Spray height impact

When the spray height from the lower trays, impacts the upper trays, the heavier, butane-rich liquid contaminates the lighter liquid on the upper trays, with heavier butane... 

Water resistance test methods include AATCC 127 (hydrostatic pressure test), AATCC 42 (impact penetration test), and AATCC 35 (rain test). In the hydrostatic pressure test, a sample is subjected to a column of increasing water pressure until leakage occurs. The impact penetration test requires water to be sprayed on the taut surface of a fabric sample from a height of two feet. The fabric is backed by a blotter of predeterrnined weight, which is reweighed after water penetration. The rain test is similar in principle to the impact penetration test. 

Perkin-Elmer M 2100 atomic absorption spectrometer with deuterium lamp background corrector. Cadmium and lead hollow cathode lamps operated at 4 mA and 7 mA, and 228.8 nm and 283.3 nm wavelength respectively. Spray chamber used without impact system. Acetylene flow-rate 1.0 1 min , air flow-rate 10 1 min (extra-lean flame). Peak height evaluation with a time constant of 0.5 s. FI peaks recorded by a printer or chrrt recorder. 

AATCC 42-1985, Water Resistance Impact Penetration Test Five hundred ml of liquid is allowed to spray from a height of 2 ft against the taut surface of a test specimen backed by a preweighed blotter. The blotter is then reweighed, and the difference in weight used to determine the amount of liquid that penetrated. 

In fluid bed agglomerators, spray nozzle height can often be used as a process control tool. This is because the height affects the intensity of the spray flux as well as the time taken for the binder droplets to impact on powder particles. The higher the nozzle is above the fluidized bed, greater the footprint, and hence, lower the spray flux. 

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