Pub Date : 2023-06-08DOI: 10.1080/07373937.2023.2219736
A. Juneja, P. Barnwal, A. K. Sharma, Banashree Naskar, Amit Kumar
Abstract Spray drying of milk is a highly energy intensive process. In this study, thermodynamic and exergoeconomic analyses of two-stage spray drying plant have been executed. This plant was analyzed on the basis of various parameters such as energy efficiency, exergy efficiency, energy improvement potential, exergy improvement potential, etc. The energy and exergy efficiency of the plant were 72.90 and 35.15%, respectively. The maximum energy improvement potential was for drying whereas maximum exergy improvement potential was for homogenizer. It indicates huge scope in the technical improvement for drying chamber and homogenizer of the plant. The highest cost of processing was for cyclone separator (percentage relative cost difference: 44%) followed by drying chamber (percentage relative cost difference: 40.71%). Highest energy destroyed was calculated for drying chamber (195.83 kJ/kg) followed by VFBD (87.62 kJ/kg). Lowest energy efficiency was calculated for VFBD (34.64%) followed by drying chamber (50.04%). Highest energy improvement potential was estimated for drying chamber (97.86 kJ/kg). Highest relative energy destruction ratio was calculated for drying chamber (52.04%) followed by VFBD (23.30%). Highest energetic factor was calculated for drying chamber (28.22%) followed by homogenizer (16.71%). Based on these analyses, it was realized that performance of the spray drying plant may be substantially improved by some design improvement of drying chamber and homogenizer only.
{"title":"Thermodynamic and exergoeconomic analyses of two-stage spray drying plant for skim milk powder production","authors":"A. Juneja, P. Barnwal, A. K. Sharma, Banashree Naskar, Amit Kumar","doi":"10.1080/07373937.2023.2219736","DOIUrl":"https://doi.org/10.1080/07373937.2023.2219736","url":null,"abstract":"Abstract Spray drying of milk is a highly energy intensive process. In this study, thermodynamic and exergoeconomic analyses of two-stage spray drying plant have been executed. This plant was analyzed on the basis of various parameters such as energy efficiency, exergy efficiency, energy improvement potential, exergy improvement potential, etc. The energy and exergy efficiency of the plant were 72.90 and 35.15%, respectively. The maximum energy improvement potential was for drying whereas maximum exergy improvement potential was for homogenizer. It indicates huge scope in the technical improvement for drying chamber and homogenizer of the plant. The highest cost of processing was for cyclone separator (percentage relative cost difference: 44%) followed by drying chamber (percentage relative cost difference: 40.71%). Highest energy destroyed was calculated for drying chamber (195.83 kJ/kg) followed by VFBD (87.62 kJ/kg). Lowest energy efficiency was calculated for VFBD (34.64%) followed by drying chamber (50.04%). Highest energy improvement potential was estimated for drying chamber (97.86 kJ/kg). Highest relative energy destruction ratio was calculated for drying chamber (52.04%) followed by VFBD (23.30%). Highest energetic factor was calculated for drying chamber (28.22%) followed by homogenizer (16.71%). Based on these analyses, it was realized that performance of the spray drying plant may be substantially improved by some design improvement of drying chamber and homogenizer only.","PeriodicalId":11374,"journal":{"name":"Drying Technology","volume":"41 1","pages":"2105 - 2118"},"PeriodicalIF":3.3,"publicationDate":"2023-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46221836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-01DOI: 10.1080/07373937.2023.2217242
Azza Dabous, S. D’ambrosio, D. Cimini, C. Schiraldi
Abstract This study aimed at evaluating the influence of compatible solutes such as ectoine and hydroxyectoine (HOE), on bacterial cell viability during freeze-drying and storage (at 4 °C and 25 °C), in comparison to the well-established use of trehalose. Three strains, namely Limosilactobacillus fermentum, Levilactobacillus brevis SP-48, and Bifidobacterium lactis HN019 were used as models demonstrating that the highest survival rate during freeze drying was observed for cells protected with HOE. Although trehalose was more effective during lyophilization, interestingly the combination of trehalose and HOE most efficiently preserved long-term cell viability (viability loss < 0.5 log units after 6 months of storage). Finally, the ability of HOE to contribute to strain resistance in simulated gastrointestinal juices was evaluated and the latter protected all the strains tested more efficiently than all the other solutes, in particular the viability was improved from 58%, 87.5%, and 94% when cells were dried with saline solution to 88%, 98.3%, and 98% when lyophilized with HOE for L. fermentum, L. brevis, and B. lactis, respectively. In conclusion, the addition of HOE to trehalose improves the stability of probiotics during storage and enhances the survivability in simulated gastrointestinal tract conditions.
