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

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%.

Flow Pattern of Solid Particles in a Double Vortex Chamber

1987 ◽  
Vol 11 (1) ◽  
pp. 5-11
Author(s):  
A.I. Georgantas ◽  
T. Krepec ◽  
C.K. Kwok
Keyword(s):  
Particle Size ◽  
Experimental Evidence ◽  
Flow Pattern ◽  
Vortex Chamber ◽  
Operating Conditions ◽  
Solid Particles ◽  
Particle Flow ◽  
Operating Parameters ◽  
Combustion Technology ◽  
Critical Particle Size

An experimentally determined air flow pattern in a double vortex chamber is utilized to predict the flow pattern of inserted solid particles. The minimum (critical) particle size retained in the vortex chamber is established in relation to different operating parameters. In view of possible applications of the double vortex chamber in combustion technology, an evaluation of the performance of the system at combustion operating conditions is also made. Experimental evidence of the predicted particle flow pattern is obtained for both cold and hot running conditions.

scholarly journals Effect of Venturi Structures on the Cleaning Performance of a Pulse Jet Baghouse

2019 ◽  
Vol 9 (18) ◽  
pp. 3687
Author(s):  
Xingcheng Liu ◽  
Henggen Shen
Keyword(s):  
Arrival Time ◽  
Test Bench ◽  
Peak Pressure ◽  
Dust Emission ◽  
Cleaning Efficiency ◽  
Cleaning Performance ◽  
Design Changes ◽  
Throat Diameter ◽  
Cleaning Cycle ◽  
Pulse Jet

In order to study the effect of venturi structures on the cleaning performance of a pulse jet baghouse, several cleaning tests are carried out applying the pulse jet test bench. Experiments are performed using different filter bags with venturi tubes of varying throat diameters and lengths. Peak pressure and peak pressure arrival time are selected to evaluate the cleaning efficiency under different conditions. On this basis, a series of comparative experiments are conducted between a typical venturi-type and a new venturi tube design on a semi-industrial pulse jet baghouse. The effects of the new venturi-type on baghouse cleaning performance and dust emission are studied. The results show that pulsing air pressure has a significant effect on bag-cleaning performance; the larger the throat diameter and the shorter the venturi length, the higher the peak pressure and the shorter the peak pressure arrival time. This improves the cleaning efficiency of the filter bags. The new venturi design changes the distribution of the cleaning pressure in the vicinity of the bag mouth, effectively extending the cleaning cycle and reducing the energy consumption as well as reducing the dust emission concentration of the baghouse.

Physics Behind the Oscillation of Pressure Tensor Autocorrelation Function for Nanocolloidal Dispersions

2008 ◽  
Vol 8 (8) ◽  
pp. 3990-3994 ◽  
Author(s):  
Tao Wang ◽  
Xinwei Wang ◽  
Zhongyang Luo ◽  
Kefa Cen
Keyword(s):  
Particle Size ◽  
Autocorrelation Function ◽  
Stress Wave ◽  
Critical Role ◽  
Careful Analysis ◽  
Liquid Interface ◽  
Solid Particles ◽  
Pressure Tensor ◽  
The Stability ◽  
Dynamics Simulations

In this work, extensive equilibrium molecular dynamics simulations are conducted to explore the physics behind the oscillation of pressure tensor autocorrelation function (PTACF) for nanocolloidal dispersions, which leads to strong instability in viscosity calculation. By reducing the particle size and density, we find the intensity of the oscillation decreases while the frequency of the oscillation becomes higher. Careful analysis of the relationship between the oscillation and nanoparticle characteristics reveals that the stress wave scattering/reflection at the particle-liquid interface plays a critical role in PTACF oscillation while the Brownian motion/vibration of solid particles has little effect. Our modeling proves that it is practical to eliminate the PTACF oscillation through suppressing the acoustic mismatch at the solid-liquid interface by designing special nanoparticle materials. It is also found when the particle size is comparable with the wavelength of the stress wave, diffraction of stress wave happens at the interface. Such effect substantially reduces the PTACF oscillation and improves the stability of viscosity calculation.

The circulating floating bed reactor: effect of particle size distribution of the carrier on ammonia conversion

2000 ◽  
Vol 41 (4-5) ◽  
pp. 393-400 ◽  
Author(s):  
J.M. Garrido-Fernandez ◽  
R. Méndez ◽  
J.M. Lema ◽  
V. Lazarova
Keyword(s):  
Particle Size ◽  
Size Distribution ◽  
G Protein ◽  
Biomass Concentration ◽  
Biomass Accumulation ◽  
Ammonia Removal ◽  
Operating Conditions ◽  
Nitrification Rate ◽  
Ammonia Conversion ◽  
Biomass Activity

