scholarly journals Influence of Grit Size and Wood Species on the Granularity of Dust Particles during Sanding

2020 ◽  
Vol 10 (22) ◽  
pp. 8165
Author(s):  
Marta Pędzik ◽  
Kinga Stuper-Szablewska ◽  
Maciej Sydor ◽  
Tomasz Rogoziński
Keyword(s):  
Particle Size ◽  
Grit Size ◽  
Dust Particles ◽  
Wood Dust ◽  
Particle Sizes ◽  
Respirable Fraction ◽  
Dust Fraction ◽  
The Mean ◽  
Oak Ash

Wood dust poses a threat to the health of employees and the risk of explosion and fire, accelerates the wear of machines, worsens the quality of processing, and requires large financial outlays for its removal. The aim of this study was to investigate the extent to which the grit size of sandpaper influences the size of the wood dust particles and the proportion of the finest particles which, when dispersed in the air, may constitute the respirable fraction. Six species of hardwood (beech, oak, ash, hornbeam, alder, and walnut), and three species of softwood (larch, pine, and spruce) were used in the research. While sanding the samples under the established laboratory conditions, the following were measured for two types of sandpapers (grit sizes P60 and P180): mean arithmetic particle size of dust and finest dust particles content (<10 µm). Based on the obtained results, we found that the largest dust particle sizes were obtained for alder, pine, and spruce; the smallest size of dust particles during sanding with both sandpapers was obtained for beech, hornbeam, oak, ash, larch, and walnut. The mean arithmetic particle sizes ranged from 327.98 µm for pine to 104.23 µm for hornbeam. The mean particle size of the dust obtained with P60 granulation paper was 1.4 times larger than that of the dust obtained with P180 granulation sandpaper. The content of the finest dust particles ranged from 0.21% for pine (P60 sandpaper) to 12.58% for beech (P180 sandpaper).The type of wood (hardwood or softwood) has a significant influence on the particle size and the content of the finest dust fraction.

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).

scholarly journals MINERAL ABUNDANCE AND PARTICLE SIZE DISTRIBUTION DERIVED FROM IN-SITU SPECTRA MEASUREMENTS OF YUTU ROVER OF CHANG’E-3

2017 ◽  
Vol XLII-3/W1 ◽  
pp. 85-89
Author(s):  
H. Lin ◽  
X. Zhang ◽  
Y. Yang ◽  
X. Wu ◽  
D. Guo
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Landing Site ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Particle Sizes ◽  
The Mean ◽  
The Difference ◽  
Yutu Rover

From geologic perspective, understanding the types, abundance, and size distributions of minerals allows us to address what geologic processes have been active on the lunar and planetary surface. The imaging spectrometer which was carried by the Yutu Rover of Chinese Chang’E-3 mission collected the reflectance at four different sites at the height of ~&amp;thinsp;1&amp;thinsp;m, providing a new insight to understand the lunar surface. The mineral composition and Particle Size Distribution (PSD) of these four sites were derived in this study using a Radiative Transfer Model (RTM) and Sparse Unmixing (SU) algorithm. The endmembers used were clinopyroxene, orthopyroxene, olivine, plagioclase and agglutinate collected from the lunar sample spectral dataset in RELAB. The results show that the agglutinate, clinopyroxene and olivine are the dominant minerals around the landing site. In location Node E, the abundance of agglutinate can reach up to 70&amp;thinsp;%, and the abundances of clinopyroxene and olivine are around 10&amp;thinsp;%. The mean particle sizes and the deviations of these endmembers were retrieved. PSDs of all these endmembers are close to normal distribution, and differences exist in the mean particle sizes, indicating the difference of space weathering rate of these endmembers.

scholarly journals THE EFFECT OF CAVITATION TREATMENT ON THE EXTINGUISHING OF PARTICLES OF OILS IN FUEL BOILERS

2019 ◽  
Vol 20 (9-10) ◽  
pp. 52-59
Author(s):  
M. A. Taymarov ◽  
R. V. Akhmetova ◽  
S. M. Margulis ◽  
L. I. Kasimova
Keyword(s):  
Particle Size ◽  
Combustion Zone ◽  
Consumption Rate ◽  
Fuel Oil ◽  
Particle Sizes ◽  
Oil Consumption ◽  
Boiler Efficiency ◽  
Large Particles ◽  
Oil Particles

