A correlation based on the physical properties of the solid particles for the evaluation of pressure drop in a two-impinging streams gas-solid reactor

AIChE Journal ◽  
1985 ◽  
Vol 31 (10) ◽  
pp. 1744-1746 ◽  
Author(s):  
Abraham Tamir ◽  
Kfir Luzzatto ◽  
Doron Sartana ◽  
Salomon Surin
2006 ◽  
Author(s):  
Bhagavatula Venkata Ramana Murthy

Fluidized beds are widely used in industries for mixing solid particles with liquids as the solid is vigorously agitated by the liquid passing through the bed and the mixing of the solid ensures that there are practically no temperature gradients in the bed even with exothermic or endothermic reactions (Mixing and the segregation in a liquid fluidized of particles with different sizes and densities", The Canadian Journal of Chemical Engineering, 1988). The violent motion of the solid particles also gives high heat transfer rates to the wall or to cooling tubes immersed in the bed. Because of the fluidity of the solid particles, it is easy to pass solid from one vessel to another. In the present experimental work, the relative density between solid and liquid phases on pressure drop under fluidized condition has been studied using the solid-liquid systems namely, glass beads-water, glass beads-kerosene, plastic beads-kerosene and diamond sugar-kerosene. Pressure drop - liquid velocity and void fraction - liquid velocity relationships have been found for all the mentioned solid-liquid systems under fluidized condition and results have been noted. The effect of the nature of the fluid on the minimum fluidization velocity and the pressure drop has been studied. In addition to the pressure drop studies, mass transfer studies have also been conducted with diamond sugar-water system with and without fluidization and results have been obtained. In addition to these, comparison of bed voidage, pressure drop and minimum fluidization velocity between denser and lighter liquids have been studied and the results have been obtained. Also, the value of rate of mass transfer with fluidization is compared that without fluidization for diamond sugar-water system and the results have been obtained.


Author(s):  
Yu. A. Taran ◽  
A. V. Kozlov ◽  
A. L. Taran

The aim of the work is to consider the mechanism of clogging the pores of the filter unit by small particles from the flow of filtrate inside them. Theoretical ideas about the process of filtering with the deposition of small particles from the filtrate on the pore walls and attribution of its fundamentals to restructuring from the original structure to the final structure allow to describe the process of clogging the pores using well studied concepts of known processes with phase transformations (in particular, crystallization). Based on this analogy and the approach to the description of the transformation of the "old" structure into a "new" one in time, using experimental data and their processing we calculated the rate of nucleation of the sediment centers (ωnucl), the linear (υlin) and volumetric rates of sediment plaques growth in the pores of the filter unit at different values of the process driving force, at different pressure difference in the system, and at different concentrations of solid particles in the suspension. Interpolation and extrapolation dependences were obtained for analyzing the mechanisms of sediments formation and growth for determining and calculating these (ωnucl, υlin) rates. Using the concepts of nonequilibrium thermodynamics to assess the influence of the driving forces we studied their influence (changes in the concentration of solid particles in the filtrate suspension and pressure drop across the filtering layer) on the dynamics of the filtration process. Using the data obtained it is possible to find the degree of clogging of through pores, which determines the filtration conditions, the filter septum type, and the filter overall dimensions.


2019 ◽  
Vol 213 ◽  
pp. 02069
Author(s):  
Tomáš Polášek ◽  
Adam Bureček ◽  
Lumír Hružík

The article is focused on mathematical simulation of the temperature influence on the pressure drop at the pump suction line. It is evaluated pressure drop depending on mineral oil flow rate. The courses of individual dependencies are determined by mathematical simulation using the ANSYS CFD computing software. The temperature affects significantly physical properties of the flowing mineral oil. In a paper is also described the experimental measurement of a mineral oil sample and determination of its physical properties depending on temperature.


2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
Dai Maolin ◽  
Wu Kaisong

In recent years, the pipeline flowing of natural gas hydrate (hereinafter NGH) slurry has been a promising technique of multiphase flowing via pipe and that of crushed hydrate mixture slurry is also a key technique in solid fluidization mining method of nondiagenetic NGH reservoir below the seabed. In this paper, by using similarity rules, a small-scale simulation model was established to shorten the calculation time. The correctness of the simulation model has been verified through comparison with experiment. Thereby, the distribution of velocity and volume fraction of each phase in the vertical pipe was obtained, and the prototype of vertical pipe was analyzed. By study on the pipe resistance, the pressure drop of slurry, when flowing in vertical pipe, could be calculated asΔP=ρgh+0.23Cρv1.8. In the end, by adjusting volume fraction of particles in the mixture slurry, the relationship between the solid particles’ volume fraction and piezometric pressure drop was obtained. When the optimal flow velocity of the slurry is 2 m/s and the ratio of NGH volume fraction to that of sand is 4 : 1, the optimal particle volume fraction ranges from 20% to 40%.