{"title":"Novel hydroxyectoines based formulations are suitable for preserving viability of Limosilactobacillus fermentum, Levilactobacillus brevis SP-48 and Bifidobacterium lactis HN019 during freeze-drying and storage, and in simulated gastrointestinal fluids","authors":"Azza Dabous, S. D’ambrosio, D. Cimini, C. Schiraldi","doi":"10.1080/07373937.2023.2217242","DOIUrl":"https://doi.org/10.1080/07373937.2023.2217242","url":null,"abstract":"Abstract This study aimed at evaluating the influence of compatible solutes such as ectoine and hydroxyectoine (HOE), on bacterial cell viability during freeze-drying and storage (at 4 °C and 25 °C), in comparison to the well-established use of trehalose. Three strains, namely Limosilactobacillus fermentum, Levilactobacillus brevis SP-48, and Bifidobacterium lactis HN019 were used as models demonstrating that the highest survival rate during freeze drying was observed for cells protected with HOE. Although trehalose was more effective during lyophilization, interestingly the combination of trehalose and HOE most efficiently preserved long-term cell viability (viability loss < 0.5 log units after 6 months of storage). Finally, the ability of HOE to contribute to strain resistance in simulated gastrointestinal juices was evaluated and the latter protected all the strains tested more efficiently than all the other solutes, in particular the viability was improved from 58%, 87.5%, and 94% when cells were dried with saline solution to 88%, 98.3%, and 98% when lyophilized with HOE for L. fermentum, L. brevis, and B. lactis, respectively. In conclusion, the addition of HOE to trehalose improves the stability of probiotics during storage and enhances the survivability in simulated gastrointestinal tract conditions.","PeriodicalId":11374,"journal":{"name":"Drying Technology","volume":"41 1","pages":"2062 - 2073"},"PeriodicalIF":3.3,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47965776","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-31DOI: 10.1080/07373937.2023.2212053
Nobusuke Kobayashi, Takumi Ito, H. Ooki, Y. Itaya
{"title":"Acceleration of sludge drying using resin emulsions and estimation of drying acceleration mechanism","authors":"Nobusuke Kobayashi, Takumi Ito, H. Ooki, Y. Itaya","doi":"10.1080/07373937.2023.2212053","DOIUrl":"https://doi.org/10.1080/07373937.2023.2212053","url":null,"abstract":"","PeriodicalId":11374,"journal":{"name":"Drying Technology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47263352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-26DOI: 10.1080/07373937.2023.2216774
J. Frank, Marcus Schlitter, J. Hinrichs, R. Kohlus
{"title":"Fluidized bed drying of dairy gel granules supported by in-line monitoring of the water content","authors":"J. Frank, Marcus Schlitter, J. Hinrichs, R. Kohlus","doi":"10.1080/07373937.2023.2216774","DOIUrl":"https://doi.org/10.1080/07373937.2023.2216774","url":null,"abstract":"","PeriodicalId":11374,"journal":{"name":"Drying Technology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46615180","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-25DOI: 10.1080/07373937.2023.2213767
X. Li, Kaimin Yang, Yuancheng Wang, Xinming Du
Abstract In present article, the soybean packed bed was generated based on the Discrete Element Method, and the distribution of radial porosity and airflow path of the packed bed were analyzed. The porosity distribution of the packed bed is not uniform, and it is larger near the wall. However, it is lower near the central axis, resulting in a larger airflow tortuosity in this area. Based on the thermal non-equilibrium principle, the double-diffusion heat and moisture transfer model of grain pile was developed. The double-diffusion model was verified and validated using experimental data from the relative literature on soybean thin-layer drying, and the mean relative deviation was 1.74–4.47% between the simulated and the experimental results. The model was applied to the drying process of soybean packed bed, and the influence of drying air temperature and inlet air velocity on drying was analyzed. It was shown that the moisture transfer rate of soybean is mainly affected by the drying air temperature and the moisture content of soybean. At constant air temperature of 35 °C, 45 °C, 55 °C, and 65 °C, and drying air relative humidity of 17%, 21%, 25%, and 30%, respectively, the drying rates were 0.086, 0.089, 0.093, and 0.098%(d.b.)/min, respectively (within the first 10 min). The drying with the stepwise temperature makes the drying rate curve abnormal. Compared with the constant temperature drying at 45 °C, when the drying air temperature changes from the initial value of 55 °C and 35 °C to the end value of 40 °C and 65 °C, respectively. It was observed that drying the packed bed moisture content to 14.5%(d.b.) saves time as much as 80, 110, and 130 min.
