Mill Applications Research Articles

Insights into the Genetic Architecture of Bran Friability and Water Retention Capacity, Two Important Traits for Whole Grain End-Use Quality in Winter Wheat.

Bran friability (particle size distribution after milling) and water retention capacity (WRC) impact wheat bran functionality in whole grain milling and baking applications. The goal of this study was to identify genomic regions and underlying genes that may be responsible for these traits. The Hard Winter Wheat Association Mapping Panel, which comprised 299 lines from breeding programs in the Great Plains region of the US, was used in a genome-wide association study. Bran friability ranged from 34.5% to 65.9% (median, 51.1%) and WRC ranged from 159% to 458% (median, 331%). Two single-nucleotide polymorphisms (SNPs) on chromosome 5D were significantly associated with bran friability, accounting for 11–12% of the phenotypic variation. One of these SNPs was located within the Puroindoline-b gene, which is known for influencing endosperm texture. Two SNPs on chromosome 4A were tentatively associated with WRC, accounting for 4.6% and 4.4% of phenotypic variation. The favorable alleles at the SNP sites were present in only 15% (friability) and 34% (WRC) of lines, indicating a need to develop new germplasm for these whole-grain end-use quality traits. Validation of these findings in independent populations will be useful for breeding winter wheat cultivars with improved functionality for whole grain food applications.

High-speed machining of aluminium alloy using vegetable oil based small quantity lubrication

In an attempt to investigate the effectiveness of vegetable oil based small quantity lubrication in high-speed machining of aluminium, this study finds that its usefulness is more significant in an intermittent cutting process like end milling than in turning, where continuous cutting happens. The investigation was carried out using small quantity lubrication aerosol, produced by air atomization of sunflower oil at the rate of 100 ml/h for each cutting zone. In the high-speed turning operations, uncoated and polycrystalline diamond–tipped WC inserts were used. 5%–20% reduction of cutting force could be realized by small quantity lubrication application, compared to dry environment. The highest order of reduction was observed when the cutting velocity was increased from 700 to 1000 m/min. At lower velocities, small quantity lubrication effect was almost insignificant. However, high-speed end milling operations received substantially superior benefit by small quantity lubrication application. The reduction of feed force was 30% or more among different cutting speeds. The beneficial effect of small quantity lubrication application was significantly more in machining commercially pure 1050 grade of aluminium than 7075 alloy. The required prevalence of the thick-film lubrication at the interface of chip and tool rake for arresting any possible diffusion of aluminium to tool material was significant in the intermittent cutting since every cutting edge drew in fresh micro-droplets of lubricant before resuming cutting in its next cycle of engagement with workpiece. Interestingly, the end milling performance of small quantity lubrication–assisted uncoated carbide was so good that diamond-coated tools were not necessary. Surface roughness profiles, chip morphology and traces of built up edge formation were critically investigated and the results clearly indicated the predominantly more favourable outcome of small quantity lubrication application in end milling, compared to turning.

Biochar production from palm oil mill residues and application of the biochar to adsorb carbon dioxide

The amount of palm oil mill residues increases rapidly and will become a severe problem in the future. One potential technique for alleviating this concerning environmental problem is to convert these residues into biochar by the pyrolysis process. Pyrolysis of three types of palm oil mill residues (namely, palm kernel shells, empty palm fruit bunches, and oil palm fibers) was conducted in a fixed bed reactor at 500 °C and 2 L/min of nitrogen flow rate for 60 min. The optimization of biochar production was performed using the Box-Behnken design and analyzed using response surface methodology. The effects of three potential factors, including pyrolysis temperatures, nitrogen flow rates, and biomass particle sizes, were studied. The results showed that the highest biochar yield (44.91 wt%) was obtained from pyrolysis of palm kernel shells at 525 °C with a nitrogen flow rate of 2 L/min and a particle size of 750 μm. Application of biochar produced from palm kernel shells for carbon dioxide capture was tested in a packed bed adsorber of 3.0 g of biochar sample by flowing 1,400 ppm of carbon dioxide in the gas feed mixture at 2.5 L/min. The capacity of the biochar sample for CO2 adsorption was 0.46 mmol/g.

