The First and Second Law Analyses of Thermodynamics of Potato Slices Drying Process

2017 ◽  
Vol 32 (4) ◽  
pp. 7-25
Author(s):  
A.K. Srivastava ◽  
S.K. Shukla ◽  
U.K. Singh
Keyword(s):  
Second Law ◽  
Drying Process ◽  
Potato Slices

The first and second law analyses of thermodynamic of pumpkin drying process

2006 ◽  
Vol 72 (4) ◽  
pp. 320-331 ◽  
Author(s):  
E. Kavak Akpinar ◽  
A. Midilli ◽  
Y. Bicer
Keyword(s):  
Second Law ◽  
Drying Process

Thermodynamic analysis of drying process in a diagonal-batch dryer developed for batch uniformity using potato slices

2016 ◽  
Vol 169 ◽  
pp. 238-249 ◽  
Author(s):  
Waseem Amjad ◽  
Oliver Hensel ◽  
Anjum Munir ◽  
Albert Esper ◽  
Barbara Sturm
Keyword(s):  
Thermodynamic Analysis ◽  
Drying Process ◽  
Potato Slices

scholarly journals ANALISIS EKSERGI PENGERINGAN IRISAN TEMULAWAK

2016 ◽  
Vol 36 (01) ◽  
pp. 96
Author(s):  
Lamhot Parulian Manalu ◽  
Armansyah Halomoan Tambunan
Keyword(s):  
Exergy Analysis ◽  
Second Law Of Thermodynamics ◽  
Exergy Efficiency ◽  
Energy Utilization ◽  
Second Law ◽  
Process Conditions ◽  
Drying Process ◽  
Conservation Of Energy ◽  
Thin Layer Drying ◽  
Curcuma Xanthorrhiza

Java turmeric (Curcuma xanthorrhiza Roxb.) is a medicinal plant used as raw material for making herbal medicine, its rhizome cut into slices and dried so called simplicia. Curcuma has a harvest moisture content is high enough to need a great energy for drying. Generally, the theory used to analyze the energy efficiency is the first law of thermodynamics that describes the principle of conservation of energy. However, this theory has limitations in measuring the loss of energy quality. To determine whether the energy used in the drying process has been used optimally in terms of quality, the second law of thermodynamics -known as exergy analysis- is used. The purpose of this study is to determine the efficiency of the thin layer drying of curcuma slices with exergy analysis. The results show that the process conditions affect the energy utilization ratio and exergy efficiency of drying. Exergy analysis method based on the second law of thermodynamics has been used to determine the amount of exergy destroyed so that the efficiency of the drying process can be determined more accurately. Exergy efficiency varies between 96.5%-100% for temperatures of 50 °C to 70 °C at 40% RH and 82.3% - 100% for 20% to 40% RH at 50 °C.Keywords: Drying, energy, exergy efficiency, curcuma slices ABSTRAKTemulawak (Curcuma xanthorrhiza Roxb.) merupakan tanaman obat yang simplisianya digunakan sebagai bahan baku pembuatan jamu atau obat tradisional. Pengeringan merupakan proses utama dalam memproduksi simplisia. Untuk menganalisis efisiensi energi suatu proses pengeringan umumnya digunakan hukum termodinamika pertama yang menjelaskan tentang prinsip kekekalan energi. Akan tetapi teori ini mempunyai keterbatasan dalam mengukur penurunan kualitas energi. Untuk mengetahui apakah energi yang digunakan pada proses pengeringan sudah digunakan secara optimal dari sisi kualitas, digunakan hukum termodinamika kedua atau yang dikenal dengan analisis eksergi. Tujuan penelitian ini adalah menentukan efisiensi proses pengeringan lapisan tipis irisan temulawak dengan metode analisis energi dan eksergi. Dalam studi ini, metode analisis energi dan eksergi berdasarkan hukum termodinamika pertama dan kedua telah digunakan untuk menghitung rasio penggunaan energi dan besaran eksergi yang musnah (exergy loss). sehingga efisiensi proses pengeringan irisan temulawak dapat ditentukan secara akurat. Hasil penelitian menunjukkan bahwa kondisi proses pengeringan mempengaruhi rasio penggunaan energi dan efisiensi eksergi pengeringan. Semakin tinggi suhu dan RH pengeringan maka rasio penggunaan energi semakin rendah dan efisiensi eksergi semakin tinggi. Efisiensi eksergi pengeringan temulawak bervariasi antara 96,5%-100% untuk selang suhu 50 oC hingga 70 oC pada RH 40% serta 82,3% - 100% untuk selang RH 20% hingga 40% pada suhu 50 oC. Kata kunci: Pengeringan, energi, efisiensi eksergi, temulawak

scholarly journals Estimation of thermophysical propreties of far infrared vacuum drying potato by application of inverse approach

2020 ◽  
pp. 225-225
Author(s):  
Vangelce Mitrevski ◽  
Aleksandar Dedinac ◽  
Cvetanka Mitrevska
Keyword(s):  
Far Infrared ◽  
Moisture Diffusivity ◽  
Vacuum Drying ◽  
Transient Temperature ◽  
Drying Process ◽  
Body Dimension ◽  
Drying Time ◽  
Inverse Approach ◽  
Marquardt Method ◽  
Potato Slices

In this paper the estimation of the moisture diffusivity, together with other thermophysical properties of a far-infrared vacuum dried of potato slices by using an inverse approach were studied. In direct problem a mathematical model of the far-infrared vacuum drying process of shrinking bodies was used. The Levenberg-Marquardt method was used to solve the inverse problem. An analysis of the influence of the vacuum pressure, temperature of heaters, drying body dimension, and drying time, that enables the design of the proper experiments by using the so-called D-optimum criterion was conducted. The estimated values of moisture diffusivity of potato obtained from this study are within the range from 5.14?10-8 to 5.01?10-9 m2 s-1. The experimental transient temperature and moisture content changes during the far infrared vacuum drying were compared with numerical calculated values.

Video real-time imaging of artificial membranes during freeze-drying by cryo-electron microscopy

1988 ◽  
Vol 46 ◽  
pp. 16-17
Author(s):  
Alan S. Rudolph ◽  
Ronald R. Price
Keyword(s):  
Real Time ◽  
Self Assembly ◽  
Freeze Drying ◽  
Video Capture ◽  
Drying Process ◽  
Artificial Membranes ◽  
The Past ◽  
Cryo Electron Microscopy ◽  
Spherical Structures ◽  
Capture Techniques

We have employed cryoelectron microscopy to visualize events that occur during the freeze-drying of artificial membranes by employing real time video capture techniques. Artificial membranes or liposomes which are spherical structures within internal aqueous space are stabilized by water which provides the driving force for spontaneous self-assembly of these structures. Previous assays of damage to these structures which are induced by freeze drying reveal that the two principal deleterious events that occur are 1) fusion of liposomes and 2) leakage of contents trapped within the liposome [1]. In the past the only way to access these events was to examine the liposomes following the dehydration event. This technique allows the event to be monitored in real time as the liposomes destabilize and as water is sublimed at cryo temperatures in the vacuum of the microscope. The method by which liposomes are compromised by freeze-drying are largely unknown. This technique has shown that cryo-protectants such as glycerol and carbohydrates are able to maintain liposomal structure throughout the drying process.

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