Search Results (10)

This paper presents the dedusting systems of a wheat mill in SC Agro Chirnogi, located in the southeastern area of Romania, and the physical characteristics of the material at the inlet, specifically at the base of the bagfilter systems. Samples were taken from both the dust removal system of the wheat cleaning technological phase (before milling) and from the dust removal system of the mill itself. It was found that the average particle size of the material at the cleaning section filter is between 1.191 and 0.563 mm, and the particle size of the material at the grinding section filter is between 0.278 and 0.186 mm, with their particle size distribution mainly following an exponential Rosin–Rammler distribution. Also, the bulk density of the material in the two bag filters ranges between 401 and 667 kg/m³ at the inlet and between 452 and 632 kg/m³ at the outlet of the cleaning technological phase filter. At the mill grinding section filter, the bulk density was between 426 and 506 kg/m³ at the inlet and between 422 and 580 kg/m³ at the outlet. The density of the material was between 854 and 1282 kg/m³ for the last fractions at the exit of the cleaning section filter and between 1309 and 1323 kg/m³ at the grinding section filter. Determinations were also made for other characteristics. Full article

The rise of the global tea industry market, influenced by the growing demands for healthier diet options, resulted in the constant increase in herbal tea production. In accordance, increased production leads to increased waste generation, especially in the area of filter tea production, which generates waste in the form of powdered plant material with particle sizes lower than 0.315 mm. The generated amount of this powdered plant material, also called herbal dust, can vary in the range from 10 to 40% of the total processed plant, and it is often considered waste only due to its size. Therefore, within this study, ultrasound-assisted extraction (UAE) was utilized for the extraction of green tea (Camellia sinensis L.), lemon balm (Melissa officinalis L.), and hibiscus (Hibiscus sabdariffa L.) herbal dust, and the quality of the obtained extracts was evaluated in terms of total phenolic content (TPC) and phenolic profile. In addition, UAE was conducted on the three different amplitudes (20, 60, and 100%) and two different extraction times (5 and 10 min) in order to investigate and compare the influence of different extraction parameters. The results showed that the maximum TPC for green tea, hibiscus, and lemon balm herbal dust was 152.91 ± 0.74, 60.63 ± 0.10, and 356.22 ± 3.13 mg GAE/g DE, respectively. HPLC analysis conducted for all of the obtained extracts confirmed the presence of several phenolic compounds, with the highest concentrations of epigallocatechin gallate (EGCG) for the extracts of green tea, and neochlorogenic acid for hibiscus herbal dust extracts. The HPLC analysis of the lemon balm extracts recorded the highest concentration of rosmarinic acid for all of the UAE conditions. The results reported within this study indicate that previously considered waste, herbal dust plant material can be successfully extracted by application of UAE and that the obtained extracts exhibit concentrations of bioactive compounds comparable to the extracts of the commercially available plant material. Full article

This article presents measurements of the emission of salt dust discharged into the atmosphere in the Wieliczka Salt Mine. Industrial tests have been carried out cyclically since 2004. The research methodology included six measurements of the salt dust’s mass increments on the filters, including three before the inlet to the desalination installation and three measurements at the emitter outlet. In order to limit errors resulting from the diversity of concentrations in the mixture of dosed brine, three series of measurements are carried out each time. The proposed research methodology uses the Aspirator Stationary (AS-50) gravimetric aspirator for measurements with a designed probe adjusted to the characteristics of the dedusting installation used. The conducted tests allowed calculation of the efficiency of the scrubber and confirm the usefulness of the measuring probe used. Moreover, long-term and cyclical measurements make it possible to observe the effectiveness of the installation and salt production using the wet system from brine obtained in the mine. The proposed method is an innovative solution for monitoring salt-dust emissions in mining applications. Full article

Although the LiDAR sensor provides high-resolution point cloud data, its performance degrades when exposed to dust environments, which may cause a failure in perception for robotics applications. To address this issue, our study designed an intensity-based filter that can remove dust particles from LiDAR data in two steps. In the first step, it identifies potential points that are likely to be dust by using intensity information. The second step involves analyzing the point density around selected points and removing them if they do not meet the threshold criterion. To test the proposed filter, we collected experimental data sets under the existence of dust and manually labeled them. Using these data, the de-dusting performance of the designed filter was evaluated and compared to several types of conventional filters. The proposed filter outperforms the conventional ones in achieving the best performance with the highest F1 score and removing dust without sacrificing the original surrounding data. Full article

Affected by the uneven concentration of coal dust and low illumination, most of the images captured in the top-coal caving face have low definition, high haze and serious noise. In order to improve the visual effect of underground images captured in the top-coal caving face, a novel single-channel Retinex dedusting algorithm with frequency domain prior information is proposed to solve the problem that Retinex defogging algorithm cannot effectively defog and denoise, simultaneously, while preserving image details. Our work is inspired by the simple and intuitive observation that the low frequency component of dust-free image will be amplified in the symmetrical spectrum after adding dusts. A single-channel multiscale Retinex algorithm with color restoration (MSRCR) in YIQ space is proposed to restore the foggy approximate component in wavelet domain. After that the multiscale convolution enhancement and fast non-local means (FNLM) filter are used to minimize noise of detail components while retaining sufficient details. Finally, a dust-free image is reconstructed to the spatial domain and the color is restored by white balance. By comparing with the state-of-the-art image dedusting and defogging algorithms, the experimental results have shown that the proposed algorithm has higher contrast and visibility in both subjective and objective analysis while retaining sufficient details. Full article

