Experimental and Numerical Investigations on Conductive Drying of Phosphate Washing Waste Clay

Morocco is the leading producer of phosphate and its derivatives in the world with a total production of 35 Mt. However, the extraction and the valorization of this mine generate huge quantities of phosphate washing waste clay (PHWWC) that constitute a main environmental and economic concern. To facilitate this waste clay storage and handling, it is necessary to decrease its moisture content that represents 80% of PHWWC. The present paper is devoted to studying the conductive drying of PHWWC. Drying experiments were conducted in a laboratory pilot. Afterwards, the experiment results were implemented in a one-dimensional numerical model of heat and mass transfer in a porous media to identify the drying parameters and performances. It was found that most of the water contained in PHWWC is free water that is removed with a constant drying rate. The volume reduction with a marked cracks phenomenon attained 65% without any significant effect of drying temperature and sample thickness. The effective moisture diffusivity of the PHWWC for a conductive drying process is ranged between 10−9 and 1.1 × 10−8 m2·s−1. The thermal efficiency of the drying system is up to 86%. The results could be used for the purpose of design and scale-up of the industrial dryer based on laboratory-scale experiments.

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An active indirect solar system for food products drying

Acta Chimica Slovaca ◽

10.2478/acs-2019-0020 ◽

2019 ◽

Vol 12 (1) ◽

pp. 142-149 ◽

Cited By ~ 1

Author(s):

Abdul Wasim Noori ◽

Mohammad Jafar Royen ◽

Juma Haydary

Keyword(s):

Ambient Temperature ◽

Air Temperature ◽

Food Products ◽

Sample Thickness ◽

Drying Process ◽

Rectangular Section ◽

Drying Time ◽

Solar Dryer ◽

Temperature And Humidity ◽

Drying System

AbstractAn energy independent active indirect solar drying system for the study of food products drying at specific climate conditions was developed and tested. As a model material, sliced tomato was selected because of its short shelf live, high humidity and potential to be a high value dried product. Indirect solar dryer enabled complete protection of the dried material against sunlight, birds, insects, rain and dust during the drying process. The solar dryer system design includes a rectangular section (1000 × 600 × 400) mm chamber and a flat solar collector (1500 × 600 × 100) mm with the surface area of 0.9 m2. Air flow was induced by a fan installed at the inlet of the collector and powered by a photovoltaic solar panel and a battery system. Temperature and humidity of air were monitored at the collector inlet, collector outlet and the drying chamber outlet. The key element of the collector is a 10.5 m long rectangular section aluminum pipe (55 × 35) mm coated with an absorption layer. The maximum dryer capacity is around 3 kg of wet material (sliced tomato) per batch. Average air temperature increase in the collector was measured to be 30 °C during the winter season. Air relative humidity decreased from 21 % to 15 % after passing through the collector. The moisture of tomato slices decreased from the initial value of 92 % down to 22 % during the time of the experiment (30 h). Quality of tomatoes dried using the designed solar dryer differed significantly in color as well as in texture from those dried by the commonly used methods, like an open sun drying system. Equilibrium moisture content of the product was reached after 30 h in December when the maximum outside temperature was 17.6 °C. The tomato mass decreased from 333 g to 33.15 g; the mass loss being approximately 90 %. The heated air temperature and humidity at the dryer inlet and outlet were influenced by the change of the ambient temperature and humidity during the day. Variation of the drying rate with the change of the ambient temperature and humidity was observed. During summer, when the sun radiation increases, the drying time for sliced tomato with 9 mm thickness decreased from 25 h to 15 h. The sample thickness also has an impact on the drying process. When the sample thickness increased from 9 mm to 12 mm, the drying time increased from 15 h to 20 h of active device time.

