Spray Nozzles 30
Spray Nozzles 30 : Spray Characteristics 9: Drop Size Distribution: The size and/or volume distribution of drops in a spray is typically expressed by the size versus the cumulative volume percent. Relative Span Factor: Comparing drop size distributions from alternate nozzles can be confusing. The Relative Span Factor (RSF) reduces the distribution to a single number. The parameter indicates the uniformity of the drop size distribution. The closer this number is to one, the more uniform the spray will be (i. e. tightest distribution, smallest variance from the maximum drop size, Dmax, to the minimum drop size, Dmin). RSF provides a practical means for comparing various drop size distributions. Drop size measurement: The three most widely used methods of drop size measurements are laser diffraction, optical imaging, and phase Doppler. All of these optical methods are non-intrusive. If all the drops had the same velocity, the measurements of drop size would be the identical for all methods. However, there is a significant difference between the velocity of larger and smaller drops. These optical methods are classified as either spatial or flux based. A spatial sampling method measures the drops in a finite measurement volume. The residence time of drops in the measurement volume affects the results. The flux-based methods sample continually over a measurement cross-section
No records Found