Synergistic optimization of filter bag arrangement and shape for vortex suppression flow equalization and resistance reduction in a straight-through baghouse dust collector

Context Microplastics are present in ruminant production systems. Aims This study quantified the effects of polystyrene microplastic particle size and concentration on in vitro feed digestibility and ruminal degradation kinetics. Methods The Ankom filter bag method was used to investigate the effects of two sizes of microplastic particles (5 and 15 μm) at five concentrations (0.0, 0.5, 1.0, 3.0, and 5.0 g/L), and five incubation times (96, 72, 48, 24, and 6 h) on the in vitro dry matter degradability (IVDMD) of several different silage types. The Tilley and Terry method was used to assess if results were replicable to another common in vitro method. For the Tilley and Terry method, the effects of two sizes of microplastic particles (5 and 15 μm) at five concentrations (0.0, 0.5, 1.0, 3.0, and 5.0 g/L), and two incubation times (96 and 48 h) on the IVDMD of one silage type were investigated. Key results Microplastic exposure of any combination of particle size and concentration did not affect the IVDMD for any of the silage types or in vitro methods investigated, irrespective to the incubation time (P > 0.05). Conclusions In isolation of host effects, virgin polystyrene microplastic particles do not impact silage digestibility when 5 or 15 μm in size and at concentrations ≤ 5.0 g/L of ruminal liquor. Implications Research is necessary to confirm whether in vitro findings can be transferred to in vivo models and to investigate other polymers and weathered plastic.

ABSTRACT This study investigated the effects of different partial harvest frequencies on the cultivation of the green macroalga Ulva ohnoi using water from whiteleg shrimp Penaeus vannamei biofloc systems over 6 weeks. Specimens of U. ohnoi reproduced in the laboratory were stocked at 1 g of fresh weight (FW) l‒1 in 50 l tanks. Four experimental groups were evaluated: three partial harvest frequencies (every 7, 14 and 21 days), where biomass exceeding the initial stocking of 1 g FW l‒1 was removed from the tanks, and full harvest at 42 days, at which point the partial harvest treatments were also fully harvested. Each group had six replicates for a total of 24 experimental units. Weekly, water from a shrimp biofloc tank was filtered with a 20 µm bag filter and used to fill the algae tanks, whose previous water was discarded. Weighing the algae after removing water with a manual centrifuge was performed weekly. Standing biomass was highest in the 42-day group from week 4 onwards (p < 0.05), while growth rates showed significant differences primarily in weeks 2 and 3, with the 7 day partial harvest frequency showing higher rates (p < 0.05). Final yield and nitrogen and carbon removals did not differ between treatments (p > 0.05), whereas phosphorus removal was significantly higher in the 42-day harvest group (p < 0.05). This indicates that cumulative biomass production was similar among harvest regimes, supporting the feasibility of a single 42-day harvest. In conclusion, a 42-day harvest interval can simplify operational management by reducing frequent harvests while maintaining yield and improving nutrient removal in U. ohnoi cultivation within a decoupled biofloc-based integrated system with shrimp compared with different partial harvest regimes.

CFD analysis and parameter optimization of explosion suppression powder injection in a bag filter

Abstract To address dust re-entrainment and non-uniform cleaning caused by strong airflow impact in traditional methods, this study proposes two optimized pulse-blow approaches: rectangular and cosine function pulses. Comparative analysis shows that rectangular pulse jet expands the cleaning range through periodic impacts, while cosine pulse jet enables more uniform particle removal and controlled diffusion owing to its gradual pressure variation. The results indicate that the cosine pulse method performs best in terms of particle distribution uniformity, top residual removal, and overall cleaning efficiency, achieving approximately 70% dust removal, about 5% higher than conventional jet. This provides a useful reference for optimizing cleaning processes in baghouse dust collectors.

