Mesh Screen Research Articles

In Situ Oil Separation and Collection from Water under Surface Wave Condition.

Removal of oil from water is strongly desired due to environmental pollution, and related studies are mainly limited to the material itself. Here, we propose an oil-water separation device, called a floating well, which includes a container for oil collection and a modified mesh screen for oil separation. The mesh screen is superhydrophilic to oil and superhydrophobic to water. The oil removal experiment was performed in a basin. Under the calm surface condition, the oil collection efficiency is shown to be 42-69%. The inadequate oil collection is explained by the breakdown of a thin oil film above water to form an oil-free area, preventing direct contact between the separator and the oil. Sustained by a wave generator, we are surprised to find that with a low-frequency surface wave, the oil collection efficiency is increased to 98%, and the collection speed reaches 2.5 times that under the calm surface condition. The almost complete collection is due to the sustained contact between the separator and the oil, under which the surface wave continuously drives the oil film toward the separator from elsewhere, thus the oil-free area cannot be formed. Our work presents a new clue for large-scale in situ applications, in which the nature wave energy of river/sea can be the driving force for continuous oil separation and collection.

In-situ phase separation to improve phase change heat transfer performance

Phase change is widely applied in thermal-power conversion, cooling and thermal management, influencing efficiency, safety and cost of energy systems. The complicated mass, momentum and energy exchanges between two-phases causes large pressure drops, critical heat fluxes and flow instabilities. Here, a review on phase separation principle for phase change heat transfer is provided. The phase separation principle is presented in a theoretical form. Design and operation of phase separation for evaporator, condenser and heat pipe are commented. Because phase separation assigns pathways for liquid and vapor, it improves pool boiling performance and eliminates flow instability for micro-evaporator. For micro-condenser, the lined pin fins array creates liquid and vapor passages. The expanded liquid passage adapts increased flow rate to increased flow passage area for liquid. Pin fins are effective for filmwise condensation to increase heat transfer coefficients at low cost of pumping power. Phase separation for macro-condenser was fulfilled by suspending mesh screen membrane tube in condenser tube to confine vapor in annular region, yielding enhanced thin film condensation. Phase separation was commented on smart heat pipe. Superhydrophilic evaporator and superhydrophobic condenser generate nucleate mechanism, achieving increased heat transfer coefficients when heat loads increase. Perspective of phase separation was discussed.

Fundamental Study of the Production of Paper Ash Made from Paper Sludge II : Development of Paper Ash Application Technology to Improve the Bulk and Save Drying Energy of Paperboard

In this study, paper ash generated during the incineration process of paper sludge was applied to measure the bulk, strength, and drying energy reduction of paperboard to assess the possibility of using it as an inorganic additive in paperboard mills. Three types of paper ash were fabricated by incineration, crushed, and fractionated with three different screen sizes, and their physical properties were measured. The fabricated paper ashes were added to Korean old corrugated containers (KOCC) stock to make handsheets, and their physical properties and drying energy reduction were determined. In addition, paper ash particles classified into 200 mesh screens were surface-modified with cationic polyacrylamide (C-PAM), and the handsheets were manufactured to analyze the strength improvement effect of paperboard. The bulk and the drying energy reduction improved as the paper ashes were added into the KOCC stock, but the tensile index, compression index, and burst strength decreased. In particular, the higher the average particle size of the paper ash, the higher the bulk and the drying energy reduction, but the lower the strength. The surface modification of the paper ash with C-PAM was effective in improving the strength. Therefore, paper ash made of paper sludge collected from specialty paper mills is effective in improving the bulk and drying energy reduction of paperboard, and surface modification with C-PAM is required to prevent the deterioration of paper strength.

