Numerical Optimization of a Gravity Dust-Catcher for Improving Operation Efficiency

Gravity dust-catchers are widely utilized in steelmaking plants to separate particles from the gas flow produced by the blast furnace (BF). The BF recycle system often experiences high total suspended solid (TSS) levels with a significant increase in sludge generation. This increased sludge generation results in higher costs in operation, chemical treatment and sludge removal. Due to the environmental limitations inside an operating dust-catcher, direct measurement of operating conditions can be extremely difficult. Computational fluid dynamics (CFD) models provide a method of gaining an understanding of the operating conditions and phenomena that occur inside a blast furnace dust-catcher on both full process and detailed levels. In this paper, a numerical geometry of the dust-catcher is designed and simulated under typical operating conditions. The Discrete Phase Model (DPM) is employed to track the flow patterns and paths of dust particles. The collection efficiency performance is evaluated at different conditions (quarter full, half full, and three quarter full). From these results, an alternative design to enhance process efficiency is proposed and investigated.

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Influence of elements thickness of separation devices on the finely dispersed particles collection efficiency

MATEC Web of Conferences ◽

10.1051/matecconf/201822402073 ◽

2018 ◽

Vol 224 ◽

pp. 02073 ◽

Cited By ~ 9

Author(s):

Andrey V. Dmitriev ◽

Vadim E. Zinurov ◽

Oksana S. Dmitrieva

Keyword(s):

Flow Structure ◽

Gas Flow ◽

Collection Efficiency ◽

Separation Process ◽

Process Efficiency ◽

Dust Particles ◽

Optimum Thickness ◽

Beam Elements ◽

Dispersed Particles ◽

Separation Devices

This article presents a rectangular separator, developed by the authors, for purification of a multiphase gas flow from the finely dispersed particles with a diameter of up to 10 µm. In order to increase the separation process efficiency, a research was conducted to determine the optimum thickness of I-beam elements within the separator at different values of the flow inlet rate and length of I-beam elements. It was found that change in the wall thickness of elements leads to a change in the flow structure, which causes a decrease in the dust particles collection efficiency.

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Interaction of Shock and Expansion Wave With Solid Particles in Supersonic Flows

Volume 2: Symposia and General Papers, Parts A and B ◽

10.1115/fedsm2002-31223 ◽

2002 ◽

Author(s):

Ali Dolatabadi ◽

Javad Mostaghimi ◽

Valerian Pershin

Keyword(s):

Mach Number ◽

Flow Regime ◽

Drag Force ◽

Gas Flow ◽

Volume Fraction ◽

Supersonic Flows ◽

Operating Conditions ◽

Solid Particles ◽

Process Efficiency ◽

Two Phase

Interaction of solid particles with shock and expansions in supersonic flows is analyzed. In this analysis, a dense cloud of solid particulates is modeled by using a fully Eulerian approach. The dispersed flow and the gas flow were considered in the Eulerian frame whereby most of the physical aspects of the gas-particle flow can be incorporated. In addition to the momentum and energy exchanges in the form of source terms appearing in the governing equations, the two phases were strongly coupled by considering the volume fraction of the particulate phase in the equations. The simulation performed for a High Velocity Oxy-Fuel (HVOF) process under typical operating conditions in which the powder loading is high and the two-phase flow is not dilute near the injection port. The simulations showed large variations in the flow regime in the region that most of the particles exist. Unlike the results corresponding to the Lagrangian approach, the flow becomes subsonic near the centerline and the drag force decreases significantly since the relative Mach number is small. The validation experiments showed that the variation of flow regime by changing the relative Mach number could significantly change the particle drag force, and consequently process efficiency.

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Effects of Flow Baffles on Flow Profile, Pressure Drop and Classification Performance in Classifiers

Processes ◽

10.3390/pr9071213 ◽

2021 ◽

Vol 9 (7) ◽

pp. 1213

Author(s):

Michael Betz ◽

Marco Gleiss ◽

Hermann Nirschl

Keyword(s):