Three Circulating Floating Bed Reactors (CFBR) R1, R2 and R3 with 20% v/v of a plastic carrier with different size distribution were operated to study the effect of the particles size of the carrier on biomass accumulation and nitrification performance. Operating conditions were similar in the three systems: ammonia concentrations around 50 mg-N–NH4+/ L, ammonia loading rates up to 1.2 kg N–NH4+/m3·d and temperatures between 14 and 27°C. Accumulation of nitrite was observed until day 65th. This w as result both of the inhibition of nitrite oxidation by free ammonia until day 20th and the insignificant accumulation of a biomass with low nitrite oxidising capacity between days 20 and 65th. Ammonia conversion rate and removal efficiency were higher in the reactor with lower particle size, R3 (nitrification rate of 1.1 kg N–NH4+/m3·d and ammonia removal of 97% at 16°C), than in R2 or R1 (nitrification rate of 1.0 kg N–NH4+/m3·d and ammonia removal of 90% at 16°C). The better efficiency in R3 was obtained as a result of the higher specific surface of the biofilm developed. Biomass activity was similar in the three reactors (2.2 and 1.12 g N/g protein · d at 30 and 15°C, respectively). Both the biomass evolution with time and biomass retention in the systems was practically not influenced by the size of particle. Biomass concentration of 1.2 g protein/L was retained in the carrier and up to 20% of the newly produced biomass was retained in the CFBRs.

scholarly journals Evaluation of Marblewood Dust’s (Marmaroxylon racemosum) Effect on Ignition Risk

2021 ◽  
Vol 11 (15) ◽  
pp. 6874
Author(s):  
Miroslava Vandličkova ◽  
Iveta Markova ◽  
Katarina Holla ◽  
Stanislava Gašpercová
Keyword(s):  
Particle Size ◽  
Dust Particles ◽  
Wood Dust ◽  
Sieve Analysis ◽  
Granulometric Analysis ◽  
Analysis Measurement ◽  
Risk Research ◽  
Minimum Ignition Temperature ◽  
The Impact

The paper deals with the selected characteristics, such as moisture, average bulk density, and fraction size, of tropical marblewood dust (Marmaroxylon racemosum) that influence its ignition risk. Research was focused on sieve analysis, granulometric analysis, measurement of moisture level in the dust, and determination of the minimum ignition temperatures of airborne tropical dust and dust layers. Samples were prepared using a Makita 9556CR 1400W grinder and K36 sandpaper for the purpose of selecting the percentages of the various fractions (<63, 63, 71, 100, 200, 315, 500 μm). The samples were sized on an automatic vibratory sieve machine Retsch AS 200. More than 65% of the particles were determined to be under 100 μm. The focus was on microfractions of tropical wood dust (particles with a diameter of ≤100 µm) and on the impact assessment of particle size (particle size <100 µm) on the minimum ignition temperatures of airborne tropical dust and dust layers. The minimum ignition temperature of airborne marblewood dust decreased with the particle size to the level of 400 °C (particle size 63 μm).

Penetration Dynamics of Solid Particles into Liquids High-Speed Experimental Results and Modelling

2005 ◽  
Vol 473-474 ◽  
pp. 429-434 ◽  
Author(s):  
Olga Verezub ◽  
György Kaptay ◽  
Tomiharu Matsushita ◽  
Kusuhiro Mukai
Keyword(s):  
Contact Angle ◽  
Particle Size ◽  
Aqueous Solutions ◽  
Particle Velocity ◽  
Weber Number ◽  
High Speed ◽  
Solid Particles ◽  
Bulk Liquid ◽  
Distilled Water ◽  
Critical Weber Number

Penetration of model solid particles (polymer, teflon, nylon, alumina) into transparent model liquids (distilled water and aqueous solutions of KI) were recorded by a high speed (500 frames per second) camera, while the particles were dropped from different heights vertically on the still surface of the liquids. In all cases a cavity has been found to form behind the solid particle, penetrating into the liquid. For each particle/liquid combination the critical dropping height has been measured, above which the particle was able to penetrate into the bulk liquid. Based on this, the critical impact particle velocity, and also the critical Weber number of penetration have been established. The critical Weber number of penetration was modelled as a function of the contact angle, particle size and the ratio of the density of solid particles to the density of the liquid.

scholarly journals A 2-D model for Intermediate Temperature Solid Oxide Fuel Cells Preliminarily Validated on Local Values

Catalysts ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 36 ◽  
Author(s):  
Bruno Conti ◽  
Barbara Bosio ◽  
Stephen John McPhail ◽  
Francesca Santoni ◽  
Davide Pumiglia ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Operating Conditions ◽  
Solid Oxide ◽  
Intermediate Temperature ◽  
Physical Parameters ◽  
Local Concentration ◽  
Oxide Fuel ◽  
Molten Carbonate ◽  
Experimental Apparatus ◽  
Set Up

