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20152
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Subject: Farm, Machinery and Power × Author: KAU × End date: 2015 × Start date: 2011 × Type: Thesis ×
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    ThesisItemOpen Access
    Evaluation of physiological cost and subjective assessment of existing coconut climbing devices
    (Department of Farm Power Machinery and Energy, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 2015) Hameeda Bindu, Vahab; KAU; Bini, Sam
    At present there are different models of coconut climbing devices available in the market. Most of the climbing devices safety and efficiency aspects are not being studied and needs to be comparatively evaluated and modified. In this study five coconut climbing devices were selected, those are Sit and climb type (TNAU model), Standing type (Chemberi model), KAU coconut palm climber (developed at KCAET), Kerasureksha (Model developed at ARS, Mannuthy) and CPCRI model coconut climbing device. Pertinent anthropometric dimensions of human subjects with reference to the dimensions and positions of the functional components of coconut climbing devices was identified and 35 different body dimensions useful for the design or redesign of coconut climbing devices were recorded by following standard anthropometric procedure. Ten subjects (five each for men and women) were selected, conforming to statistical requirements of anthropometric dimensions. The selected ten subjects were screened for normal health through medical and bio-clinical investigations which includes Electro Cardio Graph (ECG), blood pressure and bio-clinical analysis. Selected ten subjects were calibrated in the laboratory by indirect assessment of oxygen uptake. The relationship between the heart rate and oxygen consumption of the subjects was found to be linear for all the subjects. Then energy cost of operation of the selected coconut climbing devices were computed by multiplying the oxygen consumed by the subject during the trial period with the calorific value of oxygen as 20.88 kJ lit-1. Energy cost is comparatively less for KAU coconut palm climber with other models. Mean energy cost of male subjects during the operation of KAU coconut palm climber is 23.16 kJ min-1 and female shows 25.73 kJ min-1. Variation of heart rate and energy cost of both male and female for selected five models were statistically analyzed. Female subjects are significantly differed in both heart rate and energy cost on different coconut climbing devices and all the female subjects showed minimum heart rate while operating KAU coconut palm climbing device. But male subjects are shown any significant difference for both heart rate and energy cost. But they shows comparatively less heart rate for KAU coconut palm climbing device. The oxygen uptake in terms of VO2 max was minimum for KAU coconut palm climber (58.53 per cent) while it was 65.22 per cent for Sit and climb type (TNAU model) for male operators. Similarly for female subjects, minimum for KAU coconut palm climber (74.30 per cent). Sit and climb type (TNAU model) is difficult in operation compared with other devices. Major discomfort was happened in left thigh, right thigh, left foot and right foot. Based on these results it was found that KAU coconut palm climber and Kerasuraksha coconut climbing device were identified as more suitable for climbers than other climbing devices. Seating unit of Kerasuraksha coconut climbing device and pedal unit of KAU coconut palm climber were ergonomically comfortable for the climbing operator and developed a new model by incorporating the constructional behavior of both KAU coconut palm climber and Kerasuraksha coconut climbing device. Energy expenditure of new model for male is decreased by the rate of 10.8per cent when compared to Sit and climb type (TNAU model and with KAU coconut palm climber it is comparable. In the case of female subjects, Energy cost of new model was decreased by 7.8 per cent with Kerasuraksha coconut climbing device and 6.2 per cent with Sit and climb type (TNAU model) and it is comparable with KAU coconut palm climber. Mean VO2, VO2 max and work pulse of new model is 1.10, 58.16 per cent and 69.70 beats min-1 for male and for female it is 1.22, 73.45 per cent and 81.10 beats min-1 respectively. These values are comparatively less than value of other five models. The time required for climbing new model was 65.01 sec for male subjects which are less than other five selected coconut climbing devices and same trend for female also. The setting time of the new model was 65 sec while for KAU coconut palm climber it was 150 sec. Time was reduced by 56.67 per cent compare to KAU coconut palm climber
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    ThesisItemOpen Access
    Modification and testing of a coleus harvester
    (Department of Farm Power Machinery and Energy, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 2015) Younus, A; KAU; Jayan, P R
    Coleus (Solenostemon rotundifolius) commonly known as Chinese potato, is a major tuber crop of Kerala used for vegetable purpuse, raised purely as a rain fed crop from June to December. Manual harvesting of coleus is done by using spade, which is very tedious and time consuming, bruises and injuries. To overcome these problems and decreasing the cost of harvesting operation, a self propelled coleus harvester was modified and field tested. The developed coleus harvester was an attachment to a mini tiller, which consists of a prime mover, a digger, rotary blade, and driven wheels. As and when the tiller moves, digger pierced into the soil at a depth of 10-15 cm to digout the rhizomes that lie inside the soil. The uprooted coleus were then pushed out by means of the rotary splasher. The scattered coleus lying in the raised bed were collected easily and hence the harvesting becomes easier and faster. The rotary slasher are the rotating blades attached to the rear side of the tiller which was modified in such a way that they were removed and rubber flaps of 75 x 75 x 0.3 mm were fastened to the shank of the rotary blade. A set of larger wheels were designed and fabricated separately with diameter of 80 cm. The performance of the modified coleus harvester was compared with respect to time, fuel consumption, capacity and percentage of damage of coleus separately with flat and angular tynes. The performance on time taken (s) to dig out coleus with 6- tyne and 10 - tyne flat and angular digger revealed that while using 6 - tynes, the time taken and fuel consumption (ml) were highest in beds of 70 x 30 cm, whereas minimum were in the bed size of 50 x 30 cm The capacity of coleus harvester with 6 -tyne and 10 - tyne flat and angular diggers were determined. It is noted that the uprooted was the highest in beds of 50 x 20 cm, whereas minimum weight uprooted was in the bed size of 50 x 40 cm when operated with 6 flat tynes. When 10 angular tynes were used, it is noted that the weight (kg) of coleus uprooted was the highest in beds of 70 x 30 cm and minimum weight uprooted was in the bed size of 50 x 20 cm. Thus the average capacity of the harvester was observed as 1069 kg.h -1.The percentage of damage of coleus observed was the highest in beds of 70 x 30 cm, whereas minimum was in the bed size of 70 x 40 cm while using 6 - tynes. Performance analysis of a commercial harvester (TNAU ginger harvester) indicated that the vibrating mechanism provided was useful to obtain the coleus in clumps after harvest. In field operation it was not possible for uprooting coleus in the beds having more than 30 cm height. The field capacity of the modified coleus harvester is 0.057 ha.h-1. At the present wage rate of Rs 500 per day, the total cost of operation by manual method is about Rs 31,250 per ha. Whereas harvesting by the harvester, the total cost of operation is Rs 7680 per ha. Hence the savings over conventional method is Rs 24,470 per ha. The field efficiency of the harvester was calculated as 95 %. The performance of the machine was tested with two types of tynes - flat and angular with 6 - tyne and 10 - tynes. Time to harvest one bed of crop, fuel consumed for harvesting one bed, capacity of the harvester and percentage of damaged tubers were calculated. Among two types of flat tynes, the minimum time for harvesting one bed was achieved using 6 - tynes (21.66 min) and its fuel consumption was also less compared with 10 - of tynes. The average capacity of the machine was obtained as 1061 kg h-1.Percentage of damaged tubers was 5% corresponding to 6 - tynes. In the case of angular tynes, the shortest time for harvesting was achieved with 10 - tynes and the corresponding fuel consumption was 19 m1. The percentage of damaged tubers was 8% with 10 - tynes and was little high compared with 6 - tynes.