Pulse-jet cartridge filter is one of the high efficiency dust collectors for capturing ultra-fine powder. The incomplete cleaning becomes a difficult problem in the application of filter cartridge. ...However, most of the existing studies are focused on the cleaning performance of the circular cartridge in vertical filters, and there are few studies on the cleaning performance of elliptical horizontal cartridge filters. In this study, the effects of different venturis on the pressure drop of dust collector and the static pressure acting on the inner wall of the elliptical filter cartridge were investigated through numerical simulation and experiment. When the venturi throat diameter is 160 mm, the minimum pressure drop and the maximum peak pulse pressure of the inner wall can be obtained. The mechanism of venturi improving collection efficiency of elliptical filter cartridge is revealed by the flow field analysis method. The magnitude of peak pressure P1 to P3 are about 1.4–2.7, 1.1–1.7 and 1.1–1.4 times that of without venturi. The injection distance and pulse-jet tank pressure can be reduced by venturi. The results are helpful for the design and improvement of pulse-jet cleaning horizontal cartridge filters.
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•The cleaning performance of elliptical filter cartridge have been analyzed systematically.•The venturi throat size on cleaning performance have been optimized.•The mechanism of improving the cleaning effect by venturi is explained.•The peak pressure at the adverse side of elliptical filter cartridge can be greatly increased by optimized venturi.•Using the optimized venturi can reduced the injection distance and pulse-jet airflow pressure.
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•Flow field and pressure distribution of two types filter cartridges were studied.•Cone diameter, cone height and height of inner cone was investigated.•Analyzed reasons for ...differences in pressure distribution at various measuring points.•Arranged the parameters that affect the magnitude of the average peak static pressure.•Appropriate cone parameters for good cleaning performance were obtained.
The double-layer filter cartridge with an inner cone was designed to improve the pulse-jet cleaning performance of the filter cartridge. The flow field and pressure variation of the double-layer filter cartridge were investigated with the help of numerical simulations. The pressure at the inner wall of the filter cartridge was explored by varying three parameters: the height of the cone (h), the diameter of the cone (D) and the distance between the top of the inner cone and the baffle (H). The results showed that for conventional filter cartridge, influenced by the angle of the pulse-jet, the airflow got sufficiently expanded after the pulse-jet airflow reached the middle of the filter cartridge, and the pressure at the top of the filter cartridge was slight. It was found that the cone diameter and the distance between the top of the inner cone and the baffle had a significant effect on the pressure of the inner wall of filter cartridges, with the distance between the top of the inner cone and the baffle had the most excellent effect and the height of the cone had the slightest effect. Compared with conventional filter cartridges, the peak pressure at measurement point O1 of the optimized double-layer filter cartridge (h = 120 mm, D = 160 mm, H = 0 mm) was increased by 543.3%. The coefficient of variation (C.V.) of the pressure at the inner wall of the outer filter cartridge was significantly reduced, indicating that the pulse-jet cleaning effect of the optimized double-layer filter cartridge was significantly improved. This study can provide theoretical support to reveal the mechanism of pulse-jet cleaning of double-layer filter cartridges and technical support to optimize the design of double-layer filter cartridges.
•Grain-loaded cartridges cause much wider distribution than lead pellet cartridges.•Satellite entry holes were detected in all shots from 50cm distance.•Chokes did not affect the distribution in most ...of the shots at same distances.
Commercial grain-loaded cartridges for shotguns have been recently associated with injuries and fatalities. These cartridges are generally used as a scare gun for large animals, with a little probability of causing harm. Almost all grain-loaded cartridges contain one type of cereal grain, such as bulgur wheat, wheat or vetch seed, instead of lead pellets. Our study aimed to investigate the shot range estimation of grain-loaded cartridges and assess the variations from conventional lead pellet cartridges.
In this study, eight different brands of grain-loaded cartridges were used. The inspections and measurements were made with cartridges that contain cereal grains, gunpowder and wads. Shots were made from 50, 100, 200, 300, 500cm with modified and improved cylinder chokes. Diameter of grain distribution patterns on targets were measured. These measurements were evaluated statistically considering brand, choke and distance variables.
Both satellite entry holes and central entry holes were detected in all shots that were fired from 50cm distance. The smallest average diameter of grain distribution pattern between 8 different brands were measured as 14.3, 38.3, 58.5 and 83.4cm for 100, 200, 300 and 500cm respectively with modified choke. Gathered data from this study was compared with the studies conducted with conventional cartridges and differences were determined. It was detected that the grain-loaded cartridges showed much wider distribution on targets at the same shooting distance with the same and similar barrel lengths and choke values compared to conventional lead pellet containing cartridges.
