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Theses

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1995 - 19962
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Subject: Agricultural Engineering × Author: KAU × End date: 1996 × Start date: 1994 × Type: Thesis × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Dynamics of power transmission in tractor mounted paddy reaper
    (Department of Farm Power Machinery and Energy, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1996) Sushilendra; KAU; Sivaswami, M
    A tractor front mounted 2.2 m wide paddy reaper windrower was evaluated to find out the optimum forward speed, cutterbar speed, conveyor belt speed and engine speed for different field conditions to achieve better harvesting and windrowing pattern, Maximum field capacity and field efficiency with less harvesting losses. Three PTO pulleys of 17.78 cm, 19.03 cm and 20.32 cm diameter with internal splines were fabricated and used with an engine speed from 1000 to 2000 rpm with four gears in low range and first gear in high range. In addition to pneumatic tyres, a pair of special cage wheels and a simple collection unit were developed and evaluated. In water submerged fields with special cage wheels and PTO pulley of 17.78 cm diameter better results were observed when reaper was operated at an engine speed of 1500 rpm with third low gear with a forward speed of 0.95 m/s. The optimum cutterbar index and conveyor index were found to be 1.56 and 2.30 respectively. The actual field capacity was 0.38 ha/hr and field efficiency was 54 per cent. The crops were found to throw within 10 cm from the discharge plate with an tiller angle of more than 85 degree with only 1.54 per cent of total loss of grain. When the soil is moist and pneumatic wheels fail to give sufficient traction, the special cage wheels were used with a PTO pulley of 19.03 cm diameter. An engine speed of 1400 rpm with third gear and with a forward speed 0.90 m/s was found to give satisfactory performance. The optimum cutterbar index was 1.66 and conveyor index was 2.45. The reaper had the field capacity of 0.36 ha/hr with field efficiency of 53 per cent. The windrowed crop were found to throw within a distance of 13.5 cm with 85 degree of tillers angle with total grin loss of 1.55 per cent. For dry fields, the reaper with pneumatic wheels was found to operate satisfactorily with 20.32 cm diameter PTO pulley at an engine speed of 1300 rpm with fourth gear and with a forward speed of 1.00 m/s. The optimum cutterbar index was 1.48 and conveyor index was 2.19. The actual field capacity was 0.38 ha/hr and field efficiency was 50.66 per cent. The tillers angle was 85 degrees with total grain loss of 1.62 per cent. It is found that the better field performance was achieved when the reaper is operated at a cutterbar speed of 1.50 m/s and conveyor belt speed of 2.20 m/s. A simple crop collection unit of size 1. 5m x 0.7m x 0.35m was developed with the provision for conveying the windrowed crop directly into the collection box. The unit was field evaluated with reaper. The box was found to fill within 10 m of travel and problems were observed in its manoeuv reability, loading and unloading of box and increased idle time.
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    ThesisItemOpen Access
    Design fabrication and testing of a low cost greenhouse
    (Department of Irrigation and Drainage Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1995) Ajayambikadevi, S J; KAU; Remadevi, A N
    Controlled environment agriculture in the form of greenhouses, low tunnels and cloches are being practiced at commercial levels in many countries. Among these the greenhouses are the best for active environmental control. The major hurdle for adopting greenhouse cultivation is its high initial investment. Considering the importance of developing greenhouses of simple design with low initial investment, the thesis entitled ‘Design, Fabrication and Testing of a Low Cost Greehouse’ was undertaken. A greenhouse of size 12 m x 3 m was constructed at the Instructional Farm, KCAET, Tavanur. The structure was gable shaped. The main structural members were hoops, ridge line mechanism, foundation material and the structure for pad gripping and fan replacement. Ultraviolet stabilized polyethylene film was used as the glazing material. The fan and pad system of cooling in which the air is cooled by the moist air drawn through the wetted pads was adopted. The system was designed based on the rate of air to be removed from the greenhouse. A fan of maximum air flow rate of 10450 m3 /hr and a pad of size 3000 mm x 1200 mm was found necessary to satisfy the cooling requirements. The climatological parameters namely dry bulb temperature, wet bulb temperature and intensity of solar radiation were measured both inside and outside the greenhouse. The cooling system was operated for various time intervals and the observations were taken under cooled and uncooled conditions of the greenhouse. The temperature inside the greenhouse was higher than that outside. The maximum temperature recorded inside the greenhouse was 47.60C without cooling and 38.50C with cooling. Longitudinal temperature gradient of 50C existed between the fan end and pad end of the greenhouse. Cooling increased the relative humidity inside the greenhouse. Variation in humidity existed between the pad end and the fan end. A desired temperature and relative humidity can be maintained inside a greenhouse by operating the cooling system for various time intervals. The variation of solar intensity inside the greenhouse was similar to that outside. The polyethylene cover transmitted 60 per cent of the solar radiation incident on it. The average efficiency of the pad was 65 per cent. The cost of construction was Rs. 375.58 per square metre.