Analysis of the Physical Properties of Seeds of Selected Viburnum Species for the Needs of Seed Sorting Operations

Viburnum is a genus of colorful and ornamental plants popular in landscape design on account of their high esthetic appeal. The physical properties of viburnum seeds have not been investigated in the literature to date. Therefore, the aim of this study was to characterize the seeds of selected Viburnum species and to search for potential relationships between their physical attributes for the needs of seed sorting operations. The basic physical parameters of the seeds of six Viburnum species were measured, and the relationships between these attributes were determined in correlation and regression analyses. The average values of the evaluated parameters were determined in the following range: terminal velocity—from 5.6 to 7.9 m s−1, thickness—from 1.39 to 1.87 mm, width—from 3.59 to 6.33 mm, length—from 5.58 to 7.44 mm, angle of external friction—from 36.7 to 43.8°, mass—from 16.7 to 35.0 mg. The seeds of V. dasyanthum, V. lentago and V. sargentii should be sorted in air separators, and the seeds of V. lantana and V. opulus should be processed with the use of mesh screens with round apertures to obtain uniform size fractions. The seeds of V. rhytodophyllum cannot be effectively sorted into batches with uniform seed mass, but they can be separated into groups with similar dimensions.

ANN modeling and residual analysis on screening efficiency of coal in vibrating screen

ABSTRACT In this paper, coal screening in vibrating screen was carried out with the size ranges of −6 mm + 4 mm, −4 mm + 2 mm, and −2 mm + 0.5 mm. The vibrating screen was newly designed with flexibility in angle and frequency. The vibrating screen experimentation was carried out by varying screen mesh, angle, and screen frequency. During the screening, the angle was kept constant, and frequency was varied to obtain each size range’s screening efficiency. The experimental results of screening efficiency were evaluated for each size fraction range of coal. The maximum efficiency for screening coal with −6 mm+4 mm, −4 mm+2 mm, and −2 mm+0.5 mm size range obtained was 87.60%, 80.93%, and 62.96%, respectively. Further, the prediction model was developed for each size range using a feed-backward artificial neural network (ANN) to consider the back-propagation error technique. For each screening condition, 10 ANN models were developed with the variation in 1–10 different neurons. ANN has provided mathematical models with a 99.9% regression coefficient for predicting each size range’s screening efficiency. Furthermore, the residuals of each optimal ANN model were analyzed using a normal probability plot and histogram. The ANN model’s accuracy was obtained from the residual analysis by evaluating four different model conditions, i.e., independence, homoscedasticity, normality, and mean error.

Clogging Model for Coarse and Fine Filtering Cloths of Filtering Cylindrical Elements, Preventing Sedimentation of Mechanical Impurities in Their Gap

In this paper we propose a method for preventing sedimentation of solid particles in the lower part of the gap between filtering cylindrical elements of coarse and fine purification by increasing the size of the meshes and total thickness of the first downstream gas flow layers of the fine filtering element in excess of the maximum diameter of solid particles. Experimental corroboration for the proposed method showed absence of solid particles’ sedimentation in the lower part of the gap between filtering cylindrical elements of coarse and fine purification and clogging of their meshes. As a result of the experiments, we found that the maximum sedimentation of mechanical impurities inside the first screens of the fine filtering cloth is achieved when their meshes’ size and screens’ thickness are, respectively, equal to three and two and a half maximum diameters of a solid particle. We developed a mathematical model that describes the clogging dynamics of filtering elements, where pressure losses in the first section with constant mesh sizes of all screens and in the second section with a sequential decrease in mesh sizes have different clogging rates and therefore are calculated separately from each other. The clogging process at each section of the multilayer filter cloth is represented as a successive decrease in the effective screening area of the screen meshes. The mathematical model makes it possible to prevent the sedimentation of mechanical impurities in the gap between gas filter elements of coarse and fine purification and allows to analytically determine the clogging degree at any time of operation, depending on the pressure losses’ values.

Bovine ossein powder: effect of particle size on its physicochemical and functional characteristics and its application in emulsion‐type sausage

SummaryOssein (OS) powder was prepared from bovine bone, ground and sieved through mesh screens to obtain two different particle sizes of 50 (OS50) and 200 mesh (OS200). Regarding OS property determination, average particle diameters of the OS50 and the OS200 were 260.08 ± 6.48 μm and 51.79 ± 0.39 μm, respectively. Based on non‐reducing electrophoresis, both OS samples consisted of α1‐ and α2‐chain of type I collagen. Fourier transform infrared spectra revealed the presence of triple helical structure with partial unfolding of which the OS200 showed the greater denaturation extent. The OS200 also showed higher emulsion activity but lower oil absorption than those of the OS50. The emulsion‐type sausages containing OS powders (0.5% w/w) exhibited significantly lower total fluid, water, and fat releases than those of the sausages without OS. The OS200‐containing sausages exhibited the lowest expressible water and received the highest hedonic scores in texture and overall acceptance from consumer panel.

