scholarly journals Kinetic parameters identification of conductive enhanced hot air drying process of food waste

2020 ◽  
pp. 223-223
Author(s):  
Mihailo Milanovic ◽  
Mirko Komatina ◽  
Ivan Zlatanovic ◽  
Nebojsa Manic ◽  
Dragi Antonijevic
Keyword(s):  
Food Industry ◽  
Convective Drying ◽  
Diffusivity Coefficient ◽  
Drying Method ◽  
Drying Process ◽  
Air Velocity ◽  
Drying Time ◽  
Hot Air ◽  
Air Temperatures ◽  
Drying Curves

The efficient utilization of waste from food industry is possible after thermal treatment of the material. This treatment should be economically feasible and compromise the energy efficient drying process. The main goal of this investigation is to determine drying characteristics of nectarine pomace as a waste from food industry. The measurements were performed in an experimental dryer by combined conductive-convective drying method with disk-shaped samples of 5, 7 and 10mm thickness and 100 mm in diameter at the air temperatures of 30, 40, 50, 60 and 70oC, hot plate temperatures of 50, 60 an 70oC and air velocity of 1.5 m/s. The drying curves were compared to a few semi-theoretical mathematical models. The Logarithmic model showed the best correspondence. On the basis of experiments, it is determined that the drying process takes place in a falling rate period and it is accepted that the main mechanism of moisture removal is diffusion. The effective coefficient of diffusion was determined using experimental results by calculating the slope of the drying curves. Drying time and equilibrium moisture are determined for each experiment. Analysis of drying curves showed that the conductive-enhanced drying method reduces drying times and increases the diffusivity coefficient. The character of drying rate curves for conductive-enhanced drying was analyzed and compared with pure convective drying of nectarine pomace.

scholarly journals Influence of Drying Temperatures on Effective Diffusivity of Custard Apple Pulp

2021 ◽  
Vol 9 (VII) ◽  
pp. 3470-3475
Author(s):  
Narotam Soni
Keyword(s):  
Temperature Increase ◽  
Effective Diffusivity ◽  
Moisture Diffusivity ◽  
Convective Drying ◽  
Drying Method ◽  
Drying Process ◽  
Air Velocity ◽  
Drying Time ◽  
Custard Apple ◽  
Higher Temperature

Fresh custard apple pulp was dehydrated using convective drying method to study the effect of drying temperatures on effective diffusivity of custard apple pulp. Dehydration characteristics of custard apple pulp for the convective drying experiment were studied. Moisture diffusivity (Deff) at 50, 55, 60 and 65° C temperatures was ranged from 3.20 x10-9 m2/s to 4.80 x 10-9 m2/s and activation energy was found 29.436 kJ/mol at air velocity of 2 m/s. The average drying time was decreased 16.67, 10.00 and 22.22 for per 5 °C temperature increase. It was also found that greater drying effect of 22 per cent reduction in drying time was observed for 60 to 65 °C temperature increase. During the drying experiment and data were recorded, it was found that highest drying rate during the drying process was about thrice of the average drying time. It can be deduced from the study that drying process was fast at higher temperature and as the drying temperature increased the effective moisture diffusivity was also increased.

scholarly journals Influence of Different Hot Air Drying Temperatures on Drying Kinetics, Shrinkage, and Colour of Persimmon Slices

Foods ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 101 ◽  
Author(s):  
Senadeera ◽  
Adiletta ◽  
Önal ◽  
Di Matteo ◽  
Russo
Keyword(s):  
Moisture Content ◽  
Quadratic Model ◽  
Drying Process ◽  
Air Velocity ◽  
Hot Air Drying ◽  
Drying Time ◽  
Air Drying ◽  
Drying Characteristics ◽  
Drying Temperature ◽  
Hot Air

Drying characteristics of persimmon, cv. “Rojo Brillante”, slabs were experimentally determined in a hot air convective drier at drying temperatures of 45, 50, 55, 60, and 65 °C at a fixed air velocity of 2.3 m/s. It was observed that the drying temperature affected the drying time, shrinkage, and colour. Four empirical mathematical models namely, Enderson and Pabis, Page, Logarithmic, and Two term, were evaluated in order to deeply understand the drying process (moisture ratio). The Page model described the best representation of the experimental drying data at all investigated temperatures (45, 50, 55, 60, 65 °C). According to the evaluation of the shrinkage models, the Quadratic model provided the best representation of the volumetric shrinkage of persimmons as a function of moisture content. Overall, higher drying temperature (65 °C) improved the colour retention of dried persimmon slabs.

