Critical Condition for Merging of Two Bubbling Jets

The critical condition for a bubbling jet to attach to an adjacent vertical wall was represented by (3.1) as a function of gas flow rate and the distance between the nozzle exit and the side wall. In this section, we will derive a critical condition for two bubbling jets to merge with each other in a water bath. 

A schematic of the experimental apparams is shown in Fig. 3.34. The test vessel made of transparent acrylic resin has an inner diameter, D, of 0.4 m and a height, H, of 1.2 m. The depth of water, Hl, is 0.35,0.50, or 0.65 m. The inner diameter of two top lance nozzles, rfm, is 2.0 x 10 m. The nozzles are made of brass pipe, and the wettability of the nozzle by water is quite good. The horizontal distance between the two nozzles, Lh, is varied from 0.02 to 0.10 m at equal intervals of 0.02 m, and the vertical distance between them, Ly, is zero, that is, on the same horizontal plane. 

The gas flow rates issuing out of the nozzles, 2gi and 2g2. are varied from 0.50 X 10 to 500 X 10 m /s. The behavior of the two bubbling jets is then observed by eye inspection. For convenience, interacting patterns of the two bubbling jets are elassified into the following four categories. 

a critical condition describing no merging between the two bubbling jets is determined for Q = That is, the boundary between (b) and (c) is determined. 

Second, the critical condition is determined for unequal gas flow rates. 

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This result indicates that the critical condition for merging of two bubbling jets is dependent only on the dispersion radius of the bubbling jet, i.e., only on the gas flow rate. 

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