Big Fish or Small Fish? Differential Ichthyoarchaeological Representation Revealed by Different Recovery Methods in the Atacama Desert Coast, Northern Chile

ABSTRACT Recovery methods and techniques for archaeological sampling can yield major differences in abundance and anatomo-taxonomical representation of animals, affecting past social and ecological reconstruction. Despite being a common organic material in archaeological sites, faunal remains typically exhibit differential preservation of species and skeletal elements due to pre- and post-depositional processes. This is particularly true for small-sized animals such as certain species of fish, whose often small and fragile fragments are difficult to recover and identify. Here, we present the results of a comparative analysis between two ichthyoarchaeological assemblages from Caleta Vitor 3 in northern Chile (CV3, 18°45′09″ S), an Early to Middle Holocene (9.2–7.6 ka cal BP) Chinchorro shell midden site. We compare samples obtained and processed, both in the field and the lab, using different recovery techniques. We developed a data standardisation procedure to compare and evaluate skeletal representation, taxa distribution and variations throughout the stratigraphic sequence. Our results show that mesh screen size affects not only the abundance and density of fish but also species representation. Moreover, the identification of small pelagic fish at CV3 sheds further light upon prehistoric fishing strategies and social organisation during the site’s early occupation.

Evaluation of 24-h screen deployments as a standardized platform to monitor Gambierdiscus populations in the Florida Keys and U.S. Virgin Islands

Anchored mesh screens have been suggested as a standardized approach to monitor the cell abundances of epiphytic dinoflagellates in benthic habitats, including toxigenic members of the Gambierdiscus genus responsible for ciguatera poisoning (CP). Here we deployed screens for 24h at eight sites in the Florida Keys and St. Thomas (US Virgin Islands) to evaluate their performance relative to the traditional method of assessing Gambierdiscus abundance in which cell counts are normalized to wet weight of host algae. The 30-month study (April 2013 – August 2015) involved monthly sampling at sites where screens were suspended at near-bottom locations for a 24h period and retrieved, with concurrent collections of macrophytes; including Halimeda, Laurencia, and Thalassia in the Florida Keys, and Dictyota in both regions. Gambierdiscus cells were identified and enumerated in the screen and macrophyte samples, and several regression techniques were evaluated (linear regression using untransformed and log-transformed data; negative binomial distribution (NBD) regression) to determine how well the screen-derived data could estimate algal cell concentrations on the host algae. In all cases, the NBD models performed the best based on Akaike Information Criteria values, although 38% of the regressions were not statistically-significant, including all of the St. Thomas sites. The r2 values were all < 0.75 and averaged 0.36, indicating relatively poor fit of the screen data. False negative results (regression models underestimating actual cell abundances) were common occurrences, ranging from 5 to 74% of the scenarios tested. In summary, these results indicate that 24h screen deployments do not appear to be consistent in all situations. Caution is therefore needed when considering 24h screens as a standardized monitoring approach for quantifying Gambierdiscus population dynamics across geography and ecosystems. Furthermore, neutral (artificial) substrates may not adequately capture either the host preference or palatability that likely influence the initial vector of toxin incorporation in the food web via herbivory on these macrophytes.

Numerical Wire Mesh Model for the Simulation of Noise-Reduction Devices

This study deals with the development of a numerical wire mesh screen model for the unsteady simulation of aeroacoustic configurations. Such devices are indeed of growing interest for practical applications because they potentially lead to significant noise-reduction effects. Numerical simulations including wire mesh screens are therefore of major interest to optimize their possible location and properties, as well as to get a better understanding of the involved physical phenomena. On the basis of several finely resolved unsteady simulations (direct numerical simulation and large-eddy simulation) of the flow through an isolated wire mesh sample, a numerical wire mesh screen model is proposed and calibrated. An application of the method to the tandem cylinder test case is then performed for different screen locations and porosities. The introduction of wire mesh screens in the flow is observed to lead in some cases to a significant reduction of the radiated noise, by up to 8 dB.