Discrete element modeling and simulation of non-spherical particles using polyhedrons and super-ellipsoids

A composite contact algorithm for a complex particle system containing polyhedrons and super-ellipsoids is proposed in this paper to simulate the grinding process of ore in a ball mill. In this algorithm, the contacts between polyhedrons are calculated based on the overlapping volume method, and the contacts between super-ellipsoids are determined by a deepest point method. The contacts between super-ellipsoids and polyhedrons are obtained by transforming super-ellipsoids into polyhedrons, and then using the overlapping volume method between the polyhedrons. The increase in the number of faces of the super-ellipsoid contributes to the closer shape to the real shape. In this paper, experimental researches and numerical simulations are carried out to validate the accuracy of this composite contact algorithm. Furthermore, the influence of the ratio of super-ellipsoids and polyhedrons, the number of faces of converted super-ellipsoid, and the sharpness of the super-ellipsoid on the computational efficiency are compared in both box filling process and particles mixing process in a rotating tumbler. Finally, the stability and feasibility of this composite contact algorithm is tested in a ball mill application containing more particles.

РОЛЬ ЖЕЛЕЗО СОДЕРЖАЩЕГО КОМПОНЕНТА В СОСТАВЕ ПЕРЛИТОВОГО ГЕОПОЛИМЕРА НА ЕГО ФАЗОВЫЕ И СТРУКТУРНЫЕ ТРАНСФОРМАЦИИ

Normally, the component composition of building materials makes a significant contribution when formation of final performance properties of them. Moreover, new types of binding systems, in spite of their poor knowledge, this effect on the structural characteristics of final composites also takes place. In this work, perlite-based geopolymer binder as an example, was studied.
 In framework of the study, it was found that the application of grinding mill with a metal lining leads to the formation of Fe- milling yield, which is included into crushed raw materials (perlite) com-position.
 It was established that the particles of the resulting Fe- component are nanoscaled.
 The X-ray phase and chemical analyzes were used to determine the mechanism of the effect of the Fe- component on the properties of perlite-based geopolymer. 
 Microstructure of the hardened geopolymer paste were studied using SEM microscopy. Phase and mineral composition of geopolymer paste obtained by XRD-analysis showed, when the hardening process, nanosized iron hydroxide or bernalite Fe(OH)3(H2O)0.25 is formed in the geopolymer system, that is 5 times more than metallic iron. This is initiates the structure destruction and confirmed by the low values compressive strength of the geopolymer stone.
 Keywords: Fe-bearing component, metallic milling yield, geopolymer binder, friable structure, the Scherrer formula

Prediction and modeling of roughness in ball end milling with tool-surface inclination

The quality of mill finishing of shaped surfaces is influenced by a number of input parameters. Current automated manufacturing systems allow adaptation of the machining process aiming at the final surface quality. Despite all the advantages, these systems require a behavioural model, a prediction of the output, based on the input parameters. Some of these models are summarized in this paper, including contemporary evaluated models as well as their functional dependencies; moreover, offers an application of mill finishing with a ball-end cutter incorporating tool axis or surface inclination.

Prediction of Stability Lobe Diagrams in High-Speed Milling by Operational Modal Analysis

Self-excited regenerative vibration or chatter limits the primary requirements like productivity, surface finish and dimensional accuracy of high-speed machining. It is the most critical factor that severely affects the tool-life and life of the machine tool. Out of several methods followed for suppressing and avoiding chatter, machining conditions chosen with stability lobe diagram is the most reliable way. Stability lobe diagrams are typically generated by knowing specific cutting force coefficients and tool point frequency response functions (FRFs). Inaccurate use of tool point FRFs significantly affects the stable regions of stability lobe diagrams. As tool-point FRFs are influenced by gyroscopic effect, centrifugal force, thermal change in bearing dynamics, etc. during machining, it is important to consider the effect of these factors on tool point FRFs in order to generate accurate stability lobe diagrams. The present work covers a new approach for estimating tool point FRFs during machining operations, employing cutting tool vibration signals. For measuring the vibration at the tip of end mill at different spindle speeds, a non-contact laser vibrometer is used. In order to remove the tooth pass frequency and its harmonics from the measured signals, a comb filter is employed. The filtered signal is subjected to Operational Modal Analysis (OMA) in order to derive tool point FRFs. With the estimated FRFs at different spindle speeds, the stability lobe diagrams are drawn for high-speed milling machine. Comparative study of stability lobe diagrams, drawn with static modal analysis and Operational Modal Analysis, have shown that the cutting conditions chosen from stability lobe diagram derived with OMA, are found to be more realistic for avoiding chatter during high-speed milling applications.