Thallium (Tl) poses a significant pollution risk due to its high volatility during clinker calcination. Thermodynamic calculations and multi-stage monitoring have revealed that, despite sulfur suppression, over 90% of Tl volatilised as thallium chloride at 900°C due to chlorine. Volatilised Tl migrated with gas, condensing in cooler zones, enriching Tl in mill-outlet raw meal. The recycling of Tl-enriched dust from the suspension preheater boiler and bag filter further intensified the Tl enrichment in the kiln-feed raw meal. As this enriched material reached the two-stage cyclone, it re-adsorbed and condensed Tl from the gas and reintroduced Tl back into the high-temperature zone again, forming an internal ‘volatilisation-condensation’ cycle. After calcination, only 0–27.85% of input Tl resided in the clinker, while the bypass system released merely 1.31–6.66%. Crucially, the bag filter efficiently intercepted volatile Tl, preventing detectable Tl emissions from kiln gas. Therefore, despite high volatility, the internal cycle, effective dust capture and dust recycling led to closed-loop circulation and enrichment of most Tl within the system, preventing environmental release. In addition, co-processing Tl-containing solid waste amplified the imbalance between Tl input and output, leading to greater internal circulation and enrichment within the kiln system, without significantly altering clinker Tl content or emissions.

Our objective was to evaluate the influence of substrate dispersion method and particle size on in vitro digestibility, gas production kinetics and composition, and fermentation characteristics of different feed types. Alfalfa hay, tall fescue hay, ground corn, soybean meal, and a total mixed ration (TMR) were used as substrates. Treatments were designed according to a 2 × 2 × 5 factorial arrangement: two substrate dispersion methods (loose substrate and in filter bags), two particle sizes (1 mm and 2 mm), and five feeds. Filter bags decreased (P ≤ 0.001) digestibility and gas production compared with loose samples. Filter bags decreased digestibility and total gas production to a greater extent for forages, whereas the effects on concentrate feeds were less pronounced. Using filter bags decreased (P ≤ 0.015) both methane production and methane concentration in headspace gas across all feeds. Substrates incubated in filter bags showed a lower molar proportion of acetate and a greater molar proportion of propionate than loose substrates (P&amp;lt; 0.001). In general, energy-rich feeds incubated using filter bags had a decreased (P ≤ 0.036) acetate-to-propionate ratio, while substrate dispersion method did not influence (P ≥ 0.16) the VFA profile of protein-rich feeds. Incubating substrates in filter bags alters in vitro digestibility, gas production, and fermentation characteristics regardless of particle size. However, the magnitude of responses is greater for forage-based feeds than concentrate feeds.

Introduction. In Ukraine, the problem of stress has become extremely relevant due to the complex social, economic and psychological realities caused by ongoing military conflict and its long-term consequences. One of the most common approaches to the prevention and symptomatic management of stress-related conditions is the use of sedatives, hypnotics or nootropics, particularly herbal origin with milder effect and a relatively low incidence of adverse reactions. The Aim of the Study is to analyze the Ukrainian pharmaceutical market of OTC-medicines used for the symptomatic management of stress. Research Methods. The study utilized data from State register of medicines of Ukraine, the Pharmacist’s Protocol “Symptomatic treatment of stress”, the Compendium online, the resources “Apteki.ua”, “Tabletki.ua”. Results and Discussion. The analysis shows that as of September 1, 2025, 85 trade names of overthe- counter medicines recommended for the symptomatic treatment of stress disorders were registered on the pharmaceutical market of Ukraine. Structural analysis according to the ATC classification reveals that 85.8 % of the range belong to the subgroup N05 CM “Hypnotic and sedatives”. Analysis of the market segment by production characteristic indicates that 78 % of the range is domestic and 22 % is foreign-made. It was established that solids prevail by type of dosage form: film-coated tablets (21 %), tablets (11 %), sublingual tablets (6 %), capsules (15 %), and herbal raw materials in packs and filter bags (9 %). The liquid dosage forms include tinctures (21 %), oral solutions (10 %), and oral drops (6 %). It was determined that the range of drugs is dominated by combined preparations of natural origin – 85.8 % based on dry, thick or liquid extracts of St. John’s wort herb, valerian root, motherwort herb, passionflower herb, lemon balm herb. Conclusions. The obtained data can be used to optimize pharmaceutical care, improve rational drug selection, and support evidence-based decision-making in the healthcare of stress management.

