scholarly journals Studies of the Combined Modes of Microwave Grain Drying

2018 ◽  
Vol 12 (6) ◽  
pp. 25-30
Author(s):  
Sergey A. Pavlov ◽  
Igor A. Pekhalsky ◽  
Nikolay G. Nikolay G. Kynev
Keyword(s):  
Moisture Content ◽  
Microwave Pulse ◽  
Raw Materials ◽  
Removal Rate ◽  
Pause Duration ◽  
Microwave Drying ◽  
Flow Density ◽  
Moisture Removal ◽  
Moisture Movement ◽  
Vegetable Raw Materials

Abstract. To ensure the high quality of the materials being dried, one of the most promising ways to dehydrate vegetable raw materials is drying under the action of electromagnetic radiation (microwave drying). Microwave drying is widely used in various industries, in particular, in the food and woodworking industries. (Research purpose) Calculation of the microwave pulse and pause duration; their experimental determination, as well as the determination of the moisture removal rate at the pulse moment and the depth of pulse penetration into the layer. (Materials and methods) When drying in a microwave field, the gradient of moisture content in the material prevents the moisture movement towards the surface, internal cracks can be formed as well. Therefore, the combined methods of drying can yield the best results. The pulse duration has been calculated by the permissible increment of the grain temperature, the pause duration has been determined by assuming that during the pulse, moisture from the caryopsis kernel is pushed out and cooled under isothermal conditions by an air flow. (Results and discussion) It has been confirmed that at a microwave pulse energy duration of 4, 6, and 10 s, the speed of blow-off and blowdown of the layer with external air was 0.5 m per second. When grain is cooled by natural convection, the pulse time is 10 s, the pause time is 1, 2, 3, and 5 min. For the blow-off mode, the pulse exposure time was 6 and 10 s, that of blow-off - 0.5, 1.0, and 1.5 minutes. The maximum duration of the microwave pulse was determined by the flow density of allowable grain heating and the fraction of heat required for the evaporation of moisture when heated to 20-25 degrees. (Conclusions) The pause duration is determined by the grain cooling time to the temperature preceding the pulse. It has been experimentally established that the calculated values of the pulse and pause duration with an accuracy of 15 percent for grain with a moisture content of 20-24 percent at a microwave flow density of 0.7 kilowatts per square meter, at a depth of the microwave energy penetration into the grain by 70 percent, do not exceed 20-22 mm, and the moisture removal rate is 0.1-0.15 percent.

Investigation on drying characteristics of high titanium slag using microwave heating

2017 ◽  
Vol 6 (1) ◽  
Author(s):  
Xuefeng Liao ◽  
Guo Chen ◽  
Qianqian Liu ◽  
Jin Chen ◽  
Jinhui Peng
Keyword(s):  
Moisture Content ◽  
Microwave Heating ◽  
Raw Materials ◽  
Adsorbed Water ◽  
Scientific Basis ◽  
Microwave Drying ◽  
Optimum Conditions ◽  
Drying Time ◽  
Titanium Slag ◽  
Selective Heating

AbstractIn the present study, the moisture of high titanium slag was chosen as the research object. Taking advantage of selective heating of microwave and the specific inductive capacity of water, the drying experiment of high titanium slag using microwave heating have been carried out. The results revealed that the presence of moisture in the form of high titanium slag was adsorbed water, and the wet sample possesses excellent wave-adsorbing performance; the bed depth preferred was no larger than 10 mm, with moisture content at around 3%. The microwave drying process was divided into two stages: the constant-stage and the deceleration-stage. The optimum conditions were identified to be microwave power of 700 W, sample mass of 200 g, bed depth of 10 mm and drying time of 50 s. The dehydration extent can reach 90% and moisture content remains at 0.3% under the optimum conditions. The demonstration of microwave drying techniques can be applied effectively and efficiently into the treatment processing of drying of the raw materials of metallurgy and chemical industry with the theoretical and scientific basis.

scholarly journals Effect of Pads and Thickness of Paddy on Moisture Removal under Sun Drying

2021 ◽  
Author(s):  
A. Narmilan ◽  
G. Niroash ◽  
M.I.M. Mowjood ◽  
A.T.A. Akram
Keyword(s):  
Sri Lanka ◽  
Moisture Content ◽  
Removal Rate ◽  
Initial Moisture Content ◽  
Storage Period ◽  
Moisture Removal ◽  
Drying Time ◽  
Sun Drying ◽  
Regular Time ◽  
Paddy Farmers

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.