Ips sexdentatus Mass-Trapping: Mitigation of Its Negative Effects on Saproxylic Beetles Larger Than the Target

Research Highlights: We investigated the negative effects of bark beetle mass trapping, especially non-target catches among the target’s natural enemies. Slot traps modified with mesh screen and escape windows were tested to improve their selectiveness. Background and Objectives: Two of the main natural enemies of bark beetles, Thanasimus formicarius (L.) and Temnoscheila caerulea (Olivier), are frequently trapped in high numbers in Ips sexdentatus (Böerner) pheromone traps, along with other saproxylic insects; this may lead to much larger pest populations in the successive 4–20 beetle generations. From 2016–2019, during I. sexdentatus mass-trapping in a pine forest of Tuscany (Italy), non-target catches were tallied. Trap modifications were evaluated to mitigate non-target catches, especially those concerning bark beetles’ natural enemies. Materials and Methods: A total of 25 bark-beetle slot traps were placed about 75 m apart in a pine stand infested by I. sexdentatus. Traps were baited with I. sexdentatus aggregation pheromone, whose main components are ipsenol, ipsdienol, and 2-methyl-3-buten-2-ol. Catches were collected every 10 days from March to December. In 2019, 13 traps were modified by applying a 6-mm mesh screen on top of the collection container and by providing three 60 mm × 8 mm escape windows immediately above the screen. These “modified traps” and their captures were considered separately from the 12 remaining “standard traps.” All bark beetle species were recorded, as well as all beetle species &gt; 8 mm. Results: Overall, target catches amounted for &lt;10% of the total beetle catches. The most-collected species was the bark beetle Orthotomicus erosus Wollaston. Trap modification allowed the escape of larger species, resulting in the reduction of the average size of caught specimens. Even though non-target catches among predators were still high, the proportion of major predators (T. formicarius and T. caerulea) to bark beetles showed a statistically significant reduction of predator catches in modified traps, an encouraging outcome. Conclusions: Trap modifications may mitigate the problem of non-target catches during mass trapping, especially reducing catches of beetle species larger than the target. However, the key is to schedule mass trapping only during those seasons when the target adults are more active than the main predator adults, thus limiting their catches and, consequently, the negative effects on pest management and biodiversity.

Heavy metal pollution removal from water using a cost-effective bio-adsorbent

One of the worldwide environmental issues is water contamination by toxic heavy metals. Copper is considered one of the most common heavy metals founded in industrial wastes, and it has potential impacts on the ecosystem and human health. In order to remove copper from synthetic water, an economically effective adsorbent is required. Thus, this work evaluated the adsorption of copper by utilizing Westland Irish peat moss. The adsorbent was prepared by washing the Westland Irish peat moss using an acidic bath for half an hour with a continuous shaken process, then the mixture was centrifuged to separate the peat moss particles, which was washed using deionized water and dried using an oven. The dried sample was ground and sieved at 80 mesh screen before it was used as an adsorbent. The experiments were accomplished in a batch system as a function of initial solution pH, contact time as well as peat moss dosage. The maximum copper removal, 94.8%, was obtained at a pH of 6, optimum adsorption-equilibrium time of 80 minutes, and peat moss dosage of 7.5 g/L. Irish peat moss as an economically effective adsorbent was satisfactorily employed to remove copper from synthetic water.

Artificial neural network modeling for predicting the screening efficiency of coal with varying moisture content in the vibrating screen

ABSTRACT In India, coal is one of the prime sources of energy used in the power generation and metallurgy sector. The processing of coal below 3 mm is not successfully carried out in India. The quality of coal below 3 mm can be improved by decreasing the coal’s particle size, which reduces the ash percentage of coal. Screening is one of the significant beneficiation techniques used to reduce the size fraction of coal. The difficult to process coal of size −3 + 1 mm was selected in the present work. In this work, an attempt has been made to screen the coal of size −2 + 1 mm from −3 + 1 mm using a 2 mm screen mesh in the vibrating screen generated at different moisture content, angle, and frequency of the deck. The performance of the vibrating screen was evaluated using screening efficiency. Furthermore, prediction using a feed backward artificial neural network (ANN) model was developed on the experimental results for ten different neuron conditions. From the results, it was clear that the prediction results obtained from the ANN model were in good correlation with the experimental results.

