FIG. 20 A plot of experimental data from Skripov [6] for the homogeneous boiling of pentane. The part ACB is the normal superheat limit. As the temperature is increased, so the time required for explosive boiling of liquid drops rapidly decreases. In going from 145.6 to 146.0°C, the waiting time drops from 550 to about 0.5 sec. If the superheated liquid droplets are exposed to radiation, very much lower superheats are needed to cause bubble nucleation. Temperatures as low as 129.5°C can cause bubble formation.

doi:10.1201/9780203021262-161

Chapter

FIG. 20 A plot of experimental data from Skripov [6] for the homogeneous boiling of pentane. The part ACB is the normal superheat limit. As the temperature is increased, so the time required for explosive boiling of liquid drops rapidly decreases. In going from 145.6 to 146.0°C, the waiting time drops from 550 to about 0.5 sec. If the superheated liquid droplets are exposed to radiation, very much lower superheats are needed to cause bubble nucleation. Temperatures as low as 129.5°C can cause bubble formation.

Chapter

FIG. 20 A plot of experimental data from Skripov [6] for the homogeneous boiling of pentane. The part ACB is the normal superheat limit. As the temperature is increased, so the time required for explosive boiling of liquid drops rapidly decreases. In going from 145.6 to 146.0°C, the waiting time drops from 550 to about 0.5 sec. If the superheated liquid droplets are exposed to radiation, very much lower superheats are needed to cause bubble nucleation. Temperatures as low as 129.5°C can cause bubble formation.

ABSTRACT

Two main techniques other than electrolytic methods have been used to obtain data on the nucleation of gas bubbles in aqueous media. These are pressure release (as used by Lubetkin, and Hemmingsen and coworkers) and chemical (as used by Noyes, Bowers, and Hey among others). In the former technique, water is saturated with the study gas at an elevated pressure, then the pressure is released down to a target pressure (P′) often atmospheric. Bubbles form, rise, and burst and the gas is released into the headspace. This

Author(s) σ(ce/cb) or (ce−cb)a Notes Sides [65] ~100 A maximum value

H2 O2 CO2 Cl2 1.54 1.36 1.08 1.018

release is studied by the pressure rise (if the vessel is immediately resealed) or by measuring the amount of gas evolved, or by acoustically counting bubbles [38]. In the chemical generation of bubbles, the Supersaturation is evaluated by measuring the total gas released, usually sonicating the solution to ensure complete gas evolution (Table 7).