PhD Thesis
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Item Investigations on physico -mechanical properties of coconut palm for the design and development of a coconut palm climber(Department of Farm Machinery and power engineering, Kelappaji College of Agricultural Engineering and Food Technology, Tavanur, 2025-06-10) Ayisha Mangat; Sureshkumar, P KCoconut palm (Cocos nucifera L.) is a versatile tree with global cultivation spanning about 12 million hectares. India leads in production, contributing around 31.45% of the world's total coconut output. In Kerala, coconut is the second most important crop after paddy, producing 5,921 million nuts annually. Despite its widespread cultivation, harvesting remains a significant challenge due to a shortage of skilled labor, youth reluctance to pursue coconut harvesting as a career, health risks, and the lack of proper mechanical climbing devices. A study was conducted to investigate the physico-mechanical properties of the coconut palm such as height of palm, girth at different levels, inclination of palm trunk with respect to ground and hardness, with the aim of developing a climbing device. It was collected from three districts viz. Malappuram, Palakkad and Thrissur. Two instruments namely Inclinometer and Tree hardness tester were developed for measuring inclination and hardness of live palm as there are no instruments readily available for those measurements. A comparative study of some existing models of coconut palm climbers like Chemberi model, TNAU model, CPCRI model, KAU coconut palm climber, KAU Kera Suraksha, and Chachoos Maramkeri was conducted to identify their important features. Additionally, an engine-operated coconut climbing device was also studied. The height ranges from 8 to 18 m for tall varieties and for dwarf varieties it ranges from 3 to 8m. The GBH of coconut palm comes within the range of 60 to 100 cm. The maximum number of palms falls in the range of 80-85 cm GBH. The crown width comes within a range of 7-12 m, with an average value of 9-9.5 cm. The inclination was categorized into four groups and the data reveals that 92.1% of the palms fall under the "Erect" category. Hardness of palm trunk was measured using the developed Tree hardness tester with three different indenter tools of different head geometries like wedge, spherical, and square. It was measured at four different penetration depths such as 1 mm, 2 mm, 3 mm and 4 mm. All tools demonstrate a reduction in hardness as penetration depth increases. Highest hardness recorded is 6.85 N mm-2 for sphere shaped tool. The Wedge tool experiences the sharpest decline in hardness with depth, suggesting that its penetration becomes easier as it moves deeper into the palm. Based on the preliminary study of the physico-mechanical properties of coconut palms and the analysis of the features of existing climbing devices, some functional requirements were identified for designing a new coconut climber. A conceptual design was then finalized and the subsystems were developed to meet these requirements. The components of the designed climbing device were Extendable Mechanism, Hauling mechanism, Safety mechanism, Top fixture ring and Mounting fixture and transport aid. The extendable mechanism comprised a telescopic rung ladder with three sections, each measuring 4.6 meters, designed to reach a height of 12 m. The extension to its full length is facilitated by a hauling system that includes steel wire rope and pulley, a winch mechanism, and a power source. The power required to lift the ladder and climber to a height of 12 m was calculated based on the weight to be lifted and the desired lifting speed. A 1 hp electric motor was selected as the power source to efficiently operate the hauling mechanism and lift the ladder to the required height. Suitable speed reduction mechanism for the winch system with a speed reduction ratio of 60:1 was selected to get the desired climbing velocity of 0.14 ms-1 . The telescopic ladder is securely supported on the palm trunk using a top fixture ring that prevents the ladder from sliding sideways. Self-adjusting, spring-loaded rollers were incorporated within the top ring to accommodate the varying girth dimensions of the palm trunk corresponding diameters ranging from 200 mm to 320 mm, representing the minimum and maximum trunk diameters observed in the field.A sturdy, trapezoidal-shaped basket