Merging Length of Two Bubbling Jets

Considering these circumstances, the merging distance //c, is described in this section, based on experimental data obtained from a water model. 

Two top lances are used to inject air into a water bath contained in a cylindrical vessel (see Fig. 3.34). The vessel has an inner diameter D of 30 x 10 m and a height of 40 X 10 m. Each top lance is bent at an angle of 180°, and its exit is contracted to form a single-hole nozzle. The height from the bottom of the vessel to the nozzle tip is 4.5 x 10 m. The depth from the nozzle exit to the bath surface, H], is varied from 10 x 10 to 30 x 10 m with equal intervals of 10 x 10 m. The inner diameter of the nozzle, dm, is 2.0 x 10 or 4.0 x 10 m. The gas flow rate 2g varies from 10 x 10 to 100 x 10 m /s. The horizontal distance between the two nozzles, Lh, varies over a wide range. Photographs of the two bubbling jets subjected to the Coanda effect are then taken with a still camera. 

This relation is valid for the following modified Froude number. 

The measured values of He for different bath depths are also approximated by (3.26), as partly demonstrated in Fig. 3.40. Consequently, the bath depth Hi hardly affects the merging length under the experimental conditions considered. The work done per unit time by the buoyancy force acting on bubbles to liquid around a bubbling jet, Pb, is expressed by [30,31]  

The experimental results reveal that the buoyancy force does not have much effect on the merging length because Q and H are nearly independent of 

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