PRESSURE AND DISCHARGE VARIATION REGULATION THROUGH OPERATING TECHNIQUE IN LEVER OPERATED KNAPSACK SPRAYER

Abstract

The operating pressure and discharge rate at the nozzle of Lever Operated Knapsack (LOK) sprayer varies due to variation in air pressure in pressure chamber. Therefore the variation in chamber air pressure was analysed theoretically and the pressure head and discharge variation values were calculated and verified by actual observations. By conventional operating technique the theoretical pressure head variation at the nozzle during the start and end of stroke for studied sprayer was in the range of 3x10⁵ to 5.72x10⁵ Pa and discharge variation at the nozzle was 8.42x10^-6 m³/sec. to ll.26xl0^-6 m³/sec. The new operating technique where the air pressure in the chamber was built up initially helped in regulating this range of variation of pressure and discharge rates. Thus, when operating pressure of 3.0xl0⁵ Pa absolute air pressure was builtup in pressure chamber, the pressure variation at the nozzle during the start and end of stroke was 3x10⁵ to 3.68x10⁵ and discharge variation at the nozzle was 8.42x10^-6 -9.23x10^-6 m³/sec only. The actual observations showed that predicted values were within 2.2%. Thus uniform application rate during operation was achieved.