"The smoking device with the medium frit measured the largest surface area to volume ratio of the bubbles in both stages and was found to have the best filtration properties. Following this trend, the piece with the large frit (second largest surface area to ratio of bubbles), also had increased filtration properties when compared to the T2 (Toker2) device that contained no fritted element. While the T2 (Toker2) device was able to filter some of the particulate mass from the smoke, it was concluded in all tests performed that the filtration efficacy was significantly less than that of the pieces with the fritted glass. In addition to the ability to filter particulate mass from the smoke, the devices including the fritted glass features were particularly effective in removing PAH’s from the smoke, which are known to be carcinogenic, when compared to the standard T2 (Toker2) device.
The data in this report corresponds well with literature transport phenomena knowledge. Henry’s law states that when a gas is in contact with the surface of a liquid, the amount of gas that will go into solution is proportional to the partial pressure of that gas. It is also known that the smaller the bubble greater the equilibrium pressure and higher contact surface area. So, in short, creating smaller bubbles maximizes the gas flux and results in better gas transfer between the media. The device tested seems to do just that."
Gary Fielding, PHD Associate Scientist Mechanical & Materials Engineering