Intermediate Temperature Solid Oxide Fuel Cell (IT-SOFC) technology offers interesting opportunities in the panorama of a larger penetration of renewable and distributed power generation, namely high electrical efficiency at manageable scales for both remote and industrial applications. In order to optimize the performance and the operating conditions of such a pre-commercial technology, an effective synergy between experimentation and simulation is fundamental. For this purpose, starting from the SIMFC (SIMulation of Fuel Cells) code set-up and successfully validated for Molten Carbonate Fuel Cells, a new version of the code has been developed for IT-SOFCs. The new release of the code allows the calculation of the maps of the main electrical, chemical, and physical parameters on the cell plane of planar IT-SOFCs fed in co-flow. A semi-empirical kinetic formulation has been set-up, identifying the related parameters thanks to a devoted series of experiments, and integrated in SIMFC. Thanks to a multi-sampling innovative experimental apparatus the simultaneous measurement of temperature and gas composition on the cell plane was possible, so that a preliminary validation of the model on local values was carried out. A good agreement between experimental and simulated data was achieved in terms of cell voltages and local temperatures, but also, for the first time, in terms of local concentration on the cell plane, encouraging further developments. This numerical tool is proposed for a better interpretation of the phenomena occurring in IT-SOFCs and a consequential optimization of their performance.

Modeling and Experimental Validation of the Effective Bulk Modulus of a Mixture of Hydraulic Oil and Air

2014 ◽  
Vol 136 (5) ◽  
Author(s):  
Hossein Gholizadeh ◽  
Doug Bitner ◽  
Richard Burton ◽  
Greg Schoenau
Keyword(s):  
Experimental Data ◽  
Bulk Modulus ◽  
Theoretical Models ◽  
Operating Conditions ◽  
Air Bubbles ◽  
Pressure Sensitivity ◽  
Hydraulic Oil ◽  
Effective Bulk Modulus ◽  
Experimental Apparatus ◽  
Major Factors

It is well known that the presence of entrained air bubbles in hydraulic oil can significantly reduce the effective bulk modulus of hydraulic oil. The effective bulk modulus of a mixture of oil and air as pressure changes is considerably different than when the oil and air are not mixed. Theoretical models have been proposed in the literature to simulate the pressure sensitivity of the effective bulk modulus of this mixture. However, limited amounts of experimental data are available to prove the validity of the models under various operating conditions. The major factors that affect pressure sensitivity of the effective bulk modulus of the mixture are the amount of air bubbles, their size and the distribution, and rate of compression of the mixture. An experimental apparatus was designed to investigate the effect of these variables on the effective bulk modulus of the mixture. The experimental results were compared with existing theoretical models, and it was found that the theoretical models only matched the experimental data under specific conditions. The purpose of this paper is to specify the conditions in which the current theoretical models can be used to represent the real behavior of the pressure sensitivity of the effective bulk modulus of the mixture. Additionally, a new theoretical model is proposed for situations where the current models fail to truly represent the experimental data.

scholarly journals Cefquinome Controlled Size Submicron Particles Precipitation by SEDS Process Using Annular Gap Nozzle

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Kefeng Xiao ◽  
Weiqiang Wang ◽  
Dedong Hu ◽  
Yanpeng Qu ◽  
Zhihui Hao ◽  
...  
Keyword(s):  
Particle Size ◽  
Xrd Analysis ◽  
Solution Concentration ◽  
Operating Conditions ◽  
Submicron Particles ◽  
Optimal Operating ◽  
Surface Appearance ◽  
Precipitation Temperature ◽  
Annular Gap ◽  
Feeding Speed

An annular gap nozzle was applied in solution enhanced dispersion by supercritical fluids (SEDS) process to prepare cefquinome controlled size submicron particles so as to enhance their efficacy. Analysis results of orthogonal experiments indicated that the concentration of solution was the primary factor to affect particle sizes in SEDS process, and feeding speed of solution, precipitation pressure, and precipitation temperature ranked second to fourth. Meanwhile, the optimal operating conditions were that solution concentration was 100 mg/mL, feeding speed was 9 mL/min, precipitation pressure was 10 MPa, and precipitation temperature was 316 K. The confirmatory experiment showed that D50 of processed cefquinome particles in optimal operating conditions was 0.73 μm. Moreover, univariate effect analysis showed that the cefquinome particle size increased with the increase of concentration of the solution or precipitation pressure but decreased with the increase of solution feeding speed. When precipitation temperature increased, the cefquinome particle size showed highest point. Moreover, characterization of processed cefquinome particles was analyzed by SEM, FT-IR, and XRD. Analysis results indicated that the surface appearance of processed cefquinome particles was flakes. The chemical structure of processed cefquinome particles was not changed, and the crystallinity of processed cefquinome particles was a little lower than that of raw cefquinome particles.

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