scholarly journals SIMULATION OF RECIRCULATION TYPE DRYER USING PNEUMATIC CONVEYORS

2021 ◽  
Vol 56 (4) ◽  
pp. 385-393
Author(s):  
Totok Prasetyo ◽  
Dwiana Hendrawati ◽  
Anis Roihatin ◽  
Bayu Rudiyanto

Recirculating rice dryers are suitable for a large amount of loading capacity. It generally comprises two parts, the tempering section, a drying section, and the grains are dried intermittently until the final moisture content of the grains can be achieved. Wet grains are initially dried for about 11 minutes within the drying section of the dryer. The grains then are conveyed to the tempering section, stored for about 40 to 50 minutes. At every passes, about less than 2% (wb). The moisture content can be removed from the grains. The number of passes required to accomplish a drying process in a recirculation dryer depends on the initial moisture content and the amount of rough rice to be dried. The drying and tempering duration can be adjusted through a mechanical valve. The purpose of this study was to examine the performance of recirculating dryers equipped with pneumatic conveyors instead of bucket elevators to reduce electricity cost and heated using a proper blend between kerosene and jatropha oil. Several experimental runs were conducted under a constant drying temperature of 60℃ and were controlled by adjusting the fuel consumption rate. The experimental results showed that the drying efficiency was in the range of 22.2% to 31.1%, the specific energy consumption was between 3,475-4,785 MJ/kg H2O evaporated, fuel consumption at 0.95 to 1.15 liters/hr, and the drying rate was 0.9% per day. Using 465 kg of rough rice, the entire drying operation required 10 hours of drying time with 74.3% of head yield. The mathematical model used in this study also had indicated close agreement with experimental data.

2011 ◽  
Vol 194-196 ◽  
pp. 1442-1448
Author(s):  
Jian Jun Hu ◽  
Quan Guo Zhang ◽  
Hao Huang

The constant temperature drying experiment on wheat straw at different initial moisture content and drying temperature were made with comprehensive thermal analyzer. The impact of initial moisture content, drying temperature and drying time on wheat straw procedure were reviewed, and the optimum drying result of wheat straw were gotten when initial moisture content was 32.5% and drying temperature was 100°C .The process of wheat straw drying was divided into three sections about preheating, constant temperature and falling rate drying. Regression equations on different sections were established by regression analysis, the result show that parabolic equation in preheating section, linear equation in constant rate drying section and power curve in falling rate drying section. Experiment data and reference frame from conclusion above were useful to crop straw drying technology.


Agrotek ◽  
2018 ◽  
Vol 2 (6) ◽  
Author(s):  
Wilson Palelingan Aman

<em>A research about cocoa beans drying used solar tunnel dryer with photovoltaic module driven have conducted in Manokwari. Solar tunnel dryer used in this research adapted from type Hohenheim with photovoltaic module and integrated air heat collector has been installed at the Department of Agricultural Technology, Papua State University Manokwari to dried cocoa beans. The objectives of this research were to design solar tunnel dryer and evaluate it�s performance in dryed cocoa beans. The result obtained was a new construction of solar tunnel dryer for cocoa beans with dimensions 6 m of length and 0,9 m of wide. The dryer completed with photovoltaic module to drive the blowers of hot drying air. �Performance test of the dryer showed that drying of 10 kg of cocoa beans with initial moisture content about 70% wet basis needed 13 hours of drying time to achieved final moisture content about 7,17% wet basis. The drying time achieved was faster compared than traditional solar drying that needed 20 hours of drying time. The maximum temperature achieved in drying chamber was 60 <sup>o</sup>C.</em>


Horticulturae ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 40
Author(s):  
Vincenzo Alfeo ◽  
Diego Planeta ◽  
Salvatore Velotto ◽  
Rosa Palmeri ◽  
Aldo Todaro

Solar drying and convective oven drying of cherry tomatoes (Solanum lycopersicum) were compared. The changes in the chemical parameters of tomatoes and principal drying parameters were recorded during the drying process. Drying curves were fitted to several mathematical models, and the effects of air temperature during drying were evaluated by multiple regression analyses, comparing to previously reported models. Models for drying conditions indicated a final water content of 30% (semidry products) and 15% (dry products) was achieved, comparing sun-drying and convective oven drying at three different temperatures. After 26–28 h of sun drying, the tomato tissue had reached a moisture content of 15%. However, less drying time, about 10–11 h, was needed when starting with an initial moisture content of 92%. The tomato tissue had high ORAC and polyphenol content values after convective oven drying at 60 °C. The dried tomato samples had a satisfactory taste, color and antioxidant values.