was hinged to the top of the ladder section for operator safety. A safety harness was also recommended for enhanced protection. All the components were mounted on a trolley platform with provisions for rotational control and tilt control. Finite element analysis of the ladder and mounting fixture was done. The values for ladder show that the deformation and stress reach a maximum of 76.612 mm and 70.814 MPa, respectively for an applied load of 1500 N. For mounting fixture, the deformation was 2.7766 mm and stress was 205.76 MPa. The time taken for climbing a 12 m height coconut palm including setting time was 130 seconds and that for climbing down including dismantling was 120 seconds. The climber requires an initial investment of ₹95,000, has a lifespan of 15 years, and a resale value of ₹9,500. The total operating cost of the device was ₹240 per hour, while the cost of climbing per tree was ₹40, assuming six trees were climbed per hour.Item Development and ergonomic evaluation of spading machine as an attachment to power tiller(Department of Farm Machinery and Power Engineering, Kelappaji College of Agricultural Engineering and Technology ,Tavanur, 2023-12-19) Chandrashekar; Bini SamTillage is the physical manipulation of soil with tools and equipment to achieve good tilth for enhanced seed generation and subsequent crop growth. A spading machine works as an alternative to the plough for primary tillage. There are limitations in manual spading and tractor operated spading in small and marginal fields. Manual spading needs more labour, takes longer time, more energy and high cost per cultivable area. The depth of cut is also low while using a manual spade. Tractor operated spading machines have their own set of limitations in small fields, and their cost was also out of reach for small and marginal farmers. These factors lead to the development of a spading machine as an attachment to power tiller. A power tiller (6.7 kW) was selected as a prime mover for the spading machine. The developed spading machine consists of gear box, power transmission system, frame, crank shaft, connecting rod, spade and depth gauge wheel. A laboratory model of spading machine was fabricated and tested to finalize the optimum machine parameters for the development of new spading machine. The actual field capacity of power tiller operated spading machine was 0.1132 ha h-1 which is higher than the traditional method (0.008 ha h-1). Overall, the maximum field efficiency 87 per cent was achieved at the forward speed of 2.1 km h- 1, when the depth of cut was 10 cm at 30° spade angle and 200 rpm crankshaft speed. It was observed that the actual field capacity and field efficiency of spading machine increased with increase in forward speed and was higher with trapezoidal shape blade than triangular blade since it covers more area per unit time. The maximum clod mean weight diameter of 15 mm was recorded at a forward speed of 1.5 km h−1 with crankshaft speed 100 rpm. The minimum draft requirement and fuel consumption of spading machine were 820 N and 0.87 l h-1 recorded at a forward speed of 1.5 km h−1 with 10 cm depth of cut. The minimum heart rate of 95 beats min-1 was recorded at 1.5 km h-1 forward speed of power tiller and the maximum heart rate 125 beats min-1 was observed at 2.1 km h-1 forward speed of the power tiller. A significant variation in energy expenditure of spading operation was noticed at 5 per cent level with different forward speeds. Minimum energy expenditure rate of 12.26 kJ min-1 was obtained at 1.5 km h-1 forward speed of the power tiller and the maximum energy expenditure rate 21.82 kJ min-1 was noted at 2.1 km h-1 forward speed respectively. The grade of work was “moderately heavy” for power tiller operated spading machine and ‘heavy” for traditional method. Maximum aerobic capacity of subjects varied from 1.75 to 2.08 l min-1. The mean values of AWL (VO2 Max) for all subjects varied from 40 to 47 per cent indicated that the spading machine could not be operated continuously for 8 hours without frequent rest pauses. The overall discomfort rating was 4.6, 5.1 and 5.7 at 1.5, 1.8 and 2.1 km h-1 respectively and it was scaled as “moderate discomfort”. Overall safety rating was scaled as “moderately secure and less fear”. Overall ease of operation rating was scaled as “Less difficulty” with a score of 4, 4.3 and 4.6 at forward speeds of 1.5, 1.8 and 2.1 