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Theses

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1996 - 19984
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Author: KAU × End date: 1999 × Start date: 1996 × Thesis Type: M.Tech ×
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    ThesisItemOpen Access
    Development of a power operated black pepper thresher
    (Department of Farm Power Machinery and Energy, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1998) Suma Nair; KAU; Jippu Jacob
    A power operated black pepper thresher comprising mainly of a threshing drum and a concave; both lined with thermofoam, was developed. It was driven by a O.S-hp, 3-phase, variable speed motor. Pepper spikes were fed into the thresher and the threshed material from all the outlets were collected and separated into berries, damaged berries, unthreshed spikes, partially threshed spikes, and partially threshed spikes with unthreshed berries. The weights of all the fractions were recorded. The values of the threshing efficiency, the percentage of damaged berries, and the capacity were calculated. A three-factor factorial experiment was conducted taking the feed rate, the peripheral velocity, and the contact length as the independent variables, and the threshing efficiency, the percentage of damaged berries, and the capacity as the dependent variables. From the analyses of data, it was seen that all the independent variables exerted significant influence on the threshing efficiency, the percentage of damaged berries, and the capacity. In general, threshing efficiency showed an increasing trend atincreased feed rates for all the different contact lengths. It was most influenced by the peripheral velocity. Threshing efficiency was found to peak around 300 m1min. beyond which it showed a decrease. The percentage of damage was observed to be higher at higher feed rates and lower peripheral velocities. The values of percentage of damage was only between 0.05-0.55 %, which indicated that the therrnofoam assisted in reducing damage to the berries. The capacity showed an increase with the feed rate. However, it did not vary much as the contact lengths were changed. The capacity generally increased with increase in peripheral velocity. A multiple regression equation was developed for the prediction of the power requirement. The maximum power requirement of 0.46 hp was at a feed rate of 50 kglh and a peripheral velocity of 296.9 m1min. The cost of threshing using this thresher was only Rs 1.42 per kilogram, showing that the thresher was very economical. It was highly cost effective compared to the cost of manual threshing which is Rs 6.01 per kilogram.
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    ThesisItemOpen Access
    Development and performance evaluation of a black pepper skinner
    (Department of Farm Power Machinery and Energy, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1996) Anandabose, D; KAU; Jippu Jacob
    A power operated black pepper skinner was developed, tested and its performance evaluated. The major parts were two cylinder – concave assemblies, a hopper, a feed roll, an inclined belt separator assembly and a variable speed electric motor with a speed reduction unit of 10:1 ratio. The decortications took place as a result of the compressive and the shearing forces acting upon the pepper berries fed between the rotating drum and the stationary concave. A 3 – factor, Factorial Experiment in Completely Randomized Design (CRD) with feed rate, drum speed and surface condition as factors was adopted. The maximum overall decorticating efficiency was observed at the feed rate of 12 kg/h and drum speed of 20 rpm for both the surface types. The maximum decorticating efficiency observed for coir-mat was 91.5 and that observed for rubber surface was 94.2. The effectiveness of wholeness of kernels was found to show lower values for the highest speed of 25 rpm due to the crushing of berries. The maximum overall decorticating efficiency recorded for coir – mat was 87.7 per cent and that recorded for rubber sheet was 90.3 per cent. The study showed that the parameters of feed rate, drum speed, and surface type, have significant influenz on decorticating efficiency, effectiveness of wholeness of kernals and overall decorticating efficiency.
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    ThesisItemOpen Access
    Development and evaluation of a low cost power operated paddy thresher-cum-winnower
    (Department of Farm Power Machinery and Energy, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1996) Sureshkumar, P K; KAU; Sankaranarayanan, M R
    Since threshing is labour intensive and involves considerable human drudgery and as the threshers now available are not suitable for small and marginal farmers, a Low Cost Power Operated Paddy Thresher Cum Winnower has been developed and tested. The machine consists of a threshing unit of wire loop cylinder and cover, a winnowing unit, a grain collecting tray, prime mover, power transmission system and the main frame. The power required to operate the machine is taken from a 2 hp electric motor and is transmitted to the cylinder and blower shafts by V- belt and pulley arrangement. Two labourers can hold the crop against the threshing cylinder. The optimum cylinder speed is 400 rpm. The capacity of the thresher at 16.0 per cent moisture content of the crop is 300 hg per hour. Threshing and cleaning efficiencies are 99.25 and 91.82 per cent respectively. Mechanical damage to the grain is negligible. The labour requirement of the thresher cum winnower is two. The cost of the thresher cum winnower was found out to be around Rs 8000.00 and the cost of operation for threshing and winnowing was Rs 8.50 per quintal. An empirical relation between the energy requirement of the thresher and various crop and thresher parameters is P = 931.035 + 4.683 (MC) – 0.462 (PV) – 1.169 (FR) + 8.251 (G/S ratio) The moisture content of the crop and the Feed Rate have statistically significant effect on power Requirement whereas the cylinder speed and Grain/Straw ratio do not have any statistically significant effect.
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    ThesisItemOpen Access
    Modification and testing of KAU Arecanut De-husker
    (Department of Farm Power Machinery and Energy, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1996) Rajmohan, C K; KAU; Jippu, Jacob
    An arecanut dehusker consisting of mainly a pair of fluted rollers, a pressure roller assembly, a scrapper assembly, a guide chute and a feed tray was developed in this study. The arecanut was fed between the two counter- rotating fluted rollers and was pressed against these rollers by the pressure roller. The fluted rollers gripped the husk and pulled it to the rear side of the rollers. In the process the husk was ripped open and the kernel was ejected from its shell. The performance of the machine was studied at speeds of 60, 90,120,150 and 180 rpm and with three different surface characteristics of the rollers. The surface characteristics of the rollers were varied by having different number of teeth and pitch. From the studies the optimum setup of the machine for deriving maximum dehusking efficiency and minimum damage to the dehusked kernels and unhusked fruits was obtained. This was at a speed of 150 rpm against the roller surface having 30 teeth with pitch 3.9mm, width 2.0mm, and depth 1.0 mm. At this set-up the dehusking efficiency, percentage of the number of dehusked kernals and unhusked fruits damaged were 94.4, 5.5 and zero percent respectively. And also this set-up yielded an output of 23 kg of arecanut kernals per hour.