Analysis of kinetics of multicomponent, heterogeneous granular mixtures - Laminar and turbulent flow approach

Mixing of granular materials is unquestionably important. Mixing solids is common in industrial applications and frequently represents a critical stage of the processes. The effect of mixing determines the quality of the products. Achieving a gas or liquid mixture ideally homogeneous in terms of composition in the case of dissolving components is not that difficult, while in case of granular materials that usually differ in sizes and densities, obtaining a homogenous mixture is practically impossible. The aim of the paper is to present the kinetics of mixing of a multicomponent, nonhomogeneous granular mixture. For the first time in mixing of granular materials, a reference has been made to the terminology used in kinematics of fluid mixtures to determine the state of the mixture: turbulent or laminar. By means of statistical analysis the mixing process was divided into two stages. The initial phase of the process was called the stage of turbulent changes, due to large differences in the quality of the observed mixtures; the final step of the process was called the stage of laminar, stable changes, where further mixing did not result in a significant improvement in quality. The research was conducted in industrial conditions in a two-tonne mixer

Analysis of kinetics of multicomponent, heterogeneous granular mixtures - Laminar and turbulent flow approach

Mixing of granular materials is unquestionably important. Mixing solids is common in industrial applications and frequently represents a critical stage of the processes. The effect of mixing determines the quality of the products. Achieving a gas or liquid mixture ideally homogeneous in terms of composition in the case of dissolving components is not that difficult, while in case of granular materials that usually differ in sizes and densities, obtaining a homogenous mixture is practically impossible. The aim of the paper is to present the kinetics of mixing of a multicomponent, nonhomogeneous granular mixture. For the first time in mixing of granular materials, a reference has been made to the terminology used in kinematics of fluid mixtures to determine the state of the mixture: turbulent or laminar. By means of statistical analysis the mixing process was divided into two stages. The initial phase of the process was called the stage of turbulent changes, due to large differences in the quality of the observed mixtures; the final step of the process was called the stage of laminar, stable changes, where further mixing did not result in a significant improvement in quality. The research was conducted in industrial conditions in a two-tonne mixer

Fluorescence optical analysis method for assessing homogeneity of granular mixtures

This paper presents a method of optical fluorescence analysis for the evaluation of homogeneity of multicomponent grain mixtures. This method is based on the evaluation of the content of fluorescent marker. Maize with two degrees of fineness d1 = 1.25 mm and d2 = 2.00 mm was used as a tracer. Maize was covered with Rhodamine B, which emits red light under the influence of ultraviolet radiation. The tracer was introduced into the mixture before the mixing process began. Nine multicomponent grain mixtures were used. The proportion of fluorescent maize was evaluated on the basis of computer image analysis. Additionally, the fraction of the tracer was evaluated using a control method (validation of the accuracy of the proposed method). The results indicate that the degree of the tracer’s fineness influences the results obtained. The use of fluorescent maize with particle size d2 = 2.00 mm allowed to obtain results which differed less from the control method. The average size of the difference in results ranged from 0.20-0.38 for the 2.00 mm tracer and 0.38-1.34 for the 1.25 mm tracer

Use of Whey and Whey Preparations in the Food Industry – A Review

The interest in whey and whey preparations has considerably increased in recent years. Whey and whey preparations are the so-called “forgotten treasure” and, because of their unique properties, they have been “rediscovered” and have been increasingly frequently and successfully used by various production plants in the food industry. They have also been eagerly purchased by consumers who are aware of the role of whey preparations in adequate human nutrition. For many years, there has been a tendency in the food processing industry to use substitutes of ingredients in recipes of many products. This situation can be observed in the case of foods with reduced fat and sugar, or products for lacto-ovo-vegetarians. Whey - and more specifically, its preparations - can also be used as a substitute. According to many literature sources, its use can have a positive impact not only on the consumers’ health but also on the finances of many companies, by reducing the costs of raw materials, and thus production costs. This review paper presents selected uses of whey and whey preparations in the food industry. The uses of whey discussed include: meat and meat products, reduced-fat products, yoghurts and ice creams, cheeses, bakery products, confectionery and pastry products, infant formulas, and whey drinks

Financing craft enterprises associated in the polish craft association

This article concerns functioning of small and medium enterprises and in particular: craft ones. In the sector structured European Union, the abovementioned stand for 80–95% of the existing companies and moreover, they generate the biggest number of job positions and the national income. The article focuses on a selected part of SME sector: craft enterprises and especially, on financing their activities. This financing relates to both, financing craft businesses’ investments and their current operations. In the first part of the text one presents a literary query concerning the definition of a craft enterprise and the resulting from its characteristic functioning: conception and tools for financing investments and current operations of craft enterprises. In the second part, one demonstrates the results of researches on the conception and the tools for financing craft enterprises functioning on the Polish market. In the summary of the article one demonstrates conclusions concerning the ways of maintenance and (in many cases innovative) changes of the conception and the tools for financing craft enterprises. The element congruous with the basic topic of the article relating to the current functioning of a craft enterprise in the real environment (both: inner and outer one), is its functioning in the digital surrounding (including with regard to the conception of financing activities), which correlates with the dynamic development of ICT technologies. The aforementioned development together with digitalization determines many aspects of craft enterprises’ functioning; also the ones connected with financing tools and conceptions. Referring to the things stated, it is clear that ICT technologies should be taken into account in enterprise’s current activities and in other aspects of its functioning e.g. communication, as well as eservices it provides and receives