km h-1 respectively. It was observed that the, body part discomfort score was maximum for 2.1 km h-1 with a score of 43 followed by 1.8 km h-1 with a score of 33 while it was minimum at 1.5 km h-1 with a score of 25. The rest time for achieve functional effectiveness during the operation of power tiller operated spading machine was found to the 10 min followed by one hour of work. The noise level was recorded for different engine speeds, varied from 86 dB at the operator ear level to 102 dB at the engine top. The vibration level was recorded for different engine speeds, varied from 11 m s-2 at right handle to 37.6 m s-2 at engine top. The cost of prototype of power tiller operated spading machine was worked out as Rs. 50,000/-. The cost of operation per hour and hectare was determined as Rs.335/- and Rs. 3,316/- respectively. The breakeven point, payback period and benefit cost ratio of the machine is 93 h year-1, 3.5 years and 2.1:1 respectively. The saving cost of operation of machine was calculated as Rs. 6,884 ha-1 and 67.5 per cent when compared to conventional method of spading operation.Item Development and evaluation of semi-continuous microwave convective dryer for food products(Department of Processing and Food Engineering, Kelappaji College of Agricultural Engineering ,Tavanur, 2024-05-10) Alfiya, P V; Rajesh, G KThe research work aimed to develop a semi-continuous microwave convective dryer for foods and evaluate the performance of the dryer for drying of shrimp and oyster mushroom. The study also aimed to assess the shelf-life of the dried products under different packaging technologies and packaging materials. The quality of conventionally dried shrimp and oyster mushrooms were compared and evaluated with the hot air assisted microwave (HAMW) dried products. The developed HAMW drying system comprised of a drying chamber, conveyor belt, magnetron to generate microwaves at frequency of 2450 MHz±50 MHz, hot air generation system with air heater, axial fan and other controls. The drying experiments for shrimp were performed according to a second-order Box- Behnken design (BBD) with three factors at three levels: microwave power (600, 800 and 1000 W), air temperature (50, 60 and 70 °C), and air velocity (0.5, 1.0 and 1.5m/s). Drying time, water activity, and rehydration ratio was selected as the response variables. A three-factor, three-level Box-Behnken design (BBD) experimental design was used in optimizing the drying conditions for shrimp in a hot air-assisted microwave (HAMW) drying system. The optimization was performed to optimize the conditions with minimum values of drying time and water activity, and maximum value of rehydration ratio. The design plan consisted of 17 runs with 5 centre points. The optimum conditions of process variables were derived using the desirability function. Design Expert Statistical Software package 9.0.0 (Stat Ease Inc., Minneapolis, MN, USA) was used to perform statistical analysis. The moisture content of shrimp decreased from an initial value of 80.55% to a final value of 16.5% within 2.9 h of drying. HAMW drying of shrimp was represented by reduction in moisture percent as a function of drying time. Moisture ratio obtained during drying were fitted into thin layer drying models by non-linear regression analysis. Page model was identified as the best fit model with higher R2 value of 0.9984, lower χ2 value of 0.000134 and RMSE value of 0.01552. Drying efficiency of the dryer under HAMW mode was observed to be 35.71%. This was a result of volumetric hearing effect of microwave radiation combined with convective effect of hot air. The SEC value for HAMW of shrimp was found to be 1.75 kWh/kg. The total value of colour change (ΔE) determined for dried shrimp was 16.95 ± 2.14. The ‘L’ value of the dried shrimp (41.31 ± 1.63) decreased during drying whereas the ‘a’ and ‘b’ values increased from 3.56 ± 1.54 to 14.23± 2.36 and 12.42 ± 0.65 to 19.42 ± 1.61 during the drying process. 