scholarly journals Effect of Impregnation with Maltodextrin and 1,3-Dimethylol-4,5-Dihydroxyethyleneurea on the Conventional Drying Characteristics of Poplar Wood

2019 ◽  
Vol 9 (3) ◽  
pp. 473 ◽  
Author(s):  
Mingzhen Cai ◽  
Zongying Fu ◽  
Yingchun Cai ◽  
Yue Zhang ◽  
Jun Cai ◽  
...  

The drying characteristics of poplar wood (Populus adenopoda Maxim) under three treatments were investigated with the aim of improving the drying quality of the impregnated wood. Untreated materials, impregnated materials with 10% initial moisture content (MC), and impregnated materials with 20% initial MC—denoted as T1, T2, and T3, respectively—were examined during conventional drying. Relative to that of T1, the average drying rate of T2 was reduced by 46%, and that of T3 was reduced by 37%. The anti-swelling efficiency of T2 sharply increased, whereas that of T3 only slightly increased in width and thickness. The drying defects of T2 were markedly less than those of T1 and T3, attributed to the reduced residual stress and fixation of the modifier. Scanning electron microscopy indicated that large amounts of modifiers were deposited inside the cell cavity of T2, whereas small amounts of modifiers were deposited in the cell cavity of T3. The impregnation treatment generally reduced the average drying rate and MC uniformity and delayed the decrease in residual stress; however, it reduced the number of defects in the wood and considerably improved the dimensional stability of the wood. Meanwhile, impregnation treatment with increased initial MC could potentially lead to more drying defects and increase production cost.

2011 ◽  
Vol 308-310 ◽  
pp. 1586-1589
Author(s):  
Xing Zao Ma ◽  
Chang You Li ◽  
Li Li Zhang ◽  
Wen Hao Shen

In this paper, the deep-bed drying rate was analyzed under different bed depths and air temperatures. It was found that the bed depth had a greater impact on the drying efficiency, and if the initial moisture content of maize and the ventilation temperature are higher, the effect would be much more notable. The results will provide a basis for optimal design of the deep-bed drying devices.


2021 ◽  
Vol 14 (1) ◽  
pp. 26-34
Author(s):  
Della Yusfita Sari ◽  
Mustain Zamhari ◽  
Robert Junaidi

The drying process on kemplang crackers is one of the factors that determine the quality of the resulting product. Conventional drying has many disadvantages, namely fluctuating heat and poor hygiene that will affect product quality. So that kemplang crackers can be stored for a long time, it is necessary to reduce the water content of kemplang crackers. Drying kemplang crackers can use a drying rack with a biomass energy source from coconut shells. This study aims to design a tray dryer with biomass energy to obtain dryer performance based on the drying rate and to obtain a product that meets SNI No. 8272-2016. The treatments that were varied were set point temperatures of 55oC, 60oC, 65oC, and 70oC with mass variations of 50 gr, 100 gr, and 150 gr. The results showed that the optimum drying conditions at 70oC for 4 hours with an air velocity of 5.2 m/s2 obtained 9,84% moisture content in 50 gr kemplang crackers, 15.39% in 100 gr crackers and 19,2 in kemplang crackers 150 gr and a drying rate of 0,035028 kg/hour m2. The drying process requires 5,24 kg of dried coconut shell to produce heat energy of 95.358,81024 KJ with a by-product in the form of liquid smoke.


Processes ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1511
Author(s):  
Haili Liu ◽  
Haoyu Liu ◽  
Heyun Liu ◽  
Xu Zhang ◽  
Qingchao Hong ◽  
...  

To identify the microwave drying characteristics of corn, microwave drying tests were conducted on corn. By taking the moisture content, drying rate, and drying temperature as indices, this research revealed the effects of different microwave powers and loads on the microwave drying characteristics of corn. Moreover, energy consumption and quality of dried corn were analysed under different drying conditions. The results demonstrate that microwave drying has significant energy-saving effects. The energy consumption by microwave drying is less than 0.3 times that used by electrothermal drying under the same load. Both microwave power and load exert significant influences on drying characteristics. Higher microwave power results in a greater average drying rate, wherein shorter periods of time are required to reach the maximum drying rate and higher temperatures of the corn. However, the load shows the opposite tendency. The smaller the load, the higher the temperature of the corn in the early stage of drying. However, as drying continues, the temperature curve changes significantly, and the temperature rises with the increase in load in the later stage of drying. In consideration of energy consumption and dried quality, the load of corn should be increased as appropriate, and the microwave intensity should be limited to no higher than 0.7 W/g in the experiment.