Improvement of Fiber Fines Retention and Mechanical Properties of Board Paper Using Corn and Tapioca Starch- A Handsheet Study

Steadily increasing production cost in the paper industry require more efficient resource allocation and utilization of recycled materials and the use of renewable materials and additives to become more environmentally friendly. With this project, 100 g/m² TAPPI handsheets from industrial processed OCC fiber material were produced, without starch and starch in cooked and uncooked form, air-dried at 23°C and contact-dried at 120°C. Starch addition levels were 6.0, 18.0 and 24.0 kg/mt (12.0, 36.0, and 48.0 lbs./st) for pearl and cationic starch, and 2.0, 6.0 and 8.0 kg/mt (4.0, 12.0, and 16.0 lbs./st) for tapioca starch. Fines were measured with a Britt Jar devise having a 75 μm (200 mesh) screen. The highest tensile index improvement of 35.71% for uncooked tapioca starch at an addition rate of 16 lbs./st. The highest tear index improvement of 1.86% was for pearl starch at an addition rate of 12 lbs./st for the cooked &amp; contact dried application. The highest burst index improvement of the produced handsheets was for uncooked &amp; contact dried cationic starch at an addition rate of 12 lbs./st with an improvement of 21.49%. Application of pearl starch showed the largest difference in fines content at the 12 lbs./st and 48 lbs./st of fiber concentrations, reducing the fines content by 22.2% and 24.7% based on solids content respectively. Pearl starch outperformed cationic and tapioca starch products and showed the highest potential for fiber savings and net profit value.

An experimental justification of industrial water strainer brush cleaner properties

Purpose. Theoretical calculation of the friction resistance of the brush cleaner on the mesh screen of the strainer filter FRU-190-2 for industrial water. Experimental determination of the stiffness of one bristle of a brush cleaner. Experimental study of the resistance to movement of the brush cleaner on the strainer filter mesh screen. The purpose of writing this article is the theoretical calculation of the friction resistance of the brush cleaner on the strainer filter mesh screen of the industrial water strainer filter. Filters with a mesh screen are used in heavy industry for the first stage of water treatment. To design and calculate the properties of the brush cleaner, it is necessary to determine the geometric characteristics of the brush cleaner and the frictional resistance force when moving the brush cleaner on the strainer filter mesh screen. To confirm the results of the theoretical calculation of the frictional resistance of the brush cleaner, performed by methods of strength of materials, it is necessary to conduct an experimental study to determine the stiffness of one bristle of the brush cleaner and the resistance to movement of the brush cleaner bristles on the filter element. The methodology of research consists in theoretical calculation by methods of strength of materialsof friction resistance of a brush on a surface of a mesh filter element of the FRU-190-2 filter for industrial water, development of a technique of carrying out experiment, confirmation of the received analytical results of theoretical calculations by experimental researches. Findings. To determine the drag force of the brush cleaner, analytical solutions have been developed that take into account the influence of physical and geometric parameters of the bristles. Experimental confirmation of theoretical calculations is obtained. Scientific novelty is to establish and prove the cubic dependence of the force on one wire of the brush cleaner on its deflection. Analytical dependences of calculation of effort of movement of a brush on its geometrical parameters are revealed. Practical implications. The developed design technique and the results of calculations and experimental researches provide an possibility at the design stage to justification the geometric and physical properties of the brush cleaner of the strainer filter of industrial water.

Анализ пространственного распределения сообществ макрозообентоса в равнинной реке полупустынной зоны

Анализ пространственного распределения сообществ макрозообентоса в равнинной реке полупустынной зоны

Self-rotating stir mesh screen sorptive extraction for analyzing chlorpyrifos by ion mobility spectrometry.