265 Solar radiation, ambient temperature and relative humidity (RH) were measured using sensors at each hour of the study. The solar radiation intensity during the experimental conditions was observed to be in range of 320 to 840 W/m2, ambient temperature varied from 27.5 to 36.5 0C and RH from 62.45% to 77.24% on a typical day of the experiment. The moisture content of shrimp was reduced from 80.2% to 15.7% (w.b.) within 6 h of drying in the solar dryer. The drying conditions were maintained at temperature, air velocity and RH of 55±1.5 0C, 1.5 ± 0.25 m/s and 60±0.5 % respectively. The drying rate of solar and microwave dried shrimp was found to be 1.63 kg/kgh and 2.74 kg/kgh at the beginning of drying. Drying rate exhibited a maximum value of 2.74 during The average rehydration ratio was observed to be 2.39 and 2.53 for SD and HAMW drying respectively. The shrinkage percentage of SD and HAMW shrimp was observed to be 24.67 and 14.14% respectively. Storage studies of hot air assisted microwave dried and solar dried shrimps were carried out under MAP and vacuum conditions in three types of packaging materials namely LDPE (150 μ), polyester polyethylene laminate (72 μ) and metallised polyester (84 μ). Shelf life of the dried shrimps was quantified with respect to the microbial growth and other quality parameters. Maximum storage life was exhibited for SD and HAMW dried shrimp under polyethylene-polyester laminated (72 μ) packaging material. The response surface methodology plots of Oyster mushrooms showed that drying time decreased with an increase in air temperature (40 to 60℃) and microwave power (600 to 1000W). Based on the value of maximum desirability (0 to 1), optimum conditions were selected. The methodology of desired function was applied to indicate 55.05 ℃ air temperature, 1000 W microwave power and 0.81 m/s air velocity which indicated the drying time, water activity and rehydration ratio of 5.05 h and 0.532 and 2.49, respectively with a desirability value of 0.830. Moisture content of Oyster mushroom decreased from 92.35 to 8.42% within 5 h of drying. Volumetric heating effect of microwaves can be attributed for the reduction in drying time. Microwave heating falls under dielectric heating method wherein the moisture content of the product directly influences the heating rate. Drying rate exhibited maximum value of 3.47 during the initial stages in drying that can be due to the higher moisture content of sample that created more friction and heat generation due to dipole rotation. Drying efficiency of the dryer under HAMW mode for oyster mushroom was observed to be 23.12%. The SEC value for HAMW of oyster mushroom was found to be 2.71 kWh/kg. Solar drying efficiency of the collector was calculated using the whole collector area 266 and solar irradiation received instantaneously during drying. The instantaneous collector efficiency values varied in the range of 30.9 to 42.4%. The L*, a* and b* colour values of fresh mushrooms were determined to be 84.12±0.46, 3.3±0.24 and 15.57±0.62 respectively. The colour values of the microwave dried mushrooms under optimized conditions were recorded as 56.15±0.25 (L*), 4.95±0.24 (a*) and 20.85±0.51 (b*) respectively. The ‘L’ value of the dried oyster mushroom decreased whereas the ‘a’ and ‘b’ values increased during microwave convective drying. The drying rate of SD and HAMW dried oyster mushrooms were found to be 3.47 kg/kgh and 2.14 kg/kgh at the beginning of drying. Drying rate exhibited a maximum value of 3.47 during the initial stages of drying that can be due to the higher moisture content of a sample that created more friction and heat generation due to dipole rotation. Drying reduced the TPC value of oyster mushroom to 1.2 × 104 and 3.9 ×105 CFU/g respectively under MW and SD drying conditions. The optimized sample was analysed for microstructure to study the pore size distribution in the dried product. The pore size for microwave dried oyster mushroom samples ranged from 8.65 – 32.4 μm. Scanning electron microscopy analysis of microwave dried oyster mushroom showed the formation of pores of diameters ranging from 2.06 – 15.7 μm. Storage studies of hot air assisted microwave dried and solar dried oyster mushrooms were carried out under MAP and vacuum conditions in three types of packaging materials namely LDPE (150 μ), polyester polyethylene laminate (72 μ) and metallised polyester (84 μ). Shelf life of the dried oyster mushroom was quantified with respect to the microbial growth and other quality parameters and maximum value of 9 months was achieved for SD and HAMW dried oyster mushroom in polyethylene-polyester (72 μ) laminated packaging Material.Item Optimization of agronomic resources for maximizing grain and mill yield of rice(Department of Agricultural Engineering, Indian Institute of Technology, Kharagpur, 