The Protection Afforded by Various Filters Against Bacterial Suspensions in Air | 1919

 

Journal of Infectious Diseases, v.24 1919

The atomizer used was selected from among several models because it produced the finest spray. Air was supplied to the atomizer at a rate of 15 liters per minute by means of a Type A Leiman Bros. pump driven by a ¼ H.P. motor.

The absorption bottles, A1, B1, A2, and B2, are standard gas absorption bottles of 300 cc capacity and approximately 20 cm in height. Special apron bubblers are provided on the gas inlet tubes. Flowmeters in each path, positioned after the absorption bottles, measure the flow, which is maintained at the proper rate by means of pinch cocks P1 and P2.

The air is drawn through the two parallel paths by means of the same Leiman Bros. blower used in spraying the broth culture. In order that the partial vacuum created by withdrawal of the sample will not cause contaminated air to be drawn into the box through leaks, the extracted air is passed through the heated copper spiral (S) and then returned to the box. After passing through the spiral, the air travels through a long tube and cools to approximately 50°C before re-entering the box, as indicated by a thermometer.