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ThesisItem Open Access Design and development of a propeller pump(Department of Agricultural Engineering, College of Horticulture, Vellanikkara, 1984) Sasi, K; KAU; Remadevi, A N“Petti and Para” a crude form of Axial flow pump is used in Kerala for dewatering agricultural fields. It is being fabricated by local blacksmiths and there is no scientific design for the pump. For low head high discharge conditions Petti and Para is very effective, but less efficient because of faulty construction. The broad objective of the project was to develop an axial flow pump with improved efficiency which could be economically used for dewatering and for lift irrigation purposes under low head conditions. In this investigation, a good amount of attention was given to the fluid dynamics inside the axial flow pump and theoretically studied the combined affect of various parameters involved in the design of an axial flow pump. Then the parameters were compared with the approximate values given by the various researchers in the field. The requirement of the pump to be designed, at field conditions, were studied thoroughly and an one dimensional design was done. After designing and fixing the dimensions, the pump was fabricated in the Kerala Agricultural University Research Workshop at Mannuthy. Because of the lack of facilities in the Research Workshop, it was tested in the hydraulics laboratory at the Government Engineering College, Trichur. The power unit used was a 15 HP electric motor. The accessories used to measure discharge and head were a rectangular notch with Hookgauge and water manometer respectively. Testing was done with two levels of water above the impeller, one 20 cm above the impeller and the other 10 cm above the impeller. For the above two conditions, at designed head (1.5m) the maximum efficiencies obtained were 33 per cent and 29.5 per cent at discharge 121 lit/sec. and 114 lit/sec. respectively. The maximum working capacity was 165.19 lit/sec. against a head of 1 m with an efficiency of 31.95 per cent (20 cm above the impeller) In the three bladed pump, the blades were fixed to the hub by welding it to the suitably shaped (curved) M.S flats and then bolting the curved M.S. flats to the hub. The blades were twisted from 160 to 240 in a uniform variation by simple blacksmithy. The efficiency of the pump can be increased by using perfectly curved blades, which reduces eddies and skin friction. Comparing with the existing Petti and Para made by local blacksmiths, it is found that the pump is cheap as well as efficient.ThesisItem Open Access Mechanical control of the floating type aquatic weed salvinia wolesta (African payal)(Department of Agricultural Engineering, College of Horticulture, Vellanikkara, 1981) Sankaranarayanan, M R; KAU; Jose, SamuelSalvlnia molesta, locally known as ’African Payal‘ is a noxious floating type aquatic weed of common occurance, particularly in the State of Kerala in India* The infestation is the heaviest in the Kuttanadu region and in the Kole lands of Trichur District of the State, where alone more than 50,000 hectares of inland water surface is under the grip of this weed. In the present project, the possibilities of mechanical control of the Salvinia weed were investigated* The study concentrated on the development and evaluation of a prototype Salvinia harvesting Machine which utilised a novel design concept of fluidising the mass by means of a centrifugal* ejector pump combination* The machine consisted of two 5 H.P portable pumpsets as the prime mover and an ejector system mounted on a floating platform. The machine pump out the weed-water mixture into a floating filtering unit at zero lift from which the water was drained by gravity, the material was automatically loaded into a country boat. The results of tests conducted indicated that the 10 H.Pmachine was capable of pumping the Salvinia weed at an average rate of 16 T/hr at zero lift conditions. The proportion of the weed pumped was of the order of 15 % by weight of the secondary flow when pump¬ing water alone. The special features of this equipment were that it could utilise conventional Irrigation punpsets as the prime mover and that it did not allow the weed materials to be drawn into and clog the primary pump. The machine was also capable of being operated as a self propelled unit. In this project, certain accessory units such as a gather¬ing arm, a floating fence and an automatic filtering unit were also successfully developed and evaluated* In addition to load¬ing the material into a country boat, a disposal technique of pumping the weed materials into a field fermentation pond, which avoided any immediate transportation costs for the harvested material, was also investigated. It was found that the bulk density of Salvinia was of the order of 400 kg/n3. It was also found that the spread density value of the weed, depending on the stage of growth and degree of packing, could vary from 8 T/ha to 32 T/ha. A representative value for the spread density, under the still water condition at Kuttanadu, was found to toe of the order of 16 T/ht. This meant that the prototype Salvinia