A MRAS Based Model Predictive Control for Multi-Leg Based Multi-Drive System Used in Hot Rolling Mill Applications

In this paper, a multi-leg based multi-drive configuration is presented to be used in multi AC drive applications such as the hot rolling mills. The proposed configuration enjoys compactness, fewer semiconductors, and lower drive cost compared with conventional topology, making it a promising approach. In a conventional rolling mill stand, an active front-end (AFE) rectifier and two inverters are required for grid-side and motor-side connections. However, in the proposed configuration, all converters are unified using a multi-leg structure. To improve the operational performance of the drive, a model predictive control (MPC) is designed. In this approach, an individual cost function for every output, along with a comprehensive cost function containing all control objectives for the overall system, is defined. By obtaining the valid and invalid switching states of the proposed converter, the defined multi-objective cost function is minimized to find the most optimum switching states in each sampling time. In addition, to improve the robustness of the proposed multi-drive system, a model reference adaptive system (MRAS) is designed to estimate rotor speed and stator resistance. The high-performance capability of the proposed multi-drive system is evaluated in both steady and dynamic states using MATLAB/Simulink software and compared with a conventional configuration. According to simulation results, it is deduced that the independent control of the top and bottom motors in a rolling mill stand can be guaranteed using the proposed low-cost sensor-less drive.

Thermomechanical Wear Testing of Metal Matrix Composite Cladding for Potential Application in Hot Rolling Mills

Laser metal deposition (LMD) is utilized to clad the surface of a miniaturized test roll (Ø 40 mm) of tool steel. The cladding consists of two layers: a nickel alloy as intermediate layer deposited onto the surface of the steel substrate, and a metal matrix composite (MMC) as top layer consisting of spherical tungsten carbide particles embedded into the nickel alloy matrix. The thermomechanical wear behavior of the cladding is investigated on a test rig, where the test roll is pressed against an inductively heated load roll. Multiple test runs up to several hours simulating industrial loading conditions are performed. The presented testing procedure enables predicting the time‐dependent abrasive wear behavior of the cladding, in particular for hot rolling mill applications. After testing for 8 h at temperature of 650 °C and at contact pressure of approximately 1 GPa, the maximum depth of the wear mark is about 0.12 mm. Partial cracking, debonding and dissolution of the tungsten carbide particles, as well as formation of iron and chromium oxides at the surface of the wear marks occur. However, as low abrasive wear is observed, the investigated MMC may potentially be applicable for cladding rolls in steel hot rolling mills.

EFFECT OF MILL FEED SIZE DISTRIBUTION AND GRINDING MEDIA SIZE ON SIZE REDUCTION PERFORMANCE OF AN INDUSTRIAL SCALE VIBRATING BALL MILL (VBM) IN CEMENT CLINKER GRINDING

In this study, open circuit single and two stage industrial scale vibrating ball mill (VBM) grinding performance of raw (uncrushed) cement clinker was investigated using different mill feed size distributions and grinding ball size configurations. The mill was modelled for the test cases using perfect mixing mathematical modelling approach. Different ball size configurations were applied in the grinding tests to estimate the effect of ball size configuration on grinding performance. Proposed coarse ball size configuration (30-20-15mm) was determined to increase the size reduction performance of single stage VBM grinding when coarse mill feed material was fed to the VBM (F50=185μm) as compared to the finer mill feed case (F50=24μm). VBM grinding performance was determined to increase with finer mill feed material (F50=24μm) and application of finer ball size configuration (10-8-6mm) in single stage grinding case as compared to the two stage grinding case.

