Collison Nebulizer Droplet Number Output 
This describes a numerical analysis of the Collison nebulizer to determine the total number of droplets produced for a given back pressure and the count within 2 standard deviations of the mean droplet size (assuming a lognormal distribution).
To determine the number of droplets produced per jet per hour by the Collison, a resulting lognormal distribution of droplet sizes was assumed. The central concept used to determine the number of droplets produced by the Collison is that the liquid volume contained in the total of all droplets produced must be equal to the volume of liquid produced by the Collison on a per time basis. A spreadsheet was constructed with 600 diameters ranging from 0.05 µm to 20 µm in even increments on a logbasis (3 to 3 by every 0.01 ln values). The frequency of occurrence of each diameter was computed with the use of the probability distribution function for a lognormal distribution. The volume associated with each diameter was computed using the equation for the volume of a sphere. The “Solver” function in Excel was then used to determine the counts for each diameter that caused the sum of all volumes (for each diameter) to be equal to the volume generated per hour (as per the equation above) while weighting the count for each diameter by their computed frequency of occurrence. From the total number, the count between
The basis of the table is available for viewing Copyright © 2008 by BGI / Modified:
Friday, April 26, 2013