{"title":"Simulation study on coupled heat and moisture transfer in grain drying process based on discrete element and finite element method","authors":"X. Li, Kaimin Yang, Yuancheng Wang, Xinming Du","doi":"10.1080/07373937.2023.2213767","DOIUrl":"https://doi.org/10.1080/07373937.2023.2213767","url":null,"abstract":"Abstract In present article, the soybean packed bed was generated based on the Discrete Element Method, and the distribution of radial porosity and airflow path of the packed bed were analyzed. The porosity distribution of the packed bed is not uniform, and it is larger near the wall. However, it is lower near the central axis, resulting in a larger airflow tortuosity in this area. Based on the thermal non-equilibrium principle, the double-diffusion heat and moisture transfer model of grain pile was developed. The double-diffusion model was verified and validated using experimental data from the relative literature on soybean thin-layer drying, and the mean relative deviation was 1.74–4.47% between the simulated and the experimental results. The model was applied to the drying process of soybean packed bed, and the influence of drying air temperature and inlet air velocity on drying was analyzed. It was shown that the moisture transfer rate of soybean is mainly affected by the drying air temperature and the moisture content of soybean. At constant air temperature of 35 °C, 45 °C, 55 °C, and 65 °C, and drying air relative humidity of 17%, 21%, 25%, and 30%, respectively, the drying rates were 0.086, 0.089, 0.093, and 0.098%(d.b.)/min, respectively (within the first 10 min). The drying with the stepwise temperature makes the drying rate curve abnormal. Compared with the constant temperature drying at 45 °C, when the drying air temperature changes from the initial value of 55 °C and 35 °C to the end value of 40 °C and 65 °C, respectively. It was observed that drying the packed bed moisture content to 14.5%(d.b.) saves time as much as 80, 110, and 130 min.","PeriodicalId":11374,"journal":{"name":"Drying Technology","volume":"41 1","pages":"2027 - 2041"},"PeriodicalIF":3.3,"publicationDate":"2023-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42150030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-24DOI: 10.1080/07373937.2023.2213317
Rajasekar Krishnamoorthy, Raja Balakrishnan
Abstract The paper presents a detailed experimental investigation on volumetric heat transfer during intermittent spray drying of a 20% w/w of mannitol solution in a custom-made spray dryer. Unlike the conventional intermittent drying process, which achieves intermittency by pulsating the properties of the carrier gas medium, the present works achieve intermittency by pulsating the nozzle spray. The estimated volumetric heat transfer coefficient varies between 0.8 and 2 kW/m3K, and the volumetric mass transfer coefficient is between 0.6 and 2.5 s−1. The correlation for heat and mass transfer coefficients is evolved that relates the heat and mass transfer coefficient with the flow properties and thermophysical properties of both the carrier gas and the precursor fluid in terms of Ohnesorge number and Nusselt number. The investigation uses response surface analysis to analyze the effect of Reynolds number of air and Ohnesorge number of precursors on the volumetric heat transfer coefficient. The results show that a decrease in Reynolds number for a wide range and Ohnesorge number causes the volumetric heat transfer coefficient to increase.
