• Clean Technology
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• v.26 no.1
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• pp.22-29
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• 2020

Recently, as the fine dust is increased and the emission regulations of diesel engines have been tightened, interest in diesel soot filtration devices has rapidly increased. There is specifically a demand for the technological development of higher diesel exhaust gas after-treatment device efficiency. As part of this, many studies were conducted to increase exhaust gas treatment efficiency by improving the flow uniformity of the exhaust gas in the diesel particulate filter (DPF) and reducing the pressure drop between the inlet and the outlet of DPF. In this study, the effects of pressure drop by the flow rate and temperature of exhaust gas, DPF I/O ratio, Ash, and PM amount in diesel reduction device were simulated via a 12" diameter DPF and diesel oxidation catalyst (DOC) using ANSYS Fluent. As the flow rate and temperature decreased, the pressure drop decreased, whereas the PM amount affected the pressure drop more than the ash amount and the pressure drop was lower in anisotropic DPF than isotropic DPF. In the case of DPF flow uniformity, it was constant regardless of the various variables of DPF. In ESC and ETC conditions, the filtration efficiency for PM was similar regardless of anisotropic and isotropic DPF, but the filtration efficiency for PN (particle number) was higher in anisotropic DPF than isotropic DPF.

• Applied Chemistry for Engineering
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• v.26 no.2
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• pp.229-233
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• 2015

In this study, we examined the removal characteristics of suspended particulate matters which are one of carcinogens to cause lung cancer. The fine dust capture by a pilot scale filtration system depends on several important variables such as humidity, initial fine dust injection volume, and flow rate. The average concentration of particulate matters in the test chamber decreased, but the ultimate collection efficiency did not change during the filtration under high humidity, compared to those of using ambient conditions The initial injection amount of fine dust did not influence the particle capturing efficiency. When the flow rate reduced from 0.6 m/s to 0.3 m/s, the dust collection time increased approximately 1.4 times. Among all variables tested, the flow rate showed the most significant effect on the removal efficiency of fine particulate matter.

• Land and Housing Review
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• v.10 no.2
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• pp.53-58
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• 2019

Particulate matter (PM) is designated as a group 1 carcinogen by the International Agency for Research on Cancer (IARC) of the World Health Organization (WHO). In South Korea, the health threat caused by PM is the most serious level internationally. Therefore, in order to solve the urban PM problem, it is important to develop the technology that can control PM efficiently. In this study, CFD(Computational Fluid Dynamics) simulation was performed for PM pre-filter (type 1-3 with different PM collecting room) to develop a high-efficiency PM collecting device. The complex flow field and the local flow phenomenon inside the PM collecting device were understood with CFD simulation by changing the shape and size of the pre-filter. The PM removal performance can be described with flow rate through the device and PM removal efficiency. The type-1 pre-filter with 5x5 size collecting room was confirmed to have the highest efficiency. Based on the analysis results, the optimal type of pre-filter could be developed and it would be applied as an element technology included in the PM collecting device.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.36 no.5
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• pp.474-481
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• 2023

This paper is an experimental study on the optimal operating conditions of direct charging type electrospray for particulate matter collection. To perform the research, a direct charging type electrospray visualization system was configured to photograph the spray shape of microdroplets, and experiments were performed with varying electrode distance, flow rate, and applied voltage, which are the main factors affecting the particulate matter collection efficacy. Through image processing, the total number of microdroplets according to each condition was analyzed, and the number of microdroplets with a diameter of 1.5 mm or less was confirmed. In addition, by calculating the number of microdroplets per power consumption according to the applied voltage, the optimal operating conditions were derived in terms of energy consumption efficacy, and the microdroplet size distribution was analyzed under the optimal operating conditions. As a result of the experiment, it was confirmed that the optimal operating condition was at a flow rate of 10 mL/min and a voltage of -20 kV in case of 5 mm electrode distance, and at a flow rate of 15 mL/min and a voltage of -30 kV in case of 100 mm electrode distance.

• Journal of Power System Engineering
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• v.17 no.3
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• pp.17-22
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• 2013

Diesel particulate filter has been adopted in new vehicle with diesel engine. Since the flow of exhaust gas was clogged as particulate matters were deposited in the filter, it have bad effects on a fuel consumption and power. It was investigated that a particulate filtering system with vacuum pump in the exhaust gas line could be free from clogging in previous research. In this study, the effects of water injection and position of inlet port in filtering system on reducing in particulate matter were investigated. It was noticed that particulate matter were decreased remarkable by water injection and moving the position of inlet port.

