Legume Genomics and Genetics 2013, Vol.4, No.2, 3-21 http://lgg.sophiapublisher.com
Research Report
Open Access
Effect of Bulk Density, Moisture Content, and Grain Size on Vertical Airflow Resistance of Lathyrus (Lathyrus sativus L.) Grains R. N. Kenghe1 , K. R. Kenghe2 , P.M. Nimkar3 , S.S. Shirkole1 1. Department of Agricultural Process Engineering, Mahatma Phule Krishi Vidyapeeth, Rahuri- 413 722, India 2. Mechanical Engineering student, BSIT&R (W), Wagholi, Pune 3. Department of Agricultural Process Engineering, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola- 444 104, India Corresponding authors email:
[email protected];
[email protected]; Authors Legume Genomics and Genetics, 2013, Vol.4, No.2 doi: 10.5376/lgg.2013.04.0002 Received: 29 Jan., 2013 Accepted: 13 Feb., 2013 Published: 25 Feb., 2013 Copyright © 2013 Kenghe et al. This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Preferred citation for this article: Kenghe et al., 2013, Effect of Bulk Density, Moisture Content, and Grain Size on Vertical Airflow Resistance of Lathyrus (Lathyrus sativus L.) Grains, Legume Genomics and Genetics, Vol.4, No.2 3-21 (doi: 10.5376/lgg. 2013.04.0002)
Abstract The experiments were conducted to study the effect of various operating parameters on airflow resistance of lathyrus (legume) crop. The bulk density, moisture content, bed depth and grain size for lathyrus (cv. NLK-40, Pratik and Ratan) were studied at different three levels of moisture content ranged from 7.33% to 18.80%, 6.75% to 18.30% and 7.90% to 19.40 % d.b., respectively. It was observed that as airflow rate increased the pressure drop also increased significantly but not proportional for all the combinations of the operating parameters studied. At any airflow rate within experimental range, increase in moisture content resulted in decrease of pressure drop for all grains. The increase in airflow resistance was linearly proportional to bed depth for loose, medium and dense packed grain beds. The increase in grain bulk density at any moisture level resulted in an increase in pressure drop at all airflow rates. Bulk density of the densely packed lathyrus grain was found to be 9.63% to 11.67% denser as compared to the loose fill conditions. The corresponding increase in airflow resistance was about 1.41 times higher than that of loose fill condition. Smaller size grain offered significantly higher (1.61 times) airflow resistance as compared to larger size grain. The pressure drop per unit bed depth was maximum for NLK-40 followed Pratik, Ratan and soybean. Keywords Lathyrus sativus L.; Bed depth; bulk density; Grain size; Airflow resistance
jointly by Pulses Improvement Project of USAID, New Delhi; Nutritional Research Laboratory, Hyderabad; and Directorate of Agriculture and Directorate of Health, Government of Madhya Pradesh.
Background Lathyrus (Lathyrus sativus L.) locally known as 'Khesari', 'Teora', 'Lakh' and 'Lakhdi' is a protein rich legume mainly grown in dry land areas or extreme harsh conditions of relay cropping system. It is mainly grown in India, Bangladesh, Pakistan, Nepal and Ethiopia, in areas where the irrigation facilities are very limited particularly during winter cropping. Lathyrus is grown for food, fodder, as straw feed and green manure. Lathyrus crop is grown on about 1.5 million ha in India, and its production estimate is nearly about 0.8 millon tonne of grain yield annually. Nearly two third of national acreage under lathyrus is in South-eastern Madhya Pradesh and Vidarbha region of Maharashtra, in rice based cropping system having limited irrigation facilities.