scholarly journals BIOFUELS DRYING PROCESS EFFICIENCY RESEARCH / BIOKURO DŽIOVINIMO PROCESO EFEKTYVUMO TYRIMAI

2013 ◽  
Vol 5 (6) ◽  
pp. 609-614
Author(s):  
Osvaldas Šlepikas ◽  
Audrius Čereška
Keyword(s):  
Positive Impact ◽  
Ultrasonic Transducer ◽  
Process Efficiency ◽  
Convective Drying ◽  
Drying Process ◽  
Wood Pellets ◽  
Drying Time ◽  
Hot Air ◽  
Special Stand ◽  
Experimental Rig

The paper deals with biofuel drying process efficiency opportunities.Research was carried out with a special stand and performingexperiments. Experimental rig consists of an ultrasonic generator,ultrasonic transducer, a drying chamber and the humidity,temperature gauge. Tests were used for wood pellets. During theexperiment, they were irrigated with water, dried with hot air andadditionally exposed to different frequency ultrasonic vibrations.The tests results have showed that the convective drying processis combined with the ultrasonic vibrations, the drying time isreduced, which means a positive impact on the ultrasonic process.Studies have confirmed that the effectiveness of convectivedrying method combined with operating ultrasonic vibrationsincreases. Santrauka Straipsnyje nagrinėjamos biokuro džiovinimo proceso efektyvumo didinimo galimybės. Tyrimams atlikti sukurtas specialus stendas ir sudaryta eksperimento atlikimo metodika. Eksperimentinį stendą sudaro ultragarsinis generatorius, ultragarsinis keitiklis, džiovinimo kamera ir drėgmės, temperatūros matuokliai. Buvo tiriamos medžio granulės. Eksperimento metu jos buvo drėkinamos vandeniu, džiovinamos karštu oru ir papildomai veikiamos skirtingo dažnio ultragarsiniais virpesiais. Atlikus bandymus, rezultatai parodė, kad, veikiant konvekcinio džiovinimo procesą ultragarsiniais virpesiais, džiovinimo laikas sutrumpėja. Tai reiškia teigiamą ultragarso poveikį procesui. Tyrimais patvirtintas konvekcinio džiovinimo metodo efektyvumo, papildomai veikiant ultragarsiniais virpesiais, padidėjimas.

scholarly journals Effect of Temperature at Tray Position on Drying of D.ark Re.d Oni.on-slice.s at Elevated Air Velocity

2020 ◽  
Vol 9 (4) ◽  
pp. 293-296
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Moisture Ratio ◽  
Convective Drying ◽  
Flow Rate Ratio ◽  
Effect Of Temperature ◽  
Drying Process ◽  
Air Velocity ◽  
Drying Time

The convective drying process is used to dry onion-slices. The drying experiments are conducted at a drying temperature of 50oC, 60oC, 70oC, and at an air velocity of 1.99, 3.54, 5.66, and 7.52 m/s. The objective is to study the influence of tray position on drying of dark red onion. The work diverges in analyzing drying constants at air velocity beyond 2 m/s. The moisture ratio for the middle tray is greater compared to the top and bottom tray. A smaller moisture ratio is observed for 60°C compared to 50 and 70°C. Moisture removal per unit mass flow rate ratio is lowest observed for bottom tray with 60°C. The ratio of moisture content and mass flow rate for 60 and 70 °C, displays a downward trend with drying time. The randomness in the drying rate at 60 °C and 70 °C is comparatively lesser than 50 °C.

scholarly journals RESEARCH OF PLUM DRYING PROCESS

2015 ◽  
Vol 3 ◽  
pp. 494-5 ◽  
Author(s):  
Nurlan Kurmanov ◽  
Azret Shingissov ◽  
Gulzhan Kantureyeva ◽  
Zeinep Nurseitova ◽  
Baurzhan Tolysbaev ◽  
...  
Keyword(s):  
Acid Content ◽  
Ascorbic Acid Content ◽  
Drying Method ◽  
Drying Process ◽  
Air Velocity ◽  
Hot Air ◽  
Sensory Parameters ◽  
Air Dryer ◽  
Kinetics Of

In this study, the drying kinetics of a domestic plum cultivar were examined in a laboratory scale hot-air dryer, SHS-80, at an air velocity of 0.65m s-1 and within the air temperature range of 45 – 75 0С. It was found that the whole fruit dried the best. Also, the study  assessed the influence of the drying method on the quality of the domestic plum cultivar. Dried fruits were assessed for sensory parameters and ascorbic acid content. Studies have shown thatthe proposed method of drying, yields a higher absorbic acid content for the dried product  than the conventional approach.

