Malvern Instruments Spraytec, User Manual

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this is 0, meaning the spray will be vertically upward. For a vertical downward
spray the value will be 180
°
.
Set up the Radii table as described below then click Save . The new spray profile
will appear in the selection list in the Select a Spray Profile dialogue.
The Radii table
By default it is assumed that a spray is homogeneous in terms of concentration. If
users have measurement data showing the true concentration profile along the
radius of the spray, this can be entered using the Radii table:
.
R(%) – the percentage distance along the radius of the spray at which the
concentration is to be set. 0% represents the centre of the plume. 100% rep-
resents the extreme edge of the plume.
.
CvR(%)
– the relative concentration of the plume at the specified position
along the radius. Here, the most concentrated part of the plume will have a
relative concentration of 100%. The concentration at every other point is
then specified as a relative percentage of the highest concentration.
For a homogeneous spray the relative concentration at each point along the radius
would be 100%. For a nozzle where the spray is most concentrated at the centre
of the plume, the profile might be as shown in the following table in the central
column. This shows that the relative spray concentration decreases with
increasing distance from the centre, with the concentration at the plume edge
being only 20% of the concentration at the centre.
R(%)
Plume concentrated
at centre
Hollow
cone nozzle
0 100 20
15 85 25
30 75 40
45 50 60
60 40 100
75 30 60
90 25 40
100 20 20
C H A P T E R 1 0
S p r a y t e c
P a g e 1 0 . 1 5