There appear to be few studies on the nutritional aspects of lathyrus. Rahman et al (1974) and Rotter et al (1991) gave the composition for lathyrus as energy 362.3 cal, protein 31.6%, fat 2.7%, nitrogenfree extract 51.8%, crude fibre 1.1% and ash 2.2%. Resistance to airflow is a function of both product and air properties (Jayas et al., 1987). Shedd (1953) studied airflow resistance and presented equations and curves for a number of grains. The phenomenon of pressure drop in airflow through agricultural products has been widely investigated for various grains (Patterson et al., 1971; Matthies and Petterson, 1971; Haque et al., 1982; Grama et al., 1984; Kumar and Muir, 1986; Jayas, 1987; Giner and Denisienia,
The first ever effort to systematically collect the lathyrus germplasm in India was made in 1987 when seven districts of Madhya Pradesh were surveyed 14
Legume Genomics and Genetics 2013, Vol.4, No.2, 3-21 http://lgg.sophiapublisher.com increased bulk density from 805 kg/m3 to 895 kg/m3 in packed beds offered pressure drops of 771 Pa/m, 4564 Pa/m and 11677 Pa/m, respectively, as against 583 Pa/m, 2787 Pa/m and 7615 Pa/m in loosely filled beds.
1996; Nimkar and Chattopadhyay, 2003; Rajabipour et al. 2001 and Sacilik, 2004) and root vegetables (Neale and Messer, 1976; Abrams and Fish, 1982; Shahbazi and Rajabipour, 2008 and Kasaninejad and Tabil, 2009). Relationships were compiled in the ASABE D 272.3 MAR 1996 (ASABE, 2007) standard.
Table 1 Effect of moisture content on pressure drop of lathyrus at different moisture content
Airflow resistance data is useful for designing drying and aeration systems. It is necessary to generate and provide information on airflow resistance of lathyrus to designers of drying systems for proper drying of these grains by forced draft. Earlier reported studies on airflow resistance of different agricultural grains as affected by various operating parameters were reviewed which showed that no design data on the resistance to airflow of lathyrus is available.
Variety and moisture content %, (d. b.) NLK- 40 7.33 13.10 18.80 Pratik 6.75 12.60 19.40 Ratan 7.90 12.60 19.40
Therefore, the research work was planned with objective to determine pressure drop at higher airflow rates through clean grain beds of lathyrus at different levels of moisture content, bulk density, grain size and bed depth.
Representative airflow rate (m3·s-1·m-2)
Pressure drop (Pa/m)
0.5546 0.5524 0.5511
2853 2787 2721
0.5547 0.5518 0.5563
2598 2517 2441
0.5587 0.5575 0.5597
2436 2370 2304
Note: Mean values of three replications
1 Result The experimental results carried out for three moisture levels as indicated under section 3.5 for each lathyrus variety are shown in Table 1 through Table 2. However the results were presented only for 13.10%, 12.50% and 13.60% (d. b.) moisture content, respectively for NLK-40, Pratik and Ratan has been discussed.
The results obtained as experimental pressure drop for loose, medium and dense packed Pratik grain beds at grain moisture content 6.75%, 12.50% and 18.30% d.b. are as shown in Table 2. At all three moisture levels the medium and densely packed Pratik grain beds showed increase in bulk density values of about 4.84% to 5.26% and 9.69% to 10.52%, respectively, whereas, the corresponding decrease in bulk porosity values were about 8.01% to 8.51% and 16.05% to 17.02%, when compared with loose fill condition. At moisture level of 12.50% d.b. and airflow rate of 0.1708, 0.5518 m3·s-1·m-2 and 1.0794 m3·s-1·m-2, the increased bulk density from 795 kg/m3 to 875 kg/m3 in packed beds offered pressure drops of 698.9 Pa/m, 3727 Pa/m and 11202 Pa/m, respectively as against 516.6 Pa/m, 2517 Pa/m and 7713 Pa/m in loosely filled beds.
