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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 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 Designing and development of an insecticide applicator for the control of brown plant hopper(Department of Farm Power Machinery and Energy, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1988) Ramachandran, V R; KAU; Muhammad, C PThe brown planthopper Nilaparvata Lugens stal. is a dangerous pest which causes, quick and serious damage to rice in South East Asia. In India a serious damage occurred in Kerala during 1973-76, and the estimated loss in this was 12 cores of rupees. An investigation on the design and development of an insecticide applicator for the control of BPH, by spraying specifically the plant base, at a height of about 15-20 cm from the field surface, was carried outThesisItem Open Access Forms of water loss and water requirement of rice in kole lands(Department of Land and Water Resources and Conservation Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1988) Lissy Devid, Chirayath; KAU; George, T PRice is the most important and extensively cultivated food crop in Kerala. Efficient use of water for crop production has been a major concern for centuries. As the water needs of rice is many times greater than other crops, a precise knowledge of water requirement of crop attains importance for increasing production. The present investigation was taken up to estimate the losses through evaporation, transpiration, percolation and to asses the total water requirement of a medium duration rice variety jayaThesisItem Open Access Hydraulics of KAU drip irrigation system(Department of Land and Water Resources and Conservation Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1988) Susan Cherian, K; KAU; George, T PIrrigation advancements within the last decade has been astounding. Drip irrigation is one of the latest innovations for applying water to the field and it represents a definite advancement in irrigation technology. An attempt was made to study the hydraulics of microtube emitters of 1-3 mm size, Black polyethylene tube of 1" was used as main line. In the main line, three laterals of 1/2 diameter were connected. Discharge measurements were taken at different pressure heads. The total energy drop (H) in a microtube emitter is the summation of friction loss (Hf) and minor loss (Hm). There was no empirical equation available for calculating the friction drop from a microtube of size less than 4 mm. With the help of a computer, analysis was made to establish the relationships between pressure head H, length L, diameter D and discharge Q. The empirical equations obtained are 1. Combind flow condition H = 0.01402 Q1.23938/D3.54926 L0.86030 2. Turbulent flow condition H = 0.00764 Q1.82655/D4.61537 L0.77823 3. Flow in transition region H = 0.00817 Q1.56882/D3.83531 L0.83541 4. Laminar flow condition H = 0.00796 Q1.23461/D3.59105 L0.98712 Where Q = discharge, 1/hr L = length of tube, cm D = diameter of tube, mm The minor losses, viz. exit, entry, losses due to fittings and sudden contration can be expressed as a function of velocity head. The minor loss was significant because of the smaller size and short length of the microtube. The numerical solution for minor loss coefficient K was obtained in order to make the power of L unity in the estimating equations for head loss due to friction. The equations obtained are 1. Combind flow Hm = 2.34 V2/2g 2. Turbulent flow Hm = 2.14 V2/2g 3. Flow in transition region Hm = 3.18 V2/2g 4. Laminar flow Hm = 0.84 V2/2g Where V = Velocity, m/s G = acceleration due to gravity, m/s2 The empirical equations for friction drop were developed for different flow condition by fitting multiple log linear regression equations. The equations obtained are 1. Combined flow Hf = 0.00737 Q1.18905/D3.58352 L 2. Turbulent flow Hf = 0.00359 Q1.74866/D4.80544 L 3. Flow in transition region Hf = 0.00397 Q1.46302/D3.74436 L 4. Laminar flow Hf = 0.00743 Q1.22546/D3.58420 Similar to Blasius and general equations, the following equations were developed for friction factor in turbulent and laminar regions. f = 0.248/Re0.25 and f = 67.2/Re where f = friction factor Re = Reynolds number The KAU drip system has an additional component ‘Distributor’. Experiments were conducted to study the effect of distributor on flow rate. It was observed that the discharge rate was higher from the system with distributor than that of microtube having the same length. The frictional losses and the combined loss of minor and distributor for different flow conditions were estimated. Few combinations which satisfy the requirements of discharge, length and pressure head were selected for the design purpose of KAU drip irrigation system. The effect of clogging on discharge rate was studies and it was found that clogging was higher in 1 mm tube than the 2 mm and 3 mm tubes. Experiments were conducted to estimate friction loss in laterals. Hazen – Williams equation was found suitable for turbulent region and not for laminar and transition region. By adopting drip system we can bring more area under cultivation by maximum utilisation of available water. By combining improved agronomic practices along with an efficient drip irrigation system, it is possible to bring about a substantial progress in the farm front.ThesisItem Open Access Development of ejector systems for increasing the discharges of centrifugal pumps(Department of Irrigation and Drainage Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1988) Latha, A Koshy; KAU; John Thomas, KThe pump capability requirement in agriculture especially in rice production is essentially one of low lift and high capacity. Because of the low lift conditions the full capacity of the centrifugal pump cannot be used. By attaching an ejector system, the centrifugal pump is brought to work under the best efficiency condition during low lift also.ThesisItem Open Access Design, fabrication and evaluation of the performance characteristics of hydraulic ram by varying the various parameters(Department of Land and Water Resources and Conservation Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1989) Suseela, P; KAU; George, T PIn India, the agricultural production in many areas especially in hilly areas is very much affected by the non – availability of adequate power to lift water for irrigation. Main problems in enhancing irrigation facilities in hilly regions are their highly uneven topography and non availability of conventional sources of energy. The rapid depletion of conventional sources of energy and increasing demands have now focussed the attention on the need for developing a new economical and effective water lifting device which does not use the conventional sources of energy. A hydraulic ram may meet these requirements in hilly regions and can lift water without any external source of energy in the form of fuel or electricity. A hydraulic ram was designed and fabricated with cheap and commercially available materials. A constant supply head of 1.955 m was provided. Ram was designed for a maximum delivery head of 10 m. Provisions were given to vary the weight and stroke length of both the delivery valve and waste valve. A flange joint was incorporated valve and waste valve. A flange joint was incorporated between the delivery valve and air chamber to facilitate the quick opening and reinstallation of air chamber. Air chamber was fabricated with provisions to alter the volume, by changing the length of air chamber – the diameter of the air chamber was kept constant. The performance of hydraulic ram was evaluated mainly observing the delivery head – delivery discharge relationships. In each case the efficiency of the ram was evaluated. Typical performance characteristic curves were plotted for each of the changes in the conditions of operation. Effect of volume of air chamber on the performance of hydraulic ram was studied. The study revealed that the efficiency of the ram increases 1. as the weight of delivery valve increases 2. as the stroke length of delivery valve decreases 3. as the volume of air chamber increases 4. as the stroke length of waste valve decreases There is a steep reduction in delivery discharge with unit increase in delivery head. For a particular combination of waste valve, delivery valve and volume of air chamber, the maximum efficiency occurs at a moderate delivery head. For an increase in the stroke length of waste valve, there is a large reduction in best frequency. The beat frequency increases as the delivery head increases. The rate of decrease of best frequency with respect to the stroke length is higher for lower weights of was to valve. The ram stops functioning at certain low value of delivery head. This low valve of delivery head increases with increase in weight of delivery valve. Corresponding to a certain weight of delivery valve, there is a minimum weight of waste valve at which the ram functions satisfactorily. Further investigations are necessary to standardise different parts of the hydraulic rams for optimising their performance under varying conditions.