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The purpose of this paper is to develop a cyclone with an internal electric field to capture dust and fine carbon particles with less than 5 μm diameter.

The cyclone collection efficiency model described by Cooper and Alley was used to design a conventional cyclone, which was later modified by introduction of the solenoid around it to introduce an electric field. The cyclone design performance was later established using ferrosilicon powder with less than 5 μm diameter.

The cyclone was found to have a particle collection efficiency of around 25 per cent for ferrosilicon powder before the introduction of the solenoid; the introduction of the solenoid increased the particle collection efficiency to around 50 per cent and the charging of the solenoid further increased the collection efficiency to 85 per cent at 2 kV DC and 97 per cent at 3 kV DC. When the cyclone was placed back on the gasifier system and supplied with 2 kV DC, it collected up to 270 g of fine carbon particles within 150 min of operation.

The major drawback was that the highest particle collection efficiency for the cyclone could only be achieved at very high voltage (3 kV) but this could not be supplied when the cyclone was back in the gasifier system due to air ionization that results in the corona effect.

The collection of very fine particles (less than 5 μm diameter) in hot gas streams is always a challenge, particularly in biomass gasifier systems. This resulted in a high cost of gas purification or initial investments in downstream processes. The developed cyclone could cut down this expenditure since most of the particles will not go beyond the cyclone.

Electrostatics has been applied in the development of gas cleaning devices, however most of these devices tend to be too cumbersome. The developed cyclone is based on the conventional design, which is less complicated and cheap to manufacture.

The aim of the paper is to present the results of investigations of fine particle generation by small biomass combustion and the possibility of reducing the emissions by electrostatic precipitation.

The grains, wood‐logs, wood‐, mixed‐ and straw‐pellets were combusted in two stoves and two boilers. The set‐ups were operated according to DIN‐4702. Particle number concentration in the gas flow was measured by Scanning Mobility Particle Sizer and particle mass concentration was measured according to the Guidelines VDI‐2066 upstream and downstream a novel space charge electrostatic precipitator (ESP). The ESP consists of an ioniser and a grounded brush inside of a tube form grounded collector electrode.

The ESP ensures stable operation at gas temperatures up to 350°C. The use of sharp‐points high voltage electrode ensures effective particle charging at high particle number concentrations. The combustion of wood‐pellets is characterized by lower particle mass concentrations. The highest particle mass concentrations were observed by the straw‐pellets combustion. The ESP ensures particle collection with mass collection efficiency 87±3% for wood‐logs and 82±2% for wood‐pellets combustion.

The novel ESP is recommended for exhaust gas cleaning from small scale biomass combustion facilities and domestic heating units. The use of the ESP would reduce the emissions of fine aerosol into the atmosphere and improve the air quality.

The paper presents the comparative analysis of particle size distribution and particle mass concentrations in the exhaust gas from small‐scale combustion units for different types of biomass. The study confirms the possibility to reduce particle emissions by electrostatic precipitation. The originality of the technology and apparatus is patently protected.

The purpose of this study is to examine the physical processes experienced by a particle-laden gas due to various types of collisions, different heat transfer modalities and jet axis switching. Here, attention is focused on a particle-laden gas subjected to jet axis switching while experiencing fluid flow and heat transfer.

The methodology used to model and solve these complex problems is numerical simulation treated here as a two-phase turbulent flow in which the gas and the particles keep their separate identities. For the turbulent flow model, validation was achieved by comparisons with appropriate experimental data. The considered interactions between the fluid and the particles include one-way fluid–particle interactions, two-way fluid–particle interactions and particle–particle interactions.

For the fluid flow portion of the work, emphasis was placed on the particle collection efficiency and on independent variables that affect this quantity and the trajectories of the fluid and of the particles as they traverse the space between the jet orifice and the impingement plate. The extent of the effect depended on four factors: particle size, particle density, number of particles and the velocity of the fluid flow. The major effect on the heat transferred to the impingement plate occurred when direct heat transfer between the impinging particles and the plate was taken into account.