1976) Kannan, Mukundan; Pande, H KItem Development of a bund strengthening implement for paddy wetland based on soil - machine parameters(Department of Farm Machinery and Power Engineering Kelappaji College of Agricultural Engineering and Technology, Tavanur, 2018) Suma Nair; Ramachandran, V RThree models (BF1, BF2 and BF3) of a low cost, tractor drawn bund strengthening implement were developed and their performance was evaluated at three test locations, viz., Pullazhi kolepadavu in Thrissur kole lands, Kolothumpadam kolepadavu in Ponnani kole lands and Athalur, Tavanur (non-kole). The forming board type design was chosen. The major dimensions of the developed models, viz., top width, bottom width and rear height are 150, 250 and 150 mm for BF1, 200, 350 and 150 mm for BF2 and 250, 400 and 250 mm respectively. The main parts of the implement were the MS angle bar tool frame and hitch assembly of size 1150 mm x 500 mm, implement frame made of MS angle bars to connect the forming board assembly to the tool frame, modified forming boards with gathering boards attached in the front, and a 400 mm long, three sided forming case at the rear which provided a plastered finish to the formed bund. All the elements, including the forming boards and the forming case, acted like a single unit. Analyses of the various soil properties at the three test sites were also performed. The soils at Pullazhi kolepadavu and Kolothumpadam kolepadavu were silty clay while the soil at Tavanur was sandy loam in texture. The dimensions of the bunds drawn by the implements were suited to the prevalent farmers’ practice at Pullazhi and Ponnani. At Tavanur, new bunds could be drawn using the implements. At Pullazhi kole fields, models BF1 and BF2 showed a better performance in terms of strength measured as cone index. The performance of BF3 and BF4 gave the best results at Ponnani. BF2 or BF4, operated by NH 3230, were suitable to the Tavanur fields, in terms of strength of bund as assessed by cone index. Shear strength values exhibited by the manual bunds were always lesser than that by mechanically formed bunds at Pullazhi. Bunds formed by BF2 showed the highest value of 46.02 kPa at 0.2 m depth which went upto 40.81 kPa on the seventh day. The same trend was seen in Ponnani also but the bunds formed by BF3 and BF4 had the highest shear strength values.The average speed of operation ranged from minimum of 1.24 km h -1 when BF1 was operated by KTT at Tavanur, in sandy loam soils to 2.98 km h -1 when BF2 was operated by JD 5042 at Ponnani. Draft was least for BF1 operated by KTT and highest for BF3 and BF4 operated in Ponnani silt-clay. The minimum fuel consumption was noted as 2.53 L h -1 for BF1-NH 3230 combination at Tavanur while the maximum was 3.76 L h -1 for BF3-JD 5042 at Ponnani. The BF4 trials had higher consumption of 7.71 L h -1 in silty clay at Ponnani and 5.62 L h -1 in sandy loam at Tavanur. The maximum capacity of 2984.24 m h -1 was observed for BF2 operated by JD 5042 at Ponnani kole. BF4 had lower capacities as two passes of the tractor were required to complete the operation. The minimum capacity of mechanical bund strengthening implement is 906.86 m h -1 . The manual operation has a capacity of 62.5 m h -1 . Thus there is a 14 times increase in capacity of bund formation by mechanical implements. Wheel slip is within the acceptable range of 5 to 15 per cent. The cost of mechanical formation of bunds ranges from Rs. 18/- to Rs. 30/- per 100 m. while it ranges from Rs. 178/- to Rs. 227/- for manual operation. The developed implement had a FOS of 2.17. Hence, taking all observations into account, it can be summarised that the bund strengthening implement model BF2 was found suitable to Pullazhi kolepadavu in terms of size, strength, lower moisture content and higher bulk density. At Ponnani, the models BF3 and BF4 performed well. However, as BF4 operation involved a higher fuel consumption and lower capacity of bund formation, the model BF3 can be recommended. At Tavanur fields, the prevalent manual bunds showed better performance parameters. However, new bunds can be formed in the fields using the developed implements. Trial BF4 and BF3 gave better performance in these soils.Item Evaluation and refinement of low cost automation system for naturally ventilated greenhouse(Department of Soil and Water Conservation Engineering, Tavanur, 2019) Jinu, A; Abdul Hakkim, V M