Using Traveling Water Beads for Particle or Vapor Capturing*

Here, we report a new dehumidifier design with 200{\%} higher water condensation rate per volume of the device compared to the traditional dehumidifiers while decreasing air-side pressure drop due to providing straight gas flow channels for the gas stream. This structure consists of cold fresh water beads traveling down along an array of vertically aligned strings, on which the counterflowing hot humidified air stream is condensed. The water beads are generated using the intrinsic instability of liquid films flowing down a vertical thread. Offering direct contact between the water and air stream, very high interface-to-volume ratios and long resistance times for heat/mass transfer, our unique dehumidifier is cable of achieving superior heat and mass transfer rates. Additionally, using our bead generating method, we developed an efficient particle capturing unit, in which an array of traveling beads is used as the collection section to capture the charged ultra-fine particles (UFP) in the counterflowing air stream. Studies show that UFPs can enter the blood and penetrate the cell membranes. Our experimental results show that this design can remove more UFPs with significantly lower water consumption rate compared to the traditional particle capturing systems.