Design of the CFD numerical simulation-based bubble generator of jet microbubble flotation cell

The bubble generator of the ZWF6500 jet microbubble flotation cell is taken as the object to explore the influence of the structure of the generator on the physical parameters of the generator. The effect on the physical parameters of the generator produced by such structural parameters as number of air inlets, nozzle diameter, and choke diameter and position, is investigated through CFD numerical simulation. As revealed by study result, the number of air inlets produces no noticeable influence on air-carrying rate, but at a certain feed pressure, for a generator with a single air inlet, there exists a limiting air intake at a certain feed pressure, the quantity of injected pulp is only subjected to the influence of nozzle diameter, and tends to increase with the increase of nozzle diameter; the ratio of the diameters of nozzle and choke plays a vital role in control of air-carrying rate, and the larger the ratio, the higher the air-carrying rate which would finally reach an extreme value when the ratio is increased to a certain level and even begin in this case to fall down irrespective of the further increase of the said ratio; the position of choke mainly exerts an influence on the aeration quantity, and with the raising of choke position, the aeration quantity and air-carrying rate tend to first go up and then fall down, and when the choke is placed at an optimum position, a largest aeration quantity can be obtained. The study made in the paper provides the basic data for making structural optimization of bubble generator.