1.1 Effect of bulk density The results obtained as experimental pressure drop for loose, medium and dense packed NLK-40 grain beds at grain moisture content 7.33%, 13.10% and 18.80% d.b. are as shown in Table 2. Packing the grain beds at all three moisture levels resulted in increased bulk density of grain about 4.81% to 5.06% and 9.63% to 10.12% for medium and dense packed beds, respectively, whereas, the decrease in bulk porosity value was about 8.71% to 10.86% and 17.45% to 21.76%, respectively, when compared with loose fill condition. At moisture level of 13.10% d.b. and airflow rate of 0.1687 m3·s-1·m-2, 0.5524 m3·s-1·m-2 and 1.0169 m3·s-1·m-2, the
The experimental values of pressure drop for loose, medium and dense packed Ratan grain beds at grain moisture content 7.90%, 13.60% and 19.40% d.b. are as shown in Table 2. For grain beds of medium 15
Legume Genomics and Genetics 2013, Vol.4, No.2, 3-21 http://lgg.sophiapublisher.com airflow rates 0.1708 m3·s-1·m-2, 0.5518 m3·s-1·m-2 and 1.0794 m3·s-1·m-2, respectively, while the corresponding values of pressure drop for the same airflow rates were 486.8 Pa, 2415 Pa and 7520 Pa at a depth of 400 mm and 516.6 Pa, 2517 Pa and 7713 Pa, respectively at a depth of 600 mm..
and dense packing at all the three moisture levels resulted in increased bulk density of about 4.93% to 5.29% and 9.87% to 10.59%, respectively whereas, the corresponding decrease in bulk porosity value was about 7.73% to 8.92% and 17.10% to 17.87%, respectively, when compared with loose fill condition. At moisture level of 13.60% d.b. and airflow rate of 0.1748 m3·s-1·m-2, 0.6224 m3·s-1·m-2 and 1.0193 m3·s-1·m-2, the increased bulk density from 770 to 850 kg/m3 in packed beds offered pressure drops of 587.6 Pa/m, 4102 Pa/m and 9475 Pa/m, respectively as against 425.4 Pa/m, 2861 Pa/m and 6761 Pa/m in loosely filled beds.
Whereas, in case of Ratan similar trend was followed as other two varieties. For 200 mm bed depth the airflow resistance values were 364.6 Pa, 2674 Pa and 6442 Pa at airflow rates 0.1748 m3·s-1·m-2, 0.6224 m3·s-1·m-2 and 1.0193 m3·s-1·m-2, respectively, while the corresponding values of pressure drop for the same airflow rates were 395.2 Pa, 2750 Pa and 6609 Pa at a depth of 400 mm and 425.4 Pa, 2861 Pa and 6761 Pa, respectively at a depth of 600 mm.
1.2 Effect of bed depth and airflow In order to study the effect of bed depth and airflow on pressure drop, only loose fill grain beds of NLK-40, Pratik and Ratan at their middle moisture contents of 13.10%, 12.50% and 13.60% d.b. were considered. In order to interpret the results regarding the effect of bed depth and airflow on pressure drop, three representative airflow rates were considered which represented the low, medium and high range of airflows under the study.
1.3 Effect of moisture content The results indicated in Table 1 shows that for all grain samples the pressure drop decreased with increase in the moisture content. For loosely filled beds of NLK-40 at moisture content between 7.33 to 18.80% d.b. and at the representative airflow rate of 0.5546 m3·s-1·m-2, 0.5524 m3·s-1·m-2 and 0.5511 m3·s-1·m-2, it was found that with increase in moisture content the pressure drops were decreased from 2853 Pa/m to 2721 Pa/m.
The results obtained regarding the airflow resistance of lathyrus as affected by bed depth and airflow rate is as given Table 1. It was observed that pressure drop was found linearly increased with the increase in grain bed depth and it was disproportionate to airflow for lathyrus grains.
In case of Pratik beds in the moisture range of 6.75% to 19.40% d.b. and at the airflow rate of 0.5547 m3·s-1·m-2, 0.5518 m3·s-1·m-2 and 0.5563 m3·s-1·m-2, with increase in moisture content the pressure drops were decreased from 2598 Pa/m to 2441 Pa/m. Whereas, for Ratan beds in the moisture range of 7.90% to 19.40% d.b. and at the airflow rate of 0.5587 m3·s-1·m-2, 0.5575 m3·s-1·m-2 and 0.5597 m3·s-1·m-2 with increase in moisture content the pressure drops were decreased from 2436 Pa/m to 2304 Pa/m, respectively.