Pressure Loss ◽

Collection Efficiency ◽

Flow Behavior ◽

Classification Performance ◽

Operating Conditions ◽

Flow Profile ◽

Discrete Phase Model ◽

Operation Conditions ◽

Air Classifier ◽

The Impact

This paper presents a study of the use of flow baffles inside a centrifugal air classifier. An air classifier belongs to the most widely used classification devices in mills in the mineral industry, which is why there is a great interest in optimizing the process flow and pressure loss. Using Computational Fluid Dynamics (CFD), the flow profile in a classifier without and with flow baffles is systematically compared. In the simulations, turbulence effects are modeled with the realizable k–ε model, and the Multiple Reference Frame approach (MRF) is used to represent the rotation of the classifier wheel. The discrete phase model is used to predict the collection efficiency. The effects on the pressure loss and the classification efficiency of the classifier are considered for two operating conditions. In addition, a comparison with experimental data is performed. Firstly, the simulations and experiments show good agreement. Furthermore, the investigations show that the use of flow baffles is suitable for optimizing the flow behavior in the classifier, especially in reducing the pressure loss and therefore energy costs. Moreover, the flow baffles have an impact on the classification performance. The impact depends on the operation conditions, especially the classifier speed. At low classifier speeds, the classifier without flow baffles separates more efficiently; as the speed increases, the classification performance of the classifier with flow baffles improves.

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Efficiency of aluminum and iron electrodes in removal of colour, turbidity and total suspended solid from biologically treated municipal wastewater

Journal of Applied and Natural Science ◽

10.31018/jans.v7i2.686 ◽

2015 ◽

Vol 7 (2) ◽

pp. 799-805

Author(s):

Arun Kumar Sharma ◽

A.K. Chopra

Keyword(s):

Municipal Wastewater ◽

Operating Time ◽

Total Suspended Solid ◽

Suspended Solid ◽

Operating Conditions ◽

Optimum Operating ◽

Electrode Consumption ◽

Electrode Combination ◽

Initial Ph ◽

Treated Municipal Wastewater

The present investigation was undertaken to observe the effect of different combinations of aluminium and iron (Al-Al, Al-Fe, Fe-Fe and Fe-Al) electrodes on the removal of colour, turbidity (TD) and total suspended solids (TSS) of biologically treated municipal wastewater ( BTMW) using applied potential (V), operating time (OT) and initial pH. The maximum removal of colour (98.7 %) and TSS (96.89 %) was found with the use of Al-Al combination with optimum operating conditions (Voltage: 40 V; OT: 40 mins.; IED: 1.0 cm; EA: 160 cm2; initial pH: 7.5 and ST: 30 mins). It was interesting to note that TD of BTMW was completely removed at these optimal operating conditions. The economic evaluation of electrode combinations was observed to be in the order of Fe-Al (1.17 US $/m3)> Al-Fe (1.11 US $/m3)> Fe-Fe (1.08 US $/m3) >Al-Al (1.01 US $/m3) in terms of energy and electrode consumption. Thus, the BTMW can be effectively treated with the Al-Al electrode combination in comparison to other electrode combinations (Al-Fe , Fe-Fe and Fe-Al).

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Efektivitas Biokoagulan Cangkang Telur Ayam Ras dan Kulit Pisang Kepok (Musa Balbisiana ABB) dalam Menurunkan Turbiditas, TDS, dan TSS dari Limbah Cair Industri Farmasi

al-Kimiya ◽

10.15575/ak.v7i1.6615 ◽

2020 ◽

Vol 7 (1) ◽

pp. 47-54

Author(s):

Hesty Nuur Hanifah ◽

Ginayanti Hadisoebroto ◽

Turyati Turyati ◽

Ineu Sintia Anggraeni

Keyword(s):