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Konsumsi Energi Pada Alat Pengering Surya dan Tipe Bak Untuk Pengeringan Biji Kakao

Jurnal Sains dan Teknologi Indonesia ◽

10.29122/jsti.v17i3.3433 ◽

2019 ◽

Vol 17 (3) ◽

Author(s):

Lamhot P. Manalu

Keyword(s):

Specific Energy ◽

Fossil Fuels ◽

Negative Impact ◽

Solar Irradiation ◽

Drying Process ◽

Food Industries ◽

Solar Dryer ◽

Agricultural Applications ◽

Drying System ◽

Drying Efficiency

Crop drying is essential for preservation in agricultural applications. It is performed either using fossil fuels in an artificial mechanical drying process or by placing the crop under the open sun. The first method is costly and has a negative impact on the environment, while the second method is totally dependent on the weather. The drying process requires a lot of energy in relation to the amount of water that must be evaporated from the product. It is estimated that 12% of the total energy used by the food industries and agriculture absorbed in this process. Due to the limitation of energy resources, it is important to keep researching and developing of diversification and optimization of energy This study aims to assess the use of energy for cocoa drying using solar energy dryer and bin-type dryer, as well as to determine the drying efficiency of each type of dryer. The results showed that the efficiency of the solar dryer drying system ranges between 36% to 46%, while the tub-type dryers between 21.7% to 33.1%. The specific energy of solar dryer ranged from 6.17-7.87 MJ / kg, while the tub-type dryers 8.58-13.63 MJ / kg. Dryer efficiency is influenced by the level of solar irradiation and the amount of drying load, the higher the irradiation received and more cocoa beans are dried, the drying efficiency is also higher and the specific energy further down.Proses pengeringan memerlukan banyak energi sehubungan dengan banyaknya air yang harus diuapkan dari bahan yang dikeringkan. Pengeringan dapat dilakukan dengan menggunakan pengering mekanis berbahan bakar fosil atau dengan menempatkan produk di bawah matahari terbuka. Metode pertama adalah mahal dan memiliki dampak negatif pada lingkungan, sedangkan metode kedua sangat tergantung pada cuaca. Diperkirakan bahwa 12% dari total energi yang dipergunakan oleh industri pangan dan pertanian diserap untuk proses ini. Mengingat semakin terbatasnya sumber energi bahan bakar minyak maka usaha diversifikasi dan optimasi energi untuk pengeringan perlu terus diteliti dan dikembangkan. Salah satunya adalah pemanfaatan energi surya sebagai sumber energi terbarukan. Penelitian ini bertujuan untuk mengkaji penggunaan energi untuk pengeringan kakao dengan memakai pengering energi surya dan pengering tipe bak, serta untuk mengetahui efisiensi pengeringan dari masing-masing tipe pengering. Hasil kajian menunjukkan bahwa efisiensi total sistem pengeringan alat pengering surya berkisar antara 36% dan 46%, sedangkan pengering tipe bak antara 21.7% dan 33.1%. Kebutuhan energi spesifik alat pengering surya berkisar antara 6.17-7.87 MJ/kg, sedangkan alat pengering tipe bak 8.58-13.63 MJ/kg. Efisiensi alat pengering dipengaruhi oleh tingkat iradiasi surya dan jumlah beban pengeringan, semakin tinggi iradiasi yang diterima pengering serta semakin banyak biji kakao yang dikeringkan, maka efisiensi pengeringan juga semakin tinggi dan kebutuhan energi spesifik semakin turun.Keywords: energy, efficiency, cocoa, solar dryer, bin-type dryer.

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Beyond the Fife and Drum: Northern Protestant Working Class Cultures

Public Voices ◽

10.22140/pv.204 ◽

2017 ◽

Vol 9 (1) ◽

pp. 73

Author(s):

Paul Burgess

Keyword(s):

Northern Ireland ◽

Working Class ◽

World Order ◽

Cultural Traditions ◽

One Dimensional ◽

Dimensional Image ◽

The Troubles ◽

Meaning Systems ◽

The World ◽

Symbolic Systems

The author contends that throughout the duration of the present conflict in NorthernIreland, the world has been repeatedly given a one-dimensional image of this culture depicting it as mainly a product of ethnicity and also a reflection of class sentiment and lived experience.As drummer and songwriter of Ruefrex, a musical band internationally renowned for its songs about the Troubles conflict in Northern Ireland, Burgess discusses the need to express Protestant cultural traditions and identity through words and music. Citing Weber’s argument that individuals need to understand the world and their environment and that this understanding is influenced by perceptions of world order and attitudes and interpretations of symbolic systems or structures, the author argues that losing the importance of symbolic structures in relation to actual events will result in failure to understand why communities embrace meaning systems that are centrally informed by symbol and ritual. In his mind, rather than seeking to promote an understanding of Protestant or Catholic reality, it is important to speculate how the practice of difference might be used in developing any kind of reality of co-operation and co-ordination