This paper deals with issues never before dealt with in the published literature: the effect of jet axis switching on the fluid mechanics of gas-particle flows without heat transfer and the effect of jet axis switching and the presence of particles on jet impingement heat transfer. The overall focus of the work is on the impact of jet axis switching on particle-laden fluid flow and heat transfer.

This purpose of the paper is to examine the multi-channel cyclone created at the Vilnius Gediminas Technical University (VGTU) Research Institute of Environmental Protection. The paper aims to predict the possible trajectories of solid particle motion in the cyclone with reference to the mechanical forces only.

The numerical calculations were performed on the basis of experimental results. The system of differential equations describing particle motion in the cyclone is analysed and numerically solved using Runge–Kutta–Fehlberg method. Research consists of three examples that illustrate the impact of particle density and velocity on collection and analyses the particle motion trajectories in the first and second channels of the cyclone.

Numerical calculations were performed according to the data from Vilnius Gediminas Technical University Research Institute of Environmental Protection. The particulate matter of wood ash and granite were used. The collection of solid particles of different size was examined when the air inflow velocity varies from 10 to 20 m/s. The possible motion trajectories of the solid particles are defined and the parameters of collected particles have been discussed.

The obtained results can be used for the analysis of air cleaning efficiency and particulate matter removal from air in a multi-channel cyclone.

The results lead us to improve the structure of the cyclone so as to effectively collect the solid particles of different size.

This paper presents the results obtained for the multi-channel cyclone created at the Vilnius Gediminas Technical University Research Institute of Environmental Protection.

This study aims to focus on the submicron particles (with diameter of 0.2-1.0 μm) of the ambient air from a coal-fired power plant. A systematic examination of their morphology, particle size and chemical element will be analyzed, so as to provide more scientific information and theoretical basis for the formation and control method of inhalable particles, as well as data support for environmental impact and ecological effects assessments.

In this paper, the morphology, size distribution and elemental characteristics of submicron particles from ambient air of a coal-fired power plant are studied by single particle analysis.

The results show that atmospheric particles in coal-fired power plant are mainly spherical particles, and most of them are soot aggregates adhered or coated with other particles with few rectangle particles. The particles collected in the afternoon and evening are mainly of spherical particles, and small-sized particles collected in the morning are mainly spherical ones, while the overall concentration is larger than that of the spherical particles in the size range above 0.5 μm. The results indicated that the larger-sized spherical particles have a lower concentration.

Coal-fired power plants are still the main supply of electricity in China, but the inhalable particles, especially sub-micron particles (0.1-1.0 μm) cannot be effectively captured by the dust removal device from the coal-fired power plant. Thus, a large amount of inhalable particles is emitted into the atmosphere, becoming the major air pollutants in China.

Smoke and dust emissions from industrial furnaces can do great harm to the environment and human health. This paper aims to analyze the morphology, diameter and elements of the submicron particles from the furnace flues and the nearby ambient air by using two typical industrial furnaces, the sintering furnace and the electric furnace.

Two typical industrial furnaces, the sintering furnace and the electric furnace, were chosen in this study, to analyze the morphology, diameter and elements of the submicron particles from the furnace flues and the near-by ambient air.

The results show that the particles from the two furnaces are mainly in the small sizes of 0.3-0.6 μm. Particles from sintering plant flue are mainly spherical and rich in K and Cl, whereas those from the electric plant flue are mainly particles rich in metal elements, such as Zn and Fe, and have different morphology.

The particles in the atmosphere nearby the two furnaces contain aged particles from the flue, lots of spherical particles, rectangle particles and various aggregations. The elements of those particles are complex.

The oil, flux, and solder added to a hot air solder leveling tool creates an emission of oil mist, acidic gases, and solid metal compounds. The oil tends to form into very fine droplets, resulting in exhaust opacity. Diffusion type fiber bed filters are the optimal choice for the removal of oil mist. For optimal filter efficiency the exhaust stream should be cooled. A wet scrubber upstream of the filter will cool the exhaust stream through water evaporation. Additionally, the scrubber will remove acid vapor and coarse solids from the exhaust. The characteristic quality of a coalescing fiber bed filter is its ability to continuously drain liquid. The defining parameter in the service life of a fiber bed filter is the solids in the exhaust stream. These solids can lodge in the fibers and block a portion of the void area, and hence increase the filter pressure drop. In an attempt to extend filter life, a study was conducted for the use of detergents to clean the filter. These studies show that a detergent can extend filter life in the H.A.S.L. application by removing a blocking agent from the filter. Further tests are planned at additional locations to examine the performance at sites that use other ingredient formulations in the flux, oil, and solder.