2018 ◽  
Vol 3 (2) ◽  
pp. 351-360
Author(s):  
Athul Fadhli ◽  
Diswandi Nurba ◽  
Raida Agustina

Abstrak. Jagung merupakan tanaman penghasil karbohidrat terpenting. Pengeringan jagung pipil menggunakan alat pengering merupakan proses untuk menghasilkan jagung pipil yang siap diolah untuk pembuatan tepung jagung dengan batas kadar air tertentu sehingga menghaslkan jagung pipil dengan kualitas yang baik. Tujuan penelitian ini adalah untuk mengkaji karakteristik pengeringan biji jagung menggunakan alat pengering surya Termodifikasi. Metode penelitian  menggunakan 3,15 kilogram jagung pipil dengan kadar air awal 22% untuk proses pengeringan. Parameter yang dianalisis terkait alat pengering kolektor surya yaitu temperatur, kelembaban relatif, kecepatan udara dan iradiasi surya, sedangkan parameter yang dianalisis terkait bahan yaitu kadar air, lama waktu pengeringan, laju pengeringan dan organoleptik. Prosedur penelitian terdiri dari pengujian kosong dan pengujian dengan menggunakan jagung pipil. Hasil penelitian menunjukkan bahwa temperatur rata-rata dalam rak pengering sebelum dilakukan modifikasi yaitu 44,4oC, temperatur rata-rata setelah dilakukan modifikasi yaitu 55,5oC dan temperatur rata-rata rak pengering pada pengeringan menggunakan jagung pipil yaitu 46,96oC. Kelembaban relatif rata-rata dalam rak pengering sebelum dilakukan modifikasi yaitu 40,1%, kelembaban relatif rata-rata dalam rak pengering setelah modifikasi yaitu 35,1% dan kelembaban relatif rata-rata pengeringan menggunakan jagung pipil yaitu 44,45%. Dari hasil pengukuran tersebut menunjukkan bahwa nilai temperatur dan kelembaban pada alat setelah modifikasi lebih baik dibandingkan sebelum alat dimodifikasi. Pengukuran temperatur dan kelembaban relatif terdiri dari 4 titik pengukuran yaitu rak 1A,1B dan rak 2A, 2B. Kecepatan udara rata-rata yang diukur konstan yaitu 0,7 m/s pada ruang pengering, sedangkan lingkungan 1,1 m/s. Total iradiasi surya selama pengeringan yaitu 1848,84 W/m2. Kadar air jagung pipil masing-masing rak yaitu rak 1A 14,29%, rak 1B 14,47%, rak 2A 13,91% dan rak 2B 14,1%. Hasil dari pengujian organoleptik, panelis agak menyukai jagung pipil yang dikeringkan menggunakan alat pengering tersebut.Characteristics of Seed Drying (Zea mays L.) Using a Modified Adriyarkara Solar DryerAbstract. Corn is the most important carbohydrate plant. Drying corn using a drying tool is a process to produce corn that are ready to be processed for making corn flour with a certain water content limit so as to produce corn with good quality. The purpose of this study was to examine the characteristics of drying of corn kernels using a modified solar dryer. The research method used 3,15 kilogram of corn milled with the initial moisture content of 22% for drying process. The parameters analyzed in relation to solar collector dryers are temperature, relative humidity, air velocity and solar irradiation, while the parameters analyzed are materials such as moisture content, drying time, drying rate and organoleptic. The research procedure consists of unloaded testing and testing using corn. The results showed that the average temperature in the dryer tray before modification was 44,4°C, the average temperature after modification was 55,5°C and the average temperature of the dryer tray on drying using corn was 46,96oC. The average relative humidity in the dryer tray before modification is 40,1%, the average relative humidity in the dryer tray after modification is 35,1% and the average relative humidity of drying using corn is 44,45%. From the measurement results show that the value of temperature and humidity in the tool after modification is better than before. Measurement of temperature and relative humidity consist of 4 point of measurement that is tray 1A, 1B and tray 2A, 2B. Average mean air velocity measured is 0,7 m/s at the dryer room, while the environment is 1,1 m/s. Total solar irradiation during drying is 1848,84 W/m2. Moisture level of corn each shelves tray 1A is 14,29%, tray 1B is 14.47%, tray 2A is 13,91% and tray 2B is 14,1%. As a result of organoleptic testing, panelists rather like dried corn using the dryer.