Harvesting Machine would be capable of clearing the weed from a hectare in 10 working hours* The estimated cost of such an operation amounted to Rs.280/- per hectare which compared favourably with the reported costs of Rs.900/- to Rs.2700/- per hectare for manual collection and disposal of the weed. It is considered that the present work is a signi¬ficant contribution to solving the problem of African Payal infestation in Kerala State.ThesisItem Open Access Optimum thresher parameters for high moist paddy(Department of Farm Power Machinery and Energy, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1993) Hamza, Mollakadavath; KAU; Sivaswami, MThe study undertaken by the newly development 1 hp paddy thresher to optimise its parameters for high moist paddy revealed that the peripheral velocity from 10.80 to 21.72 m/s on the rasp – bar, spike tooth, double directional spiral cylinders didn’t influence much on the threshing efficiency. When the moisture content was increased to 35 per cent, the threshing efficiency was brought down from 98.4 to 92 per cent for rasp – bar cylinder and was increased from 88 per cent to 94 per cent in the case of double directional spiral cylinder. The maximum threshing efficiency of 99 percent was achieved for spike tooth cylinder at 19.2 per cent moisture level. The maximum threshing efficiency of 94% and the maximum output of 340 kg/h were achieved with the double directional spiral cylinder when the moisture content was 35% per cent. The proto – type thresher was found to reduce the cost of threshing to 81 per cent and reduction in labour to 85.16 per cent compared to the manual threshing.ThesisItem Open Access Hydraulics of border strip irrigation on level or nearly levely rice fields(Department of Agricultural Engineering, College of Horticulture, Vellanikkara, 1983) Visalakshi, K P; KAU; George, T PIn Kerala, more than seventy per cent of the double cropped rice fields lie fallow during summer months. Rice cannot be grown during this season because of the limited availability of water and the very low water use efficiency that can be attained during this season. The development of a technology for efficient use of limited water available during summer is necessary to make use of these rice fallows for cultivating crops other than rice. As most of the area is under paddy during first and second crop seasons, the level of the land cannot be disturbed. But now, there is no any satisfactory method of irrigation suitable for irrigating nearly level rice fallows. The objective of this project was to study the hydraulics of border strip irrigation in nearly level lands and to recommend suitable specifications. The experiment was done at the Agronomic Research Station, Chalakudy during 1981-82. It consisted of five replications of four treatments. The treatments were two widths of 4m and 6m combined with two discharge rates of 2 1/sec/m and 4 1/sec/m, the length of strip in all cases being 45m. The surface gradient was 0.03815 per cent in the direction of natural slope. Altogether seven irrigations were given at an interval of seven days. Blackgram seeds were dibbled in the field after the first irrigation and cultural practices as recommended in the package of practices were followed. The time of advance of waterfront, the depth of flow and the time of recession of tail water were observed at every 5m length for each strip. The cutoff length was chosen as 77 per cent from the upstream end. The hydraulic gradient, hydraulic resistance and velocity of flow for each irrigation were determined. The advance and recession curves were drawn. The results of the experiment revealed that a discharge rate of 2 1/sec/m is the best for irrigating nearly level borders of 4m and 6m widths. The depth of irrigation could be limited to 5 cm even in soils having high rate of infiltration. The lower discharge rate of 2 1/sec/m reduced the time of ponding at the downstream end and this minimized the wastage due to deep percolation at the downstream end. Soil erosion in the strip was minimum at this rate of discharge, and long strips upto 45m length in loamy sand could be irrigated with high degree of efficiency. As only a low rate of discharge is required to practice this method, even in areas having limited availability of water, an additional crop can be profitably raised. It is estimated that the water needed to raise one hectare of rice in summer months can be more profitably used to raise about 4 ha. of any other crop. Hence, growing rice during summer season should be discouraged and the land should be utilized to raise other remunerative crops like pulses, oilseeds and vegetables. Now the Government has decided to provide water not only for rice but also for other seasonal crops during the summer months. But now, there is no satisfactory method of irrigation for nearly level fields. Border strip method of irrigation is hardly practiced anywhere in Kerala, even though this is a very popular method in the other parts of India for raising cereals, pulses and oilseeds. However, this method is practiced there on sloping lands. Since the present study revealed that this method can be practiced efficiently on