www.tjprc.org editor@tjprc.org PERFORMANCE EVALUATION OF A CENTRIFUGAL BLOWER OF AIR ASSISTED SPRAYER FOR ORCHARD PESTICIDE APPLICATION K. G. DHANDE 1 , RAVI MATHUR 2 & AJAY SHARMA 3 1 Associate Professor (FMP), Dr. B. S. Konkan Krishi Vidyapeeth, Dapoli, Ratnagiri, Maharashtra, India 2 & 3 Professor (FMPE), College of Technology and Agricultural Engineering, MPAUT, Udaipur, Rajasthan, India ABSTRACT In air carrier sprayer, spray liquid is carried to the target by air. The volume of air required is equal to the volume of the tree for effective coverage. The centrifugal fan with a forward curved blade and blower casing was designed to deliver the air of 3 m 3 /s for 35 hp tractor operated air assisted sprayer for orchard pesticide application on Mango orchard. The blade shape, blade inlet and outlet angle and blade inclination angles which have the best performance were considered. The keeping all other design parameter constant, three centrifugal impeller (fan) with 36, 40 and 44 number of blades was design and developed. The performance of the developed blower was evaluated tested at five blower speed in laboratory as per AMCA standard to know the best operating parameter for efficient and economical operation. The best performance was observed for Blower B with 40 blades and was selected for development of air assisted sprayer. KEYWORDS: Centrifugal Blower, Blower Speed, Air Discharge, Air Pressure, Casing, Input Power, Blower Efficiency Received: Jun 16, 2016; Accepted: Jul 01, 2016; Published: Jul 15, 2016; Paper Id.: IJASRAUG201617 INTRODUCTION The deposition of spray droplets, requirement of air volume in air assisted spraying system and pesticide application rates are mainly influenced by canopy characteristics, like leaf area index and leaf area density. The average size of tractor available in India is 35 hp and present spraying systems are not suitable for 35 hp tractor. Considering the constraints of available power, canopy characteristics, canopy height of mango tree blanket application is not possible. The suitable alternative will be localized application by air-assisted system operated by 35 hp tractors. A centrifugal impeller with a forward curved blade impeller was designed for the required air velocity and volume to be suitable for used on air assisted sprayer for Alphanso Mango trees. Samson (1987) studied effect of blade number and outlet blade angle on blower performance. The rate of increase of flow rate decreases as the blade number increase from 24 to 30 still increased in blade number may reduce flow passage considerably to cause some resistance to the fluid flow. The 120 0 outlet blade angle, the reduced flow passing due to increase blade number to 30 was not affect much incases of the air flow. He also mentioned that selection of number of blade should be finalized at the cost of input power to the blower as well as discharge. Shah et al. (2003) carried out assessment of forward and backward curved radial tipped centrifugal fans. They observed that the pressure head generated by forward curve radial tipped centrifugal fan was higher than that for backward curved radial tipped centrifugal fan. At 50 % and 75 % damping conditions, efficiencies of backward curved radial tipped centrifugal fans were 93.9 % and 81 %, while that for forward curved radial tipped centrifugal fan, these values were 87.5% and 66 % respectively at 2800 rpm. Original Article International Journal of Agricultural Science and Research (IJASR) ISSN(P): 2250-0057; ISSN(E): 2321-0087 Vol. 6, Issue 4, Aug 2016, 119-130 © TJPRC Pvt. Ltd.