Processes ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 2277
Author(s):  
Karn Chitsuthipakorn ◽  
Sa-nguansak Thanapornpoonpong

A scaled-up process for paddy drying was developed using hot air (HA) combined with radio frequency (RF) heating. The study was conducted using hot air (control treatment) arranged in descending order in four temperature levels, namely 80 °C at moisture content of 25–26%, 70 °C at moisture content of 20–25%, 60 °C at moisture content of 17–20%, and 50 °C at moisture content of 13–17%, as well as with hot air combined with radio frequency (HA/RF) at different paddy temperatures (45–60 °C) by adjusting the appropriate RF energy when passing through RF heating chamber, namely HA/RF45, HA/RF50, HA/RF55, and HA/RF60. Each treatment was performed in three replicates and data were statistically analyzed in a randomized complete block design. The quality attributes of paddies affected by the drying process were assessed: fissure percentage, color, milling quality, and sensory evaluation. The drying efficiency showed that the drying time and the specific energy consumption could be decreased by up to 54.44% and 23.17% at HA/RF60 and HA/RF45, respectively. As the RF heating temperature increased, the fissure percentage of brown rice kernels at HA/RF45 and HA was not significantly impacted. Regarding color evaluation, combining RF heating and convective drying at all given conditions could be statistically applied in terms of the b*, WI, and ΔE* value. Considering the milling yield of HA as the baseline, head rice yield was maximized at HA/RF45, while bran yield reached the maximum at HA/RF60. The liking score of cooked rice after it was dried using the HA method was the highest. This study concludes that the HA/RF45 was the most appropriate drying condition, and this may provide preliminary exposure to the industrial drying of paddies.


Author(s):  
A. Narmilan ◽  
G. Niroash ◽  
M.I.M. Mowjood ◽  
A.T.A. Akram

Background: Sun drying is a popular post-harvest operation to maintain rice quality during the storage period. Farmers use different pads and thicknesses for sun drying of paddy in Ampara district, Sri Lanka. A study was conducted to evaluate the suitability and effectiveness of the drying pad and thickness as practiced by local paddy farmers during the sun drying process.Methods: The grain with an initial moisture content of 28% (dry basis) was sun dried with four types of drying pads and five levels of thickness of grain. This experiment was conducted between 8.30 am and 4.30 pm at the South Eastern University of Sri Lanka in August 2020. The moisture contents of the grain were measured at regular time intervals.Result: It was found that the duration of drying of paddy from 28% to 13% moisture content on a dry basis was 300 to 540 minutes depending upon the drying pad and thickness. The tarpaulin is reasonable at shallow thickness with less time to reach the necessary moisture level than other drying pads. Black polythene and fertilizer bag can be utilized for sun drying of paddy at 4 cm thickness with 130 minutes. It was found that with an increase in the thickness of paddy from 0.5 cm to 4 cm, the drying time increases. A statistically significant interaction was obtained between drying pads and thickness level on moisture removal of paddy. Therefore, the moisture removal rate differs with the drying pad and thickness of the paddy under open sun drying.


2020 ◽  
Vol 50 (1) ◽  
pp. 79-86
Author(s):  
Elena Verboloz ◽  
Marina Ivanova ◽  
Vera Demchenko ◽  
Sergey Fartukov ◽  
Nikita Evona

