scholarly journals Features of cascading disk-gear extrusion of plastics

Author(s):  
Anastasiia Kovba ◽  
Mykola Shved ◽  
Dmytro Shved

The relevant task of today is to improve the installations for thermostat extrusion, in order to increase the indicators of resource/energy efficiency. The study of the features peculiar to the loading and melting area (LMA) and the elimination of shortcomings can significantly reduce the energy costs of the process. To achieve high-quality results in cascading disk-gear extrusion, the main methods of the dispersion melting of thermoplastic granules are analyzed, taking into account all the features of the physical model of the extrusion process. The dispersion model of melting is achieved by observing a limited supply of raw materials to the loading area. This ensures the intensification of the process and significantly reduces the total length of the LMA. In this case, the length of the area with the most filled channel directly depends on the resistance of the disk zone. With increasing resistance, the polymer stopper moves to the loading neck. The polymer is gradually compacted, and each leakage of the LMA is periodically filled. From the rotating disk heated to 107 oC, samples of the polymer were removed and cut into separate sections. Previously, to facilitate the process of visual research, the polymer was colored with 0.5% blue pigment. The results of the analysis confirmed the performance of the proposed physical model for the processes occuring in the disk-gear extruder. As a result, it is possible to calculate the time over which the granules stay in the LMA and the length of the screw cutting in this area, depending on the performance. Taking into account all the features of the disk-gear extrusion process allows creating an upgraded productive, resource-efficient installation and implementing it into practice.

2009 ◽  
Vol 630 ◽  
pp. 77-84 ◽  
Author(s):  
Guillaume Girard ◽  
J. Barresi ◽  
C. Dupuis ◽  
G. Riverin

Scrap rate, throughput, alloy recovery and raw materials are all areas of the casthouse which usually get substantial attention as means of either increasing profits or reducing costs. However, furnaces, which are often overlooked by the casthouse, can also deliver surprisingly high savings. Moreover, these potential savings can only magnify as energy costs and pressures to reduce carbon footprint increase. This paper gives an insight into where savings can be achieved by a casthouse with proper furnace operation. Knowledge of how a furnace should be operated is often neglected but as this paper tries to highlight, developing this knowledge can be extremely worthwhile.


Author(s):  
K. Boddenberg ◽  
B. Kock ◽  
M. Dorfman ◽  
L. Russo ◽  
M. Nestler

Abstract Air separation plants use centrifugal compressors where air and electrical energy are the only raw materials used in the production process. So energy costs play a crucial role and the compressors are heavily penalized when guaranteed performance levels are not achieved. In order to better generate performance, abradable coatings, previously used in the gas turbine industry, have been designed into turbocompressors. This paper will show the optimization and performance improvements of a new aluminium silicon-boron nitride material.


2018 ◽  
Vol 82 (1) ◽  
Author(s):  
А. В. Гаврилов ◽  
Ігор Віталійович Безбах ◽  
Всеволод Петрович Мордынский ◽  
Олег Григорьевич Бурдо

Рассмотрены мировые тенденции на рынке сушеных продуктов и концентратов. Анализируются энерготехнологии основных процессов обезвоживания – выпарки и сушки. Сравниваются современные технологи обезвоживания и обсуждаются научно-технические противоречия процессов выпарки и сушки. Показаны энергетические преимущества выпарки и ограничения по конечному влагосодержанию готового продукта. Приведены модели материальных балансов при комбинированных технологиях «выпарка - сушка». Представлены инновационные разработки техники обезвоживания – термомеханический агрегат и микроволновой вакуум-выпарной аппарат. Обсуждаются конструктивные варианты агрегата, возможности решать в нем параллельно задачи дробления, плющения, перемешивания и транспортировки продукта. Обоснованы механизмы интенсификации процесса тепломассопереноса в термомеханическом агрегате. Приведены значения коэффициентов теплопередачи в термомеханических агрегатах при обработке сырья в консервных, молочных, пищеконцентратных и винодельческих производствах. Проведено сравнение удельных энергетических затрат в термомеханическом агрегате и в традиционных ленточных и барабанных сушилках. Исследуются инновационные технологии обезвоживания в электромагнитных полях. Показаны перспективы сушилок с электромагнитным подводом энергии микроволнового диапазона. Исследуются процессы выпаривания в традиционных аппаратах и в вакуумных микроволновых.  Приведены модели трансформации, транспорта и потерь энергии в традиционной технологии производства томатной пасты и в установке с термомеханическим агрегатом с ротационным термосифоном. Показано, что инновационная технология позволяет на 40% интенсифицировать процесс выпарки и на 35% снизить удельные расходы энергии. Обоснованы перспективы ступенчатых схем обезвоживания «выпарка - сушка». Проведено развитие методов энергетического менеджмента для исследования энергетической эффективности на основе нового числа подобия – числа энергетического действия.  The world tendencies in the dried products and concentrates market are considered. The energy technologies of the basic processes of dehydration (evaporation and drying) are analyzed. Modern dehydration technologies are compared and the scientific and technical contradictions of the processes of evaporation and drying are discussed. The energy advantages of the evaporation and the limitations by the final moisture content of the finished product are shown. Models of material balances with combined technologies of "evaporation - drying" are given. Innovative developments in dehydration engineering are presented - a thermomechanical unit and a microwave vacuum evaporator. The constructive variants of the unit are discussed, the possibilities of solving in it the tasks of crushing, flattening, mixing and transporting the product in parallel. The mechanisms of intensification of the process of heat and mass transfer in a thermomechanical aggregate are justified. The values of the heat transfer coefficients in thermomechanical aggregates are given for the processing of raw materials in canning, dairy, food-concentrates and wineries. The specific energy costs in a thermomechanical aggregate and in traditional belt and cylinder dryers are compared. Innovative technologies of dehydration in electromagnetic fields are investigated. The prospects of dryers with electromagnetic energy supply of the microwave range are shown. Evaporation processes are studied in conventional apparatuses and in vacuum microwave ones. Models of transformation, transport and energy losses in the traditional technology of tomato paste production and in a device with a thermomechanical unit with a rotary thermosyphon are presented. It is shown that the innovative technology allows to intensify the process of evaporation by 40% and to reduce the energy consumption by 35%. The prospects of stepwise dehydration schemes of "evaporation - drying" are substantiated. Energy management methods have been developed to study energy efficiency based on a new number of similarity – the number of energy actions.