Total Suspended Solid ◽

Suspended Solid ◽

Ph Optimum ◽

Musa Balbisiana

Koagulasi merupakan tahap awal dalam proses pengolahan limbah cair. Salah satu industri yang berpotensi untuk menimbulkan pencemaran air bila limbah cairnya tidak dikelola dengan baik adalah industri farmasi. Cangkang telur ayam ras dan kulit pisang kepok merupakan limbah padat yang belum termanfaatkan, padahal kedua bahan tersebut mengandung zat-zat yang bisa membantu dalam proses koagulasi. Oleh karena itu, peneliti tertarik untuk mengembangkan biokoagulan dari cangkang telur ayam ras dan kulit pisang kepok. Penelitian ini bertujuan untuk mengetahui efektivitas dari cangkang telur ayam ras dan kulit pisang kepok sebagai biokoagulan dalam menurunkan nilai turbiditas, TDS (Total Disolved Solid) dan TSS (Total Suspended Solid) dari limbah cair industri farmasi. Alat yang digunakan dalam penelitian ini adalah jartest. Sampel air limbah yang digunakan dalam percobaan ini yaitu sampel air limbah industri farmasi dari PT Sinkona Indonesia Lestari. Berdasarkan hasil penelitian menunjukkan bahwa biokoagulan cangkang telur ayam mempunyai dosis optimum yaitu 50 g/500 mL dan pada pH optimum 8 terjadi penurunan turbiditas sebesar 81,18%, TDS sebesar 24,3% dan TSS sebesar 82,05%. Sedangkan biokoagulan kulit pisang kepok mempunyai dosis optimum 5 g/500 ml dan pada pH optimum 2 terjadi penurunan turbiditas sebesar 94,9%, TDS 51,3% dan TSS 83,2%. Dari data tersebut bisa disimpulkan bahwa cangkang telur ayam ras dan kulit pisang kepok bisa dimanfaatkan sebagai biokoagulan untuk pengolahan limbah cair dari industri farmasi.

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Experimental Studies Concerning the Semipermeable Membrane Separation Efficiency for 134Cs, 137Cs, 57Co, 58Co, 60Co, 54Mn in Liquid Radioactive Waste I. Treatment of secondary waste from POD decontamination procedure

Revista de Chimie ◽

10.37358/rc.08.5.1825 ◽

2008 ◽

Vol 59 (5) ◽

Cited By ~ 4

Author(s):

Mirela Dulama ◽

Nicoleta Deneanu ◽

Cristian Dulama ◽

Margarit Pavelescu

Keyword(s):

Membrane Separation ◽

Separation Efficiency ◽

Liquid Radioactive Waste ◽

Experimental Studies ◽

Experimental Tests ◽

Suspended Solid ◽

Process Efficiency ◽

Active Charcoal ◽

Precipitation Process ◽

Pre Treatment

The paper presents the experimental tests concerning the treatment by membrane techniques of radioactive aqueous waste. Solutions, which have been treated by using the bench-scale installation, were radioactive simulated secondary wastes from the decontamination process with modified POD. Generally, an increasing of the retention is observed for most of the contaminants in the reverse osmosis experiments with pre-treatment steps. The main reason for taking a chemical treatment approach was to selectively remove soluble contaminants from the waste. In the optimization part of the precipitation step, several precipitation processes were compared. Based on this comparison, mixed [Fe(CN)6]4-/Al3+/Fe2+ was selected as a precipitation process applicable for precipitation of radionuclides and flocculation of suspended solid. Increased efficiencies for cesium radionuclides removal were obtained in natural zeolite adsorption pre-treatment stages and this was due to the fact that volcanic tuff used has a special affinity for this element. Usually, the addition of powdered active charcoal serves as an advanced purifying method used to remove organic compounds and residual radionuclides; thus by analyzing the experimental data (for POD wastes) one can observe a decreasing of about 50% for cobalt isotopes subsequently to the active charcoal adsorption.. The semipermeable membranes were used, which were prepared by the researchers from the Research Center for Macromolecular Materials and Membranes, Bucharest. The process efficiency was monitored by gamma spectrometry.

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Tanning Wastewater Treatment by Ultrafiltration: Process Efficiency and Fouling Behavior

Membranes ◽

10.3390/membranes11070461 ◽

2021 ◽

Vol 11 (7) ◽

pp. 461

Author(s):

Fu Yang ◽

Zhengkun Huang ◽

Jun Huang ◽

Chongde Wu ◽

Rongqing Zhou ◽

...