Roughness Parameters Calculation By Means Of On-Line Vibration Monitoring Emerging From AWJ Interaction With Material

The paper deals with a study of relations between the measured Ra, Rq, Rz surface roughness parameters, the traverse speed of cutting head v and the vibration parameters, PtP, RMS, vRa, generated during abrasive water jet cutting of the AISI 309 stainless steel. Equations for prediction of the surface roughness parameters were derived according to the vibration parameter and the traverse speed of cutting head. Accuracy of the equations is described according to the Euclidean distances. The results are suitable for an on-line control model simulating abrasive water jet cutting and machining using an accompanying physical phenomenon for the process control which eliminates intervention of the operator

Sustainable Bioplastics for Food Packaging Produced from Renewable Natural Sources

It is crucial to find an effective, environmentally acceptable solution, such as bioplastics or biodegradable plastics, to the world’s rising plastics demand and the resulting ecological destruction. This study has focused on the environmentally friendly production of bioplastic samples derived from corn starch, rice starch, and tapioca starch, with various calcium carbonate filler concentrations as binders. Two different plasticizers, glycerol and sorbitol, were employed singly and in a rich blend. To test the differences in the physical and chemical properties (water content, absorption of moisture, water solubility, dissolution rate in alcohol, biodegradation in soil, tensile strength, elastic modulus, and FT-IR) of the produced samples, nine samples from each of the three types of bioplastics were produced using various ratios and blends of the fillers and plasticizers. The produced bioplastic samples have a multitude of features that make them appropriate for a variety of applications. The test results show that the starch-based bioplastics that have been suggested would be a better alternative material to be used in the packaging sectors

Multiobjective Optimization of Chemically Assisted Magnetic Abrasive Finishing (MAF) on Inconel 625 Tubes Using Genetic Algorithm: Modeling and Microstructural Analysis

The demand for the surface integrity of complex structures is drastically increasing in the field of aerospace, marine and automotive industry. Therefore, Inconel alloy, due to its superior attributes, has a wide scope for the improvement in surface integrity. To achieve the precise surface finish and enhance the process performance, process optimization is necessary. In current paper, chemically assisted MAF process parameters were optimized using the genetic algorithm (GA) approach during finishing of Inconel 625 tubes. Regression models were developed for improvement in internal surface finish (PIISF), improvement in external surface finish (PIESF), and material removal (MR) using Design expert software. Then, the surface microstructure of Inconel 625 tubes was analyzed using scanning electron microscopy (SEM). ANOVA analysis predicts that processing time and abrasive size have the highest percentage contribution in improving the surface finish and material removal. Multioptimization results suggested to set the level of processing time (A) at 75 min, surface rotational speed (B) at 60 RPM, weight % of abrasives (C) at 30%, chemical concentration (D) at 500 gm/lt and abrasive size (E) at 40 microns to obtain optimal parameters for PIISF, PIESF and MR responses

In Situ Micro-Observation of Surface Roughness and Fracture Mechanism in Metal Microforming of Thin Copper Sheets with Newly Developed Compact Testing Apparatus

A better understanding of material deformation behaviours with changes in size is crucial to the design and operation of metal microforming processes. In order to facilitate the investigation of size effects, material deformation behaviours needed to be determined directly from material characterizations. This study was aimed at the design and manufacture of a compact universal testing machine (UTM) compatible with a 3D laser-confocal microscope to observe the deformation behaviour of materials in real-time. In this study, uniaxial micro tensile testing was conducted on three different thin (0.05 mm, 0.1 mm, and 0.3 mm) copper specimens with characteristic dimensions at micro scales. Micro tensile experimental runs were carried out on copper specimens with varying grain sizes on the newly developed apparatus under a 3D laser-confocal microscope. Microscale experiments under 3D laser-confocal microscope provided not only a method to observe the microstructure of materials, but also a novel way to observe the early stages of fracture mechanisms. From real-time examination using the newly developed compact testing apparatus, we discovered that fracture behaviour was mostly brought about by the concave surface formed by free surface roughening. Findings with high stability were discovered while moving with the sample grasped along the drive screw in the graphical plot of a crosshead’s displacement against time. Our results also showed very low mechanical noise (detected during the displacement of the crosshead), which indicated that there were no additional effects on the machine, such as vibrations or shifts in speed that could influence performance. The engineering stress-strain plots of the pure copper-tests with various thicknesses or samples depicted a level of stress necessary to initiate plastic flowing inside the material. From these results, we observed that strength and ductility declined with decreasing thickness. The influence of thickness on fracture-strain, observed during tensile testing, made it clear that the elongation-at-break of the pure-copper foils intensely decreased with decreases in thickness. The relative average surface-roughness Ra was evaluated, which showed us that the surface-roughness escalated with the increasing trend of plasticity deformation (plastic strain) ε. For better understanding of the effects of plastic strain on surface roughness prior to material fractures, micro tensile tests were performed on the newly developed machine under a 3D laser-confocal-microscope. We observed that homogeneous surface roughness was caused by plastic strain, which further formed the concave surface that led to the fracture points. Finally, we concluded that surface roughness was one of the crucial factors influencing the fracture behaviour of metallic sheet-strips in metal microforming. We found that this type of testing apparatus could be designed and manufactured within a manageable budget