Increased seawater temperature leads to harmful algal blooms (HABs), which releases toxic materials and extracellular polymeric substances (EPS) that are harmful to both humans and the environment. ...Reverse osmosis (RO) with cartridge filter (CF) as the pretreatment process is often used for desalination process. However, the EPS causes severe fouling on the CF, and RO membrane. Disinfectants, such as NaOCl and ClO2, are commonly used to remove biofouling, because they can oxidize and kill microorganisms. Therefore, our study aims to utilize NaOCl and ClO2 during the CF-RO process to minimize the algal growth within the system and minimize the fouling induced by EPS. Results from this study show that CF can remove more than 50% of protein and 14% of polysaccharides but is not effective in removing toxins. However, with disinfectants, toxic materials were completely oxidized. Improved removal of EPS with CF improved overall performance. The flux reduction in RO process without disinfection was over 60%, however, the flux decline was about 44% and 10% with NaOCl and ClO2, respectively. Both disinfectants were found to be effective, however use of ClO2 is recommended because it is less damaging the membrane, yet more effective in enhancing the performance.
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•Disinfection efficiency of NaOCl and ClO2 in CF-RO during algal bloom was compared.•NaOCl and ClO2 effectively inactivate algae and remove EPS, especially protein.•ClO2 is a better disinfectant than NaOCl in CF-RO in algal bloom condition.
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•The opposing pulsed-jet cleaning performance improved by an annular-slit nozzle.•The cleaning at the upper portion of filter cartridges is substantially improved.•The effects of ...nozzle settings on the cleaning performance were investigated.•The optimal settings for the cleaning with an annular-slit nozzle were suggested.
The opposing pulsed-jet cleaning with round nozzles has been recently introduced to reduce the patchy cleaning often faced during the regeneration of pleated filter cartridges in dust collectors. Additional to the primary nozzle for jetting a cleaning flow, the above technology applies an auxiliary nozzle installed at the cartridge base to launch a second flow for the cleaning. To further improve the performance, this study proposed to adopt an annular-slit nozzle as the primary-one in the above cleaning. The numerical modeling was applied to investigate the flow and pressure fields in a dust collector under the above cleaning with the settings varying the jet distance, h, from 0 to 700 mm, the delay time, Δt, from −0.125 to 0.125 s, and the pressure ratio, PR, from 0 to 4. The peak intensity and uniformity of the static pressure on the inner wall surfaces of filter cartridges during the cleaning were selected as the indicators for the cleaning performance. It is found that the cleaning performance in the cases with an annular-slit nozzle was found to be generally better than that in the cases with a round nozzle. Using an annular-slit nozzle, the air entrainment effect was enhanced, and the collision of both opposing jet flows was occurred in the position much closer to the cartridge opening. The cleaning in the case of Δt > 0 s was in general better than that in the cases of Δt < 0 s (with the optimum achieved at Δt = 0.025 s). The reasonable PR was in the range of 0.5 to 1.5 to realize effective jet airflow collision. The cleaning intensity and C.V. in the cases with an annular-slit nozzle and under the suggested settings of h = 300 mm, Δt = 0.025 s and PR = 1.5 would achieve the values of 1,050 Pa and 0.13 respectively, resulting in the 27 % and 63 % improvement on average (compared to those in the case using a round nozzle).
Introduction. In connection with legalization of autonomous cartridges loading to the rifl ed fi rearm, the matter of forensic examination of reloaded cases is growing more urgent. Aims and tasks. To ...examine the regularities of trace formation made by the reloading equipment on reloaded cases in order to identify the method of making cartridges, whose parts they have originally been, and to establish the fact of reloading by means of the same production mechanisms. Experimental part. Examination of the traces formed in the course of a shot and reloading was carried out with hunter’s .300 win mag caliber cartridge cases ejected from .300 win mag caliber Sauer 202 carbine. The following reloading equipment was used: manual threaded (single-stage and turret) presses produced by Neck, threaded molding matrices produced by Redding. Discussion of results. Reloading equipment is considered as a production mechanism depositing traces on the surface of the reloaded cases. In the case of identifi cation (selecting a group of objects from a multitude, determining their group belonging) the structural features of their cutting surfaces, their traces being imprinted on the processed parts, are studied. As a whole, they are suitable for identifying the instrument that formed them. Defects in trace-forming objects (matrices, shellhorder, etc.) can also be seen in the traces on the cases as subclass features. These features can be taken into account in the comparative study of cases to establish the fact of reloading using the same production mechanisms.
Drum type dust collector is widely used in coal mine dust workplaces. It has the advantages of large filtration area per unit volume, high dust removal efficiency and low running resistance. In the ...cartridge dust collector, the filter cartridge is the core part for dust filtering, and its dust filtering and dedusting effect is the key factor affecting the performance of the dust collector. In this design, based on the empirical formula obtained from the experimental research of the spray pipe at home and abroad, the near average flow design of each orifice is carried out for the spray pipe of the filter cartridge ash removal system, so as to achieve the equal ash removal air volume for each filter cartridge, eliminate the different ash removal effects of each filter cartridge caused by the unequal air volume at each nozzle, and prevent the filter cartridge with relatively weak ash removal strength from greatly reducing its dust filtering function due to the dust accumulation and paste.
