Development of a multineedle electroresistivity probe for measuring bubble characteristics in molten metal baths

Abstract

Precise information on the behavior of rising bubbles in molten metals is of essential importance for the enhancement of current metal-refining processes as well as the development of new refining processes agitated by gas injection. In particular, the total interfacial area between bubbles and molten metal is a key parameter, but it cannot be evaluated unless the shape of bubbles is given. Getting information on the shape of rising bubbles has been very difficult for nontransparent liquids. In this study, we developed a multineedle electroresistivity probe to detect the shape of bubbles rising in molten metal baths. The accuracy of the presently developed probe was examined for water-air and Wood's metal-He systems using a conventional two-needle electroresistivity probe and a high-speed video camera.

Gas–Liquid Two-Phase Flow

“…Previous experiments using electroresistivity probe [18,19] have shown that the shape of a bubble can be correlated as a function of the modified Weber number, We, and the modified Reynolds number, Re, as shown in Fig. 9.9.…”

Turbulence structure of bottom-blowing bubbling jet in a molten Wood’s metal bath

“…[12,20] Figure 11 shows the relative occurrence in frequency of the four turbulent motions in the He-Wood's metal bubbling jet together with those in an air-water bubbling jet. [17] In the region near the centerline (r ϭ 0), the relative occurrence in frequency of each turbulent motion was approximately 0.25, and, hence, there was no coherent structure there. In a radial region of 0 Ͻ r/b u Շ 1.0, the relative occurrence in frequency of sweep became the high- est, that of ejection followed it, and the relative occurrence in frequency of inward interaction was the lowest.…”

“…[17] The bubbles had a cross section as illustrated in Figure 5 and were classified as skirted bubbles. These bubbles rose almost straight upward and, hence, brought about the radial distribution of gas holdup with the aforementioned profile.…”

Controllable Generation of a Submillimeter Single Bubble in Molten Metal Using a Low-Pressure Macrosized Cavity

“…A selection of intrusive and nonintrusive bubble measurement techniques with relevant references are summarized in Table I. The bubble traveling in liquid can be detected by simple optical observations, optical [9] and electrical [10][11][12] probe measurements, advanced ultrasound Doppler velocimetry (UDV) [14][15][16] X-ray imaging [17] neutron radiography, [26] and sophisticated resonant spectroscopy [21][22][23][24][25] allowing measurements of the bubble size distribution in the pool.…”

“…[33] The steam bubbles transport in the primary system of an HLM cooled reactor, and the possibility that bubbles can reach the core is highly sensitive to the terminal rise velocity for submillimeter bubbles. [34] Unfortunately, there are no data available Electromagnetic sensing Optical probe [9] Capacitive or inductive measurements Conductivity probes [10][11][12] Conductivity of the liquid channel Hot wire anemometer [13] Acoustical methods:…”