Three experiments were conducted to evaluate the effects of sample grinding techniques, filter bag preparation, and postincubation washing methods on NDF disappearance and degradation kinetics. In experiments 1 and 2, samples of corn silage, alfalfa hay, grass hay, and triticale silage were dried and ground to pass a 6-mm screen, then further processed through either a 1-mm cutter mill (CUT) or a 1-mm cyclone mill (CYC). Filter bags were filled with forage samples and either prerinsed with acetone (ACE) or left untreated (CON). Experiment 1 assessed NDF disappearance from bags subjected to various washing procedures without ruminal incubation. Experiment 2 evaluated in situ NDF disappearance after 0, 3, 6, 12, and 24 h of ruminal incubation followed by different washing methods. Experiment 3 extended incubation times to 240 h and compared hand wash (HW) versus machine wash (MW) treatments. All experiments followed a randomized complete block design with forage type as a random effect and grinding method, bag preparation, and washing procedure as fixed effects. Results from experiment 1 showed ACE bags retained more NDF than CON bags, and CYC grinding increased NDF disappearance, especially with MW. In experiment 2, significant interactions among grinding, bag preparation, and washing were observed, though NDF disappearance was minimal at short incubation times (<12 h). Experiment 3 revealed higher undegraded NDF concentrations with HW and CYC grinding, with no interaction between grinding and washing methods. Cyclone grinding produced finer particles, contributing to greater NDF disappearance even in the absence of microbial activity. These findings underscore the need for methodological standardization to ensure accurate and biologically meaningful forage evaluation.

Impact of aging on the efficiency and service life of filter bags in the steel industry

A Multi-Stage Classification Approach for Predictive Maintenance of a Cyclonic Bag Filter

The current state of equipment operation for concentrating and drying dairy products, research and calculation methods for the purification of exhaust air from spray drying installations, dusted with milk powder, in bag fabric filters, in particular the filtration and pulse regeneration processes, have been analyzed. It is noted that known studies of bag filters do not contain sufficient information to substantiate the design of a filter for cleaning air from milk powder while ensuring modern environmental requirements. Taking into account the obtained data of experimental studies of filtration processes on laboratory models and full-size stands, conducted at PrJSC "Kalynivka Machine-Building Plant" (Kalynivka, Vinnytsia region), the directions of increasing the efficiency and reliability of the use of bag filters for spray drying plants are considered. Methods for calculating the aerodynamic resistance of the filter cloth – clean and dusty – and determining the equilibrium resistance of the bag filter in the process of pulse regeneration of the filter, which takes into account the load on the filtration speed, dustiness, fractional composition, compressed air pressure and pulse frequency, are proposed. A comparative calculation analysis of aerodynamic resistance was performed when using bag filters according to a single-stage cleaning scheme (directly after the drying chamber) and as a second stage of cleaning (after cyclones). It showed that in the range of their effective operation, the aerodynamic resistance in both cases is practically the same with a significant reduction in the specific dusting of fine powder in the exhaust air, which allows to ensure modern environmental indicators for harmful emissions. The effectiveness of the implemented technical solutions in industrial samples of bag filters was confirmed by the results of commissioning tests of industrial samples and during their further operation. Based on the acquired scientific and technical experience, PrJSC "Kalynivka Machine-Building Plant" (Kalynivka, Vinnytsia region) developed, manufactured and put into operation nine sets of bag filters for drying plants with a capacity of 500 to 2500 kg/h of evaporated moisture.

High-ratio biomass co-firing has emerged as a practical pathway for reducing emissions from small coal-fired power plants in remote island grids. This study evaluates the environmental performance of palm kernel shell (PKS) co-firing at 50%, 75%, and 100% blending ratios in a stoker-fired boiler at PLTU Tidore, Indonesia. Direct stack measurements and fuel characterisation were used to quantify the effects of PKS substitution on sulfur dioxide (SO₂), nitrogen oxides (NOx), particulate visibility, and ash characteristics, while also assessing the stabilizing role of a redundant baghouse filtration configuration. The strongly reduced sulfur and ash content of PKS, as detailed in the fuel analyses, led to substantial declines in SO₂ emissions. Concentrations decreased from 182.95 mg/Nm³ under coal-only operation to 16.53 mg/Nm³ during 100% PKS firing. NOx levels remained within an operationally stable range (303.87–452.14 mg/Nm³) despite non-linear fluctuations associated with fuel–temperature interactions. PKS firing also resulted in progressively lighter stack plumes and the production of finer, less clinker-forming ash. Throughout all tests, the redundant bag filter system maintained uninterrupted particulate control and prevented opacity excursions, ensuring the reliability of the environmental measurements. These results demonstrate that PKS co-firing, supported by robust filtration redundancy, provides a feasible and cost-effective approach for improving air quality performance in isolated coal-dominated grids. The findings highlight a replicable strategy for integrating biomass into small-scale thermal plants while maintaining emission stability and operational continuity.