The difficulties of burning the watered fuel oil used at the TPP as a reserve fuel for boilers are associated with its preparation by heating to reduce viscosity and the choice of a method of spraying with nozzles into the combustion zone. The quality of the preparation of fuel oil for combustion affecting the boiler efficiency is estimated by the length of the flame, the presence of burning large particles of fuel oil, the injection of coke and unburned particles onto screen and other heat-receiving surfaces. One of the ways to prepare fuel oil for combustion is cavitation treatment, which results in an emulsion consisting of fine micronsized particles. Heating of fuel oil particles after the nozzle in contact with the combustion zone is due to the flow of radiation from the burning torch. Therefore, in this article, the values of the flux density from the torch during the combustion of fuel oil are experimentally determined. The influence of particle size on the burning rate of the fuel oil M100 with the different density of the thermal radiation of the flame. It is found that the effect of cavitation treatment of fuel oil on the combustion rate is most significantly manifested in particle sizes less than 10 microns. For this purpose, the use of hydrodynamic cavitators are preferred at high fuel oil consumption rate.

scholarly journals KUALITAS PAPAN KOMPOSIT DARI LIMBAH FINIR KAYU LAPIS BERDASARKAN UKURAN PARTIKEL DAN WAKTU PENGEMPAAN DENGAN MENGGUNAKAN PEREKAT LIMBAH PLASTIK POLIPROPILENA

2019 ◽  
Vol 7 (2) ◽  
Author(s):  
Alfonsus Rodriquez ◽  
Ahmad Yani ◽  
Fathul Yusro
Keyword(s):  
Particle Size ◽  
Physical And Mechanical Properties ◽  
Particle Sizes ◽  
Hot Press ◽  
Factor B ◽  
Pressing Time ◽  
Materials Used ◽  
Absorption Thickness ◽  
Water Contents

This study aims to analyze the quality of composite boards from plywood veneers waste and polypropylene plastic waste adhesives base on particle sizes, pressing times, and both of interaction towards physical and mechanical properties also to obtain the particle sizes and pressing time properly with the result that produce the qualified standard boards of JIS A 5908-2003. This research carried out at the wood workshop, laboratory of technology and processing of woods (the faculty of forestry, university of Tanjungpura), and the laboratory of PT. Duta Pertiwi Nusantara. The materials used in this study were plywood veneers waste and polypropylene plastic by 50% : 50% comparison. The research method was utilized the completely randomized factorial design by two treatment factors. Factor A was particle sizes that consisting of 6 mesh, 8 mesh, and 10 mesh. Factor B was pressing time that consisting of 10 minutes, 15 minute, and 20 minutes. Composite boards were created by 30 x 30 x 1 size in centimetres by means the density target was 0,7 gr/cm3. The pressing was done by hot press in 180oC temperature and composite boards conditioning for 14 days. The results of this study showed that the density, water absorption, thickness, Modulus of Repture (MOR), internal bonding, holding strength of screws in the composite boards have been qualified the standard of JIS A 5908-2003. While, the water contents and Modulus of Elasticity (MOE) testing were not qualified the standard of JIS 5908-2003. The treatment that produce the optimum composite boards which quality JIS A 5908-2003 standard was on the 8 mesh particle size treatment by means of 15 minutes pressing time.Keywords: Composite Board, Particle Size, Polypropylene Plastics, Pressing Time, Veneers Waste.

scholarly journals Streaming instability of multiple particle species in protoplanetary disks

2018 ◽  
Vol 618 ◽  
pp. A75 ◽  
Author(s):  
Noemi Schaffer ◽  
Chao-Chin Yang ◽  
Anders Johansen
Keyword(s):  
Particle Size ◽  
Size Distribution ◽  
Protoplanetary Disks ◽  
Single Species ◽  
Stokes Number ◽  
Dust Particles ◽  
Particle Sizes ◽  
Particle Species ◽  
Streaming Instability ◽  
Large Particles

