Browsing by Author "John Thomas, K"

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Design and development of a high capacity Salvinia Harvester
(Department of Irrigation and Drainage Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1987) Hajilal, M S; John Thomas, K
Salvlnla molesta locally known as 'African Payal* ia a noxious floating typo aquatic weed in many parts of the humid tropics. Kerala Agricultural university developed a mechanical device to harvest this menacing weed. An investigation on the performance of the prototype Salvinia Harvester was carried out under various conditions. Prototype ejector E1 with secondary flow straight and primary flow inclined at 900 ejectors E2 and E3 with primary flow straight end secondary flow inclined at 400 and 20° respectively and ejector E4 with secondary flow straight and primary flow inclined at 300 were tested along with circular mouth (M1), adjustable rectangular mouth (M2) and elliptical mouth (M3)• Experiments were also conducted to find out the optimum depth of mouth below the water level. The study revealed that clogging was a serious problem for the prototype Salvinia Harvester, where the weed was in the initial stages of third growth phase. Ejectors E1 and E2 showed clogging when tested with all the different feeding mouths. The E4-M2 and E4-M3 combinations yielded almost identical harvesting capacity of 11 t/hr at one metre static lift mad 12 t/hr at 40 cm static lift without any problem due to clogging. All these experiments conducted revealed that the ejectors E3 and E4 can be used under ell conditions of weed growth without clogging along with mouths M2 and M3. The machine is capable of removing weeds at the rate of 16 t/hr where the spread density value was around 16kq/m2 (160 t/ha) like Kuttanadu area. Hence the machine would be capable of Removing the weeds in one hectare in 10 hours. The estimated cost of operation amounted to Rs. 353/- per hectare which compared favourably with the reported costs of Rs.900/- to Rs.2700/- per hectare for manual collection and disposal.
Development of cocoa drier
(Department of Agricultural Engineering, College of Horticulture, Vellanikkara, 1985) Abdassalam, M; John Thomas, K
An 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.
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 Koshy, A; John Thomas, K
The pump capability requirement in agriculture especially in rice production is essentially one of low lift end high capacity. Because of the low lift condi¬tions 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 lifts also. Four types of ejector systems were developed and the best one was chosen* based on the capacity ratio and multiplication factor. Experiments were conducted to find out the useful range of suction lifts in which the attachment can be advantageous. Design parameters and efficiency characteristics also were studied. The study revealed that the ejector E2 with primary flow straight and secondary flow inclined at 400 gave higher capacity ratio and multiplication factor than the other three ejectors. Hence E2 was selected for further experiments. For a suction lift of one metre E2 gave a capacity ratio of 3.4 and multiplication factor of 2.6 for the 5 HP centrifugal pumpset. With a 10 HP centrifugal pumpset E2 gave a capacity ratio of 3.6 and multipli¬cation factor 2.8, for a suction lift of one metre. E2 is also having many other advantages than the other three ejector such as easiness of fabrication and fixing. A centrifugal ejector combination requires less capital investment than buying several pumps for use at different heads. Muddy and debris laiden water can be pumped through the ejector system as it has no moving parts. Time of pumping can be reduced by the addition of an ejector system, thus saving power, either electricity or diesel. It can be fabricated in a local workshop and transportation is also very easy. The estimated cost of fabrication of the ejector system is 59.870/-
Effect of soil solarization using ldpemulch on moisture conservation and soil temperature variation
(Department of Land and Water Resources and Conservation Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1997) Anu Varughese; John Thomas, K
Soil solarization is based on mulching the soil surface with transparent polyethylene sheets which capture the solar radiation and thus heat the soil to a level lethal for various pests. Solarization is useful in the control of weeds and also helps in moisture conservation. To some extent this can satisfy the demand of water for pre sowing irrigation during the summer months by conserving the moisture in the soil. In the experiment two types of polyethylene sheets (0.10 mm and 0.05 mm) were used and three durations of solarization, i.e., 30 days, 40 days and 50 days were tried. A crop (bhindi) was sown in the area after the solarization period to know the effect of solarization on its performance. The average maximum soil temperature at 5 cm depth obtained in the non-solarized plots was 49.5°C only, but in solarized plots it went upto 56.5°C. The magnitude of rise in soil temperature of solarized treatments was higher due to 0.05 TP than 0.10 TP. The intensity of solar radiation reaching the soil surface was significantly higher in the non-solarized plots than in the solarized plots. There was significant increase in the moisture content values in the solarized plots compared to the non solarized plots at 5, 10 and 15 cm depth below the soil surface. The moisture content values in 0.05 TP solarized plots were slightly higher than in 0.10 TP solarized plots, but was not significant. In the solarized treatments, there was 37.9, 33.7 and 38.3 per cent increase in the moisture content values at 5, 10 and 15 cm depths respectively. Solarization also had significant effect in lowering the weed count as well as the dry weight of the weeds for around 5 months after the period of solarization. The yield of bhindi was significantly higher in the solarized treatments than in the non-solarized treatments. This increase in the yield of bhindi may be due to the drastic reduction in weed count and dry weight on account of solarization.
