Particle Size Of Pellets Research Articles

Mechanistic Model Advancements for Optimal Calcium Removal in Water Treatment: Integral Operation Improvements and Reactor Design Strategies

Drinking water softening has primarily prioritized public health, environmental benefits, social costs and enhanced client comfort. Annually, over 35 Gm3 of water is softened worldwide, often utilizing three main techniques: nanofiltration, ion exchange and seeded crystallization by pellet softening. However, recent modifications in pellet softening, including changes in seeding materials and acid conditioning used post-softening, have not fully achieved desired flexibility and optimization. This highlights the need of an integral approach, as drinking water softening is just one step in the drinking water treatment chain, which includes ozonation, softening, biological active carbon filtration (BACF) and sand filtration among others. In addition, pellet softening is often practiced based on operator knowledge, lacking practical key reactor performance indicators (KPIs) for efficient control. For that reason, we propose a newly and improved integral mechanistic model designed to accurately predict (1) calcite removal rates in drinking water through seeded crystallization in pellet softening reactors, (2) the saturation of the filter bed in the subsequent treatment step, (3) values for the KPIs steering the softening efficiency. Our new mechanistic model integrates insights from hydrodynamics, thermodynamics, mass transfer kinetics, nucleation and reactor engineering, focussing on critical variables such as temperature, linear velocity, pellet particle size and saturation index with respect to calcite. Our model was validated with data from the Waternet Weesperkarspel drinking water treatment plant in Amsterdam, The Netherlands, but implies universal applicability for addressing industrial challenges beyond drinking water softening. The implementation of our model proposes five effective KPIs to optimize the softening process, chemical usage, and reactor design. The advantage of this model is that it eliminates the application of numerical methods and fills a significant gap in the field by providing predictions of the carry-over (i.e., the produced CaCO3 fines leaving the fluidized bed) from water softening practices. With our model, the calcium removal rate is predicted with an average standard deviation (SD) of 40% and the consequential clogging prediction of the BACF bed with an average SD of 130%. Ultimately, our model provides crucial insights for operational management and decision-making in drinking water treatment plants, steering towards a more circular and environmentally sustainable process.

Overlapping Pellet Size Detection Method Based on Marker Watershed and GMM Image Segmentation

The particle size of pellets is an important parameter in steel big data, and the high density and high overlap rate of pellets bring a great challenge to particle size detection. To address this problem, a particle size intelligent detection algorithm with an improved watershed and a Gaussian mixture model (GMM) is proposed. First, the initial segmentation of the pellets and background is achieved by using adaptive binary segmentation, and then the secondary fine segmentation of the pellets and background is achieved by combining morphological operations such as skeleton extraction and marked watershed segmentation; then, the contour of the connected domain of pellets is calculated, and the non-overlapping pellets in the foreground and the overlapping pellets are filtered according to the roundness of their contours. Finally, the number of overlapping pellets is predicted by Gaussian reconstruction of the grayscale image of the overlapping pellets, and the number and granularity of the overlapping pellets are predicted by the Gaussian reconstruction of the overlapping pellets. The experimental results showed that the algorithm achieved a 91.98% segmentation accuracy in the experimental images. Compared with other algorithms, the algorithm can also effectively suppress the over-segmentation and under-segmentation problems, and it can effectively realize the pellet size detection of dense, overlapping pellets such as those on a pelletizing disk, which provides an effective technical means for the metallurgical performance analysis of pellet ore and intelligent pellet-making driven by big data.

Relationship between pellet formation by Aspergillus oryzae strain KB and the production of β-fructofuranosidase with high transfructosylation activity