It was observed that for NLK-40 as the bed depth increased the pressure drop also increased. For 200 mm bed depth the airflow resistance values were 517.9 Pa, 2589 Pa and 7311 Pa at airflow rates 0.1687 m3·s-1·m-2, 0.5524 m3·s-1·m-2 and 1.0169 m3·s-1·m-2, respectively, while the corresponding values of pressure drop for the same airflow rates were 563.6 Pa, 2695 Pa and 7463 Pa at a depth of 400 mm and 583 mm, 2787 Pa and 7615 Pa, respectively at a depth of 600 mm.
1.4 Effect of grain size The effect of grain size on pressure drop for, small, medium and large sized lathyrus grain viz., NLK-40, Pratik and Ratan were studied at initial moisture content of 7.33%, 6.75% and 7.90% d.b., respectively at loose filled condition. The grain sizes
In case of Pratik it was observed that as the bed depth and airflow rate increased the pressure drop also increased. For 200 mm bed depth the airflow resistance values were 455.8 Pa, 2309 Pa and 7323 Pa at 16
Legume Genomics and Genetics 2013, Vol.4, No.2, 3-21 http://lgg.sophiapublisher.com pressure drop was found to be increased with corresponding increase in moisture content of green gram and pigeonpea grains; Yang and Williams (1990) reported increase in bulk density causes increase in pressure drop through sorghum grains; Molenda et al (2005) reported relationship between grain density and pressure drop.
and bulk densities of the samples were 4.33 mm, 4.96 mm and 5.08 mm. and 830 kg/m, 825 kg/m and 810 kg/m, respectively for large, medium and small sized grains. The results indicated that the pressure drop decreased with increase in the grain size. For small size grain at the airflow rates of 0.1694 m3·s-1·m-2, 0.5546 m3·s-1·m-2 and 0.8180 m3·s-1·m-2 offered pressure drop of 614.3 Pa/m, 2853 Pa/m and 5427 Pa/m. In case of medium size grain at the airflow rate of 0.1717 m3·s-1·m-2 0.4902 m3·s-1·m-2 and 0.9500 m3·s-1·m-2 offered pressure drop of 547.0 Pa/m, 1990 Pa/m and 6447 Pa/m. Whereas, for large size grain at the airflow rates of 0.1751 m3·s-1·m-2, 0.6237 m3·s-1·m-2 and 0.9541 m3·s-1·m-2 offered pressure drop of 455.8 Pa/m, 2952 Pa/m and 6219 Pa/m. At an average representative airflow rates of 0.5140 m3·s-1·m-2, 0.5373 m3·s-1·m-2 and 0.5843 m3·s-1·m-2 offered pressure drop of 2643 Pa/m, 2264 Pa/m and 1642 Pa/m, respectively, with the corresponding increase in sizes. It is evident from the above findings that medium and small size grain offered 1.31 and 1.61 times higher pressure drop values than that of large sized grain.
2.2 Effect of bed depth It was observed that pressure drop was found linearly increased with the increase in grain bed depth and it was disproportionate to airflow for lathyrus grains.In general averaging the pressure drop of all three varieties it was noted that at a depth of 200 mm, two times increase in airflow rate increased the pressure drop by ratio of 2.20, while the ratio was 2.27 for 400 mm and 2.24 for 600 mm bed depth. However, when the bed depth was doubled from 200 mm to 400 mm, the pressure drop values were found to be increased by 1.10 times, 1.03 times and 1.00 times. The above discussed results revealed that for lathyrus grains, in general the resistance to airflow increased linearly with depth of grain bed since twice the grain bed depth nearly twice as much resistance; but twice the airflow rate offered more than as much resistance. Increase in pressure drops across these grain beds were proportionate with increase in bed depths, but were disproportionate with increase in airflow rates.