The most effective device for cleaning gases, as well as air, from dust particles is a multi-section electric filter. Electrostatic precipitators, unlike other gas cleaning methods, such as cyclones or bag filters, have several advantages, including high efficiency in cleaning gases from fine particles up to several micrometers in size, low hydraulic resistance, which reduces the energy consumption for pumping gas, and the ability to operate at high temperatures and pressures.Precipitators are widely used in numerous processes in the oil and gas industry, ensuring efficient extraction of unwanted components from gas streams. Their use improves environmental safety and efficiency of production operations. For example, in thermal power plants using fossil fuels, precipitators remove ash, soot and other solid particles formed during combustion; oil and gas refining processes, such as cracking, reforming and others, form oil mists and aerosols, electrostatic precipitators effectively trap dispersed phases, preventing contamination of equipment, reducing risks to personnel health and helping to improve the quality of final products. Particular attention should be paid to the high efficiency of electrostatic precipitators in the treatment of associated petroleum gas and the removal of sulfur-containing components, which contributes to compliance with environmental standards and an increase in the commercial value of gas.The authors proposed a modification of the electrostatic precipitator aimed at preventing turbulence and reducing the probability of particle breakthrough due to exceeding the permissible flow rate, as well as increasing the efficiency of collecting purified gas. In the course of the study, the problem of uneven distribution of flows in the supply gas duct and diffuser was revealed, which negatively affects the efficiency of its operation, leads to an increase in electricity consumption and the need for frequent maintenance of precipitation electrodes. As part of the work carried out, the authors of the article proposed a constructive solution to improve the electrostatic precipitator, supported by appropriate calculations.The implementation of the proposed changes in the design of the precipitator will increase the efficiency of purification of industrial gases, reduce operating costs and increase the service life of the equipment. The research results and design solutions can be used in the design of new and modernization of existing electrostatic precipitators used in various industries.

Against the backdrop of globally tightened environmental regulations, particularly in the Russian Federation, conventional gas-cleaning methods (cyclones, bag filters, electrostatic precipitators) used in the glass industry are becoming insufficient. These are only effective for capturing suspended particles yet not capable of removing the gaseous marker pollutants at the required level: NOx, SO2, CO. The study is aimed at developing and experimentally validating a highly efficient integrated system that enables 90…95 % removal of gaseous pollutants and approximates 100 % removal of solid particles. A silica/mullite fiber-based reducing catalyst produced entirely from domestic materials (20 cm3) achieved 95 % NO conversion at 350 °C in laboratory reactor tests. The catalytic filter element (with a surface area of 0.02 m2) installed in the pilot setup showed high simultaneous removal efficiencies for multiple pollutants: NOx – 92 %, SO2 – 96 %, at an operating temperature of 380 °C. The authors proposed an integrated purification train that includes an acid-gas neutralization reactor, reagent-dosing systems (for lime, caustic solution, and ammonia water), an inertial separator, a ceramic catalytic filter unit, as well as lime and spent reagent silos. The study was conducted using the Ceramic Pulse-Jet Filter, T Modification, Catalytic Configuration laboratory and pilot testing unit (Bakor R&amp;D Center).

Investigation of Cu-doped MnCeOx in PTFE catalytic fiber for synergistic removal of CB and NO at low temperature.