• Journal of Electrical Engineering and Technology
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• v.9 no.1
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• pp.239-246
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• 2014

Incineration is conceptually sound as a waste treatment technology. There is, however, concern over its emissions when it is improperly designed and operated. An electrostatic precipitator is one of the most commonly used devices to control particulate emissions from boilers, incinerators and some other industrial processes. In this work, a modular electrostatic precipitator with sizing of $1m{\times}1m{\times}1m$ was developed for removal of particulate matter from the exhaust gases of a small waste incinerator. Its design was based on a simple wire-and-plate concept. The corona discharge wires were connected to a positive high-voltage pulse generator, while the collection plates were grounded. The high-voltage pulse generator was used to produce the corona discharge field between the individual discharge wire and the collection plate. The particulate-laden exhaust gas flow was directed across the corona discharge field. The charged particles were deflected outward and collected on the plate. The collection efficiency was evaluated as a mass loading ratio between the difference at the inlet and the outlet to the particulate loading at the inlet of the precipitator. The collection efficiency of this modular electrostatic precipitator design was approximately 80 %.

• 한국연소학회:학술대회논문집
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• 2007.05a
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• pp.98-103
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• 2007

The number of vehicles employing diesel engines is rapidly rising. Accompanying this trend, application of an after-treatment system is strictly required as a result of reinforced exhaust regulations. The Diesel Particulate Filter (DPF) system is considered as the most efficient method to reduce particulate matter (PM), but the improvement of a regeneration performance at any engine operation point presents a considerable challenge by itself. Temperature, gas compostion and flow rate of exhaust gas are important parameters in DPF evaluation, especially regeneration process. Engine dynamometer and degment tester are generally used in DPF evaluation so far. But these test method couldn't reveal the effect of various parameters on real DPF, such as O2 concentration, amount of soot and exhaust gas temperature. This research has studied the possibility using dump combustor that used to take an approach lean premixed combustion in gas turbine for a DPF power and optimized. It is possible that utilize the system as DOC (Diesel Oxidation Catalyst) and SCR(Selective Catalytic Reduction) assessments test as well as DPF evaluation

• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.3
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• pp.50-60
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• 1996

We designed and developed the burner which would be adapted on the burner type diesel particulate trap system. The burner type particulate trap system consists of burner system to regenerate to ceramic filter, ceramic filter canister, system controller and etc. Many design factors which affect the performance of the burner system were discussed. We also investigated burner characteristics according to the operating parameters. Burned gas temperature could be controlled better by the 2nd air flow rate than the 1st one. As the space velocity increases, the axial and radial temperature gradients in the filter decreases.

• Journal of computational fluids engineering
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• v.20 no.2
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• pp.46-51
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• 2015

In this paper, we have developed numerical model for particulated flow through narrow slit using Eulerian-Granular method. Commercial software (FLUENT) was utilized as simulation tool and main focus was to identify the effect from various numerical options for modeling of solid particles as continuos phase in granular flow. Gidaspow model was chosen as basic model for solid viscosity and drag model. And lun-et-al model was used as solid pressure and radial distribution model, respectively. Several other model options in FLUENT were tested considering the cross related effect. Mass flow rate of the particulate through the slit was measured to compare. Due to the high volume density of the stacked particulates above the slit, effect from various numerical options were not significant. The numerical results from basic model were also compared with experimental results and showed very good agreement. The effects from the characteristics of particles such as diameter, angle of internal friction, and collision coefficient were also analyzed for future design of velocity resistance layer in solar thermal absorber. Angle of internal friction was found to be the dominat variable for the particle mass flow rate considerably. More defined 3D model along with energy equation for complete solar thermal absorber design is currently underway.

• Korea-Australia Rheology Journal
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• v.20 no.1
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• pp.27-34
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• 2008

Clay suspensions in liquid polymers exhibit a time-dependent behaviour that includes viscoelastic as well as thixotropic features. Because of the presence of interacting clay platelets, particulate networks can develop, which are broken down during flow and rebuild upon cessation of the flow. Here, the use of thixotropic techniques in probing flow-induced structures in nanocomposites is explored with data on a hectorite-poly(isobutylene) model system. By means of fast stress jump measurements the hydrodynamic contributions to the steady state stresses are determined as well as those caused by the stretching of the clay floes. Flow reversal measurements do not provide a clear indication of flow-induced anisotropy in the present case. The recovery of the clay microstructure upon cessation of flow is followed by means of overshoot and dynamic measurements. The development of a particulate network is detected by the appearance and growth of a low frequency plateau of the storage moduli. The modulus-frequency curves after various rest times collapse onto universal master curves, regardless of the pre-shear history or temperature. The scaling factors for this master curve are the crossover parameters. The crossover moduli are nearly a linear function of the crossover frequency, the relation being identical for recovery after shearing at different shear rates. This function depends, however, on temperature.