Green machining for the dry milling process of stainless steel 304

Dry machining represents an eco-friendly method that reduces the environmental impacts, saves energy costs, and protects operator health. This article presents a multi-response optimization which aims to enhance the power factor and decrease the energy consumption as well as the surface roughness for the dry machining of a stainless steel 304. The cutting speed ( V), depth of cut ( a), feed rate ( f), and nose radius ( r) were the processing conditions. The outputs of the optimization are the power factor, energy consumption, and surface roughness. The relationships between inputs and outputs were established using the radial basis function models. The experimental data were normalized, with the use of the Grey relational analysis. The principal component analysis is applied to calculate the weight values of technical responses. The desirability approach is used to observe the optimal values. The results showed that the technical outputs are primarily influenced by the feed rate and cutting speed. The reductions of energy consumption and surface roughness are approximately 34.85% and 57.65%, respectively, and the power factor improves around 28.83%, compared to the initial process parameter settings. The outcomes and findings of the investigated work can be used for further research in sustainable design and manufacturing as well as directly used in the knowledge-based and expert systems for dry milling applications in industrial practices.

SIFAT FISIKA TANAH PERKEBUNAN KELAPA SAWIT (Elaeis guineensis Jacq.) SETELAH DIAPLIKASI TANDAN KOSONG KELAPA SAWIT DAN LIMBAH CAIR PABRIK KELAPA SAWIT

The research aims to examine the effect of the application of waste processing palm oil mill (Empty Fruit Bunches and Palm Oil Mill Effluent) on soil physical properties. The research was conducted at the oil palm plantation at Pelalawan and Laboratory of Soil Science, Faculty of Agriculture, the University of Riau from March to May 2016. The study was conducted experimentally using a Completely Randomized Design (CRD), which consisted of 4 treatments (EFB, POME, EFB+POME and without application as control). Each treatment was repeated 3 times. EFB and POME have been applied to the land since 2001 with intervals giving every 6 months. Soil samples were applied EFB, POME, and EFB+POME taken on Blocks B3, Blocks B7 and Blocks C17. Soil samples were taken at a depth of 0-15 cm and 15-30 cm for disturbed and undisturbed soil. Parameters measured were soil water content, bulk density, particle density, total pore space, permeability, and soil color. Each parameter of the observed data was statistically analyzed using analysis of variance followed by Duncan's New Multiple Range Test (DNMRT) at 5% level, while the soil color was descriptively analyzed. The results showed that the application of a mixture of EFB+POME increased soil moisture and bulk density decrease significantly and tended to increase the total pore space and permeability and tends to be lower particle density than controls, but it was not evident when compared EFB applications and POME alone. Applications waste processing palm oil mill affected the color of the soil where the soil is black on the application mix EFB+POME (hue: 10 YR, value/chroma: 2/1), brown on the application EFB (hue: 10 YR, value/chroma: 4/3 ), dark brown on the application of POME (hue: 10 YR, value/chroma: 3/3) and yellowish-brown in without application (hue: 10 YR, value/chroma: 5/4).

Effects of olive mill wastes with different degrees of maturity on behaviour of S‑metolachlor in three soils