Ruminant in vitro methodologies use washing with neutral detergent solution (NDS) after incubation to mimic ruminant digestion, which is physiologically different compared to that of horses. Our objectives were to determine if washing feed samples with NDS before in vitro fermentation (PRE) would suppress fiber digestion versus a post-incubation wash (POST), and to compare in vitro digestibility of forage-based feed mixtures with added soluble carbohydrates (CARB), soluble protein (PROT), or soluble carbohydrates and soluble protein (C + P) to only-forage samples (CONT). Dried, ground feed mixtures sealed in ANKOM filter bags were placed in DaisyII incubators for 48 h in a split–split-plot batch culture design. Digestibility was determined as in vitro neutral detergent fiber digestibility (IVNDFD), in vitro acid detergent fiber digestibility (IVADFD), in vitro hemicellulose digestibility (IVHD), and in vitro true digestibility (IVTD). The PRE treatment decreased IVHD for CARB versus POST (p = 0.007). Pooling all mixtures, PRE decreased IVTD (p = 0.001), IVADFD (p = 0.036), and IVHD (p = 0.001) and tended to decrease IVNDFD (p = 0.072). The CARB mixture increased IVTD versus all other mixtures (p &lt; 0.001). Pre-washing with NDS suppressed in vitro fermentation by removing soluble carbohydrates. Without removal of soluble carbohydrates to mimic in vivo digestion, fiber digestibility is likely overestimated.

Animal fibre consists of the nitrogen-rich molecules in the non-digestible fraction of body tissues of prey animals, for example, in fur and bones. Animal fibre has a health effect on carnivores and; therefore, its quantification is important for nutrition research in carnivores as well as in omnivores. Traditional fibre analyses were developed to quantify the carbohydrate-based molecules of plant fibre and currently no method exists to quantify animal fibre. This study adapted the filter bag technique of the amylase-treated neutral detergent fibre method by adding a protease step to remove digestible protein from the residue to measure animal fibre. Sodium sulphite was omitted, similar to the neutral detergent residue (NDR) method, as it removes keratinaceous residues of animal origin. The amylase-treated neutral detergent residue including animal fibre (aNDRa) values were compared to the total dietary fibre (TDF) method. Test materials were lignocellulose, beet pulp, pea, barley, beef, horse meat with skin and coat, day-old chicks, rat, hair, cat faeces, faeces from bears fed a fruit-based diet and faeces from bears fed a rabbit-based diet. Several experiments preceded the validation of aNDRa with results as follows: pre-extraction of fat was sufficient when F57 bags, each containing 0.5 g of sample, were placed in a Soxhlet extractor for 1 h; grinding samples over a 2.0 instead of 1.0 mm screen in a centrifugal mill resulted in less sample loss in the F57 bags; pre-extraction of protein was sufficient when refluxed for 90 min with 5 mg protease per 0.5 g sample. The TDF concentration in beef and prey samples showed highly variable results with the TDF concentration in beef being too high showing that the TDF analysis is inaccurate to quantify animal fibre. In contrast, the aNDRa method was capable of quantifying animal fibre and plant fibre in a diverse range of samples.

Abstract Previous work has demonstrated that hindgut microbes in the horse can utilize various nitrogen sources for microbial metabolism. While microbes prefer soluble non-protein nitrogen, forages have hemicellulose-bound nitrogen (HBN) that improves fiber digestion for ruminants via hemicellulose (HEMI) and cellulose (CELL) digestion. However, it is unknown if increases in HBN-to-HEMI ratios (HBN/HEMI) improve fiber digestion in horses. Our objective was to determine if titrating HBN/HEMI increased in vitro HEMI digestibility (IVHD) and in vitro cellulose digestibility (IVCD) in horses and if fiber digestibility increased with extended incubation time (48 vs. 72 h). Four Quarter Horse geldings were fed 1.5% BW DM/d of coastal Bermudagrass hay (CBH) and 0.5 kg/d of a commercial concentrate for 14 d. On Day 14, fresh feces were collected for microbial inoculum. Feed mixtures [alfalfa hay (ALF), CBH, 60-40 ALF-CBH (A60), and 60-40 CBH-ALF (C60)] were formulated to have different HBN/HEMI. Dried, ground feed mixtures (0.5 g) sealed in F57 filter bags (n = 8/mixture; n = 16/incubation time) were pre-washed with neutral detergent solution and placed in duplicate into 8 jars between 2 DaisyII incubators (48- vs. 72-h incubation; 4 jars/incubator) in a split-split-plot batch-culture design. After incubation, samples were washed with water, dried, and weighed for residual neutral detergent fiber (NDF) then washed with acid detergent solution and 72% sulfuric acid to analyze for residual acid detergent fiber (ADF) and acid detergent lignin (ADL). A duplicate set of samples were analyzed for pre-fermentation NDF, ADF, ADL, neutral detergent insoluble crude protein (NDICP) and acid detergent insoluble crude protein (ADICP). Fiber fractions were determined as HEMI = NDF – ADF, and CELL = ADF – ADL, with HBN calculated as HBN = NDICP – ADICP. Digestibility measures were expressed as IVHD and IVCD. Data were analyzed within R Statistical Program (v4.4.0) using an ANOVA and a Pearson’s correlation with significance set at P ≤ 0.05. Mixture IVHD decreased in ALF versus all other mixtures (P &amp;lt; 0.001) with A60 similar to C60 (P = 0.12) but less than CBH (P &amp;lt; 0.01). No mixture effect occured for IVCD (P = 0.74). The 72-h incubation did not affect IVHD (P = 0.28), but increased IVCD (P &amp;lt; 0.001) compared to 48-h. Mixture IVHD was only moderately correlated to HBN/HEMI (r = -0.57; P &amp;lt; 0.01) and HBN (r = 0.61; P = 0.001), but more correlated to the ADL-to-HEMI ratio (ADL/HEMI; r = -0.88; P &amp;lt; 0.001). Overall, increasing HBN/HEMI did not improve IVHD or IVCD, likely due to increases in ADL/HEMI. However, increased retention time improved IVCD, indicating a shift in microbial fermentation from HEMI to CELL over time due to the enzymatic lag time required for CELL degradation in the hindgut of the horse.

