Thumbnail Image

Theses

Browse

1988 - 198911990 - 19933
Reset filters
End date: 1994 × Type: Thesis × Thesis Type: M.Tech ×
Reset filters

Search Results

Now showing 1 - 4 of 4
  • Thumbnail Image
    ThesisItemOpen Access
    Evaluation and modification of spike-tooth and rasp-bar type paddy threshers
    (Department of Farm Power Machinery and Energy, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1993) Sailaja, L; KAU; Sivaswami, M
    The field survey conducted on the threshing practices of paddy in Kerala revealed that the hand beating method which is more common in southern part of Kerala needed 154.7 man h/ha with an average output of 18.5 kg/man h requiring an amount of Rs. 823.5/ha whereas, in central Kerala the feet rubbing method required Rs. 1599.0/ha and needed only319.8 man h/ha with an average output of 11.27 kg/man h. The 8 hp axial flow spike-tooth type and 10 hp flow through rasp-bar type threshers were evaluated and found an average output of 50 kg/hp h and 107 kg/hp h respectively. The maximum threshing efficiency of 98.77 per cent and 97.44 per cent were recorded for the flow through rasp-bar thresher during ‘virippu’ and ‘mundakan’ seasons compared to only 95.50 per cent and 94.49 per cent respectively for spike-tooth thresher. The high moist and long paddy crops used to stick and choke in between cylinder and concave clearance and hence the concave was successfully improved to eliminate these problems. The improved concave also improved the output to 1081 kg/h and 1122.6 kg/h with an increase of 9.25 per cent and 4.27 per cent respectively during ‘virippu’ and ‘mundakan’ seasons. A maximum output of 305.7 kg/hp h was obtained for the 1 hp prototype thresher with the rasp-bar cylinder compared to the output of 256.5 kg/hp h for spike tooth cylinder. The cost of operation for the commercially available axial flow through rasp-bar threshers was found to be Rs. 400/ ha and Rs. 207/ ha respectively. The rasp-bar thresher with improved concave could save an amount of Rs. 616.5/ha which accounted to a net saving of 74.9 per cent in the cost of threshing compared to the hand beating method.
  • Thumbnail Image
    ThesisItemOpen Access
    Development and testing of a manually operated paddy dibbler
    (Department of Farm Power Machinery and Energy, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1992) Bini Sam; KAU; Sankaranarayanan, M R
    A manually operated three row paddy dibbler for dry sowing was developed and tested at Kelappaji College of Agricultural Engineering and Technology, Tavanur. The metering mechanism employed in this dibbler was unique in design. The machine consists of seed box, roller with metering mechanism, seed tube with furrow opener, frame, handles and marker. When the dibbler was operated for dibbling, the roller passing vertically through the centre of box would move upward by the soil pressure against the spring pressure. As the roller moved upward, the portion of the roller having the vertical slot would come in contact with seeds and the seeds were moved and carried to this slot. When the equipment was taken out from the soil, the soil pressure on the roller was released and due to the spring pressure the roller moved downward and the seeds carried in the slot were released and would fall through the seed tube by gravity in to the soil. During the operation of the equipment due to the downward travel of the roller and seed tube the seed hole was created for dropping the seeds. The covering of seeds with soil was carried out automatically when the equipment was taken out from the soil. The number of seeds dropped was in the range of 4 to 6 per hill. The area covered by the dibbler was 0.022 hectare per hour. The field efficiency obtained was 68.68 per cent. The mechanical damage was 4.84 per cent. The percentage losses of seeds after germination was 9.52. The fabrication cost of the dibbler including cost of material was Rs. 800/-. The operating cost of the dibbler was Rs. 16/- per hour. The cost of sowing one hectare of land was Rs. 717/- while for manual dibbling the cost of sowing was Rs. 979/- per hectare. Moreover manual dibbling is done in a bending position which is arduous to the farmer. But in the present design of dibbler, a suitable handle is provided which ensure easy and comfortable operation in a straight posture. The equipment can be fabricated locally with readily available materials and can be easily maintained by small farmers.
