scholarly journals ON CALCULATION OF DRYING KINETICS OF THERMOLABILE LIQUID DISPERSED PRODUCTS ON SUBSTRATES

2020 ◽  
Vol 63 (3) ◽  
pp. 100-107
Author(s):  
Andrey N. Pakhomov ◽  
Natalia Ts. Gatapova ◽  
Natalia V. Orlova ◽  
Yulia V. Pakhomova
Keyword(s):  
Fractal Dimension ◽  
Moisture Content ◽  
Solid Phase ◽  
Surface Film ◽  
Product Layer ◽  
Fractal Cluster ◽  
Critical Moisture Content ◽  
Critical Moisture ◽  
Horizontal Substrate ◽  
Kinetics Of

For the drying process of a liquid dispersed product layer on a horizontal substrate, a model for the formation of a solid phase particle residue is proposed. The model is based on the construction of a fractal cluster on a bounded spatial lattice according to given rules. The model is constructed on the basis of ideas about the mechanism of interaction of particles during the existence of a layer of free liquid in the drying product. The fractal model, which has the property of self-similarity of the forming structure, allows modeling spatial structures on bounded lattices and spreading the data obtained on bounded lattices to the entire volume of the simulated residue. The article provides a brief overview of the main works related to the application of the fractal concept in the modeling of micro and macroscopic structures arising during the drying of liquid products. It is shown that in order to calculate the kinetics of drying liquid dispersed products on substrates, in the case of the formation of a certain layer of surface film and the formation of a certain spatial structure of solid particles, an important task is to determine the critical moisture content. The proposed model allows modeling layers with fractal dimension lying in the range from 1.64 to 2. This range corresponds to layers in the porosity range from layers with dense monodisperse particle stacking with a coordination number of 12, to structures similar to dendrite fractals, with porosity much higher than the ordered simple cubic particle stacking. The results of fractal cluster modeling and comparison of calculated and experimental values of porosity and critical moisture content obtained in the process of drying a suspension of optical bleach CD-2 and polymethylene-B-naphthalene sulfonate under different modes of convective drying of the product layer on a fluoroplastic horizontal substrate as products characterized by a close value of the initial concentration of the solid phase (≈12%), but different values of particle sizes and the obtained values of the fractal dimension of the surface film and the dry residue are presented.

scholarly journals Study of the forms of moisture bond in coriander seeds based on analysis of drying kinetics

2020 ◽  
Vol 82 (3) ◽  
pp. 24-31
Author(s):  
S. T. Antipov ◽  
D. A. Kazartsev ◽  
A. M. Davydov ◽  
A. B. Emelyanov
Keyword(s):  
Moisture Content ◽  
The State ◽  
Binding Energies ◽  
Drying Kinetics ◽  
Rate Of Change ◽  
Qualitative Assessment ◽  
Laboratory Research ◽  
Critical Moisture Content ◽  
Critical Moisture ◽  
Kinetics Of

The article deals with the issues related to the study of the forms of connection of moisture removed during the drying of coriander seeds. A study was carried out to determine the quantitative moisture content of various forms of communication by two methods and a comparative analysis was carried out. It is shown that the existing methods for studying the forms of moisture-material bond have significant drawbacks and generally give a qualitative assessment of the state of moisture in the material or are very laborious and require lengthy laboratory research. An approach is proposed to determine the forms of moisture bond in coriander seeds based on graph-analytical analysis of the drying kinetics, which makes it possible to qualitatively and quantitatively assess the state of moisture in the seeds. With the help of a graphical editor, the curves of the kinetics of drying of coriander seeds were processed and the dependences of the value characterizing the rate of change in the rate of drying of coriander seeds on the moisture content of the product were obtained, and the introduction of a new concept into the theory of drying of this value as "acceleration of drying" was proposed. The analysis of the obtained curves is carried out, indicating the presence of extrema and points of inflection to the corresponding critical moisture content, as well as the presence of areas with a slowdown or acceleration of the drying rate change, which make it possible to establish the intervals of moisture removal with different binding energies. The approach considered in the article to determine the forms of moisture bond in coriander seeds will allow not only to give a qualitative and quantitative assessment of the state of moisture in products, but also to reduce the time spent on analysis and increase the accuracy of the results.