Author(s):  
A. A. Ijah ◽  
O. E. Olagunju ◽  
S. M. Adamu ◽  
H. C. Ozoani ◽  
F. M. Rasheed ◽  
...  

Corn as a staple farm produce are usually harvested at a point or time when the moisture content is more than 25% (wet.basis).,and therefore, it is easily attacked by fungi and other diseases causing organism and even physical damage, thereby reducing the market value of the crop.  Drying must be carried out on those products to prevent deterioration. The objectives of this research are to develop a device that can reduce the moisture content of corn using electronic components and equally carryout evaluation on the device.  Shelled corns with initial moisture content of between 25-30% (w.b.) is the major material used in this research work. A Heating element incorporated in the device supplied the needed heat which was delivered to the drying chamber by the help of a centrifugal blower. The drying experiment was carried out at three different temperature thus; 45 oC, 55 oC and 65oC. The moisture content at this varying temperature was used to determine the drying rate and the drying efficiency. The results showed clearly that the dryer air temperature affect the drying rate, the efficiency of drying, and the quality of the material. It is equally clear that the best drying rate and temperature is  65oC average 4,95% / hour, high efficient at drying temperature 55oC and 65oC equal to 86,27% and 83,51%, and best material quality with dryer temperature 55oC.


Author(s):  
S. K. Chin ◽  
Y. H. Lee ◽  
B. K. Chung

In this research, a Coulomb force assisted heat pump (CF-HP) dryer was invented for the purpose of improving the drying characteristics and product quality of biomaterials. As compared to heat pump drying alone, the assistance of Coulomb force in heat pump dryer enhanced the drying rates and effective moisture diffusivity of lemon slices up to 26%, which eventually shortened the total drying time to 40%. This saved the total energy consumption of HP drying by 31.5%. High retention of vitamin C and TPC were also found in CF-HP dried slices due to mild drying temperature and fast drying rate. Keywords: Coulomb force; Heat pump drying; Drying rate; Vitamin C; Total Phenolic Content (TPC).  


Author(s):  
JO Akowuah ◽  
HA Boateng ◽  
G Obeng Akrofi ◽  
DE Maier

The technical performance of a 3-tonne capacity flatbed grain dryer was assessed based on its drying rate and drying efficiency. In addition, the quality of maize grains dried in the drying system was investigated through stress-crack analysis and germination test. Maize grains at an initial moisture content of 18.4% ± 0.1% (wb) were dried to a safe moisture content of 13.3% ± 0.2% (wb) in 5 hours, resulting in a drying rate of 1.02%/h at a drying efficiency of 67.35%. The average temperature observed in the plenum (55.8°C±1.5°C) was about twice higher than the ambient temperature during the drying period. The use of the flatbed dryer did not have any adverse effect on the viability of grains dried with a stress-crack index of 75 and percentage germination of 90%. This study demonstrated the viability of using the flatbed biomass-assisted dryer for drying maize and can reduce post-harvest losses of maize at the smallholder level. Int. J. Agril. Res. Innov. Tech. 11(2): 37-41, Dec 2021


Author(s):  
J. Isa ◽  
O. I. Majasan ◽  
K. A. Jimoh

During milling of cereal grains, bran which is separated from the starchy endosperm of the grain is a major by-product. In this study, milled sorghum residue was dried in a cabinet dryer under different conditions (temperature and air velocity). The obtained drying data were fitted into ten existing mathematical models and obtained the best model while, the effective moisture diffusivity and activation energy of the drying process was determined using Arrhenius type approach. The result shows that the initial moisture content obtained for the sorghum residue using standard oven drying method were 41.28 ± 0.33%, 49.52 ± 0.63 % and 47.06 ± 0.42 % on wet basis for the wet residue of variety A, B and C, respectively, at equilibrium point, the final moisture content of about 12.93 ± 0.14 – 14.31± 0.07 as temperature ranges from 40 oC to 70 oC and air velocity ranges from 0.8 m/s to 1.2 m/s. During the drying process, the drying rate falls more rapidly as it was initially high as a result of more moisture in the sorghum residue and the drying rate decreases slowly until reaching the reduced moisture content. The obtained values of effective moisture diffusivity (Deff) ranges between 9.89 x 10-10 and 22.21 x 10-10 m2/s, 9.45 x 10-10 and 20.62 x 10-10 m2/s and 8.56 x 10-10 and 20.76 x 10-10 m2/s for variety A, B and C, respectively. However, the result of the modelling shows that the drying characteristics of variety A and B of the sorghum residue can be predicted using Midilli et al. model while the drying behaviour of Variety C can be predicted using Hii et al. model.