Hot Air Drying Characteristics of Sukkari Date (Phoenix dactylifera L.) and Effects of Drying Condition on Fruit Color and Texture

2015 ◽  
Vol 11 (3) ◽  
pp. 421-434 ◽  
Author(s):  
Alhussein M. Al-Awaadh ◽  
Bakri H. Hassan ◽  
Khaled M. A. Ahmed
Keyword(s):  
Phoenix Dactylifera ◽  
Fruit Color ◽  
Air Velocity ◽  
Hot Air Drying ◽  
Drying Time ◽  
Air Drying ◽  
Drying Temperature ◽  
Hot Air ◽  
Air Temperatures ◽  
Before And After

Abstract Convective hot air drying was used to dry date fruits at different air temperatures and velocities. The kinetics of drying was evaluated by 10 common models. The fruit color and texture were examined before and after drying. Drying time increased as both drying temperature and air velocity decreased. Best fits to the experimental data were provided by the Midilli and Kucuk model, followed by the logarithmic, two-term exponential, and Henderson–Pabis models. Drying affected the fruit color and texture. To minimize such changes, the range of drying temperature and air velocity should be 60–70°C and 2 m/s, respectively.

scholarly journals Improved protocol for natural convection pumpkin drying

2021 ◽  
pp. 29-39
Author(s):  
Hakim Semai ◽  
Amor Bouhdjar ◽  
Aissa Amari
Keyword(s):  
High Temperature ◽  
Effective Diffusivity ◽  
Convective Drying ◽  
Agricultural Product ◽  
Diffusivity Coefficient ◽  
Drying Time ◽  
Thin Layer Drying ◽  
Different Temperatures ◽  
Energy Consuming ◽  
Drying Curves

The most effective way to preserve agricultural product is drying. However, vegetable drying is an energy-consuming procedure. Convective drying is the mode considered in this work. The study intends to explore a new way of pumpkin drying, which reduces drying time and minimizes heat consumption. The study considers pumpkin thin slices and pumpkin samples with cubic shape. The samples were subjected to free convection airflow at different temperatures (40 °C, 46 °C, 52 °C, and 60 °C) for each run. A varying airflow temperature was also considered. Airflow velocity was generated by buoyancy forces for each temperature. Drying curves were plotted and fitted to the widely used thin-layer drying models. The modified Page model came out as the best-fitted model. The effective diffusivity coefficient was determined for each case using the slope moisture curve.  It appeared that diffusivity was high and drying time was short, for high temperature. Drying processes for slice configuration and cube configuration showed that the latter was more efficient. When applying the regime of increasing temperatures to the cubic samples, data analysis showed that effective diffusivity was higher during the third step in comparison to all the other drying temperatures and the total drying time was similar to that obtained at drying regime on high temperature. With this procedure, the final consumed energy was much less and the time was shorter.

scholarly journals Effect of Convective Drying Method of Chokeberry (Aronia melanocarpa L.) on Drying Kinetics, Bioactive Components and Sensory Characteristics of Bread with Chokeberry Powder

2019 ◽  
Author(s):  
Marko Petković ◽  
Igor Đurović ◽  
Nemanja Miletić ◽  
Jovana Radovanović
Keyword(s):  
Cell Structure ◽  
Sensory Characteristics ◽  
Convective Drying ◽  
Drying Method ◽  
Bioactive Components ◽  
Drying Process ◽  
Drying Time ◽  
Dried Fruits ◽  
Aronia Melanocarpa ◽  
Total Anthocyanins