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; John Thomas, K
Fabrication and testing of a low cost flat plate collector-cum-storage solar water heater
(Department of Farm Power Machinery and Energy, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1990) Lissy Kirian; John Thomas, K
Kabbani river basin: A study with reference to horton's laws
(Kerala Agricultural University, 1994) Jayasree, S; John Thomas, K
A quantitative analysis of the linear morphological parameters and their relationship with average monthly monsoon discharge was conducted using the data collected from the Water Resources Divisional Office, Trichur. Most of the parameters were inter-related and obeyed Morton's laws. The smallest tributaries formed the major part of the river basin. The stream flow during the periods 1976-'80 and 1981-'85 varied with the basin shape.
Model study for stream flow of Chaliyar
(Kerala Agricultural University, 1994) John Thomas, K; Jayasree, S
Performance evaluation of high discharge low head pumps
(Department of Irrigation and Drainage Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1998) Rini Rani, S; John Thomas, K
Paddy cultivation in Kuttanad and Kole lands is made possible only after large scale dewatering operations. These water logged lands have to be drained in the shortest possible time to initiate seed bed preparation. The short time available for seed bed preparation need adoption of high discharge low head pumps. The most commonly used centrifugal pump is incapable of giving corresponding increase in discharge rate even if the lift required is reduced to a minimum. So this study was undertaken to help to identify a suitable portable pump for meeting the specific requirement of drainage in Kerala. Mixed flow and axial flow pumps imported from Thailand were used for this purpose. The study included testing of lS-cm mixed and axial flow pump at the specially designed and constructed test bed at different speeds and at different water levels in the pumping sump. For each test, from the data obtained discharge, input power and efficiency were calculated. Using the calculated values performance characteristic curves were plotted and regression equations were developed for discharge efficiency, discharge - total head and discharge - input power relationship at each speed. Performance curves were also plotted keeping total static head const ant and regression equations of speed - discharge, speed - total head, speed - input power and speed efficiency relationships were developed. The maximum efficiency of IS-cm mixed flow pump was 42.16 per cent at a speed of 1000 rev/min, against a total head of 217.33 cm and a discharge rate of 49.47 L/s. The input power corresponding to this efficiency was 3.4 hp. The best performance of mixed flow pump was noted at a working speed of 1000 rev/min. The maximum efficiency of IS-cm axial flow pump tested was only 18.05 per cent at a total head of 160.55 cm and a discharge of 24.88 L/s. The corresponding speed was 2500 rev/min and input power was 2.95 hp. The best performance of axial flow pump was noted at a working speed of 2500 rev/min.
Performance evaluation of hydrocyclone filter
(Department of Irrigation and Drainage Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 2001) Damodhara Rao, M; John Thomas, K
Potential of Salvinia mo lest a (African payal) as an alternative and supplemental feed stock to cattle dung for biogas production
(Kerala Agricultural University, 1988) Sankaranarayanan, M R; John Thomas, K
The floating aquatic weed, Salvinia molesta (locally known as 'African payal') could be easily fermented and hence is a very good material for biogas production. The average gas production per kg of oven dried salvinia weed was 336 litres with a retention time of 50 days. The gas generation could be doubled when mixed with fresh cowdung in the ratio 1:1. Thus we can make up the shortage of cowdung with the use of salvinia weed for biogas production, wherever it is available.