2 Discussion 2.1 Effect of bulk density The results indicated that with increase in bulk density at any moisture content the pressure drop through grain bed was increased. Denser packing resulted in reduction in bulk porosity and therefore, increased in bulk density which contributed to increase pressure drop in lathyrus beds. The results showed that the increase in bulk density have resulted in increased resistance of lathyrus to airflow. The variation in resistance was dependent on the magnitude of airflow rate and the sample composition. However, the increase in pressure drop could not be explained solely by the change in bulk density alone; the orientation of particles also played the major role in increasing pressure drop.
The trends observed were in agreement with the results reported for soybean and oats (Henderson, 1944); Nimkar and Chattopadhyay, (2002a, 2002b, 2003) found the similar trend of increase in pressure drop through green gram ,pigeonpea and other pulse crop., Tabak et al (2004) reported similar trend for increase in bed depth shows increase in pressure drop through granular beds packed with cottonseeds; Nimkar and Khobragade, (2006) discussed the relationship of bed depth and pressure drop in moth gram packed beds.
The results obtained for the effect of grain bulk density on pressure drop are consistent with the earlier findings. Nimkar and Chattopadhyay, (2002a, 2002b reported that with increase in bulk density the
2.3 Effect of moisture content The results indicated that for all grain samples the pressure drop decreased with increase in the 17
Legume Genomics and Genetics 2013, Vol.4, No.2, 3-21 http://lgg.sophiapublisher.com desired level by adopting the method suggested by Kiani et al (2008).
moisture content. The reduction in pressure drops was possibly due to the decrease in bulk density and bulk porosity resulted from increase in moisture content. These results were in conformity with the results of Shedd (1953) for various grains and for biological material; Pagano et al (2000) obtained similar decrease in pressure drop with corresponding increase in moisture content of oat seed; Chung et al (2001) discussed the effect of moisture content on static pressure drop in sorghum and rough rice beds.
3.3 Physical Properties The relevant physical properties, viz., grain size, in situ bulk density and bulk porosity of NLK- 40, Pratik and Ratan were studied at different three levels of moisture content ranged from 7.33 to 18.80, 6.75 to 18.30 and 7.90 to 19.40 % d.b., respectively. Moisture content of grain sample was determined by adopting standard procedure suggested by Mohesenin (1986) Average of five replications was noted and reported as moisture content of the sample.
2.4 Effect of grain size The results indicated that the pressure drop decreased with increase in the grain size. The difference in pressure drop observed might be due to different physical properties, such as shape and size, which in turn, determine the bulk density and bulk porosity of the bulk sample of lathyrus grains. Shedd’s (1953) data showed the same behavior for large and small grains; Masoumi and Tabil, (2008) reported relationship of grain size and pressure drop for chickpea cultivars. Nimkar and Chattopadhyay (2003) reported that with increase in grain size the pressure drop was found decreased.
3.3.1 Grain size To characterize the grain used in this study, the geometric mean diameter was considered as the size criterion. It is the cube root of product of three axes of grain. Three major principle axes of grain were measured with the help of vernier caliper (Mitutoyo, Japan) having least count of 0.02 mm. Average observations of 100 randomly selected lathyrus grain was calculated and standard deviation was also determined. 3.3.2 Bulk density Bulk density of the grain is the ratio of its mass to bulk volume. To determine the bulk density of the grain, the method given in IS: 4333 (Part III)–1967 was used. True density was determined with toluene displacement method. Average of five replications was reported as the bulk density and true density values of grain sample.
3 Materials and Methods 3.1 Raw Material The samples of lathyrus grain varieties were procured from the National Bureau of Plant Genetic Resources (NBPGR) laboratory. The small, medium and large sized grains viz., NLK- 40, Pratik and Ratan were selected for further studies. The selected grain samples were used for determination of their relevant physical properties and resistance to airflow. For selecting grain size of the test samples to be used in the study, it was found by sieve analysis technique with the help of Ro-Tap sieve shaker and using BS standard set of sieves. Average of five replications has been reported.