{"title":"Experimental investigation on volumetric heat transfer coefficient during intermittent spray drying of mannitol solution","authors":"Rajasekar Krishnamoorthy, Raja Balakrishnan","doi":"10.1080/07373937.2023.2213317","DOIUrl":"https://doi.org/10.1080/07373937.2023.2213317","url":null,"abstract":"Abstract The paper presents a detailed experimental investigation on volumetric heat transfer during intermittent spray drying of a 20% w/w of mannitol solution in a custom-made spray dryer. Unlike the conventional intermittent drying process, which achieves intermittency by pulsating the properties of the carrier gas medium, the present works achieve intermittency by pulsating the nozzle spray. The estimated volumetric heat transfer coefficient varies between 0.8 and 2 kW/m3K, and the volumetric mass transfer coefficient is between 0.6 and 2.5 s−1. The correlation for heat and mass transfer coefficients is evolved that relates the heat and mass transfer coefficient with the flow properties and thermophysical properties of both the carrier gas and the precursor fluid in terms of Ohnesorge number and Nusselt number. The investigation uses response surface analysis to analyze the effect of Reynolds number of air and Ohnesorge number of precursors on the volumetric heat transfer coefficient. The results show that a decrease in Reynolds number for a wide range and Ohnesorge number causes the volumetric heat transfer coefficient to increase.","PeriodicalId":11374,"journal":{"name":"Drying Technology","volume":"41 1","pages":"2012 - 2026"},"PeriodicalIF":3.3,"publicationDate":"2023-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43522014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-21DOI: 10.1080/07373937.2023.2213314
P. Verlhac, S. Vessot, G. Degobert, G. Agusti, C. Cogné, J. Andrieu, L. Beney, P. Gervais, S. Moundanga
{"title":"Study and optimization of formulation parameters during freeze–drying cycles of model probiotic: Morphology characterization of lyophilisates by scanning electron microscopy","authors":"P. Verlhac, S. Vessot, G. Degobert, G. Agusti, C. Cogné, J. Andrieu, L. Beney, P. Gervais, S. Moundanga","doi":"10.1080/07373937.2023.2213314","DOIUrl":"https://doi.org/10.1080/07373937.2023.2213314","url":null,"abstract":"","PeriodicalId":11374,"journal":{"name":"Drying Technology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46271277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-19DOI: 10.1080/07373937.2023.2213312
Nivedita Wagh, S. Agashe
Abstract The advanced data analytics platform bridges the gap between industrial automation technology and new cloud-based technology. The information on the implementation of a data analytics platform to convert huge data into valuable information and use it to serve the scheduled maintenance of the components involved in the food processing industry is rarely reported in the literature. This work reports a data-driven framework for prediction and fault detection in key performance parameters for a milk spray drying process plant. The framework consists of different data analysis methods and it helps to take decisions about the selection of key performance parameters involved in improving the spray drying thermal efficiency. The neural network-based NARX model demonstrates a better performance than the linear models in the prediction of cyclone exit air temperature which is the key performance parameter in spray drying as it governs thermal efficiency. The performance of the predictive model is validated using RMSE. The ML-based classification methods are also used in the present work to classify the different faults and the decisions regarding the maintenance of the components responsible for the faults. The performance of these models was verified using a confusion matrix. It is proposed that the decision tree classifier and random forest classifier are best suitable for fault finding as their accuracy is highest at 99.83%.
