Jet Injections for Optimum Mixing in Pipe Flow

摘要

In order to mix an additive or a tracer with the fluid flowing in a pipe, it may be desirable to avoid the energy required and the possible maintenance problems for mixers or obstructions in a pipe and to avoid the relatively long flow length required for ambient mixing. Then, it may be advantageous to inject the additive as a jet into the pipe flow and to use the associated jet mixing to enhance the overall mixing process. Laboratory experiments were conducted to determine the rates of mixing with a single jet injection made at the pipe wall at various angles relative to the pipe wall and with two diametrically opposed jets. For uniform pipe flow, it was possible to identify an optimum momentum for each angle of injection. A few experiments with induced swirl in the pipe flow showed that the swirl had a significant effect on the jet mixing, especially when two jets were used.