Quantitative analysis of runoff parameters in selected river basins of Kerala
(Department of Irrigation and Drainage Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1990) Jayasree, S; John Thomas, K
The evolution of a drainage basin is the result of the flow of mass and energy and the resistance of topographical surface. Precipitation is the major source of matter and solar radiation, the source of energy. The stream flow is a function of geomorphological and hydrological factors of the river basin. The objectives of this study were to make a quantitative analysis of the effects of geomorphological and climatic factors on the stream flow and to study the inter – relationships between these factors. The selected river basins were Chaliyar and Kabbani. The specific objective was to express stream flow in terms of morphological factors and rainfall. The river basin was divided in to sub basin, each of which contains a rivergauge station. Morphological factors were measured from the map. Monthly rainfall from all the raingauge stations were collected and the arithmetical average for each sub-basin was computed. The monthly stream flow was also collected. It was found that the morphological factors were interrelated. The number of stream segments of successive order form a decreasing geometric progression whereas the length of stream segments of successive orders form an increasing geometric progression. Confluence ratio is inversely related to stream flow. Elongation and drainage area are highly correlated. A larger value for the confluence ratio indicates a more elongated basin and a lower flood peak. The sub - basins are similar to the form of a rectangle. Area and elongation are the morphological parameters strongly influencing the stream flow. Drainage density and stream frequency are highly correlated. Drainage density gets altered by the land use, vegetal cover, deforestation and urbanization. Drainage density also affect stream flow. Finally, the expressions for drainage area in terms of the main stream length, drainage density in terms of stream frequency and average monthly stream flow contributed by unit area in terms of the average monthly rainfall were obtained. The data used for the final equation was inadequate. The equation may be improved, by increasing the number of rivergauge stations and providing more representative raingauge stations.
Seawater intrusion studies for coastal aquifers
(Department of Irrigation and Drainage Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1988) Saley Abraham; John Thomas, K
Studies were conducted in three villages along the coastal areas of Trichur district, namely, Nattika, Talikulam and Edamuttam, to know the extent of sea water intrusion through aquifers. Observations were made in existing wells along an alignment normal to the coast line. Aquifer parameters and fresh water flow through the aquifer were computed making use of borehole data available for the region. The positions of the interfaces were determined using established formulae. The possible shifting of the interfaces due to reduction In fresh water discharge consequent to future increased rate of pumping was predicted. In each village, -three wells were taken for the study purpose. In all the cases, the maximum rates of pumping for various depths of wells, which will not cause sea water intrusion problems, have been deter¬mined. Chemical analysis showed that, at present there was no salt water intrusion in the wells under study. The results of the present study lead to a better understanding of the sea water intrusion problem, the determination of the position of the interfaces for various pumping rates might be effectively used in fixing the location of wells, pumping rates and depth of wells. The study would be made use of designing a ground water system in coastal areas for a better utilisation of ground water resources.
Studies on selected manually operated pumps
(Department of Farm Power Machinery and Energy, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1990) Geeta Susan Philip; John Thomas, K
Water balance study of Karuvannur river basin
(Department of Irrigation and Drainage Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1988) Santhosh Thampi, G; John Thomas, K
Water balance techniques are a way of solving important theoretical and practical hydrological problems. By using the water balance approach, it is possible to make a quantitative evaluation of the water resources and to assess any changes that might occur through the influence of man's activities. The broad objective of this project was to make a quanti-tative evaluation of the water resources of the Karuvannur River Basin. The ultimate objective was to study the monthly water balance for the basin in order to estimate the balance available for ground water recharge or depletion during the period 1976 to 1985. Monthly rainfall data at all rain gauge stations in the basin were collected. The mean monthly rainfall in the basin for each month of the period 1976 to 1985 was calculated using Thiessen polygon method. Irrigation water was identified as the other input into the basin. Data regarding the amount of water released for irrigation from the Peechi Reservoir was collected. Due to lack of data, contribution from other sources was not taken into account* Surface and subsurface in flow and out flow, into and from the basin, were assumed to be negligible. Data regarding total runoff from the basin during each month of the above period was. also collected. The amount of water used up in meeting evapotranspiration requirements was estimated. • Daily rainfall data at Ollukkara for a period of 20 years was collected and a frequency analysis was done. The result has been presented graphically. Equations for predicting annual runoff from the basin were developed. It was found that a high degree of correlation exists between annual runoff and annual rainfall values. For each month during the period 1976 to 1985, the balance water, available for ground water accretion or to be met from the ground water reservoir, (unaccounted water) was estimated. It was found that accretion to ground water occurs mainly in June, July and August, Some recharge may occur in the months of May, September, October and November also. ♦ When the water balance is calculated on an annual basis, it was found that the balance available for ground water accre¬tion is negative in 1976, 1984 and 1985. Low rainfall had been recorded during these three years. The values of the balance water available for ground water accretion or depletion (unaccounted water) when cumulated gave very high values. This may be because of unaccounted factors such as subsurface runoff from the basin, unaccounted portion of surface runoff from the basin etc. These factors could not be accounted for due to lack of data. The study underlines the necessity for using the available water resources most judiciously. It emphasises the need for adopting appropriate rain water harvesting methods for reducing runoff during the dry months. Optimum development of water resources can be achieved only through the conjunctive use of surface and ground waters.