Study on Critical Moisture Content of Unsaturated Evaporation

2014 ◽  
Vol 513-517 ◽  
pp. 2643-2646
Author(s):  
Hua Zhang ◽  
Wen Long Hu ◽  
Jin Lu Cao
Keyword(s):  
Moisture Content ◽  
Thin Layer ◽  
Measuring System ◽  
Evaporation Process ◽  
Critical Moisture Content ◽  
Whole Process ◽  
Critical Moisture ◽  
Three Stages ◽  
Soil Water Characteristic Curves ◽  
Water Contents

Thin layer evaporation tests of three types of soil were conducted by a newly designed humidity-controllable evaporation and penetration measuring system and lasted for 8 days. The whole process of sample mass variation from wet to dry was recorded in the laboratory. The critical moisture content and air-dried moisture content were obtained from evaporation curve, which divided the evaporation process of thin layer unsaturated soil into three stages, including stable rate stage, reducing rate stage and residual stage. The soil water characteristic curves of soils were predicted by Arya and Paris model, the results showed that the critical moisture contents of evaporation process were the same with the water contents corresponding to residue values of SWCC, it is significant to studying on unsaturated evaporation process.

scholarly journals Isotermas de adsorção de umidade e cinética de secagem de sementes de trevo persa (Trifolium resupinatum L.) e trevo vesiculoso (Trifolium vesiculosum) ¬¬¬¬

2020 ◽  
Vol 28 ◽  
pp. 535-548
Author(s):  
Gabriela Saldanha Soares ◽  
Scarlet Neves Tuchtenhagen ◽  
Luiz Antonio de Almeida Pinto ◽  
Carlos Alberto Severo Felipe
Keyword(s):  
Moisture Content ◽  
Adsorption Isotherms ◽  
Effective Diffusivity ◽  
Drying Kinetics ◽  
Peleg Model ◽  
Critical Moisture ◽  
Persian Clover ◽  
Trifolium Vesiculosum ◽  
Kinetics Of ◽  
Trifolium Resupinatum

The aim of this work was to obtain adsorption isotherms and to study the drying kinetics of persian clover (Trifolium resupinatum L.) and arrowleaf clover (Trifolium vesiculosum) seeds, in addition, fitting the experimental data by the predicted models of the literature. The equilibrium moisture content and the moisture adsorption behavior were found by isotherms curves at 40, 45 and 50 ºC, and the Peleg model was the most suitable. The drying kinetics was determined by thin layer assays in an air parallel flow dryer at all three temperatures. In addition, it was demonstrated the predominance of the falling drying rate period for the two species of seeds, and the critical moisture content values were approximately of 0.20 and 0.25 gwater gdry matter-1 for persian clover and arrowleaf clover seeds, respectively. The effective diffusivity values were estimated in ranges of values of 3.61×10-11 – 6.81×10-11 m² s-1 for persian clover and 6.76×10-11 – 1.15×10-10 m²s-1 for arrowleaf clover seeds and the temperature effect was expressed by an Arrhenius relation. Thus, drying kinetics confirmed the greater difficulty in moisture removal from the arrowleaf clover seeds, compared to the persian clover seeds drying, in agreement with the results obtained through adsorption isotherms.

scholarly journals Radiation-convective conveyor drying of basalt - bentonite cardboard

2019 ◽  
pp. 13-19
Author(s):  
A.V. Timoshchenko ◽  
Ye.V. Timoshchenko ◽  
O.V. Hyliienko ◽  
I.P. Bieliaieva
Keyword(s):  
Energy Efficient ◽  
Dynamic Environment ◽  
Convective Drying ◽  
Critical Moisture Content ◽  
Local Overheating ◽  
Critical Moisture ◽  
Temperature Radiation ◽  
Kinetics Of ◽  
The Heat Balance ◽  
Drying Chamber