{"title":"Monitoring exhaust air temperature and detecting faults during milk spray drying using data-driven framework","authors":"Nivedita Wagh, S. Agashe","doi":"10.1080/07373937.2023.2213312","DOIUrl":"https://doi.org/10.1080/07373937.2023.2213312","url":null,"abstract":"Abstract The advanced data analytics platform bridges the gap between industrial automation technology and new cloud-based technology. The information on the implementation of a data analytics platform to convert huge data into valuable information and use it to serve the scheduled maintenance of the components involved in the food processing industry is rarely reported in the literature. This work reports a data-driven framework for prediction and fault detection in key performance parameters for a milk spray drying process plant. The framework consists of different data analysis methods and it helps to take decisions about the selection of key performance parameters involved in improving the spray drying thermal efficiency. The neural network-based NARX model demonstrates a better performance than the linear models in the prediction of cyclone exit air temperature which is the key performance parameter in spray drying as it governs thermal efficiency. The performance of the predictive model is validated using RMSE. The ML-based classification methods are also used in the present work to classify the different faults and the decisions regarding the maintenance of the components responsible for the faults. The performance of these models was verified using a confusion matrix. It is proposed that the decision tree classifier and random forest classifier are best suitable for fault finding as their accuracy is highest at 99.83%.","PeriodicalId":11374,"journal":{"name":"Drying Technology","volume":"41 1","pages":"1991 - 2011"},"PeriodicalIF":3.3,"publicationDate":"2023-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45341385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-17DOI: 10.1080/07373937.2023.2213121
S. A. Okaiyeto, Hongwei Xiao, A. Mujumdar
The most cited article in the area of drying is on droplets. The article entitled “Capillary flow as the cause of ring stains from dried liquid drops,” has so far been cited more than 4860 times according to Web of Science. The article explains a fascinating and common phenomenon viz. why a drying droplet, such as a spilled drop of coffee, leaves a circular ring as its residue, rather than a uniform spot. It reveals how suspended solid particles flow, spread and dissipate during the liquid droplet drying process. The solid particles are uniformly distributed in an initial drop, but during drying they concentrate around the edges. Deegan et al. provided the first microscopic level description of this phenomenon, which is known as the “coffee ring effect.” They attributed the ring stains that develop as the droplets dry to capillary flow. According to Ball, the droplet’s lateral dimensions cannot simply decrease due to evaporation if the edge is fixed in situ. To replenish the liquid lost to evaporation while maintaining the contact line for continuity, there must be a net flow toward the edge. This flow carries suspended particles with it. The lack of a thorough theoretical model that can precisely forecast the drying kinetics and deposit structure is one of the main obstacles to understanding droplet drying. However, new developments in microscopy and imaging techniques have enabled researchers to directly examine the drying process and acquire an understanding of the underlying physics and chemistry behind the “coffee ring stains.” For instance, recent research has demonstrated that a droplet’s evaporation rate is influenced by a variety of variables, such as the droplet size, temperature and humidity of the surrounding environment and the characteristics of the surface it is deposited on. Using Controlled Evaporative Selfassembly (CESA) in a confined geometry provides a high degree of control over the drying dynamics and related flows, allowing for the creation of complex deposit patterns with a regularity that has never before been possible. These variables may have an impact on the deposit’s final structure, causing the development of a wide variety of geometric patterns such as coffee rings, spider webs or even larger structures that resemble volcanoes or arches or other geological formations. It is important to be able to manage the deposit structure and morphology since it can be exploited to develop unique structures in certain applications in electronics, optics and energy storage. The surface tension of liquid as well as humidity and temperature of the immediate environment, as well as the makeup of the surface on which the droplet is spilled can all have an impact on the shape, pattern and size of the stain. A stain may spread out more and appear less defined on a porous surface like paper or fabric or it may be more concentrated and have a more recognizable shape on a smooth, non-porous surface like glass or plastic. Due to the loosel
