Cavity configuration, flooding and pumping capacity of disc-type turbines in aerated stirred tanks

Gas‐filled cavity structures and local void fraction distribution in aerated stirred vessel

“…Lu and Ju (1989) did show 1 L, 2 L and '3-3' structures but only at two impeller speeds and with too little data for systematic classification into a flow regime map. Measurements in this work showed that the area of 1 L and 2 L structures in the Fr-Fl diagram is quite significant, sitting between the VC and S33 structures.…”

“…The structure was recognized as the appearance of two large cavities (2L), and was not conditioned by a steady presence on the same blades. Lu and Ju (1989) investigated impeller discharge flow using a constant temperature anemometer (CTA). They found out that large cavities of 1L and 2L structures existed steadily on the same blade at lower impeller speeds, while at higher speeds they shifted their position to other blades.…”

“…of Intelligent Systems, Joief Stefan Institute, Ljubljana, Slovenia. above structures were recognized by the transition from VC structure to structure with one, two, or up to six large cavities (Bruijn et al, 1974), or by the transition from VC structure to structures with one, two and three large cavities (Lu and Ju, 1989), followed by a very gradual transition to six large cavities (Warmoeskerken and Smith, 1982). Impeller gas-filled cavities were usually measured using a derotational technique combined with a video camera and flash photography (Bruijn et al, 1974;Warmoeskerken and Smith, 1982;Ismail et al, 1984), vibrating vane (Smith et al, 1987), hydrophones (de More, 19881, or CTA (Lu and Ju, 1989).…”

Experimental studies of ventilated cavities in a channel

“…Rennie and Valentine (1968) reported the existence of cavities. VC on impellers have been studied using a derotational technique with video camera (Bruijn et al, 1974;Warmoeskerken and Smith, 1982;Ismail et al, 1984), a vibrating vane (Smith et al, 1987), hydrophones (de More et al, 1988), a constant temperature anaemometer (Lu and Ju, 1989) and micro resistivity probe (Bombač et al, 1997). Cavity shapes such as large cavities, clinging cavities, etc.…”

Interrelation of Flooding and Complete Dispersion in Agitated Gas‐Liquid Contactors

“…The first one of these defines flooding as the ceasing of the radial motion of the bubbles in the impeller stream [1], while the other defines flooding as the ceasing of gas recirculation in the part of the vessel below the impeller [2]. Of the two definitions, the first seemed to be easier to realize experimentally and observe, and therefore, has been used extensively by most investigators [2][3][4][5][6][7][8][9][10][11][12][13][14].…”