•A sample set of cartridge cases was collected from various people firing the same gun and ammunition.•A proposed method used the statistical data from the sample set to estimate a shooter’s position ...from ejected cartridge cases.•It was found that with an increasing number of cartridge cases used for shooter position estimation, the errors and standard deviation decreased, improving estimation results.
Ejected cartridge cases in shooting incidents are useful in crime scene reconstruction to approximate the location of a shooter and the dynamics of an encounter. The purpose of this study is to propose a method to approximate a shooter’s position based on a reference sample set of cartridge case ejection patterns. This research is significant as there are no blind studies that determine the precision or errors when estimating a shooter’s position based on cartridge case ejection patterns. Understanding the errors associated with shooter position estimation may give investigators a standardized method for establishing a reference set of cartridge cases which reflect the behavior of ejection patterns under controlled variables, while having a more reliable method when estimating a shooter’s position. A reference sample set of more than 312 cartridge cases was collected from various people firing the same gun and ammunition from a known position and at different heights using a double-handed grip. The proposed method used the statistical data from the reference sample set and was tested on blind data sets to determine the errors and precision using “unknown” shooters. The blind testing sets ranged between 1 and 6 ejected cartridge cases with a known direction of fire. It was found that with an increasing number of cartridge cases used for shooter position estimation, the errors and standard deviation decreased, improving estimation results. With a blind set of 6 cartridge cases, the errors were shown to average 122 cm from the known firing position. The applicability of this method depends significantly on the type of firearm, ammunition, human factors, environment and other factors.
Background
Approximately 85% of patients with cystic fibrosis (CF) have exocrine pancreatic insufficiency (EPI) with 10% requiring supplemental nighttime enteral tube feedings. Administration of ...pancreatic enzyme replacement therapy (PERT) with nighttime feedings is fraught with challenges. RELiZORB (Alcresta Therapeutics, Inc), an in‐line lipase cartridge, delivers PERT continuously with enteral feedings. Outcomes related to the use of this in‐line lipase cartridge are lesser known. This project evaluated anthropometrics related to in‐line lipase cartridge use among pediatric patients with CF already receiving oral PERT therapy prior to nighttime enteral feedings.
Methods
Retrospective chart review was performed on 29 patients with CF and EPI receiving supplemental tube feedings and utilizing in‐line lipase cartridge for a continuous 12 month period between 2015 and 2019. Anthropometrics were evaluated 12 months before and after initiation of in‐line lipase cartridge.
Results
Compared with mean height z score at 6‐months pre–in‐line lipase cartridge, mean height z score at 6‐months post–in‐line‐lipase cartridge (adjusted mean difference AMD = 0.2540; 95% CI = 0.0487, 0.4592; P = 0.0153) and mean height z score at 12‐months post–in‐line lipase cartridge (AMD = 0.2684; 95% CI = 0.0203, 0.5166; P = 0.0340) were significantly higher. Mean weight z score at 12‐months post–in‐line‐lipase‐cartridge neared statistical significance compared with 6‐months pre–in‐line lipase cartridge (AMD = 0.2816; 95% CI = −0.0003, 0.5634; P = 0.0502) when excluding seven patients with advanced lung disease (forced expiratory volume in the first second of expiration of 40%). Weight‐for‐length or body mass index did not significantly differ compared with pre–in‐line lipase cartridge.
Conclusion
Use of in‐line lipase cartridge with enteral feeds improved anthropometrics, especially height, in pediatric patients with CF.
Due to the ever-increasing industrialization, it is critical to protect the environment and conserve water resources by developing efficient wastewater treatment methods. Traditional methods that ...simultaneously remove heavy metal ions and complex dyes are too expensive and tedious to commercialize. This work demonstrates the versatility, effectiveness, and potential of a biomass-derived adsorbent (from a mangrove fruit of Rhizophora mucronata) synthesized using a simple route for rapid adsorption of complex dyes and heavy metals with an efficiency of near unity. The cartridges were prepared using activated carbon that removes both dye molecules and heavy metal ions simultaneously from wastewater, corroborating its applicability/feasibility to treat wastewater. Owing to the high surface area (1061.5 m2g-1) and the pore volume (0.5325 cm3g-1), the adsorbent showed >99% removal efficiency in just 12 min of exposure to wastewater. The cartridge exhibits >90% removal efficiency of both dyes and heavy metals from its mixed feed solution. The Langmuir and Freundlich models successfully explained the adsorption kinetics. These developed cartridges are versatile, rapid, efficient, and promising candidates for environmental remediation.
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•Highly porous activated carbon (ACs) has been derived from the Mangrove fruit.•ACs presents outstanding efficiency in the removal of binary pollutants from water.•To accommodate experimental data, two well-known isothermal models are used.•Highly efficient cartridge demonstrates >99% removal efficiency from single feed and >90% from binary feed solution.