在干燥领域被引用最多的文章是关于液滴的。据Web of Science网站报道，这篇题为《毛细流动是干燥液滴产生环状污渍的原因》的文章迄今为止被引用了4860多次。这篇文章解释了一个有趣而普遍的现象，即为什么一个干燥的液滴，比如洒出来的咖啡，会留下一个圆形的环，而不是一个均匀的斑点。它揭示了悬浮固体颗粒在液滴干燥过程中如何流动、扩散和消散。固体颗粒在初始液滴中均匀分布，但在干燥过程中，它们在边缘周围集中。Deegan等人提供了这种现象的第一个微观层面的描述，被称为“咖啡环效应”。他们将液滴干燥时形成的环状污渍归因于毛细管流动。根据Ball的说法，如果边缘固定在原位，液滴的横向尺寸不会因为蒸发而简单地减小。为了补充蒸发损失的液体，同时保持接触线的连续性，必须有流向边缘的净流量。这种气流携带着悬浮粒子。缺乏能够准确预测液滴干燥动力学和沉积结构的完整理论模型是理解液滴干燥的主要障碍之一。然而，显微镜和成像技术的新发展使研究人员能够直接检查干燥过程，并了解“咖啡环污渍”背后的潜在物理和化学。例如，最近的研究表明，液滴的蒸发速率受到多种变量的影响，例如液滴的大小、周围环境的温度和湿度以及液滴沉积的表面特征。在受限几何结构中使用受控蒸发自组装(CESA)，可以对干燥动力学和相关流动进行高度控制，从而创建复杂的沉积模式，其规律性是前所未有的。这些变量可能对矿床的最终结构产生影响，导致各种几何图案的发展，如咖啡环、蜘蛛网，甚至更大的结构，类似于火山、拱门或其他地质构造。重要的是能够管理沉积层的结构和形态，因为它可以在电子，光学和能量存储的某些应用中开发独特的结构。液体的表面张力以及直接环境的湿度和温度，以及液滴所洒表面的构成都会对污渍的形状、图案和大小产生影响。在像纸或织物这样多孔的表面上，污渍可能会扩散得更多，看起来更不清晰，或者在像玻璃或塑料这样光滑、无孔的表面上，污渍可能会更集中，形状更容易辨认。由于颗粒之间的孔隙结构排列松散，在悬浮滴中流动性较小的椭球状颗粒比球形颗粒延长了空气进入干燥阶段的时间，从而降低了咖啡环污渍的影响。在生物学和生物技术中，液滴干燥已被用于研究细胞和蛋白质的行为。在生物医学应用中，利用生物液体干燥产生的模式来诊断疾病的概念很有趣。通过分析、理解和解释蒸发液滴形成的模式，一种简单而快速的筛查一系列危及生命的疾病的方法可能成为可能。研究人员确实已经在这方面取得了重要进展。咖啡环效应也被用于电子领域，以预定的模式沉积纳米粒子，为印刷电子产品创造导电涂层。利用咖啡环效应，在光学领域开发了高透射低反射的增透膜。与传统涂料相比，利用咖啡环效应制成的防反射涂料具有一定的优势;它们价格低廉，制作简单，可以使用多种材料，如金属、塑料和玻璃器皿。我们相信，对干燥科学技术感兴趣的读者，下次仔细审视自己无意中产生的咖啡污渍时，会反思其复杂性和大自然的创造力。也许他们将以这种方式重新构想各种工业领域的创新干燥应用!
{"title":"Understanding the coffee ring effect: how it has led to advanced applications","authors":"S. A. Okaiyeto, Hongwei Xiao, A. Mujumdar","doi":"10.1080/07373937.2023.2213121","DOIUrl":"https://doi.org/10.1080/07373937.2023.2213121","url":null,"abstract":"The most cited article in the area of drying is on droplets. The article entitled “Capillary flow as the cause of ring stains from dried liquid drops,” has so far been cited more than 4860 times according to Web of Science. The article explains a fascinating and common phenomenon viz. why a drying droplet, such as a spilled drop of coffee, leaves a circular ring as its residue, rather than a uniform spot. It reveals how suspended solid particles flow, spread and dissipate during the liquid droplet drying process. The solid particles are uniformly distributed in an initial drop, but during drying they concentrate around the edges. Deegan et al. provided the first microscopic level description of this phenomenon, which is known as the “coffee ring effect.” They attributed the ring stains that develop as the droplets dry to capillary flow. According to Ball, the droplet’s lateral dimensions cannot simply decrease due to evaporation if the edge is fixed in situ. To replenish the liquid lost to evaporation while maintaining the contact line for continuity, there must be a net flow toward the edge. This flow carries suspended particles with it. The lack of a thorough theoretical model that can precisely forecast the drying kinetics and deposit structure is one of the main obstacles to understanding droplet drying. However, new developments in microscopy and imaging techniques have enabled researchers to directly examine the drying process and acquire an understanding of the underlying physics and chemistry behind the “coffee ring stains.” For instance, recent research has demonstrated that a droplet’s evaporation rate is influenced by a variety of variables, such as the droplet size, temperature and humidity of the surrounding environment and the characteristics of the surface it is deposited on. Using Controlled Evaporative Selfassembly (CESA) in a confined geometry provides a high degree of control over the drying dynamics and related flows, allowing for the creation of complex deposit patterns with a regularity that has never before been possible. These variables may have an impact on the deposit’s final structure, causing the development of a wide variety of geometric patterns such as coffee rings, spider webs or even larger structures that resemble volcanoes or arches or other geological formations. It is important to be able to manage the deposit structure and morphology since it can be exploited to develop unique structures in certain applications in electronics, optics and energy storage. The surface tension of liquid as well as humidity and temperature of