level or nearly level fields, this is best suited for the rice fallows during the dry season. Most of the paddy fields have a mild natural slope in one directions. This slope can be used to advantage by laying the strips in the direction of natural slope. This method can be recommended to the farmers for raising a crop in the rice fallows. The specifications of border strips for nearly level lands are as follows: _______________________________________ Length of border - Upto 45m Width of border - 4 – 6m Rate of flow - 2 1/sec/m Slope - should be laid in the direction of natural slope Height of bunds separating the strips - 20 cm Base width of bunds - 30 cm __ThesisItem Open Access Development of cocoa drier(Department of Agricultural Engineering, College of Horticulture, Vellanikkara, 1985) Abdassalam, M; KAU; John Thomas, KAn investigation for the development of an electrically heated, multistage, agitation type cocoa drier, suitable for the Kerala conditions for drying of cocoa beans without impairing the quality, was conducted in the Agricultural Engineering Department of the College of Horticulture under the Kerala Agricultural University. The mini box fermentation method developed in Kerala Agricultural University was selected for fermentation of the beans. The fermented cocoa beans were dried in the sun. The process of sun drying continued upto seven days. The pH of dried beans was 5.2, which was very close to the pH range, 5.3 to 5.5 for good quality beans as per international standards. Hence, the quality of the beans was considered satisfactory. A bulb heated drier developed earlier in K.A.U. was tested* The capacity of the drier tested was 30 kg of fermented beans. The bean could be dried to the desired moisture content in 38 hours. The moisture content of the dried beans was about eight per cent. From the result it was found that for drying one kg of fermented beans approximately 0.760 K.W.H. of electrical energy was required. pH of the dried beans was 5.00. The bulb heated drier was modified and fitted with a 500 watts electric coil heater was also tested. Beans were dried to the desired moisture content in 34 hours. Moisture content of the dried beans was about eight per cent. The result showed that approximately 0.57 K.W.H. of electrical energy was required for drying one kg of fermented beans. The quality of the dried bean was satisfactory because pH of the dried beans was 5.0.The cost of drying per kg of fermented beans was Re.0.47. A modified C.P.C.R.I. model drier of capacity 60 kg of fermented beans was fabricated, tested and economics worked out. For attaining the required moisture content of about eight per cent, the time taken was 64 hours. The result revealed that approximately 0.533 K.W.H. of electrical energy and an amount of Re. 0.36, was required for drying one kg of fermented beans. pH of the dried bean was 5.1 and hence quality of the dried bean was also satisfactory. The modified C.P.C.R.I. model drier fitted with an half h.p. electric motor and a blower was also tested.Beans were dried to the desired moisture content in 42 hours. The result showed that for drying one kg of fermented beans approximately 0.610 K.W.H. of electrical energy was required. Cost of drying per kg of fermented bean was Re. 0.56, Quality of the dried bean was satisfactory since pH was 5.2. An agitation type electrically heated multistage drier of 90 kg capacity was designed, fabricated, tested and its economics was worked out. Tests were carried out with two quantities of cocoa (i.e. 90 kg, and 60 kg), 3 3 different quantity of air (i.e. 0.4 m /second, 0.2 m / second) and varying temperatures (i.e. 56°C, 47°C and 42°C). Air temperature and humidity at various sections of the drier were noted. Also the weight loss of the bean at every hour of drying was noted by using an infrared moisture meter, and the final pH of the dried bean by using a pH meter. From the experiment, using various quantities of beans, with different temperature and air flow, it was found that for drying 90 kg of cocoa beans a temperature of 47°C and air flow rate of 0,4 m3/sec was optimum, for this type of drier. The energy consumed/kg of bean was appromimately 0.69 K.W.H. The pH of the dried beans was found to be 5.3 and hence the quality of the dried bean was satisfactory. Cost of drying per kg of fermented bean was Re. 0.45. One of the objectives of this project was to evolve suitable design of an equipment for drying large quantities of cocoa beans. With this in view an agitation type multistage drier of 2000 kg capacity of fermented beans was designed. Prom the cost analysis it was seen that the cost of drying one kg of bean was only Re. 0.22. The cost of the drier was about Rs.23,000/-. The advantage of agitation type multistage drier are as follows. As the beans were moving in the drier better uniformity in drying was achieved and they were not exposed to high temperature continuously which helped in maintaining the quality of the beans. The drying time was reduced considerably. Energy consumption was less and cost of drying was only 50 per cent compared to other driers. Due to stage by stage drying the loss of heat is reduced and hence