  • Thumbnail Image
    ThesisItemOpen Access
    Design fabrication and testing of a cashewnut decorticator
    (Department of Farm Power Machinery and Energy, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1993) Joby Bastian; KAU; Jippu Jacob
    A manually operated cashewnut decorticator is designed, developed and evaluated. The major parts are top blade assembly, and linkage assembly, 2-blade bottom assembly, and linkage assembly. The whole assembly is fixed on a work table. The steamed cashewnut is placed manually between the top and bottom blades. Upon pressing the pedal the top and bottom blades slit the two long sides of the nut. The two bottom blades are then opened wide with a cam splitting open the shell in to two halves. The kernel is released from the shell. The efficiency in decorticating is 88 per cent while the percentage of the number of kernels damaged is 12. The capacity of the machine is 900 nuts/h. The important physical properties of nuts were also studied. It is kidney shaped. Its mean size is 32.40 mm long, 24.60 mm wide and 17.60mm thick. The average kernel size is 26.00 mm long, 17.20 mm wide and 12 mm thick. The average thickness of the shell is 3.20 mm. The average weight of the nut is 7.0 g while that of the kernel is 2.1 g. considering its performance the mechanism is sound. It is recommended for further studies and modifications.
  • Thumbnail Image
    ThesisItemOpen Access
    Evaluation of the characteristics of petti and para (axial flow pump)
    (Department of Irrigation and Drainage Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1988) Jose, Abraham; KAU; John Thomas, K
    ‘Petti and Para’ is the most popular pumping equipment used in Kuttanad and Kole lands of Kerala for dewatering agricultural fields. It is a local adaptation of the class of pumps called axial flow or propeller pumps. It is fabricated by local blacksmith using their practical experience and is very popular in low head high discharge requirements especially for drainage purposes. The project was undertaken to evaluate scientifically the ‘Petti and Para’ and to suggest improvement to its design. Field survey had been conducted to study the general characteristics of the existing ‘Petti and Para’ and the energy requirements for punja and additional crop. Field pumping tests were conducted on 15 hp and 20 hp ‘Petti and Para’ using standard methods, to evaluate its characteristics. A small propeller pump was developed talking into consideration the specific requirements of Kuttanad, so that the results could be utilised in bigger units through the principles of similitude. The pump was designed as a high specific speed unit (280 rpm) operating at high rotational speed (1900 rpm), so that its physical dimensions were small. The field survey showed that ‘Petti and Para’ are operating at low speed of 300 rpm. The most common type of ‘Petti and Para’ in use are 10 hp, 15 hp, 20 hp, 30 hp and 50 hp units. A 10 hp unit has an impeller diameter of 44 cm and 50 hp unit has an impeller diameter of 79 cm. The average energy consumption for dewatering during punja crop was 309.8 kwh per hectare and that for additional crop was 444.5 kwh/ha. The efficiency of a 15 hp ‘Petti and Para’ having an impeller diameter 52 cm was about 20%. It could pump water at a rate of 217.75 to 143.60 1/s against a total head of 65 cm to 100 cm. A perfectly maintained 20 hp ‘Petti and Para’ could pump water at a rate of 369.5 to 281.2 1/s under total head of 73.2 to 132.01 cm. The efficiency of the unit varied between 21.47 to 25.96 %. The newly developed propeller pump having an impeller diameter of 145 mm was tested at constant static head of 120 cm. It could pump water at a rate 39.64 to 13.34 1/s against a total head of 183.1 to 283.02 cm. The efficiency of the unit varied between 23.72 to 9.6 Input power varied between 4.076 to 5.21 hp, while utilising a 10 hp induction motor as power unit. Due to lack of time this work is inconclusive. Further elaborate studies are necessary for making specific recommendation for the improvement in the efficiency of ‘Petti and Para’.