solvent is introduced for debottlenecking of CO 2 separation problem encountered in cryogenic distillation units. The technique involves the addition of a portion of produced C 4 + (NGL) stream (natural gas liquid stream comprising iso-butane and heavier components) to the top section of a CO 2 stripper followed by C 2/C 3 (ethane and propane) stripping of recovered C 2 + (ethane and heavier components) stream. Detail description of the proposed technique for producing greater than 96% CO 2-rich injection gas without external solvent is presented. According to the proposed approach, high quality C 2/C 3 and C 4 + products with the corresponding purities of 89.6% and 99.6% suitable as feedstocks for gas and petrochemical processing units are also obtained. Sharp separation of CO 2 from recovered hydrocarbon mixtures by the proposed technique and recycling it to petroleum reservoirs is an important issue regarding the optimization of EOR processes and greenhouse gas emission control.

Structure of the bubbling layer in oxidation of liquid-phase feedstock with air

The change in the radius of the rising gas-liquid stream in the bubbling layer of an air — liquid system was investigated as a function of the temperature and properties of the liquid in laboratory conditions. A method is proposed for the comparative estimation of the radius of this stream in industrial units using the Galilei number, Morton number, and the dynamic viscosity of the liquid.

Fire exposure of liquid‐filled vessels

AbstractPressure vessels in the chemical industry generally have top‐mounted pressure relief valves (PRVs) sized to handle fire exposure and other possible scenarios. Designers usually assume that the fire scenario causes liquid to boil and vapor to vent, regardless of the initial liquid level. Under some circumstances, however, a high liquid level, together with thermal expansion, can result in a vessel being full of liquid when the PRV opens. If so, the initial fluid discharged through the PRV would be a two‐phase gas‐liquid stream.This paper analyzes non‐reactive phenomena occurring during the heat‐up and venting process in non‐agitated liquid‐filled pressure vessels. A new criterion is developed to determine if the vapor‐venting sizing assumption is justified. Results from several cases show that pressures in most liquid‐filled vessels sized for vapor‐only flow will be below the ASME Code‐allowable values during fire exposure. Hence, the common industry practice of ignoring two‐phase flow when sizing fire cases is usually justified.

Liquid flow through holes in the wall of a direct-flow centrifugal component

Theoretical and experimental researches are reported for characteristics affecting the liquid flow during separation from a spiral gas-liquid stream in a centrifugal separator. Formulas are derived for the flow coefficient and pressure difference at the inner and outer sides of the wall.

Cooling products with gas-liquid stream controlled by microcomputer

Cooling products with gas-liquid stream controlled by microcomputer

Quenching articles with a computer-controlled gas-liquid stream

Quenching articles with a computer-controlled gas-liquid stream

Heat transfer between gas-liquid spray stream flowing perpendicularly to the row of the cylinders

Experimental investigation and analysis of heat transfer process between a gas-liquid spray flow and the row of smooth cylinders placed in the surface perpendicular to the flow has been performed. Among others, there was taken into account in the analysis the phenomenon of droplets bouncing and omitting the cylinder as well as the phenomenon of the evaporation process from the liquid film surface.

Local measurement of gas content

The article examines problems related to the proper use and accuracy of methods of measuring local gas content in a gas-liquid stream.

Structure of pressure pulsations in a horizontal gas-liquid stream

Structure of pressure pulsations in a horizontal gas-liquid stream

Experimental investigation of velocity profiles in a horizontal gas-liquid stream

Experimental investigation of velocity profiles in a horizontal gas-liquid stream

Some spectral and pulsation characteristics of a horizontal gas-liquid stream

Some spectral and pulsation characteristics of a horizontal gas-liquid stream

Character of flow in rising gas-liquid stream in fixed bed of granular material

Character of flow in rising gas-liquid stream in fixed bed of granular material

Experimental investigation of horizontal two-phase flow by an electrodiffusion method

The results of an experimental investigation of the local mean and fluctuating friction at the wall of a horizontal tube are presented for the case where a gas-liquid stream flows in the tube with a wide range of regime parameters. The electrodiffusion method is used for measuring the friction. Curves of the tangential stresses along the perimeter of the tube as well as along its length are constructed, permitting an objective determination of certain flow regimes. The experimental results are compared with those of the existing computational methods.

A device for distributing an ascending gas-liquid stream

A device for distributing an ascending gas-liquid stream

Wave processes in a gas-liquid stream

Experimental data are presented on the wave characteristics of the interphase boundary in separated gas-liquid wave flow. An estimate is given of the influence of the waves on the magnitude of the head loss by the friction of the gas-liquid mixture in a horizontal tube.