Fluidization behavior of oil-contaminated sand

2007 ◽  
Vol 61 (2) ◽  
Author(s):  
M. Hartman ◽  
O. Trnka ◽  
M. Pohořelý

AbstractHydrodynamic behavior of oil-polluted particles of sand was investigated in transparent glass column. The onset of fluidization of sand beds increased with the oil content of the bed. An increase of cohesive forces related to the higher content of liquid (oil) caused deterioration of the quality of fluidization. An empirical correlation was developed to predict the dimensionless gas velocity that keeps the bed of sticky particles fluidized. Results of this work can be employed for the design of fluidized-bed remediation units for oil-polluted sands and soils.

Author(s):  
Priya Deepa ◽  
K. Saravanan

Fluidized beds are extensively used in petrochemical, chemical process industries, pharmaceutical, food and biotechnology industries. They are preferred to process materials with wide range of particle size distribution and offer even temperature distribution and excellent heat and mass transfer. To improve the quality of fluidized bed, mechanical stirring can be employed along with aeration. Hence, an attempt was made to study the hydrodynamics of stirred fluidized bed using air-water system. The characteristics of the fluidized bed can be well understood by studying its hydrodynamics. Pressure drop is one of the vital factor which affects the performance of fluidized bed. Hence, the effects of gas velocity and stirrer speed on pressure drop and power were studied for both stirred and unstirred bed conditions. It was observed that pressure drop and power increases with increase in gas velocity and stirrer speed. Also, the pressure drop and power is low for the stirred bed condition than the unstirred bed condition.


2019 ◽  
Vol 118 ◽  
pp. 02011
Author(s):  
Su Pan ◽  
Yu Pengfeng ◽  
Linbo Liu ◽  
Han Jing ◽  
Xiao Shen

The coal as fired, with unidentified characteristics of the coal gangue, was burned on a 300MW circulating fluidized bed unit. The equipment of the coal conveying system was damaged and the boiler operation was unstable. In response to the problems, the coal quality data and storage conditions of the coal were examined and the site was spot-checked to evaluate the coal quality characteristics. At the same time, the typical representative parameters of the coal handling system and boiler operation were selected. According to the analysis of coal quality and coal storage, the coal quality fluctuates greatly and the uniformity of particle size distribution is poor. There is actually the coal gangue with hard texture and hard to grind in the coal pile. The coal gangue will have adverse effects on the fine screening machine, fine crusher and other equipment. After burned this type of coal, the fluidized quality of the boiler bed is degraded to make an impact on the safe and stable operation of the boiler. It is recommended that the coal should be screened and then burned into the furnace to ensure safe and stable operation of the boiler.


1995 ◽  
Vol 1 (2) ◽  
pp. 99-105 ◽  
Author(s):  
Yoon-Bong Hahn ◽  
In-Sik Nam ◽  
Dae-Gyu Park ◽  
II-Ok Lee

Author(s):  
P. Fede ◽  
O. Simonin ◽  
I. Ghouila

Three dimensional unsteady numerical simulations of dense pressurized polydisperse fluidized bed have been carried out. The geometry is a medium-scale industrial pilot for ethylene polymerization. The numerical simulation have been performed with a polydisperse collision model. The consistency of the polydisperse model predictions with the monodisperse ones is shown. The results show that the pressure distribution and the mean vertical gas velocity are not modified by polydispersion of the solid phase. In contrast, the solid particle species are not identically distributed in the fluidized bed indicating the presence of particle segregation.


2021 ◽  
pp. 90-104
Author(s):  
L. V. Taranova ◽  
A. G. Mozyrev ◽  
V. G. Gabdrakipova ◽  
A. M. Glazunov

The article deals with the issues of improving the quality of highly watered well production fluid processing using chemical demulsifier reactants at crude oil processing facilities; the analysis of the use of the reactants at the Samotlor field has been made. The article presents the results of the study of the effectiveness of the "Hercules 2202 grade A" and "SNPH-4460-2" demulsifiers in comparison with the indicators of oil and bottom water processing achieved in the presence of the reactants used at existing facilities; their optimal consumption has been determined. The study has shown that the selected demulsifiers provide the required quality of the oil and water under processing at the considered oil processing facilities and can be used along with the basic reactants for these facilities. On the basis of total indicators, the best results have been achieved using "Hercules 2202 grade A" with the improved indicators of water cut and residual oil content in water by 33.9 % and 2.8 % while reducing the reactant consumption by 9.7 % compared to the basic demulsifier.


2017 ◽  
Vol 47 (10) ◽  
Author(s):  
Elza Brandão Santana ◽  
Maria da Conceição da Costa Valente ◽  
Lorena Gomes Corumbá ◽  
Elisangela Lima Andrade ◽  
Cristiane Maria Leal Costa ◽  
...  