Feasibility Tests for a Two-Stage Batch Dryer for Curing Farmer Stock Peanuts1

1999 ◽  
Vol 26 (2) ◽  
pp. 68-73 ◽  
Author(s):  
C. L. Butts ◽  
M. S. Omary
Keyword(s):  
Seed Germination ◽  
Moisture Content ◽  
Removal Rate ◽  
Initial Moisture Content ◽  
Moisture Removal ◽  
Two Stage ◽  
Drying Time ◽  
Milling Quality ◽  
System A ◽  
Support Price

Abstract A two-stage batch dryer for farmer stock peanut was developed by a commercial grain dryer manufacturer and tested at a commercial peanut buying point during the 1996 and 1997 harvests. A 7.3-m diameter grain bin provided the superstructure for two peanut curing chambers. Each chamber had an approximate capacity of 18,000 kg of in-shell peanuts. Comparisons between conventional peanut curing wagons and the bin dryer were conducted. Recorded data included temperature and relative humidity in both type dryers, drying time, moisture content throughout curing, farmers stock grades, milling quality, and seed germination. A total of 451,717 kg were cured in the two-stage dryer and 215,460 kg in conventional dryers. The initial moisture content of peanuts averaged 19% wet basis and dried at an average moisture removal rate of 0.45%/hr. The moisture removal rates for the two dryers were not significantly different. The final moisture content averaged 11%. Moisture content at the time of grading averaged 9%. Farmers stock grades and milling quality were not significantly different. The average quota support price, including LSK for peanuts cured in conventional dryers, was $630.47/1000 kg compared to $636.08/1000-kg peanuts cured in the two-stage dryer. Seed germination averaged 75.8 and 76.1% for conventional and bin-dried peanuts, respectively. The twostage batch dryer was comparable to the current wagon-drying system. A single batch in the two-stage dryer was equivalent to three peanut wagons.

scholarly journals Profil Suhu dan Kadar Air Kayu dalam Pengeringan Oven Pemanas dan Gelombang Mikro (Temperature and Moisture Content Profiles of Woods in Heating and Microwave Ovens Drying)

2021 ◽  
Vol 17 (2) ◽  
pp. 160-171
Author(s):  
Trisna Priadi ◽  
Gunes T W Giyarto
Keyword(s):  
Moisture Content ◽  
Microwave Oven ◽  
Microwave Drying ◽  
Temperature Profiles ◽  
Moisture Profile ◽  
Moisture Movement ◽  
Oven Drying ◽  
Pinus Oocarpa ◽  
Moisture Profiles ◽  
Made In

This research aimed to evaluate the profile of temperature and moisture content in Pinus oocarpa wood being dried with heating oven and microwave oven.  The size of samples were (25x70x120) mm3.  The temperature profiles in heating oven and microwave oven drying were taken every 10 minutes and 0.5 minutes, respectively. The moisture profiles in heating oven and microwave oven drying were made in every 24 hours and 10 minutes, respectively.  The heating oven was set at 60 °C, while microwave oven was set for 2 minutes intermittently with 5 minutes break.  In microwave drying, the temperature inside the boards increased faster and higher compared to that in the heating oven, which resulted in a faster moisture movement to the board’s surface.  The drying rate of pine increased 48-72 times in microwave compared to that in heating oven.  The moisture content in the centre of boards being dried in heating oven was much higher than that of in the outer parts.  On the other hand, the moisture profile in the woods being dried in microwave oven distributed more evenly.

scholarly journals Extrusion technologies of feed and food including biomass of insects (review)

2020 ◽  
Vol 21 (3) ◽  
pp. 233-244
Author(s):  
V. I. Pakhomov ◽  
S. V. Braginets ◽  
O. N. Bakhchevnikov ◽  
A. S. Alferov ◽  
D. V. Rudoy
Keyword(s):  
Moisture Content ◽  
Water Absorption ◽  
Water Solubility ◽  
Raw Materials ◽  
Absorption Index ◽  
Raw Material ◽  
Content Increase ◽  
Value Of Water ◽  
Vegetable Raw Materials ◽  
Insect Biomass

The review deals with the problems of extrusion of feed and food including biomass of insects. Inclusion of insects into the composition of feed and food increases their nutritional value through enrichment with protein and fat. Extrusion of the flour from ground and dried insects blended with vegetable raw material, generally presented by grinded grain, is most commonly used. However, the blend of crude larvae of insects and grinded vegetable raw materials can be also successfully extruded. Specific regularities of processes of insect biomass and vegetable raw material extrusion have been developed. It has been established, that with increase in insect content in the extrudate, its color becomes darker, the surface less smooth, the structure more layered. The hardness declines, the value of water absorption index decreases, the value of water solubility index and its moisture content increase. Variation in the rate of raw material feed into the extruder allows to change the properties of a finished extrudate. As the value of raw materials feed increases, the water absorption index of the extrudate and its moisture content decrease, but the water solubility index increases. Rational parameters of the extrusion process general for all blends of vegetable raw materials and insect biomass as well as the nature of their influence on properties of finished extrudate have not been determined yet. The problem of extrusion raw materials for the production of feed and food containing biomass of insects is promising but requires carrying out supplementary studies.