The radial drift and diffusion of dust particles in protoplanetary disks affect both the opacity and temperature of such disks, as well as the location and timing of planetesimal formation. In this paper, we present results of numerical simulations of particle-gas dynamics in protoplanetary disks that include dust grains with various size distributions. We have considered three scenarios in terms of particle size ranges, one where the Stokes number τs = 10−1−100, one where τs = 10−4−10−1, and finally one where τs = 10−3−100. Moreover, we considered both discrete and continuous distributions in particle size. In accordance with previous works we find in our multispecies simulations that different particle sizes interact via the gas and as a result their dynamics changes compared to the single-species case. The larger species trigger the streaming instability and create turbulence that drives the diffusion of the solid materials. We measured the radial equilibrium velocity of the system and find that the radial drift velocity of the large particles is reduced in the multispecies simulations and that the small particle species move on average outwards. We also varied the steepness of the size distribution, such that the exponent of the solid number density distribution, dN∕da ∝ a−q, is either q = 3 or q = 4. Overall, we find that the steepness of the size distribution and the discrete versus continuous approach have little impact on the results. The level of diffusion and drift rates are mainly dictated by the range of particle sizes. We measured the scale height of the particles and observe that small grains are stirred up well above the sedimented midplane layer where the large particles reside. Our measured diffusion and drift parameters can be used in coagulation models for planet formation as well as to understand relative mixing of the components of primitive meteorites (matrix, chondrules and CAIs) prior to inclusion in their parent bodies.

scholarly journals THE MEASUREMENT AND DISTRIBUTION OF WOOD DUST

2010 ◽  
Vol 41 (1) ◽  
pp. 25 ◽  
Author(s):  
Andrea Rosario Proto ◽  
Giuseppe Zimbalatti ◽  
Martino Negri
Keyword(s):  
Health And Safety ◽  
Qualitative Assessment ◽  
Dust Particles ◽  
Wood Dust ◽  
High Concentration ◽  
Dust Emissions ◽  
Carcinogenic Agents ◽  
Prevention Model ◽  
Number Of Particles

In Italy, the woodworking industry presents many issues in terms of occupational health and safety. This study on exposure to wood dust could contribute to the realization of a prevention model in order to limit exposure to carcinogenic agents to the worker. The sampling methodology illustrated the analysis of dust emissions from the woodworking machinery in operation throughout the various processing cycles. The quantitative and qualitative assessment of exposure was performed using two different methodologies. The levels of wood dust were determined according to EN indications and sampling was conducted using IOM and Cyclon personal samplers. The qualitative research of wood dust was performed using an advanced laser air particle counter. This allowed the number of particles present to be counted in real time. The results obtained allowed for an accurate assessment of the quality of the dust emitted inside the workplace during the various processing phases. The study highlighted the distribution of air particles within the different size classes, the exact number of both thin and ultra-thin dusts, and confirmed the high concentration of thin dust particles which can be very harmful to humans.

Carbon Quality of Four-Year-Old Woodchips in a Denitrification Bed Treating Agricultural Drainage Water

2018 ◽  
Vol 61 (3) ◽  
pp. 995-1000 ◽  
Author(s):  
Ehsan Ghane ◽  
Gary W. Feyereisen ◽  
Carl J. Rosen ◽  
Ulrike W. Tschirner
Keyword(s):  
Particle Size ◽  
Drainage Water ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Agricultural Drainage ◽  
Carbon Quality ◽  
The Mean ◽  
Lignocellulose Index ◽  
Effect Of Age

Abstract. A denitrification bed is a system that can reduce the nitrate concentration in subsurface drainage water. There is a need to investigate the carbon quality of old woodchips to gain a better understanding of the effect of age on woodchip properties. The objectives of this study were to characterize the carbon quality and carbon to nitrogen (C/N) ratio of aged woodchips and to examine the suitability of a denitrification bed for a replicated experiment. To achieve these goals, we excavated four-year-old woodchips along the length of a 106.4 m long denitrification bed near Willmar, Minnesota, and analyzed them for particle size, C/N ratio, and carbon quality. Particle size analysis showed similarities from 12.5 to 106.4 m along the bed. We found a mean C/N ratio ranging from 58.4 ±3.17 to 153.4 ±9.57 (smallest at the inlet). The mean lignocellulose index (LCI, a measure of carbon quality) of the four-year-old woodchips ranged from 0.47 to 0.57 (highest at the inlet). The woodchip particle sizes, C/N ratios, and LCI from 25.9 to 106.4 m along the bed length were similar. In conclusion, the C/N ratio and LCI of the four-year-old woodchips showed effects of decomposition and increased woodchip carbon recalcitrance over time, respectively. Keywords: Denitrifying bioreactor, Tile drainage, Water quality, Woodchip bioreactor.

scholarly journals Effect of particle sizes and sodium hydroxide concentrations on silica extraction from minerals obtained in Kalirejo village, Kokap, Kulonprogo, Yogyakarta

