scholarly journals DILUTE PHASE VERTICAL PNEUMATIC CONVEYING OF CORK STOPPERS

2006 ◽  
Vol 5 (2) ◽  
pp. 36
Author(s):  
R. Barbosa ◽  
C. Pinho

The pneumatic conveying of cork stoppers is used in the cork processingindustries with equipments designed and built purely on an empirical basis.Experimental studies to characterize this type of pneumatic transportationhave been, so far, oriented towards the study of horizontal conveying processes, either for steady state transportation or for the acceleration zone.However studies were carried out on the determination of the pressure dropon vertical transportation of cork stoppers. Here the experimental apparatusand procedure are described, and the first experimental data that have beenobtained are shown. In consequence a simple correlation for the pressure drop in the steady state region of the conveying pipe is proposed. Thecorrelation is a function of dimensionless parameters used to characterizethe two phase flow under analysis. Three standard stoppers sizes and a single pipe diameter were used in the experiments, all carried out at ambient temperature.

Author(s):  
Catalina Posada ◽  
Paulo Waltrich

The present investigation presents a comparative study between two-phase flow models and experimental data. Experimental data was obtained using a 42 m long, 0.05 m ID tube system. The experimental data include conditions for pressures ranging from 1.2 to 2.8 bara, superficial liquid velocities 0.02–0.3 m/s, and superficial gas velocity ranges 0.17–26 m/s. The experimental data was used to evaluate the performance of steady-state empirical and mechanistic models while estimating liquid holdup and pressure gradient under steady-state and oscillatory conditions. The purpose of this analysis is first to evaluate the accuracy of the models predicting the liquid holdup and pressure gradient under steady-state conditions. Then, after evaluating the models under state-steady conditions, the same models are used to predict the same parameters for oscillatory and periodic conditions for similar gas and liquid velocities. The transient multiphase flow simulator OLGA, which has been widely used in the oil and gas industry, was implemented to model one oscillatory case to evaluate the prediction improvement while using a transient instead of a steady-state model to predict oscillatory flows. For the model with best performance for steady-state pressure gradient prediction, the absolute percentage error is 12% for Uls = 0.02 m/s and 5% for Uls = 0.3. For oscillatory conditions, the absolute percentage error is 30% for Uls = 0.02 m/s and 4% for Uls = 0.3. OLGA results underpredict the experimental pressure gradient under oscillatory conditions with errors up to 30%. Therefore, it was possible to conclude that the models can predict the average of the oscillatory data almost as well as for steady-state conditions.


1983 ◽  
Vol 48 (12) ◽  
pp. 3356-3369 ◽  
Author(s):  
Vladimír Jiřičný ◽  
Vladimír Staněk

The paper gives a review of present approaches to the problem of a single- and two-phase flow in a packed bed. A new definititon has been given of the flooding point, which, as far as the theory is concerned, rigorously defines critical values of the quantities in the flooding point. At the same time, the definition enables a unambiguous experimental determination of the flooding point from experimental dependence sof the hold-up or pressure drop on the flow rate of phases. Based on extensive experimental data three alternative forms have been proposed of the versatile correlation of liquid hold-up on the velocity of liquid at the zero velocity of gas. The correlations have been formulated on the principle of automodel properties and define the appropriate relationships in terms of normalized variables related to the newly defined flooding point. The dependences on the geometry parameters of the packing and physical properties of liquid appear in the versatile correlations only implicitly. A new possibility has been shown of inverse utilization of the versatile correlations for the determination of the critical values (the flooding point) from two independent measurements of liquid hold-up in a real apparatus.


1982 ◽  
Vol 47 (8) ◽  
pp. 2190-2200 ◽  
Author(s):  
Vladimír Jiřičný ◽  
Vladimír Staněk ◽  
Jiří Šmíd ◽  
Vladimír Jelínek

Results have been presented in the paper of the tests and calibration of a tensometric scale developed for weighing packed bed columns under operating conditions. The results have shown the tensometric method to be suitable weighing packed bed columns under the two-phase flow of gas and liquid in the dynamic state. Experimental results have been presented of the steady state liquid hold-up and gas pressure drop obtained by the developed tensometric method in an experimental column 190 mm in diameter. The experimental data have been compared with those of other authors obtained by different experimental techniques.


Data in Brief ◽  
2018 ◽  
Vol 16 ◽  
pp. 527-530 ◽  
Author(s):  
Abdalellah O. Mohmmed ◽  
Mohammad S. Nasif ◽  
Hussain H. Al-Kayiem

2017 ◽  
Vol 53 (1) ◽  
pp. 199-221 ◽  
Author(s):  
Abdullah Cihan ◽  
Jens Birkholzer ◽  
Luca Trevisan ◽  
Ana Gonzalez-Nicolas ◽  
Tissa Illangasekare

1993 ◽  
Vol 115 (4) ◽  
pp. 781-783 ◽  
Author(s):  
Kiyoshi Minemura ◽  
Tomomi Uchiyama

This paper is concerned with the determination of the performance change in centrifugal pumps operating under two-phase flow conditions using the velocities and void fractions calculated under the assumption of an inviscid bubbly flow with slippage between the two phases. The estimated changes in the theoretical head are confirmed with experiments within the range of bubbly flow regime.


Author(s):  
Maral Taghva ◽  
Lars Damkilde

To protect a pressurized system from overpressure, one of the most established strategies is to install a Pressure Safety Valve (PSV). Therefore, the excess pressure of the system is relieved through a vent pipe when PSV opens. The vent pipe is also called “PSV Outlet Header”. After the process starts, a transient two-phase flow is formed inside the outlet header consisting of high speed pressurized gas interacting with existing static air. The high-speed jet compresses the static air towards the end tail of the pipe until it is discharged to the ambiance and eventually, the steady state is achieved. Here, this transient process is investigated both analytically and numerically using the method of characteristics. Riemann’s solvers and Godunov’s method are utilized to establish the solution. Propagation of shock waves and flow property alterations are clearly demonstrated throughout the simulations. The results show strong shock waves as well as high transient pressure take place inside the outlet header. This is particularly important since it indicates the significance of accounting for shock waves and transient pressure, in contrast to commonly accepted steady state calculations. More precisely, shock waves and transient pressure could lead to failure, if the pipe thickness is chosen only based on conventional steady state calculations.


1985 ◽  
Vol 21 (6) ◽  
pp. 713-718
Author(s):  
G. I. Levashenko ◽  
V. I. Antsulevich ◽  
A. I. Didyukov ◽  
V. A. Vazyulin
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