Abstract Research in ruminants has demonstrated that rumen microbes use acid detergent soluble crude protein (ADSCP) as a nitrogen source. However, it is unknown whether the hindgut microbes in the horse can use ADSCP and whether increases in acid detergent lignin (ADL) affects the use of ADSCP compared to hemicellulose (HEMI). Thus, our objectives were to determine if hindgut microbes from equine feces can use ADSCP and if in vitro digestion of ADSCP is limited by increased ADL. Four Quarter Horse geldings were fed 1.5% BW DM/d of coastal Bermudagrass hay and 0.5 kg DM/d of a commercial concentrate for 14 d. On Day 14, fresh feces were collected for microbial inoculum. Four diets were formulated to be isonitrogenous using soybean meal, coastal Bermudagrass hay, alfalfa hay, and whole oats. Mixtures were formulated to increase ADL/HEMI ratio with increasing ADSCP/HEMI ratio (H-H), increasing ADL/HEMI and decreasing ADSCP/HEMI (H-L), decreasing ADL/HEMI and increasing ADSCP/HEMI (L-H), or decreasing ADL/HEMI and decreasing ADSCP/HEMI (L-L). The dried, ground feed mixtures (0.5 g), sealed in F57 filter bags, were pre-washed with neutral detergent solution and placed in triplicate into 8 jars between 2 DaisyII incubators in a split-split-plot batch-culture design for 48 h. One bag of the triplicate was used to assay residual neutral detergent fiber (NDF) and neutral detergent insoluble crude protein (NDICP) residue. The remaining two bags of the triplicate were analyzed for residual acid detergent fiber (ADF) and acid detergent insoluble crude protein (ADICP). Fiber fractions were determined as HEMI = NDF – ADF, and CELL = ADF – ADL with ADSCP calculated as ADSCP = NDICP – ADICP. Averaging of replicates within a jar resulted in n = 8/mixture. Data were analyzed within R Statistical Program (v4.4.0) using a 3-way ANOVA with significance set at P ≤ 0.05 and trends at P ≤ 0.10. In vitro HEMI digestibility (g/kg HEMI) was greater in L-H than all other treatments (P &amp;lt; 0.001) with L-L similar to H-H (P = 0.184) but greater than H-L (P = 0.015). However, ADSCP digestibility (g/kg ADSCP) decreased in L-L compared to L-H (P = 0.05) and tended to be less than H-H (P = 0.081). When ADSCP digestibility was expressed as g/kg HEMI, H-H and L-H were greater than H-L (P = 0.02; P = 0.05) and L-L (P = 0.007; P = 0.019), respectively. These results indicate that increasing lignification of HEMI decreases digestibility of HEMI and ADSCP, and that microbes may use ADSCP as a source of carbon skeleton when HEMI digestibility is limited by ADL. Overall, increasing the amount of both ADSCP and HEMI to hindgut microbes may improve fiber digestibility in the horse.