The influence of strainer types on the flow and droplet velocity characteristicsof ceramic flat-fan nozzles
Authors: BAHADIR SAYINCI
Abstract: This study focused on determining the effect of various strainer types and their usage without strainer on the flow and droplet velocity characteristics of ceramic flat-fan nozzles. The nozzle types discussed are the standard (APE), low pressure drift reduction (ADI), and wide pressure range (AXI). The results of this study show that the orifice coefficient (k) of the ADI nozzle with a preorifice was lower than those of the API and AXI nozzles. The ball check strainers had a limiting effect on the nozzle's flow rate. The pressure exponent coefficients (n) were 0.57 for the API nozzle and 0.62 for the ADI and AXI nozzles used with ball check strainers. The n coefficient ranged from 0.47 to 0.49 for the API and AXI nozzles and from 0.50 to 0.53 for the ADI nozzle, used with typical strainers and without a strainer. The flow rate deviations of APE, ADI, and AXI nozzles used with a ball check strainer were determined as -12.0%, -11.4%, and -14.5%, respectively. The lowest Cd means were found in all nozzle types with ball check strainers, and the means were determined as 0.45, 0.58, and 0.71 for the ADI, AXI, and API nozzles, respectively. The Cd means of the nozzles with typical strainers, which is the same as usage without a strainer, were between 0.58 and 0.60 for the ADI nozzle, 0.82 and 0.85 for the AXI nozzle, and 0.91 and 0.94 for the API nozzle. Knowledge of the discharge coefficient of the nozzles used with various strainer types provided a reasonable estimation of the maximum droplet velocity at the nozzle orifice exit. The maximum droplet velocity at the nozzle orifice exit increased as droplet size increased. The droplets produced by the nozzles with ball check strainers had features that restricted the nozzle's flow. These were higher maximum velocity, kinetic energy, and stopping distance.
Keywords: Discharge coefficient, droplet velocity, flat-fan nozzle, flow rate deviation, nozzle strainer, pressure exponent
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