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Study on the Variable-Temperature Drying Process of Corn Drying in an Industrial Corn-Drying System Equipped with a Self-Adaptive Control Heat Exchanger

Applied Sciences ◽

10.3390/app11062772 ◽

2021 ◽

Vol 11 (6) ◽

pp. 2772

Author(s):

Bin Li ◽

Zhiheng Zeng ◽

Xuefeng Zhang ◽

Ye Zhang

Keyword(s):

Adaptive Control ◽

Energy Consumption ◽

Heat Loss ◽

Thermal Performance ◽

Variable Temperature ◽

The Other ◽

Drying Process ◽

Drying Kinetic ◽

Drying System ◽

Self Adaptive

To realize energy-saving and efficient industrial grain drying, the present work studied the variable-temperature drying process of corn drying in a novel industrial corn-drying system with a heat recycling and self-adaptive control function. The drying kinetics, thermal performance, heat-loss characteristics and the heat-recycling performance of the drying system under different allocations between flue gas and hot air were investigated, and the optimized drying process was proposed and compared with two constant drying processes. The results showed that the optimized drying process exhibited better drying kinetic and thermal performance than the two constant drying processes. More specifically, the total heat loss, total energy consumption and specific energy consumption of the optimized drying process were ascertained to be 36,132.85 MJ, 48,803.99 MJ and 7290.27 kJ/kg, respectively, which were lower than those of the other two processes. On the other hand, the thermal efficiency of the drying chamber for the optimized drying process was ascertained to be varied within the range of 6.81–41.71%. Overall, the validation results showed that the optimized drying process can significantly improve the drying performance of the drying system.

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Could 30 years of political controversy on needle exchange programmes in Sweden contribute to scaling-up harm reduction services in the world?

Nordic Studies on Alcohol and Drugs ◽

10.1177/1455072520965013 ◽

2020 ◽

pp. 145507252096501

Author(s):

Niklas Karlsson ◽

Torsten Berglund ◽

Anna Mia Ekström ◽

Anders Hammarberg ◽

Tuukka Tammi

Keyword(s):

Harm Reduction ◽

Drug Policy ◽

Grey Literature ◽

Scale Up ◽

Valuable Insight ◽

Control Drug ◽

Policy Domain ◽

The World ◽

Key Events ◽

Exchange Programmes

Aims: To end the hepatitis and AIDS epidemics in the world by 2030, countries are encouraged to scale-up harm reduction services and target people who inject drugs (PWID). Blood-borne viruses (BBV) among PWID spread via unsterile injection equipment sharing and to combat this, many countries have introduced needle and syringe exchange programmes (NEP), though not without controversy. Sweden’s long, complicated harm reduction policy transition has been deviant compared to the Nordic countries. After launch in 1986, no NEP were started in Sweden for 23 years, the reasons for which are analysed in this study. Methods: Policy documents, grey literature and research mainly published in 2000–2017 were collected and analysed using a hierarchical framework, to understand how continuous build-up of evidence, decisions and key events, over time influenced NEP development. Results: Sweden’s first NEP opened in a repressive-control drug policy era with a drug-free society goal. Despite high prevalence of BBV among PWID with recurring outbreaks, growing research and key-actor support including a NEP law, no NEP were launched. Political disagreements, fluctuating actor-coalitions, questioning of research, and a municipality veto against NEP, played critical roles. With an individual-centred perspective being brought into the drug policy domain, the manifestation of a dual drug and health policy track, a revised NEP law in 2017 and removal of the veto, Sweden would see fast expansion of new NEP. Conclusions: Lessons from the Swedish case could provide valuable insight for countries about to scale-up harm reduction services including how to circumvent costly time- and resource-intensive obstacles and processes involving ideological and individual moral dimensions.