LiDAR sensors have played an important role in a variety of related applications due to their merits of providing high-resolution and accurate information about the environment. However, their detection performance significantly degrades under dusty conditions, thereby making the whole perception of the vehicles prone to failure. To deal with this problem, we designed a de-dust filter using a LIOR filtering technique that offers a viable method of eliminating dust particles from the measurement data. Experimental results confirm that the proposed method is robust in the face of dust particles by successfully removing them from the measured point cloud with good filtering accuracy while maintaining rich information about the environment. Full article

We propose a dust removal technology in which a two-stage moving granular bed filter was employed using coarse and fine filtering granules. The pressure drop, collection efficiency, and dust particulate size distributions were investigated using various mass flow rates for coarse and fine granules at room temperature. In addition, the ratio of mass consumption was used to reveal the actual mass flow. The ratio of mass consumption influenced the pressure drop, collection efficiency, and dust particulate size distributions. Particulates larger than 1.775 μm were removed by the filter. Our results showed that a mass flow of 330 g/min for coarse granules and a mass flow of 1100 g/min for fine granules provided optimal collection efficiency and particulate size distribution. The proposed design can aid the development of high-temperature systems in power plants. Full article

The development of efficient materials and processes is a long-term goal for the integrated flue gas purification in industry. In this study, a large-size V-based catalytic filter (L3000 mm × Φ150 mm) was prepared by loading the catalyst emulsion into a blank filter, which demonstrated excellent performance for simultaneously removing NO_x, SO_x and dust. The laboratory investigation found that the small catalytic particles, high catalyst loading and low face velocity could improve the DeNO_x efficiency, and above 80% NO conversion could be achieved in the temperature range of 250–400 °C on the condition of <300 nm catalytic particle size, >7.41 wt % catalyst loading and <1.00 Nm/min face velocity. The negative effect of SO₂/H₂O was only observed below 300 °C, and the dust had little negative effects on DeNO_x efficiency except for the increase of pressure drop. Moreover, a 90-day industrial test of 2380 catalytic filters over 100,000 Nm³/h of flue gas (0.50 Nm/min) from a glass kiln demonstrated that the removal efficiency of both NO_x and SO_x could be maintained above 95% with great stability at 320–350 °C, and 99% dust could be removed with a pressure drop of less than 1.40 KPa. The results reported herein indicate the promising application prospect of large-size V-based catalytic filters for integrated flue gas purification in industry. Full article

Concentrations and ratio of dissolved and suspended forms of metals and metalloids (MMs) in snow cover and their deposition rates from the atmosphere in the western part of Moscow were studied. Forms of MMs were separated using a filter with pore diameter of 0.45 μm; their concentrations were measured by ICP-MS and ICP-AES methods. Anthropogenic impact in Moscow caused a significant increase in dust load (2–7 times), concentration of solid particles in snow cover (2–5 times), and mineralization of snow meltwater (5–18 times) compared to the background level. Urban snow contains Sn, Ti, Bi, Al, W, Fe, Pb, V, Cr, Rb, Mo, Mn, As, Co, Cu, Ba, Sb, Mg mainly in suspended form, and Ca and Na in dissolved form. The role of suspended MMs in the city significantly increases compared to the background region due to high dust load, usage of de-icing salts, and the change of acidic background conditions to alkaline ones. Anthropogenic emissions are the main sources of suspended Ca, W, Co, V, Sr, Ti, Mg, Na, Mo, Zn, Fe, Sb, and Cu in the snow cover of traffic zone. These elements’ concentrations in roadside snow cover exceed the background values more than 25 times. The highest concentrations and deposition rates of MMs in the snow of Moscow are localized near the large and medium roads. Full article

In this research, the idea of multicomponent, one-vessel cleaning of syngas through simultaneous dedusting and adsorption is described. Data presented were obtained with the use of a pilot-scale 60 kW_th fixed-bed GazEla reactor, coupled with a dry gas cleaning unit where mineral sorbents are injected into raw syngas at 500–650 °C, before dedusting at ceramic filters. The research primarily presents results of the application of four calcined sorbents, i.e., chalk (CaO), dolomite (MgO–CaO), halloysite (AlO–MgO–FeO), and kaolinite (AlO–MgO) for high-temperature (HT) adsorption of impurities contained in syngas from gasification of biomass. An emphasis on data regarding the stability of the filtration process is provided since the addition of coating and co-filtering materials is often necessary for keeping the filtration of syngas stable, in industrial applications. Full article