A venturi device for stable addition of foaming agent to self‐suction liquid at high flow rates

Abstract

AbstractTo achieve a stable addition of foaming agent under high flow rates, an independently designed venturi structure with self‐suction of liquid to add foaming agent was numerically simulated. We simulated the effects of different self‐suction liquid structures' diameters (diameter of the tube in which the liquid is sucked in), contraction angles, throat length, and position on the suction liquid ratio (ratio of venturi self‐suction liquid flow rate to total flow rate), compared and analyzed the data, and determined the optimal self‐suction liquid structures parameters. The suction liquid ratio shows a tendency to first stabilize and then decrease as the outlet pressure increases. When the outlet pressure in range of 0.30–0.45 MPa, the suction liquid ratio remains stable at 1.14%. However, as the outlet pressure increases, the ability of the venturi structure to add foaming agent through the self‐suction liquid decreases under high flow rates, causing the suction liquid ratio to rapidly decrease to a minimum value of 0.60 MPa. We have conducted a detailed analysis of the process and flow field of suction liquid. As the outlet pressure increases, the high‐speed area of the throat gradually shrinks, and the flow field in the diffusion section fluctuates. When the outlet pressure is 0.6 MPa and the velocity field shifts toward the upper part of the diffusion section, the cavitation area will gradually disappear and lose its liquid suction ability.