ABSTRACT: Processing of particles in a moving bed, such as a fluidized bed or a spouting bed, is commonly used in the operations of drying, coating, and granulation of particulate systems. This process has applications in the chemical, pharmaceutical and, presently, agronomical industries, especially for seed treatment/coating. This research aimed to analyze the fluid-dynamic behavior of fluidized and spouting beds with different air temperatures and loads of flaxseeds (Linum usitatissimum L.), with estimates of the fluid-dynamic parameters correlated to each process. The parameters were compared with the values obtained from classical correlations in the literature, with indications of associated percentages of deviation. Influence of fluid dynamics on the physiological quality of seeds was assessed by germination tests and the germination speed index. An analysis of the results indicated that seed processing was adequate for processing in dynamically active beds; however, temperatures above 50ºC in both beds caused significant reductions in the physiological quality of the seeds. Processing in a fluidized bed presented a smaller reduction of the physiological properties of the flaxseed.


REAKTOR ◽  
2011 ◽  
Vol 13 (3) ◽  
pp. 155 ◽  
Author(s):  
Abadi Jading ◽  
Eduard Tethool ◽  
Paulus Payung ◽  
Sarman Gultom

PHYSICOCHEMICAL CHARACTERISTICS OF SAGO STARCH OBTAINED FROM FLUIDIZED BED DRYING USING SOLAR AND BIOMASS POWERED CROSS FLOW FLUIDIZED BED DRYER. The research aim is to study the comparative quality of sago starch drying results using cross flow fluidized bed dryer powered by solar and biomass in conventional drying, particularly the chemical composition and physicochemical characteristics. This research was conducted through a drying phase of wet sago starch using a cross flow fluidized bed dryer, and drying in conventional as well as dried sago starch quality testing results are drying. The results of this study indicate that dry sago starch which has been drained by means of cross flow fluidized bed dryer has a chemical composition that does not vary much with starch which is dried by conventional drying, so that the dried sago starch produced by the dryer is very good. On the other hand the use of dryers is the more correct because the physicochemical properties of sago starch using a low drying temperature and drying time is short. Tujuan penelitian ini adalah mempelajari perbandingan kualitas pati sagu hasil pengeringan menggunakan alat pengering cross flow fluidized bed bertenaga surya dan biomassa dengan pengeringan secara konvensional, khususnya komposisi kimia dan karakteristik fisikokimia. Penelitian ini dilakukan melalui beberapa tahapan yaitu pengeringan pati sagu basah menggunakan alat pengering cross flow fluidized bed, pengeringan secara konvensional serta pengujian kualitas pati sagu kering hasil pengeringan. Hasil dari penelitian ini menunjukkan bahwa pati sagu kering yang telah dikeringkan dengan alat pengering cross flow fluidized bed memiliki komposisi kimia yang tidak berbeda jauh dengan pati yang dikeringkan dengan cara pengeringan secara konvensional, sehingga pati sagu kering yang dihasilkan oleh alat pengering tersebut sangat baik. Di sisi lain penggunaan alat pengering ini semakin memperbaiki sifat fisikokimia pati sagu sebab menggunakan suhu pengeringan yang rendah dan waktu pengeringan yang singkat.   Kata Kunci: pengering unggun terfluidakan; fisikokimia; pati sagu


1985 ◽  
Vol 35 (4) ◽  
pp. 359-374 ◽  
Author(s):  
E. F. Fashandi ◽  
R. L. Reid ◽  
W. L. Stout ◽  
J. L. Hern ◽  
O. L. Bennett

Author(s):  
Feihong Guo ◽  
Zhaoping Zhong

AbstractBased on the improved computational fluid dynamics and discrete element method (CFD-DEM), heat transfer and two-component flow of biomass and quartz sand have been studied from experiments and numerical simulation in this paper. During experiments, the particle temperature and moving images are respectively recorded by infrared thermal imager and high speed camera. With the increase of the velocity, the mixing index (MI) and the cooling rate of the particles are rising. Due to larger heat capacity and mass, the temperature of biomass drops slower than that of quartz sand. Fictitious element method is employed to solve the incompatibility of the traditional CFD-DEM where the cylindrical biomass are considered as an aggregation of numerous fictitious sphere particles arranged in certain sequence. By the comparison of data collected by infrared thermal imager and the simulated results, it can be concluded that experimental data is basically agreement with numerical simulation results. Directly affected by inflow air (25℃), the average temperature of particles in the bed height area (h>30 mm) is about 3 degrees lower than that of the other heights. When the superficial gas velocity is larger, the fluidization is good, and the gas temperature distribution is more uniform in the whole area. On the contrary, bubbles are not easy to produce and the fluidization is restricted at lower superficial gas velocity. Gas-solid heat transfer mainly exists under the bed height of 10 mm, and decreases rapidly on fluidized bed height. The mixing index (MI) is employed to quantitatively discuss the mixing effectiveness, which first rises accelerate, then rising speed decreases, finally tends to a upper limit.


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