The manuscript presents the results of the research of the kinetics of radiation drying of basalt-bentonite cardboard. It has been established that in the case of high-temperature radiation drying of cardboard, the value of the reduced first critical moisture content in the area with low values – 0.17 is observed; compared to the same indicator for convective drying of slabs 50 and 100 mm thick - 0.41 and 0.20, respectively. This feature of the process allows you to raise the temperature in the first drying chamber to 570-600°C without fear of local overheating of the material. It was noted that at the stage of the falling drying speed, which is largely implemented in the second drying chamber, in order to avoid local overheating of the material, the temperature in the chamber is limited to 440°C. The decrease in the temperature level of the process in the second drying chamber is compensated for by the active gas-dynamic environment, in which the average speed of the drying agent in the inlet action zone can reach values of ± 5 m/s. The results of the controlled operation of the pilot conveyor drying installation are given. Its satisfactory specific energy indicators are noted, which for the same type of installations can reach values of 1200-2000 kcal/kg of moisture. In conclusion, it is noted that, in addition to the traditional positions of the heat balance of the plant, an energy-efficient modernization of a conveyor drying plant should include reducing losses with a spent drying agent, with recuperative losses through walling structures, with unorganized gas exchange in the drying chamber, and such positions as efficient drying agent with the optimization of its gas dynamics in the drying chamber.

scholarly journals Impact of fast and slow desiccation on Garcinia imberti seed and seedling vigour

2018 ◽  
Vol 5 (3) ◽  
pp. 95-102
Author(s):  
M Anto ◽  
C Anilkumar
Keyword(s):  
Moisture Content ◽  
Initial Moisture Content ◽  
Germplasm Conservation ◽  
Seedling Vigour ◽  
Critical Moisture Content ◽  
Normal Seedling ◽  
Southern Western Ghats ◽  
Mean Germination Time ◽  
Critical Moisture ◽  
Activated Silica Gel

Garcinia imberti Bourd. endemic to the southern Western Ghats is classified as endangered by the IUCN (2018). The seeds as the sole means of propagation with initial moisture content (MC) of 62.8% are sensitive to desiccation. Studies on the responses of the seed to drying require ascertaining of the critical moisture content (CMC) as a basic requisite for germplasm conservation. Responses of G. imberti seeds to fast drying with activated silica gel (25 ± 2 °C, 6 ± 1% RH) and to slow drying under laboratory conditions (28 ± 2°C, 60 ± 2% RH) were evaluated for seed and seedling vigour. When the MC was reduced to 56% by 48 hours of slow drying or 6 hours of fast drying, 75 to 90% normal seedlings were produced respectively. In the case of fast dried seed (6 hours), seed associated parameters except mean germination time showed peak values with maximum germination and enhanced root length. Below the CMCs of 16.4 and 26.3% (fast and slow drying respectively), half of the tested seeds become non viable. Thus for germplasm conservation the present study proposes 6 hour’s of fast drying to retain viability and normal seedling development of G. imberti.

scholarly journals Testing methods of moisture content, critical moisture content, and germination of jamblang (Syzygium cumini (L.) Skeels) seed

2019 ◽  
Vol 8 (1) ◽  
pp. 47
Author(s):  
Miraz Nur Indraeni ◽  
Faiza Chairani Suwarno ◽  
Abdul - Qadir
Keyword(s):  
Seed Germination ◽  
Moisture Content ◽  
Seed Quality ◽  
Block Design ◽  
Syzygium Cumini ◽  
Critical Moisture Content ◽  
Testing Method ◽  
Randomized Complete Block Design ◽  
Final Count ◽  
Critical Moisture

Jamblang (Syzygium cumini (L.) Skeels) researches are still focused to identify the plant benefits, but that leads to efforts to obtain good seed quality hasn’t been done. This study aims to determine the moisture content testing method, the critical moisture content, and germination testing method (sowing media and first and final count of seed germination). Improving procedure for moisture content testing and identified the best media for germination testing was arranged in a Completely Random Design.  Determining jamblang seeds critical moisture content was arranged in a Randomized Complete Block Design. The experiments were repeated four times. Moisture content with slicing method obtained 49.57%. Jamblang seeds critical water content is 41.61% with 50% germination. The best method of germination was sand medium with fresh seeds (90%). The first count of jamblang seed germination occurs on 32 days after sowing and final count on 83 days after sowing.

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