STAG 2000 Monodisperse Aerosol Generator

The BGI STAG 2000 is a new design, air driven, monodisperse aerosol generator which continues the decades- long development work of our predecessors. It is also the first time an enclosure is commercially available. A detailed, illustrated, instruction manual has been prepared by a scientist and engineer completely familiar with the construction and operation of the instrument. A spreadsheet calculator has been constructed that permits all the requisite calculations to be performed governing the successful production of a monodisperse aerosol.

When a disc is rotated, in a horizontal plane and a liquid is caused to flow onto the center of it, centrifugal force will cause the liquid to uniformly spread outward to the periphery of the disc. If the flow of liquid is not too great and the edge of the disc is sharp, ligaments will form. The ligaments will stretch, until the surface tension, of the liquid, is overcome, at which point it will snap off and a droplet will be formed. Approximately four satellite droplets will form from the tail of the ligament. Their diameter will be about 25% of the diameter of the primary droplet. The air flow which drives the disc is directed downwards. A cover is provided which channels this airflow within the body of the instrument. The force of this air flow is sufficient to entrain and remove the satellite droplets, whilst leaving the primary droplets trajectory, unaffected. This extraction effect is further enhanced by the provision of an air ejector provided on the body of the instrument. The body of the instrument is provided with a poppet valve which has the function, of opening during start up and shutdown to provide stability to the disc.

Although the instrument can only aerosolize liquids, solid monodisperse particles may be formed by evaporation. Small solid particles, such as spores and bacteria, may be suspended in liquid and also dispersed as an aerosol.

The instrument is pneumatically controlled, in terms of disc rotational speed and satellite extraction.

References

The following references have been selected as the most historic, seminal or germane.

Walton, W.H. and W.C. Prewett, "The Production of Sprays and Mists of Uniform Drop Size by Means of Spinning Disc Type Sprayers". The Proc. Phys. Soc., Sec. B, Vol. 62, Part 6, pp. 342-350, 1949.
May, K.R., "Spinning-top Homogeneous Aerosol Generator with Shockproof Mounting", J. Sci. Instr., Vol. 43, pp. 841-842, 1966
Davies, C.N., and P.K.P Cheah, "Spinning Generators of Homogeneous Aerosols", J. Aerosol Sci., Vol. 15, pp. 719-739, 1984
Davies, C.N., and P.K.P Cheah, "The Spinning-Top Aerosol Generator-Improving the Performance", J. Aerosol Sci., Vol. 15, pp. 741-751, 1984
Gussman, R.A., "A Further Development of the May Spinning Top Aerosol Generator", Am. Ind. Hyg. Assoc. J., Vol. 42, pp. 208-212, 1981.
Mitchell, J.P., and R.L. Stone, "Improvements to the May Spinning-Top Aerosol Generator", J. Phys. Sci. Instrum., Vol. 15, pp. 565-567, 1982
Gussman, R.A., A.M. Sacco and N.M. McMahon, "Design and Calibration of A High Volume Cascade Impactor", J. Air Poll. Cont. Assoc., Vol. 23, 1973

Specifications
STAG 2000
Max height	11 in (27.9 cm)
Max width	6.5 in (16.5 cm)
Max width with enclosure	10 in (25.4 cm)
Weight	5.29 lbs (2.4 kg)
Weight with enclosure	9.26 lbs (4.2 kg)
Pneumatic Module
Overall dimensions	8 w. x 9 dp. x 10 h. (in.) 20.2 x 22.9 x 25.4 (cm)
Weight	6.17 lbs (2.8 kg)
Ordering Information Click on a part number to add that item to your Price Quote List.
STAG2000	Generator complete
10078	Enclosure
Replacement Parts
A2214	Disc (303 S.S.)
A2222	Elastomeric Dampner
10076	Needle Adjustment Assembly (to replace MkII Hydraulic Assembly)
10077	Pneumatic control module
10067	Replacement Needle (plastic Hub)

STAG 2000 Monodisperse Aerosol Generator

Applications

Features

References