Aspergillus oryzae KB produces two β-fructofuranosidases (F1 and F2). F1 has high transfructosylation activity (Ut) to produce fructooligosaccharides. F2 has high hydrolysis activity (Uh), releasing glucose and fructose. It is desirable to selectively produce F1, which can be used for production of fructooligosaccharides. Here, the relationship between filamentous pellet size and selective production of F1 in liquid culture was investigated. Our finding revealed that: (i) The mean particle size of pellets (5.88 ± 1.36 mm) was larger, and the ratio of Ut to Uh was improved (Ut/Uh = 5.0) in 10% sucrose medium compared with 1% sucrose medium (pellet size = 2.60 ± 0.37 mm; Ut/Uh = 0.96). (ii) The final culture pH of the 1% sucrose medium was 8.7; on controlling the pH of 1% sucrose medium at 5.0, increased pellet size (9.69 ± 2.01 mm) and Ut/Uh (7.8) were observed. (iii) When 3% glycerin was used as carbon source, the pellet size decreased to 1.09 ± 0.33 mm and Ut/Uh was 0.57. (iv) In medium containing 1% sucrose, the pellet size was dependent on the number of spores used in the culture inoculum, but, in these experiments, Ut/Uh was almost constant (1.05 ± 0.08). Collectively, the data show that the value of Ut/Uh is proportional to the pellet size when liquid culture of A. oryzae strain KB is performed in some conditions (such as in the presence of high sucrose concentration, low pH, or added Tween surfactant), but in other conditions Ut/Uh is independent of pellet size.

The impact of ash pellet characteristics and pellet processing parameters on ash fusion behaviour

The Ash Fusion Test (AFT) is considered to be the most popular method of characterising the melt characteristics of solid fuel ash. This study shows how pellet preparation can make significant improvements to repeatability. Pelleting pressure, pellet particle size, pellet shape, and furnace ramp rate were investigated to establish the most repeatable representation of ash melting relevant to pulverised fuel combustion in a furnace in an oxidizing atmosphere up to 1600 °C. A 5 mm machine pressed pellet was found to produce the best results as it identified the earliest initial deformation temperature (IDT), gave the least error, and displayed the greatest visible change in pellet height to enable easy identification. Reducing maximum ash particle size to <72 µm and increasing the pressure of the pelleting process was also shown to produce a 120 °C reduction in the IDT when compared with other methods. Reducing the ashing temperature and retaining volatiles lost during high temperature ashing were shown to have a negligible impact on IDT. The characteristic AFT curve was also used to quantify the extent of shrinkage and swelling during the test.

Effects of modifying diet and feed manufacture concern areas that are notorious for decreasing pellet quality

SUMMARY The production of high-quality pellets has often been described as more art than science due to the multitude of variables that affect pellet quality. The objectives of the current study were to examine the feed manufacture and pellet quality effects of 4 different feed milling concern areas. Each area of concern was evaluated using either a circumstance of low concern or a corresponding circumstance of high concern. Treatments included high or low mixer-added fat inclusion (MAF; 2.5 vs. 0.5%), high or low distillers dried grains with solubles inclusion (DDGS; 8 vs. 2%), high or low dicalcium phosphate inclusion (DCP; 1.63 vs. 0.31%), and high or low steam conditioning temperature (79 vs. 71°C). All diets were formulated to similar nutrient specifications based on commercial broiler starter recommendations. Treatments were replicated 3 times utilizing an experimental unit of 136 kg feed allotments organized as a 4 × 2 factorial arrangement in a randomized complete block design. Contrasts were performed to better understand main effect interactions. High MAF and low DCP decreased pellet durability, percent pellets, and pellet particle size (P 0.05). Extraneous variables such as corn moisture content and ambient temperature during feed manufacture likely confounded some treatment effects. A greater appreciation of variable interactive effects may benefit pellet mill operators, nutritionists, and pelleting aid vendors to better circumvent hurdles encountered during the pelleting process.