Agrika ◽  
2020 ◽  
Vol 14 (2) ◽  
pp. 140
Author(s):  
Nunik Lestari ◽  
Ratnawaty Fadilah ◽  
Andi Muhammad Akram Mukhlis ◽  
Samsuar Samsuar

ABSTRAKProses pretreatment sebelum cabai dikeringkan berperan penting untuk menghasilkan cabai kering dengan kualitas lebih baik. Penelitian ini bertujuan untuk melihat efek pretreatment LTLT blanching sebelum proses pengeringan terhadap karakteristik pengeringan dan kualitas cabai kering. Penelitian dilaksanakan dengan 12 perlakuan, yaitu pengeringan dengan pretreatment LTLT blanching pada suhu 60, 70, dan 80 oC masing-masing selama 10, 15, dan 20 menit, lalu pengeringan dengan pretreatment HTST blanching pada suhu 100 oC selama 10 detik, pengeringan tanpa pretreatment blanching di dalam alat pengering ERK, serta pengeringan tanpa pretreatment blanching di bawah sinar matahari secara langsung. Hasil penelitian menunjukkan pengaruh positif pretreatment LTLT blanching dapat mempercepat laju pengeringan, menghasilkan cabai kering dengan kadar air rendah sesuai standar SNI, menghasilkan warna cabai kering yang menarik, serta memiliki kandungan vitamin C lebih tinggi dibanding cabai kering tanpa pretreatment blanching. Secara keseluruhan, perlakuan pretreatment LTLT blanching pada suhu 80 oC selama 20 menit adalah perlakuan terbaik dari penelitian ini dengan kadar air akhir 8.17%, laju pengeringan yang tercepat, kandungan vitamin C sebesar 0.96%, dan warna yang menarik. ABSTRACTThe pretreatment before drying chilies plays an important role to produce better quality of dried chilies. This study aims to determine the pretreatment effect of LTLT blanching before the drying process on the drying characteristics and quality of dried chilies. This research was carried out with 12 treatments, namely drying with LTLT blanching pretreatment at 60, 70, and 80 oC for 10, 15, and 20 minutes respectively, then drying with HTST blanching pretreatment at 100 oC for 10 seconds, drying without pretreatment blanching in the ERK dryer, and drying without pretreatment blanching in direct sunlight. The results show the positive effect of LTLT blanching pretreatment which can accelerate the drying rate, produce dry chilies with low water content according to SNI standards, produce an attractive dried chilies color, and have a higher vitamin C than dried chilies without blanching pretreatment. Overall, pretreatment with LTLT blanching at 80 oC for 20 minutes is the best treatment in this study with a final moisture content of 8.17%, the fastest drying rate, a vitamin C content of 0.96%, and an attractive color. 


2019 ◽  
Vol 4 (02) ◽  
pp. 229-232
Author(s):  
Ravi Kumar ◽  
Vivak Kumar ◽  
G. R. Singh ◽  
B. R. Singh ◽  
Samsher . ◽  
...  

Chilli (Capsicum annuum L.) is one of the important commercial crops of India. It is a crop of tropical and subtropical regions and requires a warm humid climate. Chilli is a highly perishable vegetable with a short shelf-life and commonly encounter postharvest problems; to deal such problems, drying was done using hot air oven. Three different temperatures (50, 60 and 70 °C) use in hot air oven. Before drying chillis were slitted and treated with Butylated Hydroxy Anisole and Potassium Carbonate solution. Overall drying rate increased with temperature in hot air oven. Drying of dipsol green chilli took place in falling rate period. Initial moisture content of the green chilli was an average of 84.20±1 % w. b.


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