Introduction. Rose hips are rich in macro- and micronutrients. Unfortunately, heat treatment destroys most nutrients. Ultrasonic technologies make it possible to reduce the drying time and lower the temperature regime. The research objective was to adjust ultrasound technology to rose hip production in order to reduce the loss of vitamins and improve the quality indicators of the dried product. Study objects and methods. The research featured rose hips of the Rosa canina species collected in the south of Kazakhstan. This subspecies of wild rose is poor in vitamin C. Nevertheless, this shrub is extremely common in Russia and other countries of the Commonwealth of Independent States. The raw material was dried according to standard methods. One group of samples was treated with ultrasound, while the other served as control. Both groups underwent a sensory evaluation and were tested for moisture and vitamin C. Results and discussion. The rose hips were dried in a combination steam oven with a built-in ultrasonic wave generator. The research revealed the following optimal parameters of the ultrasound drying process: frequency of ultrasonic vibrations – 22 kHz, processing time – 2.5 h, temperature in the combination steam oven – +56°C, initial moisture content – 30%. The resulting product met the requirements of State Standard. The loss of moisture was 57%. According to State Standard 1994-93, the initial moisture content should be 15% or less. Time decreased from 360 min to 160 min, and the initial moisture was 13%. The experiment confirmed the initial hypothesis that ultrasonic treatment improves the drying process by improving quality indicators and preserving vitamin C in raw materials using. Conclusion. Ultrasound treatment during moisture removal from rose hips provides a resource-saving technology that fulfills an economically and socially important function.


Author(s):  
Geraldo A. Mabasso ◽  
Valdiney C. Siqueira ◽  
Wellytton D. Quequeto ◽  
Rodrigo A. Jordan ◽  
Elton A. S. Martins ◽  
...  

ABSTRACT Grain drying is a common process, due to its need for the maintenance of quality, but it is the activity with the highest energy demand among the postharvest stages. Thus, this study aimed to evaluate the effect of different tempering times on the energy efficiency of drying process and maintenance of cell membrane integrity of maize grains harvested with moisture content at 0.34 ± 0.01 d.b. The grains were dried in an experimental fixed-bed dryer with control of temperature and air flow conditions. The experiment was conducted in a completely randomized design with five tempering times (0, 4, 8, 12 and 16 hours) and four repetitions, where zero corresponds to continuous drying, while the remaining times correspond to the intermittent dryings. The grains were dried at the temperature of 100 ºC and air flow of 15.4 m3 min-1 t-1 until reaching moisture content of 0.16 ± 0.03 d.b. For intermittent drying, the process was interrupted with 0.22 ± 0.02 d.b. and restarted after the tempering time. The increase of tempering time led to reductions in effective drying time, specific energy consumption, electrical conductivity and damage and increase in the drying rate and overall energy efficiency. Intermittent drying reduced the drying time, being 30.25% more efficient than continuous drying.


2020 ◽  
Vol 154 ◽  
pp. 01004
Author(s):  
Ewa Golisz ◽  
Małgorzata Jaros ◽  
Szymon Głowacki

The goal of the work was to propose and verify the model of temperature changes of the convective dried biomass depending on the drying time. The algebraic temperature model of the convective dried solid, giving the possibility of its direct calculation, was based on the logistic function of growth. Temperature model was verified for convective dried biomass: vegetable and wood (poplar and willow wood chips) significantly differing in initial moisture content. Parameter W in the temperature model, defined as the coefficient of temperature rate changes reaches greater values in higher temperature of drying air and for wood biomass which has lower initial moisture content. Empirically selected parameter W allows to verify the temperature model with the relative error less than 5%.


Agrotek ◽  
2018 ◽  
Vol 2 (4) ◽  
Author(s):  
Wilson Palelingan Aman

Drying process is one of important stage in handling of agricultural products. However, this process required much energy to remove moisture from the product. Because of that, it was needed a dryer to remove water from inside of products. A dryer with solar energy as a heat source combined with heat energy from corncob biomass was designed and used in corn dried. The dryer is usually known as green house effect-hybrid (GHE-hybrid). GHE-hybrid consists of absorber, product holder, fans to remove moisture from dried product, heat exchanger, stove and water tank. The heat source used in dryer comes from solar radiation and biomass burned in stove. The objective of this research was to evaluate performance of dryer use solar energy and corncob as heating sources. Results of this research showed that drying process of 1526 kg of corn with initial moisture content 25.7% wet basic until 16.7% wet basic needed drying time of 14 hours. The corncobs that were needed to remove the moisture was about 180 kg. The energy calculated in this drying process from corncob, diesel fuel, solar radiation which were about 3150 MJ or 62%, 1739.71MJ or 34%, 204.94 MJ or 4%, respectively. The research also found that the thermal eficiency of dryer was 28%, eficiency of drying heat was 59.62%, total eficiency was 11.23% and specific energy consumption was 31522,52 kJ/kg.


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