Hamid Reza Gazor; Mohammad Reza Alizadeh
Abstract
Long time processing, high energy consumption and non-uniformity in layers moisture are common problems in paddy drying using conventional batch type dryer, leading to increase the chance of kernel breaking during milling process. In this research, drying time, grains moisture content change and energy ...
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Long time processing, high energy consumption and non-uniformity in layers moisture are common problems in paddy drying using conventional batch type dryer, leading to increase the chance of kernel breaking during milling process. In this research, drying time, grains moisture content change and energy consumption of a newly rotary dryer were compared with that of a conventional batch type dryer for paddy (Hashemi variety) drying. Besides, quality parameters as hulling milling ratio, head rice yield and white rice breaking percent were studied in paddy dried using both dryers. All Experiments were done triplicate and data analyzed using T- student method in 5% probability. Results showed that newly rotary dryer caused uniformity in drying processes and cleaning of dried paddy; but, in conventional batch type dryer, because of environmental warm air around it, drying time and energy consumption were about 9 and 8.9 percent, respectively, less than what were calculated in newly rotary dryer. Specific energy consumption for paddy moisture evaporation was 13.5 MJ/kgH2O and it was about 11 percent less than that in rotary dryer. The difference of paddy moisture contents and temperatures in top and lower part of layers of batch type dryer were 2 percent and 6 °C respectively. Milling ratio increased 3.8 percent when rotary dryer was used. Rotary dryer did not have significant effect on paddy hulling. The main effect of using rotary dryer occurred on head rice yield and it was increased about 7.5 percent, comparing with batch dryer. Using rotary dryer caused 7.8 percent decrease in broken kernels, comparing with conventional batch type dryer.
Mohammadreza Alizadeh; Didar Haghtalab
Abstract
In mechanized harvesting, it is very important to develop an appropriate rice reaper for decreasing costs and crop losses. In this study, the field performance of two rice reapers (self-propelled and knapsack power reapers) were compared with manual harvesting. The experiment was conducted in split-plot ...
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In mechanized harvesting, it is very important to develop an appropriate rice reaper for decreasing costs and crop losses. In this study, the field performance of two rice reapers (self-propelled and knapsack power reapers) were compared with manual harvesting. The experiment was conducted in split-plot design with the rice varieties as the main factor in two levels (Hashemi and Khazar) and the harvesting method as sub-factor in three levels (three harvesting methods) based on randomized complete block design in three replications. The results revealed that the effective field capacity of a self-propelled reaper (0.237 ha.h-1) and knapsack power reaper (0.048 ha.h-1) was significantly higher than that of the manual harvesting (0.0083 ha.h-1). The time required for harvesting one hectare using the self-propelled reaper, knapsack power reaper and manual method were 4.22, 20.74 and 119.71 h, respectively. The labor requirements in harvesting for manual method were 159.7 man-h.ha-1 and those of the self-propelled and knapsack power reapers were determined 52.22 and 68.74 man-h.ha-1, respectively. The harvesting losses when self-propelled reaper and knapsack power reaper are used and manual method is practiced, registered as 2.42% and 2.58 and 2.18 %, respectively. The net saving cost using self-propelled and knapsack power reapers were 7940728 and 4444297 Rial.ha-1 as compared to that of manual harvesting. The break-even point for knapsack power and self-propelled reapers were determined 2.00 and 11.42 ha.year-1, respectively.
Hamidreza Gazor; Mohammadreza Alizadeh; Mohammad Younesi
Abstract
In this research, operational process and energy consumption of paddy milling factories in three categories: conventional system (Engelberg Machine for hulling and whitening), semi modern system (Rubber roll dehusker and Engelberg whitener), modern system (Rubber roll husker and abrasive whitener) were ...
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In this research, operational process and energy consumption of paddy milling factories in three categories: conventional system (Engelberg Machine for hulling and whitening), semi modern system (Rubber roll dehusker and Engelberg whitener), modern system (Rubber roll husker and abrasive whitener) were investigated in Mazandaran province of Iran. Besides, milling efficiency, Degree of hulling, breakage percent of brown rice and white rice, degree of whitening, and quality factors gelatinization index, percentage of elongation and amylose of cooked rice were studied. Analysis of results indicated that no significant difference exist in degree of milling among conventional, semi modern and modern systems. The changes in the milling efficiency ranged between 62.45 to 63.58 percents. The milling systems had significant difference in hulling operation. Using rubber roll de husker decreased grain breakage and adding gravity separator to dehulling process increased dehulling to 96 percent. Engelberg de husker and whitener had significant effect on brown rice breakage and whitening than Rubber roll dehusker respectively. Results showed yhat, modern rice milling system had less harmful effects on rice than other systems. Rice milling systems did not have significant effect on amylose and gelatinization index of white rice. The parameters and gelatinization index varied in treatments from 21 to 22 percent and 3.97 to 3.99 respectively. Using of conventional milling system has more effect on cooked rice elongation percent than other systems. Results showed that, drying and milling of paddy consume 683.8 and 158.4 MJ thermal and electrical energy per ton respectively.
Mohammad - Hashem Rahmati; Mohammad - Reza Alizadeh; Abbas Rezaei Asl; Ebrahim Esmail Zadeh
Abstract
Determination of the proper drying methods of rough rice is one of the effective factors on reducing the grain losses. In this study effect of air temperature in three levels (40, 50 and 60 °c) equivalent radiations intensity (0.031, 0.042 and 0.053 w.cm-3) and paddy final moisture in three levels ...
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Determination of the proper drying methods of rough rice is one of the effective factors on reducing the grain losses. In this study effect of air temperature in three levels (40, 50 and 60 °c) equivalent radiations intensity (0.031, 0.042 and 0.053 w.cm-3) and paddy final moisture in three levels (8-9, 9-10 and 10-11% d.b.) on the drying time and rice milling characterization of Domsiah variety were examined in the fluidized bed dryer with two thermal sources; infrared radiation and warm air stream. The experiments were conducted in factorial layout based on completely randomized design with three replications. The results indicated that the effects of air temperature and drying method on the broken grains, cracked grains and drying time was significant (P<0.01). With increasing the air temperature from 40 to 60 °c, the cracked percent (from 5 to 14%) and broken grains (from 26 to 39 %) increased and drying time (from 964 to 242 min) decreased. In each level of air temperature, the cracked grain and broken grain at the moisture content 8-9% and air temperature of 40 °c in the infrared dryer was minimum (5.67 and 26.9%, respectively) and it was maximum at the moisture contents of 8-9% and air temperature of 60°c (14 and 39.5%, respectively).