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Optimization and Prediction of the Drying and Quality of Turnip Slices by Convective-Infrared Dryer under Various Pretreatments by RSM and ANFIS Methods

Foods ◽

10.3390/foods10020284 ◽

2021 ◽

Vol 10 (2) ◽

pp. 284

Author(s):

Ebrahim Taghinezhad ◽

Mohammad Kaveh ◽

Antoni Szumny

Keyword(s):

Energy Efficiency ◽

Color Difference ◽

Moisture Diffusivity ◽

Effective Moisture Diffusivity ◽

Diffusivity Coefficient ◽

Drying Process ◽

Anfis Model ◽

Drying Time ◽

Effective Moisture ◽

Response Variables

Drying can prolong the shelf life of a product by reducing microbial activities while facilitating its transportation and storage by decreasing the product weight and volume. The quality factors of the drying process are among the important issues in the drying of food and agricultural products. In this study, the effects of several independent variables such as the temperature of the drying air (50, 60, and 70 °C) and the thickness of the samples (2, 4, and 6 mm) were studied on the response variables including the quality indices (color difference and shrinkage) and drying factors (drying time, effective moisture diffusivity coefficient, specific energy consumption (SEC), energy efficiency and dryer efficiency) of the turnip slices dried by a hybrid convective-infrared (HCIR) dryer. Before drying, the samples were treated by three pretreatments: microwave (360 W for 2.5 min), ultrasonic (at 30 °C for 10 min) and blanching (at 90 °C for 2 min). The statistical analyses of the data and optimization of the drying process were achieved by the response surface method (RSM) and the response variables were predicted by the adaptive neuro-fuzzy inference system (ANFIS) model. The results indicated that an increase in the dryer temperature and a decline in the thickness of the sample can enhance the evaporation rate of the samples which will decrease the drying time (40–20 min), SEC (from 168.98 to 21.57 MJ/kg), color difference (from 50.59 to 15.38) and shrinkage (from 67.84% to 24.28%) while increasing the effective moisture diffusivity coefficient (from 1.007 × 10−9 to 8.11 × 10−9 m2/s), energy efficiency (from 0.89% to 15.23%) and dryer efficiency (from 2.11% to 21.2%). Compared to ultrasonic and blanching, microwave pretreatment increased the energy and drying efficiency; while the variations in the color and shrinkage were the lowest in the ultrasonic pretreatment. The optimal condition involved the temperature of 70 °C and sample thickness of 2 mm with the desirability above 0.89. The ANFIS model also managed to predict the response variables with R2 > 0.96.

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Study on Drying Characteristics of Microalgae under Different Conditions

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.724-725.296 ◽

2013 ◽

Vol 724-725 ◽

pp. 296-299

Author(s):

Chun Xiang Chen ◽

Xiao Qian Ma ◽

Xiao Cong Li ◽

Wei Ping Qin

Keyword(s):

Moisture Content ◽

Mass Loss ◽

Fresh Water ◽

Chlorella Vulgaris ◽

Drying Process ◽

Drying Time ◽

Drying Characteristics ◽

Second Stage ◽

Drying System ◽

Two Stages

To find out an alternative of coal saving, a kind of microalgae, Chlorella vulgaris (C. vulgaris) which is widespread in fresh water was studied by digital blast drying system. The effect of the moisture content, drying thickness and temperature on the drying process of C. vulgaris were investigated. The results indicated that when the drying temperature is high, the moisture content is low and the material thickness is small, the drying time is short. The drying process of C.vulgaris can be divided into two stages, and the mass loss is mainly occurred in the second stage . The results will provide guidance for design of drying process and dryer of microalgae.