3.3.3 Bulk porosity It is the percentage of volume of voids in the test sample at given moisture content. It was calculated as the ratio of the difference in the true and bulk density to true density value and expressed in percentage.
3.2 Preparation of test sample Test sample of NLK- 40, Pratik and Ratan having initial moisture content of 7.33, 6.75 and 7.90 % d. b., respectively were brought to the laboratory. To increases the moisture content; the samples were moistened with a calculated quantity of water and conditioned to raise its moisture content to the
3.4 Airflow resistance apparatus The vertical airflow resistance apparatus was fabricated under strict supervision of mechanical engineer keeping in view all the possible pressure losses through pumps, joints, elbows etc. The apparatus used in the experiments is consisted of the air blow system, airflow measurement system, 18
Legume Genomics and Genetics 2013, Vol.4, No.2, 3-21 http://lgg.sophiapublisher.com plenum chamber, test bin and pressure measurement system.
bed in the apparatus was recorded with dial gauge thermometer (Premium Instruments, USA) having a range of 0~50℃ and least count of 0.5℃. Static air pressure was recorded from the tap provided at a location of 30 mm below the perforated floor with U tube manometer filled with distilled water.
3.5 Experimental Procedure In all experiments, conditioned sample was removed from the refrigerator and left at room temperature for six hours so as to equilibrate it with the ambient temperature before using it for pressure drop measurement. Moisture content of test sample was determined before and after of each trial with an oven drying method. The experiments were carried out at three densities obtained with loose, medium and dense packed grains. Firstly, test bed was filled by the loose fill method as described by Shedd (1953). Medium and dense packed bed conditions were obtained by tapping the side wall with rubber hammer which allowed the grains to settle and thereby decreased its volume till the required depth. With the known mass of grain and volume occupied by them, in-situ bulk density of test sample was determined.
The experiments were carried out at three different bulk densities for each moisture levels of 7.33%, 13.10% and 18.80%; 6.75%, 12.50% and 18.30% and 7.90%, 13.60% and 19.40% d.b. for NLK-40, Pratik and Ratan, respectively for three bed depths (200 mm, 400 mm and 600 mm). The experiments were carried out at all possible airflow ranges. Fifteen airflow rates ranged from 0.0411≤V≤ 1.0262 m3·s-1·m-2, seventeen airflow rates ranged from 0.0450≤V≤1.0794 m3·s-1·m-2 and nineteen airflow ranged from 0.0484≤V≤1.0193 m3·s-1·m-2 for NLK-40, Pratik and Ratan, respectively. Each pressure difference, measured by the inclined manometer, was divided by the distance of the two taps to obtain the pressure drop per meter depth. The average of five replications was expressed as pressure drop in Pascal per meter for each airflow rate.
At each airflow rate, the test runs in triplicate were conducted at each bulk density level. The tests were carried out starting initially from highest airflow rate and subsequently by proceeding to lower airflow rates. The air velocity was measured at a proper position in the circular air duct with digital electric anemometer (ACD, India). Relative humidity, atmospheric pressure and temperature were measured three times during each test run and were used for airflow rate calculations to standard conditions of air at temperature of 27 ℃ and pressure of 101.325 kPa. The average of three reading corrected for standard condition was taken as the designated airflow rate. During airflow resistance studies with lathyrus beds, the temperature and relative humidity conditions recorded were (24±4.5)℃ and (40±5.5)%, respectively. During the period of experimentation the barometric pressure was recorded with a Barograph (Lawrence and Mayo, India). The relative humidity was recorded with hygrometer (Hunger Hygro, West Germany) with 1% accuracy and ambient temperature was recorded with dry and wet bulb thermometer (Zeal, England) having least count of ±1℃. Temperature of the air flowing towards grain
Authors contributions RNK designed and conducted this experiment. KRK was in charge of experimental set up fabrication in workshop as per the design done by her. PMN was responsible for technical editing and SSS was in charge of data analysis, writing and modification of manuscript. Acknowledgement This experiment was conducted with financial support of Sakal India Foundation, Pune and laboratory support from Panjabrao Deshmukh Krishi Vidyapeeth, Akola (India). We also thank one anonymous editor for his critical comments and advice on this paper. References Abram C.F., and Fish J.D., 1982, Airflow resistance of bulk piled sweet potato, Trans. ASAE., 25: 1103-1106 ASABE., 2007, Standards ASAE D272.3 Resistance to airflow of grains, seeds, and other agricultural products, and perforated metal sheets, ASABE St, Josepth, MI Chung D.S., Mahirang R.G., Kim Y.S., and Kim M. S., 2001, Effect of moisture and fine material on static pressure drops in a bed of
19
Legume Genomics and Genetics 2012, Vol.3, No.3, 14-20 http://lgg.sophiapublisher.com sorghum and rough rice, Trans. ASAE., 44(2): 331-336
Nimkar P.M., and Chattopadhyay P.K.., 2002a. Airflow resistance of
Giner S.A., and Denisienia E., 1996, Pressure drop through wheat as
green gram, J. Biosyst. Eng., 82(4): 407-414
affected by air velocity, moisture content and fines, J. Agri. Eng.