Author(s):  
Michael Tite ◽  
Gareth Hatton

Egyptian blue was first used as a pigment on tomb paintings in Egypt from around 2300 BC, and during the subsequent 3,000 years, its use both as a pigment and in the production of small objects spread throughout the Near East and Eastern Mediterranean and to the limits of the Roman Empire. During the Roman period, Egyptian blue was distributed in the form of balls of pigment up to about 15mm across, and appears to have been the most common blue pigment to be used on wall paintings throughout the Empire. Egyptian blue was both the first synthetic pigment, and one of the first materials from antiquity to be examined by modern scientific methods. A small pot containing the pigment that was found during the excavations at Pompeii in 1814 was examined by Sir Humphrey Davy. Subsequently, x-ray diffraction analysis was used to identify the compound as the calcium-copper tetrasilicate C<sub>a</sub>C<sub>u</sub>Si<sub>4</sub>O<sub>10</sub>, and to establish that Egyptian blue and the rare natural mineral cuprorivaite are the same material. Examination of Egyptian blue samples in cross-section in a scanning electron microscope (SEM) revealed that they consist of an intimate mixture of Egyptian blue crystals (i.e. C<sub>a</sub>C<sub>u</sub>Si<sub>4</sub>O<sub>10</sub>) and partially reacted quartz particles together with varying amounts of glass phase (Tite, Bimson, and Cowell 1984). At this stage it should be emphasized that, in the literature, the term Egyptian blue tends to be used to describe both crystals of calcium-copper tetrasilicate and the bulk polycrystalline material that is used as the pigment and is sometimes referred to as frit. In this chapter, the suffix ‘crystal’ or ‘mineral’ will be added when the former meaning applies, and the suffix ‘pigment’, ‘sample’, or ‘frit’ will be added when the latter meaning applies. For the current study, a small group of Roman Egyptian blue samples were examined using scanning electron microscopy (SEM) with attached analytical facilities. Using the chemical compositions of the samples, together with the description of the manufacture of Egyptian blue given by Vitruvius (Morgan 1960) at the beginning of the first century BC in his Ten Books on Architecture, an attempt is made to identify the raw materials used in the production of Roman Egyptian blue.


2015 ◽  
Vol 12 (1) ◽  
pp. 11 ◽  
Author(s):  
Evi Savitri Iriani ◽  
Kendri Wahyuningsih ◽  
Titi Candra Sunarti ◽  
Asep Wawan Permana

<p>A variety of attempts have been made to reduce the dependence on petroleum raw materials based plastics which are limited supply the mechanical properties close to conventional plastic. The objectives of research was to know the effect of  pineapple nanocellulose effective in increasing tensile strength and elongation, but the higher addition (of up to 50%) resulted in decreased elongation. The addition and without glycerol</p>


2018 ◽  
Vol 68 (331) ◽  
pp. 166
Author(s):  
S. Chhaiba ◽  
M. T. Blanco-Varela ◽  
A. Diouri

For some time the cement industry has been seeking procedures to effectively lower the higher energy costs involved in cement manufacture. Timahdit oil shale and Jerada coal waste could potentially be used as alternative raw materials to produce clinker. This study explored the possibility of applying those materials to a greener use, based on the reactivity and burnability of raw mixes containing Moroccan oil shale and coal waste. The findings showed that, irrespective of particle size, oil shale mixes delivered higher reactivity than coal waste materials, although reactivity was highest in the oil shale clinker with a particle size < 45 μm. The clinkers bearing oil shale with a particle size < 90 μm or a blend of oil shale and coal waste with a size < 45 μm contained higher proportions of alite ( > 70 %).


