Curtis Dyna-Fog 2742, Manual

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MEASURING LIQUID FLOWABILITY (VISCOSITY)
In order to achieve consistent results in generating aerosols with a volume-median-
diameter (VMD) in the sub 20 micron range, several variables must be kept under
control at the same time. The ability of an aerosol generator to consistently break up
a liquid into appropriate sized droplets depends on (3) key elements:
1 . The available energy flow (air flow) through the nozzle is governed by the
blower speed. As the air mass and its velocity through the noz z le decreases,
the droplet size (VMD) will increase assuming that the liquids viscosity and
flow rate remains constant.
2. The flow rate of the liquid governed by the speed of the liquid pump.
3. The viscosity of the liquid.
Various liquids have different viscosities. Viscosity is defined as a fluids resistance
to flow commonly measured in units of a centipoise (CP). Generally, the thicker the
liquid, the greater the viscosity and the higher the CP number. Examples of some
liquid viscosities are:
LIQUID VISCOSITY (CP)
WATER 1
DIBROM 3-4
DOW MFC 3-4
PYRETHRIN,
RESMETHRIN 6-7
DURSBAN
1.5 ULV 12-14
TECHNICAL
MALATHION 28
By measuring the flowability of a liquid, adjusting the engine speed to produce the
desired nozzle boom pressure, and by setting the flow rate on the digital readout
remote control box, accurate particle size can be achieved.
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