scholarly journals Drying behaviour observations for wood chips of grade EN14961

2021 ◽  
Vol 11 (4) ◽  
pp. 151-156
Author(s):  
Baibhaw Kumar ◽  
L. Gábor Szepesi ◽  
Zoltán Szamosi
Keyword(s):  
Renewable Energy ◽  
Moisture Content ◽  
Removal Rate ◽  
Wood Chip ◽  
Wood Chips ◽  
Moisture Removal ◽  
Solar Drying ◽  
Sun Drying ◽  
Solid Biofuels ◽  
Drying Behaviour

Solid biofuels such as woodchips have always been a significant source of fuel in the field of renewable energy. However, the drying of wood chips has been a challenge in preparing biofuels and other applications. The moisture content of below 25% in the wood chips of grade EN 14961 is considered the premium wood chip material. Solar drying emerged as a leading solution for the drying of wood chips. The paper investigates the comparison of moisture removal rate using a natural convective solar dryer compared to open sun drying developed at Miskolc, Hungary (48°06'15.0"N 20°47'30.0"E).

scholarly journals Performance Analysis of Red Chilli in a Hybrid Collector with Solar Dryer

2021 ◽  
Vol 12 (2) ◽  
pp. 1794-1802
Author(s):  
E Murali, Et. al.
Keyword(s):  
Performance Analysis ◽  
Solar Radiation ◽  
Moisture Content ◽  
Thermal Efficiency ◽  
Removal Rate ◽  
Initial Moisture Content ◽  
Weight Basis ◽  
Moisture Removal ◽  
Drying Time ◽  
Solar Dryer

This article performed various analysis on Red chilli by hybrid collector with solar dryer (HCSD). This study was carried out forced convection solar dryer which performed better in all aspects such as drying time, moisture removal rate, electrical efficiency, electrical thermal efficiency, thermal efficiency and overall thermal efficiency. In general, solar radiation was provided a sources of generating energy to drive a solar dryer. Hybrid collector has been provided the electrical and thermal energy to run a solar dryer. The solar dryer was tested by drying 12 kg of red chilli in the drying air temperature in the range of 32 0C – 56 0C. The initial moisture content of the red chilli was 71.5 % (weight basis) and was reduced to the final moisture content of 16.2 % (weight basis) in 6 consistent days with clear sunny days. The HCSD was operated between 9 hrs to 16 hrs. Finally, comparative study was also handled for better understanding in HCSD, in which solar dryer drying made better outcome than open sun drying.

scholarly journals PROBLEMATICS OF CONSTRUCTION OF MATHEMATICAL MODELS OF THE PROCESS OF MICROWAVE DRYING OF SOY

2019 ◽  
pp. 21-26
Author(s):  
Valentyna Bandura ◽  
Oleksandr Popiak
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Raw Materials ◽  
Microwave Energy ◽  
Raw Material ◽  
Microwave Drying ◽  
Drying Methods ◽  
Soybean Seeds ◽  
Drying Process ◽  
Moisture Movement

The article reviews various techniques for mathematical modeling of the soybean drying process. The purpose of this paper is to review, analyze and compare existing approaches to mathematically describe the processes of moisture movement during microwave drying of soybeans. The only way to provide mathematical modeling of the processes occurring in the soybean grain is a combination of the transformation of microwave energy into heat, the heating of dipole water molecules existing in the seed, the processes of moving moisture from the center to the grain shell and evaporation of moisture. Today, microwave drying is one of the promising areas for research, because this method is much more efficient than traditional post-harvest grain drying methods and, at the same time, poorly understood. Factors on which the process of microwave drying depends on are the speed of movement of moisture in the micropores of the product, the initial temperature and humidity of the raw material, the placement of the main magnetron relative to the object of drying and the speed of movement of raw materials in the drying chamber. The object of the study in this article was to simplify the mathematical model of soybean seeds. To intensify the process of microwave drying, it is advisable to use a combined effect, such as blowing, which increases the intensity and quality of the process of microwave dehumidification. In addition, in this case, the simultaneous use of two or more factors of influence, which allows for rapid processing of raw materials. This determines the relevance and prospects of this study. The developed criteria criterion is substantiated and described, which allows to simplify the complex calculation of microwave energy transfer processes, sample heating and moisture velocity in it. The basic approaches to the construction of a mathematical model of the soybean drying process are considered, and their expediency is determined. The analysis of various methods of mathematical description of the drying process is carried out, the main disadvantages of these methods are identified. It is established that drying soybean seeds in the microwave field is one of the most promising. A mathematical model for a combined soybean drying process with a combination of microwave drying methods and air blowing is proposed.

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