2020 ◽  
Vol 42 (1) ◽  
pp. 52-59
Author(s):  
E.M. Oliynyk ◽  
V.I. Zubenko

The article contains consolidated results of the simulation of the untreated fuel raw materials use scheme in comparison with the fuel pellets production. Specific indicators and the main factors of influence on energy, ecological and economic efficiency of biofuel use are determined. It was found that the organizational scheme of sunflower husk pelleting and pellets transportation on up to 400 km distance is a more energy-efficient solution. In this case, the main energy costs will be related specifically to the pellets production, and therefore the main direction of energy costs reduction should be the production energy efficiency increasing – electricity consumption lowering. Otherwise, in case of fuel transportation on more than 400 km distance, the main attention should be paid to the motor fuels consumption lowering and the transport load optimization. The pellets production and transportation leads to an increase in total greenhouse gas emissions compared with husk transportation on up to 2000 km distance. Therefore, husk pellets production for domestic transportation is not an effective solution from an environmental point of view. The husk transportation is economically more efficient compared to the organizational scheme of pellets production and transportation on up to 300 km distances. Financially economic efficiency is the main limiting factor at decision-making on the organizational scheme of sunflower husk use.


2021 ◽  
Vol 1 (25) ◽  
pp. 38-49
Author(s):  
S.V. Braginets ◽  
◽  
O.N. Bakhchevnikov ◽  
V.F. Khlystunov ◽  
◽  
...  

Extrusion is one of the most important technological operations in aquafeed production. Indeed, the digestibility of feed nutrients considerably increases as a result of extrusion. The review deals with the issues of vegetable and animal raw materials processing for aquafeed production through extrusion. The analysis of scientific publications discussing the monitoring subject showed that extrusion of multicomponent mixtures (compound feed) had been studied insufficiently. Research objectives were to generalize and analyze English-language scientific publications containing information on the technologies of compound fish feed extrusion, to clarify the information on the rational parameters of their implementation and the effects on the properties of finished extruded feed. Search, selection, as well as systematic review of highly cited English-language scientific articles on the research subject for the period 2000–2020, were carried out. In the course of the analysis of literary sources, it was detected that the properties of the finished extruded feed were mostly affected by the extrusion temperature, raw material moisture and screw speed. The regularities of changes in the properties of ready-extruded feed granules, as a result of changes in extrusion parameters, have been determined. The results of the analyzed scientific articles made it possible to establish the peculiarities of the extrusion of compound feed for aquaculture based on plant raw materials, in particular starch. We defined the regularities of compound fish feed extrusion containing raw materials with a considerable amount of protein of animal origin, in particular its new type: insects’ biomass. This new type of protein-containing raw materials of animal origin can successfully replace expensive fish meal in the fish feed composition. The essential factor, limiting the application of animal raw materials in fish feed, in particular insects, is its moisture, which should not exceed 30% so that the extrusion process was fully effective. Reducing the feed mixture moisture is possible when combining various types of animal and plant raw materials with high and low moisture. This will ensure the acceptable moisture of the mixture and get the high-quality extruded feed. Aquafeed extrusion is a promising trend. However, it requires additional research to determine the parameters of the extrusion process common to all types of both plant and animal raw materials and their mixtures.


Author(s):  
José Luis Hoyos-Concha ◽  
Hector Samuel Villada-Castillo ◽  
Alejandro Fernández-Quintero ◽  
Rodrigo Ortega-Toro

The extrusion of food for human and animal consumption is a unit operation that includes mixing, shearing and force to the materials related to the rheological properties of the materials in the extruder. The present work aims to study the rheological behavior of an extruded fish diet incorporating hydrolyzed protein flour processed by extrusion. The measurement was carried out online with a slit die rheometer, defining the rheological models and parameters that fit the process. During the extrusion process, the raw materials used were hydrolyzed protein meal, fish meal and cassava starch. For the results, the evaluated treatments were adjusted to the Power Law, where an increase in the shear rate decreases the viscosity of the material, corresponding to a pseudoplastic behavior. The incorporation of hydrolyzed protein flour presented a significant effect on the value of n and Klp, increasing the viscosity with the increase in the percentage of inclusion of HPH. The models obtained for the prediction of the viscosity are adjusted to the changes in shear rate, temperature and humidity of the system.


Author(s):  
Peter Rez

It is nearly always the case that the energy used to make the materials dominates, whereas the energy used in shipping either the raw materials or the finished product is usually small in comparison. For most things that we use, the embodied energy is much less than the energy consumed in operational use. When considering energy generation, there are two energy costs that should be considered. There is the energy needed to build the system, which can be thought of as a ‘capital’ or investment energy, and the energy needed to provide the fuel. For fossil fuels, the energy needed to provide the fuel dominates; for renewables, the fuel is free, so there is only an investment energy. The investment energy for nuclear power is greater than the energy needed to make the fuel, but only by a factor of about 4.


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