Reactive mixing in a pipeline with a side-tee

Fast reactions in pipelines with side-tees are experimentally investigated. The temperature rise caused by reacting sodium hydroxide with hydrochloric acid is measured at a number of monitoring points downstream of the side-tee. The distance required for the reaction to be completed is indicated by reaching a constant temperature. The experimental results are compared with results obtained using a computational fluid dynamics (CFD) model of non-reactive mixing in exactly the same set-up and under the same flow conditions. Results showed that convective mixing and not micromixing plays a limiting role in fast reactions in pipelines with side-tees. The length of the tube required for non-reactive mixing is found to be very similar to the reactive case and a function of the ratio of the main to the side velocity. It is concluded that factors such as the tee angle which enhanced non-reactive mixing in pipelines with side-tees do have a similar impact on reactive mixing in a similar geometry.