Eksergi ◽  
2021 ◽  
Vol 18 (1) ◽  
pp. 29
Author(s):  
Tutik Muji Setyoningrum ◽  
Wibiana Wulan Nandari ◽  
Sri Wahyu Murni ◽  
Muhamad Maulana Azimatun Nur
Keyword(s):  
Particle Size ◽  
Glass Ceramics ◽  
Extraction Process ◽  
Extraction Yield ◽  
Liquid Extraction ◽  
Refining Process ◽  
Particle Sizes ◽  
Small Communities ◽  
Solid Liquid

Silica is mainly used in the production of rubber, glass, cement, glass, ceramics, paper, cosmetics, electronics, paintings, healthcare and other industries. Kalirejo village has a potential abundant resource of silica minerals. However, to refine it, high cost of extraction should be done to obtain high purity of silica. Different refining methods influence different purity of the silica. The purpose of this research was to study the refining process of mineral rock silica from Kalirejo village, Kokap, Kulonprogo by emplying simple and cheap solid-liquid extraction. Extraction was done by varying the particle size at 100 - 200 mesh, while NaOH concentration was varied in 0.5 N to 5 N.  Results showed that minerals taken from Kalirejo village was dominated by silica (23%).  The largest extract (4.89 gram) was obtained at 200 mesh and using NaOH 5 N with yield of 15.07%. Higher NaOH and higher particle size enhanced the extraction yield. This finding could help small communities in Kalirejo village to enhance the quality of silica by employing simple and cheap extraction process.

scholarly journals A Comparative Study of Dry and Wet Milling of Barley Malt and Its Influence on Granulometry and Wort Composition

Beverages ◽  
2018 ◽  
Vol 4 (3) ◽  
pp. 51 ◽  
Author(s):  
Felipe Pereira de Moura ◽  
Thiago Rocha dos Santos Mathias
Keyword(s):  
Particle Size ◽  
Milling Process ◽  
Global Market ◽  
Production Costs ◽  
Wet Milling ◽  
Barley Malt ◽  
Market Sector ◽  
Yeast Strains ◽  
The Mean

Beer is a fermented drink produced from a wort comprised of barley malt, hops, and water in combination with activity from the yeast strains of the genus Saccharomyces. The beverage is consumed around the world and has a global market controlled by several multinational companies. However, in recent years, it has been possible to note an increase in the number of microbreweries and homebrewers, necessitating additional research both to develop and increase competitiveness of this market sector as well as to improve product quality and promote the reduction of production costs. The process of milling barley malt is often not considered relevant to these goals; however, this operation is influential with regard to, for example, mashing yield, the concentration of polyphenols in beer, and the quality of wort clarification. Therefore, this work evaluates the wet (10%, 20%, 30%, 40%, and 50% moisture content) and dry barley malt milling process as well as analyzes particle size distribution and the mean diameter of particles. The milled grains were submitted to a mashing process to evaluate how particle size contributes to the conversion of starch to sugars and the availability of polyphenols on sweet wort. The results indicate the best milling conditions to obtain a good mashing yield while preserving as much malt husk as possible to facilitate wort clarification.

Bark particle sizes and the modification of the physical properties of peat substrates

1999 ◽  
Vol 79 (1) ◽  
pp. 111-116 ◽  
Author(s):  
Nsalambi V. Nkongolo ◽  
Jean Caron
Keyword(s):  
Particle Size ◽  
Plant Roots ◽  
Particle Sizes ◽  
Gas Diffusivity ◽  
Diffusivity Measurements ◽  
Air Supply ◽  
Wood Bark ◽  
Porosity Measurements ◽  
Coarse Gravel

The physical quality of peat mixes is in part related to the capacity of the substrate to store and supply air and water to plant roots. During manufacturing, the mixing of various substrate components modifies the substrate characteristics. The objective of this study was to assess the changes in air storage and supply properties caused by varying the particle size of the substrate components. The substrate was composed of 40% wood bark (WB), 50% peat, and 10% coarse gravel (volume basis). Wood bark particle size was varied in a first (0–2, 2–4, 4–8 and 8–25 mm) and a second (1–2, 2–4, 4–8 and 8–16 mm) experiment. When increasing bark particle sizes to 8–25 mm or 8–16 mm, air supply characteristics, as assessed with gas diffusivity measurements, decreased to 0.78 or 0.45 its value for the 2–4 or 1–2 mm average bark particle size. This occurred despite no significant changes in air storage, as assessed from air-filled porosity measurements. Key words: Gas diffusivity, pore tortuosity, air-filled porosity, peat lite mixes, peat substrates

Sign in / Sign up

Export Citation Format

Share Document