Keyword(s):

Wastewater Treatment ◽

Shear Rate ◽

Membrane Surface ◽

Filtration Efficiency ◽

Operating Conditions ◽

Process Efficiency ◽

Transmembrane Pressure ◽

Leather Industry ◽

Pore Blocking ◽

The Impact

Ultrafiltration is a promising, environment-friendly alternative to the current physicochemical-based tannery wastewater treatment. In this work, ultrafiltration was employed to treat the tanning wastewater as an upstream process of the Zero Liquid Discharge (ZLD) system in the leather industry. The filtration efficiency and fouling behaviors were analyzed to assess the impact of membrane material and operating conditions (shear rate on the membrane surface and transmembrane pressure). The models of resistance-in-series, fouling propensity, and pore blocking were used to provide a comprehensive analysis of such a process. The results show that the process efficiency is strongly dependent on the operating conditions, while the membranes of either PES or PVDF showed similar filtration performance and fouling behavior. Reversible resistance was the main obstacle for such process. Cake formation was the main pore blocking mechanism during such process, which was independent on the operating conditions and membrane materials. The increase in shear rate significantly increased the steady-state permeation flux, thus, the filtration efficiency was improved, which resulted from both the reduction in reversible resistance and the slow-down of fouling layer accumulate rate. This is the first time that the fouling behaviors of tanning wastewater ultrafiltration were comprehensively evaluated, thus providing crucial guidance for further scientific investigation and industrial application.

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A downscaling cold model for solid flow behaviour in a top gas recycling-oxygen blast furnace

High Temperature Materials and Processes ◽

10.1515/htmp-2020-0083 ◽

2020 ◽

Vol 39 (1) ◽

pp. 447-456

Author(s):

Zhenlong An ◽

Jingbin Wang ◽

Yanjun Liu ◽

Yingli Liu ◽

Xuefeng She ◽

...

Keyword(s):

Blast Furnace ◽

Gas Flow ◽

Stagnant Zone ◽

Flow Zone ◽

Cold Model ◽

Solid Flow ◽

Oxygen Blast ◽

Top Gas Recycling ◽

Batch Weight ◽

Gas Recycling

AbstractThe top gas recycling-oxygen blast furnace (TGR-OBF) is a reasonable method used to reduce both coke rate and energy consumption in the steel industry. An important feature of this process is shaft gas injection. This article presents an experimental study on the gas–solid flow characteristics in a TGR-OBF using a two-dimensional cold model. The experimental conditions and parameters were determined using a series of similarity criteria. The results showed that the whole flow area in the TGR-OBF can be divided into four distinct flow zones, namely, the stagnant zone, the plug flow zone in the upper part of the shaft, the converging flow zone and the quasi-stagnant flow zone, which is similar to that in a traditional blast furnace. Then the effects of batch weight and the ratio (X) of the shaft injected gas flow rate to the total gas flow rate on solid flow behaviour were investigated in detail. With the increase in batch weight, the shape of the stagnant zone tends to be shorter and thicker. Furthermore, with the increase in X value from 0 to 1, the stagnant zone gradually becomes thinner and higher. The results obtained from the experiments provide fundamental data and a validation for the discrete element method–computational fluid dynamics-coupled mathematical model for TGR-OBFs for future studies.

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Investigation of the different particle size dust releases from rigid filter candles during pulse-jet cleaning

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/09544062211017931 ◽

2021 ◽

pp. 095440622110179

Author(s):

Xin Luan ◽

Zhongli Ji ◽

Longfei Liu ◽

Ruifeng Wang

Keyword(s):

Particle Size ◽

Critical Role ◽

Operating Conditions ◽

Solid Particles ◽

Dust Particles ◽

Cleaning Efficiency ◽

Term Operation ◽

Cleaning Performance ◽

Experimental Apparatus ◽

Pulse Jet

Rigid filters made of ceramic or metal are widely used to remove solid particles from hot gases at temperature above 260 °C in the petrochemical and coal industries. Pulse-jet cleaning of fine dust from rigid filter candles plays a critical role in the long-term operation of these filters. In this study, an experimental apparatus was fabricated to investigate the behavior of a 2050 mm filter candle, which included monitoring the variation of pressure dynamic characteristics over time and observing the release of dust layers that allowed an analysis of the cleaning performance of ISO 12103-1 test dusts with different particle size distributions. These results showed the release behavior of these dusts could be divided into five stages: radial expansion, axial crack, flaky release, irregular disruption and secondary deposition. The cleaning performance of smaller sized dust particles was less efficient as compared with larger sized dust particles under the same operating conditions primarily because large, flaky-shaped dust aggregates formed during the first three stages were easily broken into smaller, dispersed fragments during irregular disruption that forced more particles back to the filter surface during secondary deposition. Also, a “low-pressure and long-pulse width” cleaning method improved the cleaning efficiency of the A1 ultrafine test dust from 81.4% to 95.9%.

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