the immediate environment, as well as the makeup of the surface on which the droplet is spilled can all have an impact on the shape, pattern and size of the stain. A stain may spread out more and appear less defined on a porous surface like paper or fabric or it may be more concentrated and have a more recognizable shape on a smooth, non-porous surface like glass or plastic. Due to the loosel","PeriodicalId":11374,"journal":{"name":"Drying Technology","volume":"41 1","pages":"1083 - 1084"},"PeriodicalIF":3.3,"publicationDate":"2023-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44595044","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-11DOI: 10.1080/07373937.2023.2209805
M. Dabbour, Asmaa Hamoda, Hafida Wahia, B. Mintah, Garba Betchem, Ronghai He, Haile Ma, M. Fikry
Abstract This study focused on the influence of convection (at 40 °C and 50 °C) and freeze drying on functionality, structural properties and antioxidant potential of sunflower meal protein (SPm) and hydrolysate (SPHm). Likened to the respective convectively-dried isolates, lyophilized SPm and SPHm showed higher dispersibility and water binding efficacy, but lower oil binding efficacy (buttressed by surface hydrophobicity results) (p < 0.05). The alterations in sulfhydryl clusters and disulfide bridges due to convection drying (under varied temperatures) implied limited unfolding of SPm and SPHm structure and reduction in intermolecular interactions. Moreover, fluorescent intensity and deconvoluted Fourier transform infrared (FTIR) spectroscopy illustrated that convectively-dried (CD) preparations, considerably CDSPHm, possessed more flexible/movable secondary structures over freeze-dried isolates. Topographical study indicated that dehydrated SPHm-s had irregular small particles with partly destroyed/splitted micropores, suggesting disruption in the noncovalent bonds between SPHm-s molecules. Furthermore, isolates from the freeze drying process, notably lyophilized hydrolysate, showed higher antioxidative (DPPH scavenging, ABTS and reducing power) potential over the convectively-dried samples, supported by the analysis of amino acids composition. The current investigation could help the pharmacological and/or food industry to develop new therapeutic product and/or functional food from lyophilized isolates.
{"title":"Functional, conformational, topographical, and antioxidative properties of convectively- and freeze-dried sunflower protein and hydrolysate: a comparative investigation","authors":"M. Dabbour, Asmaa Hamoda, Hafida Wahia, B. Mintah, Garba Betchem, Ronghai He, Haile Ma, M. Fikry","doi":"10.1080/07373937.2023.2209805","DOIUrl":"https://doi.org/10.1080/07373937.2023.2209805","url":null,"abstract":"Abstract This study focused on the influence of convection (at 40 °C and 50 °C) and freeze drying on functionality, structural properties and antioxidant potential of sunflower meal protein (SPm) and hydrolysate (SPHm). Likened to the respective convectively-dried isolates, lyophilized SPm and SPHm showed higher dispersibility and water binding efficacy, but lower oil binding efficacy (buttressed by surface hydrophobicity results) (p < 0.05). The alterations in sulfhydryl clusters and disulfide bridges due to convection drying (under varied temperatures) implied limited unfolding of SPm and SPHm structure and reduction in intermolecular interactions. Moreover, fluorescent intensity and deconvoluted Fourier transform infrared (FTIR) spectroscopy illustrated that convectively-dried (CD) preparations, considerably CDSPHm, possessed more flexible/movable secondary structures over freeze-dried isolates. Topographical study indicated that dehydrated SPHm-s had irregular small particles with partly destroyed/splitted micropores, suggesting disruption in the noncovalent bonds between SPHm-s molecules. Furthermore, isolates from the freeze drying process, notably lyophilized hydrolysate, showed higher antioxidative (DPPH scavenging, ABTS and reducing power) potential over the convectively-dried samples, supported by the analysis of amino acids composition. The current investigation could help the pharmacological and/or food industry to develop new therapeutic product and/or functional food from lyophilized isolates.","PeriodicalId":11374,"journal":{"name":"Drying Technology","volume":"41 1","pages":"1962 - 1976"},"PeriodicalIF":3.3,"publicationDate":"2023-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45977178","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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