Wood pellet milling tests in a suspension-fired power plant

This paper investigates the milling behavior of two industrial wood pellet qualities (designated I1 and I2 as per ISO 17225-2:2014) in large-scale coal roller mills, each equipped with a dynamic classifier. The purpose of the study was to test if pellet comminution and subsequent particle classification (i.e., the classifier cut size) are affected by the internal pellet particle size distribution obtained after pellet disintegration in hot water. Furthermore, optimal conditions for comminuting pellets were identified. The milling behavior was assessed by determining the specific grinding energy consumption and the differential mill pressure. The size and shape of comminuted pellets sampled from burner pipes were analyzed by dynamic image analysis and sieve analysis, respectively. The results showed that the internal pellet particle size distribution affected both the milling behavior and the classifier cut size. I2 pellets with coarser internal particles than I1 pellets required more energy for milling, led to a higher mill pressure drop and showed a larger classifier cut size. Comminuted pellet particles sampled from burner pipes were notably finer than internal pellet (feed) particles. At similar mill-classifier conditions, characteristic particle sizes of 0.50 mm for comminuted I1 pellets (compared to 0.83 mm for material within I1 pellets) and of 0.56 mm for comminuted I2 pellets (compared to 1.09 mm for material within I2 pellets), respectively, were obtained. Pellet comminution at lower mill loads and lower primary airflow rates reduced the mill power consumption, the mill pressure drop, and the classifier cut size. However, this was at the expense of a higher specific grinding energy consumption. Derived 2D shape parameters for comminuted and internal pellet particles were similar. Mill operating changes had a negligible effect on the original elongated wood particle shape. To achieve the desired comminuted product fineness (i.e., the classifier cut size) with lower specific grinding energy consumption, power plant operators need to choose pellets with a finer internal particle size distribution.

Two-stage agglomeration of fine-grained herbal nettle waste

Abstract This paper compares the densification work necessary for the pressure agglomeration of fine-grained dusty nettle waste, with the densification work involved in two-stage agglomeration of the same material. In the first stage, the material was pre-densified through coating with a binder material in the form of a 5% potato starch solution, and then subjected to pressure agglomeration. A number of tests were conducted to determine the effect of the moisture content in the nettle waste (15, 18 and 21%), as well as the process temperature (50, 70, 90°C) on the values of densification work and the density of the obtained pellets. For pre-densified pellets from a mixture of nettle waste and a starch solution, the conducted tests determined the effect of pellet particle size (1, 2, and 3 mm) and the process temperature (50, 70, 90°C) on the same values. On the basis of the tests, we concluded that the introduction of a binder material and the use of two-stage agglomeration in nettle waste densification resulted in increased densification work (as compared to the densification of nettle waste alone) and increased pellet density.

Feed Intake in Guinea Fowl, Layer Hen and Pheasant as Influenced by Particle Size of Pelleted Diets*

2 Abstract: This study investigated the effect of pelleted diets prepared differing by levels of grindin g preparation (2 or 4 mm) to evaluate pellet quality and diet preferences in adult breeders poultry species: guinea fowl (Numida meleagris), layer hen (Gallus domesticus) and pheasant (Phasianus colchicus) t o improve our understanding of the diet physical structure influencing feed intake. All diets were of identical composition as well as same environment and management were provided for all treatments. The parameters evaluated in this 4 weeks feeding trial included: live body weight, feed intake, feed efficiency and pellet durability index. Body weight gain, feed intake and feed efficiency were influenced (p<0.05) by th e dietary treatments in each poultry species. The present data suggest that pellet particle size is advantageous in terms of feed intake and efficiency in poultry.

Influence of Process Variables on Physical Properties of the Pellets Using Extruder and Spheronizer

Placebo pellets containing lactose and microcrystalline cellulose (Avicel PH101®) ratio 60:40 were prepared by the extrusion-spheronization process. The influence of processing variables, including the spheronizer speed, the spheronization time, the binder type, and the concentration and amount of water content on physical properties of the pellets, were studied. The sphericity of pellets was increased with increasing spheronizer speed during wet mass process. When spheronization time was increased, sphericity, smooth surface, and particle size of pellets were increased. Increasing binder concentration will increase particle size. Pellets using HPC-M® as a binder at high spheronizer speeds showed spherical shape, narrow size distribution, and good flow properties when compared with Methocel E-15LV®, HPC-L®, and Methocel A4M®. In addition, increasing HPC-M concentration had no effect on shape and particle size of pellets. The amount of water content was found to affect shape, flow rate, and density. In summary, suitable conditions consisted of 2% w/w of HPC-M, 40% w/w of water, and 15 min of spheronization time at 951 rpm of spheronizer speed.