Laboratory and field experiments were conducted on three Mediterranean agricultural soils in so as to investigate the effects of de-oiled two-phase olive mill waste (D) and two-phase olive mill waste (W) and their level of organic matter maturity on the environmental fate of the herbicide S‑metolachlor (SM). Three Mediterranean agricultural soils were amended with fresh (D and W) and composted W (CW) wastes under laboratory conditions. Furthermore, under field conditions, one of the soils was also amended with both wastes (D and W) over 9 years in order to assess the effects of the “aging” transformation (AD and AW treatments, respectively). Significant increases in SM adsorption were observed in all the amended soils, with no reduction in the herbicide's effectiveness. The adsorption process was more reversible with the fresh organic amendments (D or W) than with CW or (even more so) with AD or AW. The fresh amendments also increased the persistence of SM; however the field-aged and composted amendments enhanced its dissipation as a result increased soil microbial activity showed by high levels of soil dehydrogenase activity. The AD- and AW-amended soils, showed the greatest decrease in leaching loss of SM (from 51.9% in original soil to 9.33% in AD and 8.05% in AW), reflecting the strong influence of adsorption-desorption processes on SM leaching. This study has shown that the application of olive mill wastes as organic amendments may be considered a useful strategy to reduce leaching of SM in soils poor in organic matter, especially if those wastes have a high level of organic matter maturity.

Photocatalytic improvement of Y3+ modified TiO2 prepared by a ball milling method and application in shrimp wastewater treatment.

Semiconductor photocatalysis is an advanced oxidation process driven by solar energy which has widespread applications in the treatment of organic pollutants in liquid and gas phases. In this work, titanium dioxide nanoparticles modified with yttrium ions (Y3+) were prepared by a ball milling method. The effects of Y3+ mole fraction, ball-to-powder weight ratio, milling time and milling rate on the photocatalytic activities were evaluated by the degradation of methylene blue (MB) under UV light. Then Y3+/TiO2 photocatalysts prepared at the optimized ball milling conditions were applied to treat shrimp wastewater under UV and visible light. Chemical oxygen demand (CODCr), 3D fluorescence spectroscopy and total organic carbon (TOC) were used to detect the water samples taken from the photocatalytic experiments. Experimental results showed that when the mole fraction was 2%, the ball-to-powder weight ratio was 4 : 1, milling time was 4 h and milling rate was 500 rpm, the reaction rate constant of MB degradation can reach up to 0.1112 min−1 which was 4.2 times as fast as pure TiO2. All Y3+/TiO2 samples showed a red shift of absorption compared to pure TiO2 and it led to a visible light absorption response. The content of surface oxygen vacancies has significantly increased and the BET specific area increased to 104 m2 g−1. The CODCr removal rates of shrimp wastewater were 43.8% and 37.5% for 2% Y3+/TiO2 under UV and visible light, respectively. Besides, the TOC removal rates were 67.5% and 38.8%, respectively. Humic-like substances and fulvic-like substances in shrimp wastewater can be mineralized after 90 minutes irradiation.

Membrane Fouling Prevention and Control Strategies in Pulp and Paper Industry Applications: A Review

Membrane separation technologies have recently received much attention, from lab-scale studies to full-scale operations, in the forest industry. However, membrane fouling comprises a signifcant obstacle to their broad application. Thus, to ensure cost-effective operation of membrane separation processes, the improved elucidation of membrane fouling and establishment of effective fouling control strategies are critical. Membrane fouling decreases process performance efciency, thereby increasing operational and maintenance costs. Although much research has been conducted in this feld, a review has not yet been undertaken to address membrane fouling in pulp and paper mill applications. Further, membrane fouling is still not fully understood. In this review, a survey of the present state of fouling management strategies in the pulp and paper industry (PPI) is presented alongside the latest advances and innovative methods in fouling management. This article also discusses the key parameters that affect membrane fouling, fouling characterization techniques, as well as fouling mechanisms and strategies that are employed for fouling control. In addition, future research opportunities related to membrane fouling control strategies in both low-pressure membranes and MBRs are proposed.