Nimkar P. M., and Chattopadhyay P.K.., 2002b, Airflow resistance of
Res., 63: 73-86
pigeonpea as affected by moisture content, bulk density and bed
Grama S.N., Bern C.J., and. Hurburgh C.R., 1984, Airflow resistance of
depth, J. Food Sci. Tech. 3y P.K.., 2003, Airflow resistance of pulse
mixtures of shelled corn and fines, Trans. ASAE., 27(1): 268-272
grains. J. Food Sci. Tech., 40(1): 28-34
Haque E., Ahmed Y.N., and Doyoe C.W., 1982, Static pressure drop in
Nimkar P.M., and Khobragade B.V., 2006, Resistance of moth gram to
fixed beds of grain as affected by grain moisture content, Trans.
airflow, International J. Food Sci. Tech., 41: 488-497
ASAE., 25 (4): 1095-1098
Neale M. A., and. Messer H.J.M., 1976. Resistance of root and bulb
Henderson S.M., 1944, Resistance of soybean and oats to airflow, J. Agri.
vegetables to airflow, J. Agri. Eng. Res., 21(3): 221-231
Eng., 25 (4): 127-128
Patterson R. J., Bakker-Arkema F.W., and Bickert. W.G., 1971, Static
Indian Standard Institution., 1967, IS: (4333 Part-III) Methods of analysis
pressure airflow relationship in packed beds of granular biological
for food grains., Determination of hectoliter weight
materials such as grain II. Trans. ASAE., 14(1): 172-174, 178
Jayas D.S., 1987, Resistance of bulk canola oilseed to airflow.,
Pagano A.M., Crozza D.E., and Nolasco S.M., 2000, Airflow resistance of
Unpublished Ph.D. Thesis Agri. Eng. Dept. University of
oat seeds: effect of airflow direction, moisture content and foreign
Saskatchewan, Saskatoon, Saskatchewan, Canada
material, J. Drying Tech., 18(1and 2): 457-468
Jayas D.S., Sokhansanj. S., Moysey E.B., and Barber E.M., 1987, Effect
Rahman Q.N., Akhtar N., and Chowdhury A.M., 1974, Proximate
of airflow direction on the resistance of canola (rapeseed) to airflow,
composition of food-stuffs in Bangladesh, Part I. Cereals and Pulses.
J. Canadian Agri. Eng., 29(2): 189-192
J. Sci. and Industrial Res., 9: 129-133
Kiani D., Kiani M., Minaei.S., Maghsoudi H., and Ghasemi. V.M., 2008, Moisture
Rotter R.G., Marquardt R.R., and Campbell C.G., 1991. The nutritional
dependent physical properties of red bean (Phaseolus
value of low lathyrogenic lathyrus (L. Sativus) for growing chicks,
vulgaris L.) grains, International Agrophysics, 22: 231-237
Brit. Poultry Sci., 32: 1055 -1067
Kumar A., and Muir W.E., 1986, Airflow resistance of wheat and barley
Rajabipour A., Shahbazi F., Mohtasebi S., and Tabatabaeefar A., 2001, Airflow resistance in walnuts, J. Agri. Sci. Tech., (3): 257-264
affected by airflow direction, filling method and dockage, Trans.