the thermal efficiency is high.ThesisItem Open Access Relative efficiency evaluation of drip and basin methods of irrigation in banana(Department of Agricultural Engineering, College of Horticulture,Vellanikara, 1985) Koshy, Vargees; KAU; Varkey, V KWell planned and efficiently utilised irrigation systems help to keep the food production in pace with the increasing population. Hence it is essential to design and adopt an efficient low cost economic irrigation system tailored to fit the local potential and needs. Out of the efficient methods of irrigation, drip method is the most promising. Drip irrigation is comparatively new to our country and needs popularisation. The relative efficiency and feasibility of a low cost drip irrigation system fabricated with the cheapest and locally available materials in relation to the conventional basin method of irrigation is tested in this experiment taking banana as the indicator crop. Plants were irrigated at the rate of 5, 10, 15 and 20 litres per day in both the methods of irrigation. Oil drums of 200 litres capacity were used as storage tanks for the drip irrigation system. 25 mm and 12 mm (dia) black low density polyethylene pipes were used for main and lateral lines respectively which were embedded at a depth of 20 cm below the ground surface. Micro-tubes of 2 mm diameter were used as drippers or emitters. The heart of this drip system was the distributor developed in K.A.U. which could deliver irrigation water at a slow rate of 1 to 2 litres per hour from each micro-tube. Physical characteristics of the soil and bio-metric observations of the plants were taken during the experiment. It was observed that there was no significant difference in the yield of plants under the drip and basin methods of irrigation. Similar results were obtained by Sivanappan et al. (1976) and Chennappa, (1977). The economy of the system was studied and it was found that, by adopting drip method of irrigation, there is a net saving of Rs. 4302 per year in one hectare. Weed growth was found to be less in the plots irrigated by drip method. Special skill is not required for the fabrication, installation, maintenance and operation of the K.A.U. drip irrigation system.ThesisItem Open Access Water balance study of Karuvannur river basin(Department of Irrigation and Drainage Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1988) Santosh, G Thampi; KAU; John Thomas, KThis study was undertaken to quantitavely assess the water resources of the Karuvannur River Basin and to study the monthly water balance in order to estimate the balance for ground waterrecharge or depletion during the period 1976 to 1985. The mean monthly rainfall over the basin during the period 1976-1985 was determined by Thiessen polygon method . Data regarding the amount of water released for irrigation from the Peechi reservoir was also collected. Due to lack of data, contribution from other sources was not taken into account. The total runoff from the basin during each month of this period was determined . The various crop combinations in the basin were identified and the area under each of these was estimated . The actual evapotranspiration during each month was estimated using the method outlined by Doorenbos and Kassam. The basin was regarded as an independent hydrologic unit . Hence surface and subsurface inflow and outflow were assumed to be negligible.ThesisItem Open Access Utilization of "salvina molesta" (African payal) for bio-gas production(Department of Agricultural Engineering, College of Horticulture, Vellanikkara, 1983) Somashekaren Nair, S; KAU; Remadevi, A NAn investigation on 'Utilization of Salvinia molesta(African Payal) for bio-gas production' was conducted in the Agricultural Engineering Department, College of Horticulture , Kerala Agricultural University, with the objective of standardizing the conditions and identifying the best generator model for optimum gas production from salvinia. From the physical and the gas production characteristic studies, salvinia was recognised as a potential raw material for bio-gas production. For the pilot plant experiments a new design was fabricated and was compared with the adaptive designs of K.V.I.C model, Bhagyalekshmi model, and horizontal type K.A.U model.ThesisItem Open Access Development of a low cost garden tractor(Department of Agricultural Engineering, College of Horticulture, Vellanikkara, 1982) Sivaswami, M; KAU; Muhammad, C PThe study was conducted with the objectives of systematic analysis of components with respect to their kinematics, dynamics and ergonomics and evaluation of traction performance and economics of low cost garden tractor. A greaves Lombardini 5.4 hp diesel engine with 1800 rpm was selected and a simple three step speed reduction system having a single stage V belt drive and double stage chain drives with a pivotted countershaft clutch have been designed. A road speed of 6.635 kmph and field speed of 3.317 kpmh were achieved by using a cone pulley arrangement with 6.00 x 12 size wheel.Correct position of various components bringe the centre of gravity of the unit with and without implement at very close to the final drive axle for easy balancing