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Free Water Influence on the Dynamic Tensile Behaviour of Concrete

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.82.45 ◽

2011 ◽

Vol 82 ◽

pp. 45-50 ◽

Cited By ~ 7

Author(s):

Benjamin Erzar ◽

Pascal Forquin

Keyword(s):

Dynamic Behaviour ◽

Free Water ◽

Dynamic Strength ◽

Fragmentation Process ◽

Tensile Behaviour ◽

Water Influence ◽

Micro Cracks ◽

The World ◽

The Difference ◽

Impact Experiments

Concrete is a material used all over the world for civil engineering but the mechanisms governing its dynamic behaviour are still not well understood. In this work, spalling tests and edge-on impact experiments have been used to determine the influence of the free-water contained in pores and micro-cracks on the dynamic strength and on the fragmentation process. Moreover, spalling tests have been also used to identify the main mechanisms leading to the difference of behaviour observed between wet and dry concrete.

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Achieving Net Zero Carbon Dioxide by Sequestering Biomass Carbon

10.20944/preprints202007.0576.v1 ◽

2020 ◽

Author(s):

Jeffrey Amelse

Keyword(s):

Carbon Dioxide ◽

Carbon Cycle ◽

Co2 Emissions ◽

Energy Demand ◽

Co2 Sequestration ◽

Fossil Fuels ◽

Scale Up ◽

Biomass Carbon ◽

Net Zero ◽

The World

Mitigation of global warming requires an understanding of where energy is produced and consumed, the magnitude of carbon dioxide generation, and proper understanding of the Carbon Cycle. The latter leads to the distinction between and need for both CO2 and biomass CARBON sequestration. Short reviews are provided for prior technologies proposed for reducing CO2 emissions from fossil fuels or substituting renewable energy, focusing on their limitations. None offer a complete solution. Of these, CO2 sequestration is poised to have the largest impact. We know how to do it. It will just cost money, and scale-up is a huge challenge. Few projects have been brought forward to semi-commercial scale. Transportation accounts for only about 30% of U.S. overall energy demand. Biofuels penetration remains small, and thus, they contribute a trivial amount of overall CO2 reduction, even though 40% of U.S. corn and 30% of soybeans are devoted to their production. Bioethanol is traced through its Carbon Cycle and shown to be both energy inefficient, and an inefficient use of biomass carbon. Both biofuels and CO2 sequestration reduce FUTURE CO2 emissions from continued use of fossil fuels. They will not remove CO2 ALREADY in the atmosphere. The only way to do that is to break the Carbon Cycle by growing biomass from atmospheric CO2 and sequestering biomass CARBON. Theoretically, sequestration of only a fraction of the world’s tree leaves, which are renewed every year, can get the world to Net Zero CO2 without disturbing the underlying forests.

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Discovering the two faces of religious charismatic action – traditional and modern: a model

Scripta Instituti Donneriani Aboensis ◽

10.30674/scripta.67259 ◽

1999 ◽

Vol 17 (1) ◽

pp. 273-304

Author(s):

Jane Williams-Hogan

Keyword(s):

Structural Characteristics ◽

Modern Society ◽

Natural World ◽

One Dimensional ◽

New Religions ◽

The World ◽

The Gift ◽

Rational Calculation ◽

Traditional Societies ◽

And Control

In this paper, the author examines the issue of charisma and prophecy in secularized societies. In traditional society the charismatic personality or the prophet brought a universalizing and rationalizing message which simultaneously expanded and penetrated the sphere of external order in the world, giving people the ability to manipulate and control the natural world. The disenchanted world is the end product of this process, when no more mysterious forces come into play, and when one can in principle master all things through rational calculation. The gift of rationality almost randomly bestowed in the ancient world becomes, for Weber, the rightful inheritance of the modern individual. Clarity brought by charisma in a dark and foreboding world loses its brilliance and its ability to beckon when the world is filled with light. In investigating charisma in only traditional societies, Weber saw charisma as one dimensional, solely as the force of rationality. So envisioned, charisma dissipates in the very act of realizing itself through the transformation of the world. Given Weber's analysis, therefore, one would not expect to find genuinely new religions emerging within our transformed and rational modern society. In the examination of the founding something that is best identified by the sociological term charisma, though obviously in modern guise, is clearly evident. This points to the possibility that charisma is not static but has the dynamic capacity to be responsive to the structural characteristics of the society in which it operates.

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