Sacilik K., 2004, Resistance of bulk poppy seeds to airflow, J. Biosyst.
ASAE, 29 (5): 1423-1426 Kashaninejad M., and Tabil L.G., 2009, Resistance of bulk pistachio nuts
Eng., 89(4): 435-443
(cv. ohadi) to airflow, J. Food Eng., 90(1): 104–109 Matthies H.J., and
Shedd C.K., 1953. Resistance of grains and seeds to airflow, J Agri. Eng.
Petersen H., 1971, New data for calculating the
34 (9): 616 -619
resistance to airflow of stored granular material, Trans. ASAE., 17(6):
Shahbazi F., and Rajabipour A., 2008, Resistance of potatoes to airflow, J. Agri. Sci. Tech., 10: 1-9
1144-1149 Molenda M., Łukaszuk J., and Horabik. J., 2005, Airflow resistance of
Tabak S., Askarov B., Rashidov U., Tabak. I., Manor G., and Shmulevich
wheat as affected by grain density and moisture content, J. Agri.
I., 2004, Airflow through granular beds packed with cottonseeds, J.
Eng., 8(4): 56-60
Biosyst. Eng., 88(2): 163-173
Masoumi A.A., and Tabil L., 2008, Vertical airflow resistance of chickpea
Yang X., and Williams D.L., 1990, Airflow resistance to grain sorghum as
cultivars as affected by bulk density and moisture content,
affected by bulk density, Trans. ASAE., 33(6): 1966-1970
International J. Food Properties, 481-494
20
Legume Genomics and Genetics 2012, Vol.3, No.3, 14-20 http://lgg.sophiapublisher.com Table 2 Mean pressure drops (Pa/m) at various airflows, bulk densities and bed depths of lathyrus at different moisture content Variety and
Airflow rate
moisture
(m3.s-1.m-2)
Bed depth (mm) 200
content, % (d.
Airflow rate
Bed depth (mm)
Airflow rate
(m3s-1m-2) 400
600
Bed depth (mm)
(m3s-1m-2) 200
400
600
200
400
600
b.) Bulk density, 805 kg m-3 NLK-
40,
Bulk density, 845 kg m-3
Bulk density, 895 kg m-3
0.1687
517.9
563.6
583
0.1679
548.3
670.2
710.8
0.1701
578.8
731.1
771
0.5524
2589
2695
2787
0.5551
3320
3442
3655
0.5598
4142
4310
4564
7311
7463
7615
1.0322
9869
10113
10357
1.0508
11149
11453
11677
13.10 % 1.0169
Bulk density, 795 kg m-3
Pratik, 12.50 %
Bulk density, 835 kg m-3
Bulk density, 875 kg m-3
0.1708
455.8
486.2
516.6
0.1722
516.6
577.4
617.9
0.1728
577.4
668.5
698.9
0.5518
2309
2415
2517
0.5566
2826
2993
3134
0.5585
3464
3585
3727
1.0794
7323
7520
7713
1.0972
8903
9176
9450
1.0915
10605
10878
-3
Ratan, 13.60 %
-3
Bulk density, 770 kg m
11202 -3
Bulk density, 810 kg m
Bulk density, 850 kg m
0.1748
364.6
395.2
425.4
0.1747
427.4
486.2
516.6
0.1761
486.2
547.5
587.6
0.6224
2674
2750
2861
0.6232
3342
3433
3555
0.5430
3889
4011
4102
1.0193
6442
6609
6761
1.0283
7809
8037
8199
1.0370
9025
9283
9475
Note: Mean values of three replications
21
