Development and operation of an improved turntable dust feeder

An improved version of a dry dispersion turntable aerosol feeder has been developed which provides greater variation, control, and reliability in aerosol output. The heart of the system is a rotating dust cylinder that permits steady delivery of dust to a turntable groove where it is picked-up by an adjustable aspirator. This design feature eliminates the need for vibrators and ensures a smooth dust flow to the dust pick-up point. Depending on the cylinder diameter, unattended operating time can be greatly increased. The aspirator incorporates an adjustable venturi and pick-up apparatus. By varying venturi adjustment and air pressure, dust pick-up under differing operating conditions can be assured. A large range in aerosol output can be achieved using different groove widths, locations, and turntable speeds. Operational performance tests show steady aerosol output over the delivery range of 100 mg/min to 50 g/min, depending on the size of the feeder. To date, two sizes of the turntable aerosol feeder have been utilized effectively resulting in dust concentrations ranging from 100 μg/m3 to 560 mg/m3.