TSI 3400A Fluidized Bed Aerosol Generator

Description of TSI 3400A

TSI’s Fluidized Bed Aerosol Generator Model 3400A* contains a fluidized bed chamber and a powder reservoir. The fluidized bed consists of 100-μm bronze beads supported by a porous screen that allows clean, dry air to pass through, yet prevents the passage of any powder.

During operation, a bead chain meters powder into the fluidized bed. As air forces its way up through the screen and into the bed, it creates a boiling action, which deagglomerates the powder and causes it to be carried upward by the airflow through a vertical elutriator.

A cyclone at the top of the vertical elutriator prevents any particles that are not fully deagglomerated from being dispersed. With a flow rate of 9 liters/min, the cyclone allows only respirable dust† to be generated. Separate flowmeters measure the bed flow rate and the bead purge flow rate.

The powder reservoir is equipped with a gear-driven rake that rocks back and forth, preventing the formation of a channel in the powder due to the movement of the bead chain through the powder reservoir. This assures a constant, even feed rate into the fluidized bed chamber. The airflow pattern through the porous screen further stabilizes the concentration of the output aerosol.

Features

•  Particle size range from 0.5 to 40 µm
• Bed of bronze beads breaks up powder agglomerates
• Stable output and concentration

Applications

• Generating dust for inhalation and toxicology studies
• Evaluating performance and calibrating dust samplers and monitors
• Dust erosion in high-speed gas flows
• Generating particles for laser velocimeter applications

Technical specifications of TSI 3400A

• Output Concentration Range: 10 to 100 mg/m3
• Powder Feed Rate Range: 3 to 30 mm3/min, adjustable (equates to a feed rate of 180 to 1800 mg/hour, assuming unit density)
• Carrier Gas Flow Rate Range: 5 to 15 liters/min at 345 KPa (50 psi)
• Particle Size Range: Related to size of powder to be dispersed. Maximum size is approximately 40-μm aerodynamic diameter; particles smaller than 0.5 μm do not deagglomerate efficiently.
• Cyclone: Stainless steel, 0.5-in. diameter, classifies respirable dust at 9 liters/min
• Power Requirements:  115, 230 VAC; 50 to 60 Hz; 45 W
• Dimensions (LWH): 264 × 368 × 150 mm (10.4 × 14.5 × 5.9 in.); with elutriator, H = 483 mm (19 in.)
• Weight: 11 kg (24 lbs)