scholarly journals Utilization of dust and ammonia from exhaust gases: new solutions for dryers with different types of fluidized bed

2018 ◽  
Vol 16 (2) ◽  
pp. 193-204 ◽  
Author(s):  
Аrtem Аrtyukhov ◽  
Nadiia Аrtyukhova
2017 ◽  
Vol 2017 (3) ◽  
pp. 63-83
Author(s):  
Mateusz Paszko

Abstract Helicopters play an important role in air-to-ground fire covering and the short-distance air-to-air fights, as well as the anti-tank missions and battlefield force transferring. The detection and survivability of helicopters on a battlefield significantly depends on their infrared emissions level, as well as the methods, equipment and systems used by potential enemy. The automatic detection systems, recognition and identification of flying objects use among other the thermo-detection methods, which rely on detecting the infrared radiation emitted by the tracked object. Furthermore, due to low-altitude and relatively low flight speed, today’s combat assets like missile weapons equipped with infrared guidance systems are one of the most important threats to the helicopters performing combat missions. Especially meaningful in a helicopter aviation is infrared emission by exhaust gases, egressed to the surroundings. Due to high temperature, exhaust gases are a major factor in detectability of a helicopter performing air combat operations. In order to increase the combat effectiveness and survivability of military helicopters, several different types of the infrared suppressor (IRS) have been developed. This paper reviews contemporary developments in this discipline, with particular examples of the infrared signature suppression systems.


2017 ◽  
Vol 77 (1) ◽  
pp. 159-166 ◽  
Author(s):  
Zhi-Long Ye ◽  
Yujun Deng ◽  
Xin Ye ◽  
Yaoyin Lou ◽  
Shaohua Chen

Abstract Fluidized granulation is one of the common methods used in wastewater treatment and resource recovery with harvesting millimeter-scale large particles. Presently, effective methods are lacking to measure the fluidized granules ranging from micro- to millimeter scales, with the consequence of ineffectively controlling and optimizing the granulation process. In this work, recovering struvite (MgNH4PO4·6H2O) from swine wastewater by using a fluidized bed was taken as an example. Image processing was applied to analyze the properties of different types of struvite granules, including morphology, particle size distribution, number density and mass concentration. Four stages of the struvite crystal evolution were therefore defined: aggregation, aggregate compaction, cluster-agglomerating and coating growth. These stages could occur simultaneously or sequentially. Up-flow rates of 30–80 mm/s in the fluidized bed sustained 600–876 g/L granular solids. Results revealed that the coating-growth granules were formed with compact aggregates or cluster-agglomerating granules as the nuclei. The growth rates for the different types of particles, including population growth, mass increase and particle size enlargement, were determined. In final, a schematic illustration for struvite granulation process is also presented.


2015 ◽  
Vol 792 ◽  
pp. 345-350
Author(s):  
Andrey Lesnykh ◽  
Sergey Golovatiy ◽  
Danil Valovik

The boiler KE-10-14 reconstructed under high-temperature furnace circulation fluidized bed has been considered. Features of the boiler with a high-temperature furnace circulation fluidized bed have been presented. The characteristics of the boiler and problem of its operation for the whole period of operation have been shown. Recommendations for improving the efficiency of boiler have been developed on the basis of conducted operational tests. The results of adjustment system sectional blast have been presented. The characteristics of the boiler on different types of coal have been compared. The application of HTCFB furnace as well as carry out commissioning activities has made it possible to increase the effectiveness of the KE-10-14 boiler.


2014 ◽  
Vol 132 ◽  
pp. 70-76 ◽  
Author(s):  
Justina Racyte ◽  
Doekle R. Yntema ◽  
Laura Kazlauskaite ◽  
Anne-Claire Dubois ◽  
Harry Bruning ◽  
...  

2018 ◽  
Vol 40 (4) ◽  
pp. 83-90
Author(s):  
K.V. Simeiko

The main products of high-temperature pyrolysis of methane are carbon and hydrogen. Due to their unique physical and chemical properties, pyrocarbon and pyrographite can be used in various industries and energy. Hydrogen is an energy-efficient and environmentally friendly energy carrier. Despite the large number of research works on methane pyrolysis, carrying out of this process in the electrothermal fluidized bed (ETFB) is not studied enough. The purpose of the study is to determine the thermophysical characteristics of the process of methane pyrolysis (the main products of the reaction are hydrogen and pyrocarbon) in reactors with different types of ETFB. The temperature of the complete disposition of methane to carbon and hydrogen is 800 K. This value is based on the thermodynamic calculations. A laboratory and a pilot plant with a different type of ETFB have been created for this process. Experimental studies of the process of methane pyrolysis had been carried out on these plants and experimental data were compared with the calculations. The method which allows to determine the amount of precipitated carbon has been developed. It is based on the gas analysis data. Nusselt's criterion for different types of reactors with ETFB has been calculated. It was showed that electrothermal heating of a fluidized bed of conductive particles is much more efficient than the external electric heating of a fluidized bed. This result is based on previous researches. It is explained by the direct influence of the plasma of microcircuits and by advantages of heat generation directly in the middle of the fluidized bed. Taking into account the obtained results and the specifics of the application of the pyrocarbon coating on dielectric materials, a scheme of a reactor with ETFB, which allows to use both external heating and classical ETFB at the same time, has been developed.


2013 ◽  
Vol 11 (1) ◽  
pp. 57-68 ◽  
Author(s):  
Werner O. Filtvedt ◽  
Trygve Mongstad ◽  
Arve Holt ◽  
Morten Melaaen ◽  
Hallgeir Klette

Abstract: For an installed silicon-based solar cell panel, about 40% of the energy needed for fabrication is consumed for production of the silicon feedstock. Reducing the energy consumption in this step is therefore crucial in order to minimize the energy payback time and cost of the technology. The most promising alternative to the conventional methods is to use fluidized bed reactors. In this article, we report the results from a novel reactor layout with a selectively cooled distribution arrangement. Important aspects of fludized bed monitoring and operation are described. Two different operation regimes are stated yielding hence porous and dense growth. Further, the method of encapsulating fines by means of more dense depositions is verified, and the nature of the scavenged material is characterized. Also, two different types of fines formation are identified and accounted for.


2020 ◽  
Vol 26 (3) ◽  
pp. 267-276
Author(s):  
Naveedul Syed

This study focusses on the description of the internal state of a modified fluidized bed separator also known as the reflux classifier. The device is a highperformance beneficiating technology employed in many mineral and coal processing industries. A 2D continuum model was used to examine the transport behavior of solid particles within the reflux classifier for a multicomponent mixture under continuous operating conditions. Three different types of feeds comprising solid particles of size ranging 49?421 ?m and densities equal to 1400, 2490 and 5000 kg/m3 were simulated simultaneously under identical process conditions. The feed flux and fluidization velocity were kept at 0.0037 m3/m2s and 0.022 m/s, respectively. A comparison of the simulation results showed that the value of separation size shifted towards lower values, 340, 181 and 90 ?m, when the density of the feed was changed from 1400 to 2490 and 5000 kg/m3, respectively. The data generated through simulations was used to demonstrate the movement of solid particle within the inclined section by plotting the net flux of the solid particles across the inclined channel width. It was observed that the net flux of finer solid particles was higher than the coarser ones within the inclined section.


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