시판 국산밀가루의 품질특성과 건면 제조적성

Purpose: This study assessed the quality of commercial Korean domestic wheat flours and their dry noodle-making performance. Methods: Six commercial Korean domestic wheat flours produced from different millers and a commercial all-purpose flour as a control were analyzed for moisture, ash and protein contents, solvent retention capacity (SRC), mixograph, and noodle making performance of dry noodles. Results: The moisture content of the commercial Korean domestic wheat flours varied according to the millers. The ash content of them was significantly higher than that of commercial all-purpose flour. The SRC results showed all Korean domestic flours had much lower lactic acid SRC values and gluten performance index (GPI) than the control. Mixograph data showed that one of the commercial Korean domestic flours (flour D) showed a very narrow bandwidth due to the higher damaged starch and arabinoxylan contribution based on high sodium carbonate and sucrose SRC values. Dry noodles made with commercial Korean domestic wheat flours produced significantly higher turbidity of cooked water and weight gain of cooked noodle than that with the control flour. In addition, the texture of cooked noodles made with commercial Korean domestic wheat flours was less viscoelastic, as illustrated by the less springiness, cohesiveness, gumminess and chewiness, compared to the control. Conclusion: Overall, the dry noodle-making performance of commercial Korean domestic wheat flours was inferior to that of commercial all-purpose flour due to the higher ash content and lower GPI. Lowering milling extraction and application of enzymes for reducing water absorption capacity of flour might improve the dry noodle-making performance.

Stiffness performance index based posture and feed orientation optimization in robotic milling process

Abstract Industrial robots are promising and competitive alternatives for performing machining operations. A relatively low stiffness is the major constraint for the widespread use of industrial robots in machining applications. In this study, the stiffness properties of an industrial robot are analyzed to improve the machining accuracy of robotic milling, and optimization methods for the robot posture and tool feed orientation are established. First, based on the relationship between the external force and deformation of the robot end effector (EE), the normal stiffness performance index (NSPI) of the surface, which is derived from the comprehensive stiffness performance index (CSPI), is proposed to evaluate the robot stiffness performance for a given posture. The NSPI is proven to be independent of the magnitudes of the external forces and dependent on the directions of these forces. A distribution rule is then proposed for the NSPI with respect to any direction in the Cartesian space for a given posture, which clearly reveals the anisotropic property of the robot stiffness. By maximizing the NSPI, an optimization model is established to optimize the posture of a six degree-of-freedom (DOF) industrial robot in a milling application. Using the NSPI, the optimized tool feed orientation for robot planar milling is obtained. Finally, the results of the robot milling experiments are discussed to illustrate the feasibility and effectiveness of the proposed optimization methods.

Modeling of Five-Phase, Self-Excited Induction Generator for Wind Mill Application

Wind turbines with higher power ratings are desired to reduce construction cost and maintenance time and increase energy yields. Three-phase induction generators are widely used in renewable power generation. Self-excited, squirrel cage induction generators are ideally suited for remote, standalone applications of low and medium power generation. The emerging multiphase induction generator (MPIG) with phases more than three is receiving significant attention for high power applications. This paper aspires at the performance investigation of five-phase induction generator (FPIG) in self-excited mode for standalone wind applications. The dynamic model of FPIG is developed using Matlab/Simulink. The performance of wind-driven FPIG under different operating conditions has been analyzed. The process of voltage build-up, current and torque under no load and loaded conditions are presented. The results are compared with three-phase self-excited induction generator (SEIG) to show the effectiveness of FPIG for high-power wind generation.

Determination of the content of alkyl ketene dimer in its latex by an ionic-liquid assisted headspace gas chromatography

This paper reports on an ionic-liquid assisted headspace gas chromatographic (HS-GC) for the determination of the content of alkyl ketene dimer (AKD) in its latex samples, in which the GC system was equipped with a thermal conductivity detector (TCD). The method was based on the AKD hydrolysis conducted in 1-butyl-3-methylimidazolium chloride (ionic-liquid) added medium at 100°C for 10min in a closed headspace sample vial, and the measured CO2 (the resulting product of the hydrolysis) by HS-GC. The results showed that the present method has a good measurement precision (RSD <2.3%) and accuracy (recoveries from 96 − 105%), and the limit of quantitation (LOQ) is 0.9%. The present method is very suitable to be used for the routine check of AKD content in its latex sample in mill applications. The study also showed that the content of AKD in the tested commercial latex samples were in the range of 3.5–12%.

A study on the application of mill scale-derived magnetite particles for adsorptive removal of phosphate from wastewater

A study on the application of mill scale-derived magnetite particles for adsorptive removal of phosphate from wastewater