The effects of three dehydration temperatures at 50, 60 and 70 °C of convective drying method on fresh fruits of black chokeberries (Aronia melanocarpa L.) were evaluated. The drying temperatures were found to have significantly different effects on the characteristics of dried fruits and powders, made by the dried fruits. The maximum drying rate at a temperature of 50 °C was 59 g/h, at 60 °C 102 g/h, and at 70 °C 115 g/h, and thus the drying time was 37 hours, 27 hours and 23 hours respectively. The drying temperature at 50 °C caused the least damage to the cell structure of the fresh chokeberries, bioactive components (anthocyanins, flavonoids, phenols) and total antioxidativity. The dehydrated chokeberries at the temperature of 50 °C had the highest ratio of total anthocyanins (376.89 ± 5.73 mg cyn-3-glu / 100 g dm), total flavonoids (1037.19 ± 3.83 mg CE / 100 g dm), phenols (1918.79 ± 3.26 mg GAE / 100 g dm) and antioxidant activity (37.11 ± 0.28 mg TE / 100 g dm). The drying process at a temperature of 50 °C required longer drying period, higher energy need and produced the chokeberry powder, which gave the bread with the best sensory characteristics, compared to a drying process at a temperature of 60 °C and 70 °C.

scholarly journals An improved protocol for natural convective drying of pumpkin

2021 ◽  
Vol 48 (1) ◽  
pp. 29-39
Author(s):  
Hakim Semai ◽  
Amor Bouhdjar ◽  
Aissa Amari
Keyword(s):  
High Temperature ◽  
Effective Diffusivity ◽  
Convective Drying ◽  
Agricultural Product ◽  
Diffusivity Coefficient ◽  
Drying Time ◽  
Thin Layer Drying ◽  
Different Temperatures ◽  
Energy Consuming ◽  
Drying Curves

The most effective way to preserve agricultural product is drying. However, vegetable drying is an energy-consuming procedure. Convective drying is the mode considered in this work. The study intends to explore a new way of pumpkin drying, which reduces drying time and minimizes heat consumption. The study considers pumpkin thin slices and pumpkin samples with cubic shape. The samples were subjected to free convection airflow at different temperatures (40 °C, 46 °C, 52 °C, and 60 °C) for each run. A varying airflow temperature was also considered. Airflow velocity was generated by buoyancy forces for each temperature. Drying curves were plotted and fitted to the widely used thin-layer drying models. The modified Page model came out as the best-fitted model. The effective diffusivity coefficient was determined for each case using the slope moisture curve. It appeared that diffusivity was high and drying time was short, for high temperature. Drying processes for slice configuration and cube configuration showed that the latter was more efficient. When applying the regime of increasing temperatures to the cubic samples, data analysis showed that effective diffusivity was higher during the third step in comparison to all the other drying temperatures and the total drying time was similar to that obtained at drying regime on high temperature. With this procedure, the final consumed energy was much less and the time was shorter.

Experimental Investigation to Evaluate the Effective Moisture Diffusivity and Activation Energy of Cassava (Manihot Esculenta) under Convective Drying

2021 ◽  
Author(s):  
Pathiwat Waramit ◽  
Bundit Krittakom ◽  
Ratinun Luampon
Keyword(s):  
Activation Energy ◽  
Type Equation ◽  
Moisture Diffusivity ◽  
Experimental Results ◽  
Effective Moisture Diffusivity ◽  
Convective Drying ◽  
Air Velocity ◽  
Drying Time ◽  
Hot Air ◽  
Effective Moisture

Investigation of effective moisture diffusivity (Deff) and activation energy (Ea) of cassava were conducted under convective drying at temperature and velocity of 60, 70 and 80 °C, and 1.0, 1.5 and 2.0 m/s, respectively. In the experiment, cassava was sliced into 3 mm-thickness and dried under given conditions until mass was saturated. Deff and Ea were described by Fick’s second law and Arrhenius-type equation, respectively. The experimental results indicated that the increase in Deff was significantly affected by increasing the hot air temperature and velocity. The slope method was used to calculate average Deff, and results were found to range from 3.83 × 10–9 – 9.86 × 10–9 m2/s. The Ea was found to decrease with an increase in hot air velocity, ranging from 21.23– 24.92 kJ/mol. Additionally, Moisture content (Mw) and Drying rate (DR) were also used to describe the drying kinetics. From the experimental results, Mw and DR decreased with an increase in drying time. DR increased with an increase in temperature and velocity causing Mw to rapidly decrease and drying time to reduce. The highest DR was found to be 0.55 gwater/min at temperature of 80 °C and velocity of 2.0 m/s.

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