A mesh screen was electrochemically coated with polypyrrole and used as a sorptive extractor device, for the first time. This configuration acts in such a way that it is self-rotating in the presence of a magnetic force and can be used for extraction and concentration of analytes. Actually, applying a mesh screen instead of a bar or plate in sorptive extraction provided a more effective contact area between the sorptive materials and sample solution, resulting in higher sorption efficiency. The device performance was assessed by using chlorpyrifos pesticide as a model analyte. A thermal desorption unit was coupled to an ion mobility spectrometer and applied for evaporating the extracted analyte. Different parameters affecting the extraction efficiency during the electro-polymerization and the extraction process, including the time of electrodeposition, the concentration of pyrrole, oxalic acid and salt, temperature and time of extraction, and the stirring rate of the extractor device were investigated and optimized, simultaneously. The detection and quantification limits of the method were calculated to be 0.035 and 0.1 μg L-1, respectively. The linear dynamic range obtained was from 0.1 to 20 μg L-1, with a determination coefficient of 0.9984. The intra-day and inter-day-relative standard deviations (RSD, n = 3) were lower than 3% and 8%, respectively. Under the optimal conditions, the absolute recovery and the enrichment factor were found to be 97% and 5820, respectively. Finally, the relative recoveries of the proposed method were calculated to be in the range of 86-111% for spiked water, wastewater, and apple samples. The results obtained from the method were validated by EPA method 622.

Periodic Flow Purging System for Harvesting Fibers from Screens

ABSTRACT Fiber length is believed to be an important factor in determining various toxicological responses to asbestos and other bio-persistent fibers. Length classification of fibers thus is crucial for toxicological assessment. Nylon mesh screens have been shown to be effective in separating fibers by length. In this note, we report development of a purging flow system for harvesting fibers from a nylon net screen, with the aim of separating airborne fibers by length. We evaluated the performance of this purging flow system by examining the lengths of glass fibers collected on a screen. Fibers aerosolized by vortex shaking were provided to 10 µm and 20 µm mesh screens, and the fibers collected on each screen were purged periodically with a backflow. The length of the purged fibers was measured and compared to that of fibers washed from the screen. The mean length of fibers on the screen is larger than that of the fibers in the original test aerosol. The mean length of the backflow purged fibers is smaller than that of the fibers from the washed screen. The results indicate that the purging flow system with screens can harvest the longer fibers from the original aerosol.

Experimental and transient thermal analysis of screen mesh wick heat pipe

Transient thermal analysis of a screen mesh wick heat pipe is performed with a screen mesh numbers 60 and 100 using de-ionized water as working fluid, which is applicable in electronics cooling. Based on evaporation and condensation phenomenon heat pipe is operating. Experiments are conducted (ranging from 20Watts-160Watts) with different inclination angles (15,30,60,90) for calculation of thermal resistance(Rth) and heat transfer coefficient (h), at different mass flow rates and heat inputs. Computational transient thermal analysis is done for the same heat inputs using ANSYS 16.0. It is observed that thermal resistance decreases with increase in heat input [maximum at 0.042(°C//W), minimum at 0.023 (°C/W)] because fluid molecular bonding decreases with increase in heat input. Heat transfer coefficient values are maximum at 8800 (W/m2K) for transient thermal analysis and 8500 (W/m2K) for experimental. The Heat transfer coefficient is more in thermal analysis when compared to experimental results because heat loss is less in ANSYS and more in practical. At 60 W of heat input the maximum Heat transfer coefficient is found.

A Simplified Model for the Prediction of the Erosion of a Metal Screen for Sand Control

In oil drilling processes, sand production in the oil layer is a common issue, generally mitigated by means of sand control screens. To prevent or reduce the risk of damage of these screens and to improve the related service life, it is necessary to investigate the related erosion dynamics. In this study, a screen mesh model based on the flow field similarity theory is proposed to overcome the otherwise too complex geometric structure of this type of equipment. Such model is optimized using experimental data. The predicted results are in good agreement with the measured values, and the error is less than 15%. The results also show that the simplified geometric screen model and the optimized Zhang et al. erosion model have high reliability; therefore, they could effective be used to select underground screen meshes and improve the design of production process.