Nanoparticles have been studied as additives to lubrication oils for reducing friction and wear. The purpose of this paper is to investigate the effect of nanofluid on engine oil and friction reduction in a real engine.

The nanoparticles were prepared using a high‐temperature arc in a vacuum chamber to vaporize the Ti metal, and then condensed into a dispersant to form the TiO₂ nanofluid, which was used as lubricant additive. Experiments were performed in both real engine running and test rig.

It was found that the engine oil with nanofluid additive with an ethylene glycol dispersant of nanoparticles, had gelled after 10‐h of engine running. The problem of oil gelation (jelly‐like) was solved by replacing the dispersant with paraffin oil. The engine oil with TiO₂ nanoparticle additive exhibited lower friction force as compared to the original oil. The experiment showed that a smaller particle size exhibits better friction reduction with particle size ranging from 59 to 220 nm.

The paper is restricted to findings based on the dispersed nanoparticles in fluid as additive for engine lubrication oil.

The test results are useful for the application of nanofluid additive for engine oil.

Most previous researches in this field were executed on tribotester, rather than the actual engine. This paper describes experimental methods and equipment designed to investigate the application of TiO₂ nanofluid as lubricant additive in internal combustion engine.

Polymer-particle composites, which have demonstrated wide applications ranging from energy harvesting and storage, biomedical applications, electronics and environmental sensing to aerospace applications, have been investigated for decades. However, fabricating polymer-particle composites with controlled distribution of particles in polymer continues to be a fundamental challenge. As to date, a few additive manufacturing (AM) technologies can fabricate composites, however, with a limited choice of materials or limited dispersion control. Against this background, this research investigated a hybrid polymer-particle composite manufacturing process, projection electro-stereolithography (PES) process, which integrates electrostatic deposition and projection based stereolithography (SL) technologies.

In PES process, a photoconductive film collects charged particles in the regions illuminated by light. Then, collected particles are transferred from the film to a polymer layer with defined patterns. Lastly, a digital mask is used to pattern the light irradiation of the digital micromirror device chip, selectively curing the photopolymer liquid resin and particles of that layer. By transferring particles from the photoconductive film to the photopolymer in a projection-based SL system, multi-material composites with locally controlled dispersions could be produced. A proof-of-concept PES testbed was developed. Various test cases have been performed to verify the feasibility and effectiveness of the developed approach.

Challenges in this novel AM process, including process design, particle patterning and transferring, are addressed in this paper. It is found that particles can be transferred to a layer of partially cured resin completely and accurately, by using the stamping approach. The transferring rate is related to stamping force and degree of conversion of the recipient layer. The developed hybrid process can fabricate polymer-particle composites with arbitrary dispersion pattern, unlimited printable height and complicated geometries.

Although an electrostatic deposition process has been investigated as a 3D printing technology for many years, it is the first attempt to integrate it with projection SL for fabricating multi-material polymer composite components. The novel hybrid process offers unique benefits including local dispersion control, arbitrary filling patterns, wide range of materials, unlimited printable height and arbitrary complicated geometries.

The aim of this paper is to provide basic information on the types of particulate cyclones separators used in the chemical and process industries, their principles of operation and factors affecting their performance.

A general review of the types of particle cleaning cyclones used in the chemical and process industries was carried out and the principles guiding their operation and performance discussed. Information which could aid the choice of cyclone for new applications is also discussed.

It was concluded that the choice of cyclone for any application is associated with a trade‐off between two contrasting performance indicators (collection efficiency and pressure drop). Adequate and accurate data gathering is essential right from the design stage for smooth operation of cyclone.

The paper highlights the general principle of operation of cyclone separators and the factors that affect their performance.