2014 ◽  
Vol 24 (6) ◽  
pp. 1378-1388 ◽  
Author(s):  
Qian Lijuan ◽  
Xianyu Chu

Purpose – The purpose of this paper is to use comprehensive model to investigate the effects of particle physical properties on in-flight nano-particles behavior for the radio frequency suspension plasma spray. Design/methodology/approach – In this paper, both the effects thermal properties of solvent and solid particle on the evolution of particle size, velocity and temperature are discussed. Besides, the numerical analysis is also conducted to investigate the influences of particle physical properties on the characteristic distributions of particles for poly-disperse cases. Findings – Results show the thermal properties of solvent have critical effects on the discharged point of the solid particles, but little influence on the final particle velocity and size, as well as their distributions. The final state of particle temperature is mainly determined by the solid particle thermal properties, especially depending on the boiling point. Originality/value – Most of the former studies took the experimental approaches and mainly focussed on the operating conditions effects. While beyond the operating conditions, the variety of particle physical and thermal properties also has strong effect on particle heating performance.


2021 ◽  
Vol 342 ◽  
pp. 06002
Author(s):  
Daniel Ion Matei ◽  
Marin Silviu Nan ◽  
Cristian Aron ◽  
Cristina Lapadusi-Macesaru

The separation of particles with big inertial mass transported in the air, is most often done with the help of cyclones, due to their resistance to wear at contact with abrasive particles. However, pneumatic conveying of heavy and abrasive granular material mixed with fines, are problematic even for cyclone hardened inlets. The paper studies a new method of dividing the main airflow in two airstreams, one further divided in more smaller streams to achieve the laminar regime, by using a corrugated shaped inlet. Thus generating an improvement in impact resistance, overall cyclone grade efficiency and decreasing pressure drop.


1986 ◽  
Vol 19 (1) ◽  
pp. 56-61 ◽  
Author(s):  
YASUO HATATE ◽  
HIROSHI NOMURA ◽  
TAKANORI FUJITA ◽  
SHUICHI TAJIRI ◽  
NOBUYUKI HIDAKA ◽  
...  

2016 ◽  
Vol 78 (6-4) ◽  
Author(s):  
Ratchanon Piemjaiswang ◽  
Kongpob Ratanathammapan ◽  
Prapan Kunchonthara ◽  
Pornpote Piumsomboon ◽  
Benjapon Chalermsinsuwan

A numerical simulation technique was employed to model the two phase flow in cyclones using computational fluid dynamics (CFD). Three different inlet angles of cyclone, including 45, 0 and -45 degrees were compared to describe the efficiency of the conventional cyclone with the modified inlet angle ones. The results showed that the interaction between solid particles in dilute system could be neglected. The pressure drop was decreased when the inlet angle of the cyclone increased. The cyclone with 45 degrees inlet angle tended to have the lowest pressure drop. The collection efficiency was improved with 45 degrees inlet angle due to high swirling motion of gas flow. 


2014 ◽  
Vol 38 (2) ◽  
pp. 174-182 ◽  
Author(s):  
Fengping An ◽  
Dongzhao Qiu ◽  
Hongbo Song ◽  
Xiaoqi Wu ◽  
Jinhua Tong ◽  
...  

2010 ◽  
Vol 660-661 ◽  
pp. 1118-1123
Author(s):  
Marcos V. Rodrigues ◽  
Marcos A.S. Barrozo ◽  
José Renato Coury

The aim of the present work is to verify experimentally the influence of the charge level on collection efficiency during the first stages of filtration. A charge classifier was used to measure the charge level of the aerosol as a function of particle diameter. The filter was made of polypropylene with diameter of 0.047 m and a thickness of 2.6 mm. The solid particles used as test dust were a phosphate rock powder (density 2940 kg/m3 and average Stokes diameter of 3.40 m). The aerosol was dispersed by a TSI Venturi type generator. The particle charging was achieved by a corona charger. In all the tests performed, a linear relation between the particles acquired charge and their diameter was observed. A gradual increase of the charge level was observed with an increase of the tension in the corona charger (0, -3, -6 kV). The filtration results indicated that the global collection efficiency of the filter was very sensitive to the variation of the charge level of the particles. Both efficiency and pressure drop increased when the charge level increased. During the tests, the small increase in pressure drop indicated that the cake had not yet been formed.


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